Received: from sol.tis.com by magellan.TIS.COM id aa01243; 14 Dec 94 9:45 EST Received: from sol.tis.com(192.33.112.100) by relay via smap (V1.3) id sma017680; Wed Dec 14 09:47:17 1994 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA16375; Wed, 14 Dec 94 09:44:52 EST Message-Id: <9412141444.AA16375@tis.com> Reply-To: James M Galvin To: dns-security@tis.com Subject: draft minutes of San Jose meeting Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----- =_aaaaaaaaaa0" Content-Id: <4020.787416310.0@tis.com> Date: Wed, 14 Dec 1994 09:45:11 -0500 From: James M Galvin ------- =_aaaaaaaaaa0 Content-Type: text/plain; charset="us-ascii" Content-ID: <4020.787416310.1@tis.com> Enclosed below is the draft minutes of the San Jose meeting from last week. Please submit comments and revisions to me or the mailing list by tuesday, December 20. I will revise the minutes and submit them to the Secretariat for publication on wednesday, December 21. Thanks, Jim ------- =_aaaaaaaaaa0 Content-Type: text/plain; charset="us-ascii" Content-ID: <4020.787416310.2@tis.com> Content-Description: DNS Security San Jose Minutes The DNS Security Working Group met on Wednesday, December 7, at the San Jose IETF. It began with a review of the differences between the Ohta-san and Eastlake/Kaufman proposals. It was noted that this version of both documents have many similarities, with most differences in the underlying details. The gross level differences identified were as follows. o The Ohta-san proposal does not include an explicit discussion of key management or distribution while Eastlake/Kaufman does. o The Ohta-san proposal does not include a revocation mechanism while Eastlake/Kaufman does. o The Ohta-san proposal specifies the creation of 8 new resource records for each algorithm supported while Eastlake/Kaufman specifies 2 new resource records --- a key RR and a signature RR --- each with an embedded algorithm identifier. With respect to the first two differences, it was pointed out that the Ohta-san proposal could be augmented to include the necessary discussion. There was detailed discussion of the operational implications of the last difference. The issues raised included: 1. Having separate resource records for each algorithm allows servers/clients to easily request exactly those signature and keys records they need. 2. Having a single resource record with an embedded algorithm identifier allows clients/servers to know immediately if a zone is secure without having to query for all possible algorithms. At the completion of the discussion the chair called for a consensus from the working group as to which proposal represented the best direction for the working group at this time. The working group chose the Eastlake/Kaufman proposal. The remainder of the time was devoted to a discussion of three technical issues. revocation choice of algorithm signing of non-authoritative data On the topic of revocation, the working group concluded that this mechanism was not need by secure DNS. Instead, the document should indicate that the expiration time of the signature should be a small multiple of the original TTL for the resource record, thus requiring that the data be re-signed on a regular schedule. The principal motivation for this was that the working group believed that any revocation mechanism conflicted with the TTL mechanism of the DNS insofar as it was attempting to clear caches of invalid data. Further, the mechanism proposed specified that revocation records be distributed on a space available basis, so there was no guarantee that in fact it would be available for processing. On the topic of algorithm choices, a brief comparison of Diffie-Hellman/ElGamal and RSA was presented. It was noted that with respect to signature verification RSA outperformed Diffie-Hellman/ElGamal by several orders of magnitude. In addition, the size of an RSA signature was at most half the size of a comparable Diffie-Hellman/ElGamal signature. There was brief mention of the problems of export and use of cryptography internationally but no conclusion was reached. The working group agreed that no change in the choice of RSA was appropriate at this time. With respect to the signing of non-authoritative data, in particular zone delegation information, Ohta-san's proposal explicitly pointed out that it was not necessary to do this as long as the key of the child zone was signed by the parent's key. The discussion noted that with Eastlake/Kaufman, if the data was signed, there would be 3 signature records in addition to the KEY, NS, and A records that were returned, which would have an unfavorably high probability of exceeding the payload maximum for a UDP packet. Eastlake/Kaufman agreed to revise their proposal to recommend that servers allow for the NS and A record signature records to not be included if they do not fit, since they are not required. ------- =_aaaaaaaaaa0--   Received: from sol.tis.com by magellan.TIS.COM id aa25142; 16 Dec 94 16:51 EST Received: from gw.home.vix.com(192.5.5.1) by relay via smap (V1.3) id sma003550; Fri Dec 16 16:52:56 1994 Received: by gw.home.vix.com id AA14455; Fri, 16 Dec 94 12:16:41 -0800 Message-Id: <9412162016.AA14455@gw.home.vix.com> X-Btw: vix.com is also gw.home.vix.com and vixie.sf.ca.us To: dns-security@tis.com Cc: Jim McCoy Subject: Jim McCoy: Searching for Kaufman/Eastlake DNS changes Date: Fri, 16 Dec 1994 12:16:40 -0800 From: Paul A Vixie someone please reply to jim? ------- Forwarded Message From: mccoy@io.com (Jim McCoy) Message-Id: <199412161914.NAA13729@pentagon.io.com> Subject: Searching for Kaufman/Eastlake DNS changes To: paul@vix.com Date: Fri, 16 Dec 1994 13:14:17 -0600 (CST) X-Mailer: ELM [version 2.4 PL23] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 393 Hi there. Rich Salz suggested you might be the guy to contact to see if there is a ref implementation of the Kaufman/Eastlake DNS mods for the SIG and KEY RRs. If there is I would love a pointer to it. Also, I seem to remember hearing about a list discussing DNS security in general but can't remeber the address, is there such a list and if so what is the sub address? Thanks, jim mccoy ------- End of Forwarded Message   Received: from sol.tis.com by magellan.TIS.COM id aa06876; 23 Dec 94 11:06 EST Received: from sol.tis.com(192.33.112.100) by relay via smap (V1.3) id sma015706; Fri Dec 23 11:08:11 1994 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA24990; Fri, 23 Dec 94 11:05:48 EST Message-Id: <9412231605.AA24990@tis.com> Reply-To: James M Galvin To: minutes@cnri.reston.va.us Cc: dns-security@tis.com Subject: DNS Security Minutes Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pem-signature"; micalg="rsa-md5"; boundary="----- =_aaaaaaaaaa1" Date: Fri, 23 Dec 1994 11:06:30 -0500 From: James M Galvin ------- =_aaaaaaaaaa1 Content-Type: multipart/mixed; boundary="----- =_aaaaaaaaaa0" Content-ID: <21370.788198782.2@tis.com> ------- =_aaaaaaaaaa0 Content-Type: text/plain; charset="us-ascii" Content-ID: <21370.788198782.3@tis.com> Enclosed below are the minutes of the DNS Security Working Group meeting at the San Jose IETF. Jim ------- =_aaaaaaaaaa0 Content-Type: text/plain; charset="us-ascii" Content-ID: <21370.788198782.4@tis.com> Content-Description: DNS Security Minutes DNS Security WG Meeting Minutes December 1994 San Jose Recorded by Jim Galvin, Chair The DNS Security Working Group met on Wednesday, December 7, at the San Jose IETF. It began with a review of the differences between the Ohta-san and Eastlake/Kaufman proposals. It was noted that this version of both documents have many similarities, with most differences in the underlying details. The gross level differences identified were as follows. o The Ohta-san proposal does not include an explicit discussion of key management or distribution while Eastlake/Kaufman does. o The Ohta-san proposal does not include a revocation mechanism while Eastlake/Kaufman does. o The Ohta-san proposal specifies the creation of 8 new resource records for each algorithm supported while Eastlake/Kaufman specifies 2 new resource records --- a key RR and a signature RR --- each with an embedded algorithm identifier. With respect to the first two differences, it was pointed out that the Ohta-san proposal could be augmented to include the necessary discussion. There was detailed discussion of the operational implications of the last difference. The issues raised included: 1. Having separate resource records for each algorithm allows servers/clients to easily request exactly those signature and keys records they need. 2. Having a single resource record with an embedded algorithm identifier allows clients/servers to know immediately if a zone is secure without having to query for all possible algorithms. At the completion of the discussion the chair called for a consensus from the working group as to which proposal represented the best direction for the working group at this time. The working group chose the Eastlake/Kaufman proposal. The remainder of the time was devoted to a discussion of three technical issues. revocation choice of algorithm signing of non-authoritative data On the topic of revocation, the working group concluded that this mechanism was not need by secure DNS. Instead, the document should indicate that the expiration time of the signature should be a small multiple of the original TTL for the resource record, thus requiring that the data be re-signed on a regular schedule. The principal motivation for this was that the working group believed that any revocation mechanism conflicted with the TTL mechanism of the DNS insofar as it was attempting to clear caches of invalid data. Further, the mechanism proposed specified that revocation records be distributed on a space available basis, so there was no guarantee that in fact it would be available for processing. On the topic of algorithm choices, a brief comparison of Diffie-Hellman/ElGamal and RSA was presented. It was noted that with respect to signature verification RSA outperformed Diffie-Hellman/ElGamal by several orders of magnitude. In addition, the size of an RSA signature was at most half the size of a comparable Diffie-Hellman/ElGamal signature. There was brief mention of the problems of export and use of cryptography internationally but no conclusion was reached. The working group agreed that no change in the choice of RSA was appropriate at this time. With respect to the signing of non-authoritative data, in particular zone delegation information, Ohta-san's proposal explicitly pointed out that it was not necessary to do this as long as the key of the child zone was signed by the parent's key. The discussion noted that with Eastlake/Kaufman, if the data was signed, there would be 3 signature records in addition to the KEY, NS, and A records that were returned, which would have an unfavorably high probability of exceeding the payload maximum for a UDP packet. Eastlake/Kaufman agreed to revise their proposal to recommend that servers allow for the NS and A record signature records to not be included if they do not fit, since they are not required. ------- =_aaaaaaaaaa0-- ------- =_aaaaaaaaaa1 Content-Type: application/pem-signature Content-ID: <21370.788198782.1@tis.com> Content-Transfer-Encoding: quoted-printable Version: 5 Originator-ID: PK,MHkwCgYEVQgBAQICAwADawAwaAJhAMAHQ45ywA357G4fqQ61aoC1fO6B= ekJmG4475mJkwGIUxvDkwuxe/EFdPkXDGBxzdGrW1iuh5K8kl8KRGJ9wh1HU4TrghGdhn0Lw8g= G67Dmb5cBhY9DGwq0CDnrpKZV3cQIDAQAB,EN,2,galvin@tis.com MIC-Info: RSA-MD5,RSA,e2nXm/oDqkIBqZiPWLA89SxczFV7NkWmwcf1Jjmh+PyeY7/1xcN0= O945/aZGqwn8wbPOimxHzjPkN82CVS2kan/OPEJU09C5RAavEOU31ru0qBNYcHlLzBlLdob9dD= 4O ------- =_aaaaaaaaaa1--   Received: from sol.tis.com by magellan.TIS.COM id aa10421; 24 Dec 94 3:04 EST Received: from inet-gw-1.pa.dec.com(16.1.0.22) by relay via smap (V1.3) id sma026018; Sat Dec 24 03:06:02 1994 Received: from skidrow.tay.dec.com by inet-gw-1.pa.dec.com (5.65/10Aug94) id AA27182; Sat, 24 Dec 94 00:02:35 -0800 Received: by skidrow.tay.dec.com (5.65/MS-081993); id AA14806; Sat, 24 Dec 1994 03:07:20 -0500 Message-Id: <9412240807.AA14806@skidrow.tay.dec.com> To: dns-security@tis.com Cc: dee@lkg.dec.com Subject: updated draft Date: Sat, 24 Dec 94 03:07:19 -0500 From: "Donald E. Eastlake 3rd (Beast)" X-Mts: smtp I have updated the draft based on discussions at the IETF and some later email with the implementors. Unforuntately, in a few hours, I'll be leaving on vacation and will probably be out of touch for a week. I look forward to reading your comments on my return. I'm not sending this to internet-drafts but plan to send the next version. Donald --------------------------------------------------------------------------- Donald E. Eastlake, III DTN: 226-6577(w) dee@lkg.dec.com 550 King St, LKG2-1/BB3 1-508-486-6577(w) dee@ranger.enet.dec.com Littleton, MA 01460 USA 1-508-486-7417(fax) 1-508-287-4877(h) DNS Security Working Group Donald E. Eastlake, 3rd INTERNET-DRAFT DEC Charles W. Kaufman Iris Expires: 23 Jun 1995 24 Dec 1994 Domain Name System Protocol Security Extensions ------ ---- ------ -------- -------- ---------- Status of This Document This draft, file name draft-ietf-dnssec-secext-03.txt, is intended to be become a proposed standard RFC. Distribution of this document is unlimited. Comments should be sent to the DNS Security Working Group mailing list or to the authors. This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months. Internet-Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet- Drafts as reference material or to cite them other than as a ``working draft'' or ``work in progress.'' To learn the current status of any Internet-Draft, please check the 1id-abstracts.txt listing contained in the Internet-Drafts Shadow Directories on ds.internic.net, nic.nordu.net, ftp.isi.edu, munnari.oz.au, or ftp.is.co.za. Eastlake, Kaufman [Page 1] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 Abstract The Domain Name System (DNS) has become a critical operational part of the Internet infrastructure yet it has no strong security mechanisms to assure data integrity or authentication. Extensions to the DNS are described that provide these services to security aware resolvers or applications through the use of cryptographic digital signatures. These digital signatures are included in secured zones as resource records. Security can still be provided even through non-security aware DNS servers. The extensions also provide for the storage of authenticated public keys in the DNS. This storage of keys can support a general public key distribution service as well as DNS security. The stored keys enable security aware resolvers to learn the authenticating key of zones in addition to keys for which they are initially configured. Keys associated with DNS names can be retrieved to support other protocols. Provision is made for a variety of key types and algorithms. In addition, the security extensions provide for the optional authentication of DNS protocol transactions. Acknowledgements The significant contributions of the following persons (in alphabetic order) to this draft are gratefully acknowledged: Madelyn Badger, James M. Galvin, Olafur Gudmundsson, Sandy Murphy, Masataka Ohta, Jeffrey I. Schiller. Eastlake, Kaufman [Page 2] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 Table of Contents [Table of Contents gets moved here from the end] Eastlake, Kaufman [Page 3] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 [pg 2, ToC] Eastlake, Kaufman [Page 4] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 1. Introduction This draft describes extensions of the DNS protocol to support DNS security and public key distribution. This draft assumes that the reader is familiar with the Domain Name System, particularly as described in RFCs 1034 and 1035. Eastlake, Kaufman [Page 5] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 2. Brief Overview of the Extensions The DNS protocol extensions provide three distinct services: key distribution as described in section 2.2 below, data origin authentication as described in section 2.3 below, and transaction authentication, described in section 2.4 below. 2.1 Services Not Provided It is part of the design philosophy of the DNS that the data in it is public and that the DNS gives the same answers to all inquirers. Following this philosophy, no attempt has been made to include any sort of access control lists or other means to differentiate inquirers. In addition, no effort has been made to provide for any confidentiality for queries or responses. (This service may be available via an IP network level security protocol for which there is current an IETF working group.) 2.2 Key Distribution The resource records are defined to associate keys with DNS names. This permits the DNS to be used as a general public key distribution mechanism in support of the data origin authentication and transaction authentication DNS services as well as other security services such as IP level security. The syntax of a KEY resource record is described in Section 3. It includes the name of the entity the key is associated with (frequently but not always the KEY resource record owner name), an algorithm identifier, flags indicating the type of entity the key is associated with and/or asserting that there is no key associated with that entity, and the actual public key parameters. Under conditions described in Section 3, security aware DNS servers will automatically attempt to return KEY resources as additional information, along with those actually requested, to minimize query traffic. Eastlake, Kaufman [Page 6] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 2.3 Data Origin Authentication and Integrity Security is provided by associating with resource records in the DNS cryptographically generated digital signatures. Commonly, there will be a single private key that signs for an entire zone. If a security aware resolver reliably learns the public key of the zone, it can verify that all the data read was properly authorized and is reasonably current. The expected implementation is for the zone private key to be kept off-line and used to re-sign all of the records in the zone periodically. The data origin authentication key belongs to the zone and not to the servers that store copies of the data. That means compromise of a server or even all servers for a zone will not affect the degree of assurance that a resolver has that the data is genuine. A resolver can learn the public key of a zone either by reading it from DNS or by having it staticly configured. To reliably learn the public key by reading it from DNS, the key itself must be signed. Thus, to provide a reasonable degree of security, the resolver must be configured with at least the public key of one zone. From that, it can securely read the public keys of other zones if the intervening zones in the DNS tree are secure. It is in principle more secure to have the resolver manually configured with the public keys of multiple zones, since then the compromise of a single zone would not permit the faking of information from other zones. It is also more administratively cumbersome, however, particularly when public keys change. Adding origin authentication and integrity requires no change to the "on-the-wire" DNS protocol beyond the addition of the signature resource types (and, as a practical matter, the key resource type needed for key distribution). This service can be supported by existing resolver and server implementations so long as they could support the additional resource types. If signatures are always separately retrieved and verified when retrieving the information they authenticate, there will be more trips to the server and performance will suffer. To avoid this, security aware servers mitigate that degradation by automatically sending exactly the signature(s) needed. 2.3.2 The SIG Resource Record The syntax of a SIG resource record (signature) is described in Section 4. It includes the type of the RR(s) being signed, the name of the signer, the time at which the signature was created, the time it expires (when it is no longer to be believed), its original time Eastlake, Kaufman [Page 7] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 to live (which may be longer than its current time to live but cannot be shorter), the cryptographic algorithm in use, and the actual signature. Every name in a zone supporting signed data will have associated with it at least one SIG resource record for each resource type under that name. A security aware server supporting the performance enhanced version of the DNS protocol security extensions will attempt to return, with all records retrieved, the corresponding SIGs. If a server does not support the protocol, the resolver must retrieve all the SIG records for a name and select the one or ones that sign the resource record(s) that resolver is interested in. 2.3.3 Authenticating Name Non-existence The above security mechanism provides only a way to sign existing RRs in a zone. Data origin authentication is not obviously provided for the non-existence of a domain name in a zone. This gap is filled by the NXD RR which authenticatably asserts a range of non-existent names in a zone. The owner of the NXD RR is the start of such a ranger and its RDATA is the end of the range; however, there are additional complexities due to wildcards. Section 6 below covers the NXD RR. 2.3.5 Special Problems With Time-to-Live A digital signature will fail to verify if any change has occurred to the data between the time it was originally signed and the time the signature is verified. This conflicts with our desire to have the time-to-live field tick down when resource records are cached. This could be avoided by leaving the time-to-live out of the digital signature, but that would allow unscrupulous secondaries to set arbitrarily long time to live values undetected. Instead, we include the "original" time-to-live in the signature and communicate that data in addition to the current time-to-live. Unscrupulous servers under this scheme can manipulate the time to live but a security aware resolver will bound the TTL value it uses at the original signed value. Separately, signatures include a time signed and an expiration time. A resolver that knows an absolute time can determine securely whether a signature has expired. It is not possible to rely solely on the signature expiration as a substitute for the TTL, however, singe non-security aware servers must still be supported. Eastlake, Kaufman [Page 8] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 2.3.5 Signers Other Than The Zone There are two general cases where a SIG resource record is signed by other than the zone private key. One is for future support of dynamic update where an entity is permitted to authenticate/update its own records. The public key of the entity must be present in the DNS and be appropriately signed but the other RR(s) may be signed with the entity's key. The other is for support of transaction authentication as described in Section 2.3 below. 2.3 DNS Transaction Authentication The data origin authentication service described above protects resource records but provides no protection for DNS message headers. If header bits are falsely set by a server, there is little that can be done. However, it is possible to add transaction authentication. Such authentication means that a resolver can be sure it is getting messages from the server it thinks it queried and that the response is from the query it sent and that these messages have not been diddled in transit. This is accomplished by optionally adding a special SIG resource record to end of the reply which digitally signs the concatenation of the server's response and the resolver's query. The private key used belongs to the host composing the reply, not to the zone being queried. The corresponding public key is stored in and retrieved from the DNS. Because replies are highly variable, message authentication SIGs can not be pre-calculated. Thus it will be necessary to keep the private key on-line, for example in software or in a directly connected piece of hardware. DNS level transaction authentication would be unnecessary if a lower level (i.e., IP level) end-to-end security protocol were available. However, such a protocol is not yet standardized and when it is, there will be a considerable time during which there will be systems on which it will be hard to add IPSEC but relatively easy to replace the DNS components. Eastlake, Kaufman [Page 9] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 3. The KEY Resource Record The KEY RR is used to document a key that is associated with a DNS name. It will be a public key as only public keys are stored in the DNS. This can be the public key of a zone owner, of a host or other end entity, or a user. A KEY RR is, like any other RR, authenticated by a SIG RR. Security aware DNS implementations should be designed to handle at least two simultaneously valid keys of the same type associated with a name. The type number for the KEY RR is 25. 3.1 KEY RDATA format The RDATA for a KEY RR consists of an object name, flags, the algorithm version, and the public key itself. The format is as follows: 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / +- object name +---------------+---------------+ / | flags | algorithm | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / + - public key / / / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-/ The object name, and the flags octets are described in Sections 3.2 and 3.3 below respectively. The flags must be examined before any following data as they control its the format and even whether there is any following data. The algorithm and public key fields are described in Section 3.4. The format of the public key is algorithm dependent. 3.2 Object Types and DNS Names and Keys The public key in a KEY RR belongs to the object named in the object name field. Frequently this will also be the owner name of the KEY RR. But they will be different in the case of the key or keys stored under a zone's name for the zone's superzone or keys that are stored for cross certification of other zones. The DNS object name may refer to up to three different things. For Eastlake, Kaufman [Page 10] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 example, dee.lkg.dec.com could be (1) a zone, (2) a host or other end entity , and (3) the mapping into a DNS name of the user or account dee@lkg.dec.com . Thus, there are flags in the KEY RR to indicate with which of these roles the object name and public key are associated as described below. Although the same name can be used for up to all three of these contexts, such overloading of a name is discouraged. It is also possible to use the same key for different things with the same name or even different names, but this is strongly discouraged. In particular, the use of a zone key as a non-zone key will usually require that the key be kept on line and thereby become much more vulnerable. It would be desirable for the growth of DNS to be managed so that additional possible simultaneous uses for names are NOT added. New uses should be distinguished by exclusive domains. For example, all IP autonomous system numbers have been mapped into the in-as.arpa domain [draft-ietf-dnssec-as-map-*.txt] and all telephone numbers in the world have been mapped into the tpc.int domain [RFC 1530]. This is much preferable to having the same name possibly be an autonomous system number, telephone number, and/or host as well as a zone and a user. In addition to the name type bits, there are three control bits, the "no key" bit, the "experimental" bit, and the "signatory" bit, as described below. 3.3 The KEY RR Flag Octet In the "flags" field: Bit 0 is the "no key" bit. If this bit is on, there is no key information and the RR stops with the flags octet. By the use of this bit, a signed KEY RR can authenticatably assert that, for example, a zone is not secured. Bits 1 is the "experimental" bit. Keys may be associated with zones, entities, or users for experimental, trial, or optional use, in which case this bit will be one. If this bit is a zero, it means that the use or availability of security based on the key is "mandatory". Thus, if this bit is off for a zone, the zone should be assumed secured by SIG RRs and any responses indicating the zone is not secured should be considered bogus. Similarly, if this bit were off for a host key and attempts to negotiate IP-security with the host produced indications that IP-security was not supported, it should be assumed that the host has been compromised or communications with it are being spoofed. On the other hand, if this Eastlake, Kaufman [Page 11] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 bit were a one, the host might very well sometimes operate in a secure mode and at other times operate without the availability of IP-security. The experimental bit, like all other aspects of the KEY RR, is only effective if the KEY RR is appropriately signed by a SIG RR. The experimental bit must be zero for safe secure operation and should only be a one for a minimal transition period. Bit 2 is the "signatory" bit. It indicates that the key can validly sign RRs of the same name. If the owner name is a wildcard, then RRs with any name which is in the wildcard's scope can be signed including NS and corresponding zone KEY RRs to carve out a subzone. This bit is meaningless for zone keys which always have authority to sign any RRs in the zone. The signatory bit, like all other aspects of the KEY RR, is only effective if the KEY RR is appropriately signed by a SIG RR. Bits 3-4 are reserved and must be zero. If they are found non- zero, they should be ignored and the KEY RR used as indicated by the other flags. Bit 5 on indicates that this is a key associated with a "user" or "account" at an end entity, usually a host. The coding of the owner name is that used for the responsible individual mailbox in the SOA record: The owner name is the user name as the name of a node under the entity name. For example, "j.random_user" on host.subdomain.domain could have a public key associated through a KEY RR with name j\.random_user.host.subdomain.domain. It could be used in an IP-security protocol where authentication of a user was desired. This key would be useful in IP or other security for a user level service such a telnet, ftp, rlogin, etc. Bit 6 on indicates that this is a key associated with the non- zone entity whose name is the RR owner name. This will commonly be a host but could, in some parts of the DNS tree, be some other type of entity such as an Autonomous System [draft-ietf-dnssec-as-map-*.txt]. This is the public key used in connection with the optional DNS transaction authentication service that can be used if the owner name is a DNS server host. It could also be used in an IP-security protocol where authentication of a host was desired. Bit 7 on indicates that this is a zone key for the zone whose name is the RSA RR owner name. This is the fundamental type of DNS data origin authentication public key. 3.4 The KEY Algorithm Version and MD5/RSA Algorithm This octet is the key algorithm version parallel to the same field for the SIG resource. The MD5/RSA algorithm described in this draft Eastlake, Kaufman [Page 12] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 is number 1. Version numbers 2 through 253 are available for assignment should sufficient reason arise. However, the designation of a new version could have a major impact on interoperability and requires an IETF standards action. Version 254 is reserved for private use and will never be assigned a specific algorithm. For version 254, the public key area shown in the packet diagram above will actually begin with an Object Identifier (OID) indicating the private algorithm in use and the remainder of the combined area is whatever is required by that algorithm. Algorithm versions 0 and 255 are reserved. If the no key bit is zero and the algorithm field is 1, indicating the MD5/RSA algorithm, the public key filed is structured as follows: 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | public key exponent |modulus length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / +- modulus / | / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The public key modulus field is a multiprecision unsigned integer. The "modulus length" is an unsigned octet which is the actual modulus length minus 64. This limits keys to a maximum of 255+64 or 319 octets and a minimum of 64 octets. Although moduluses of less than 512 significant bits are not permitted, due to the weak security they provide, they can be represented by using leading zeros. 3.5 KEY RRs in the Construction of Responses An explicit request for KEY RRs does not cause any special additional information processing except, of course, for the corresponding SIG RR from a security aware server. Security aware DNS servers will include KEY RRs as additional information in responses where appropriate as follows: On the retrieval of NS RRs, the zone key KEY RR(s) for the zone served by these name servers will be included. If not all additional info will fit, the KEY RR(s) have lower priority than type A glue RRs. On retrieval of type A RRs, the end entity KEY RR(s) will be included. On inclusion of A RRs as additional information, their KEY RRs will also be included but with lower priority than the relevant A Eastlake, Kaufman [Page 13] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 RRs. 3.6 File Representation of KEY RRs KEY RRs may appear as lines in a zone data file. In the RDATA portion, the object name appears first. The flag octet and algorithm version octets are then represented as unsigned integers; however, if the "no key" flag is on in the flags, nothing appears after the flag octet. If the algorithm specified is the MD5/RSA algorithm, then the exponent and modulus appear. The public key exponent is an unsigned integer from 3 to 16777215. The public key modulus can be quite large, up to 319 octets. It is the last data field and is represented in base 64 (see Appendix) and may be divided up into any number of white space separated substrings, down to single base 64 digits, which are concatenated to obtain the full signature. These substrings can span lines using the standard parenthesis. If an algorithm from 2 through 253 is specified, the public key parameters required by that algorithm are given. If the algorithm specified is number 254, then an OID appears followed by whatever is required for the private algorithm. An implementation that does not understand a particular standard or private algorithm should attempt to parse the rest of the line as one or more base 64 substrings to be concatenated to yield the key parameters. Algorithm versions 0 and 255 are reserved. Eastlake, Kaufman [Page 14] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 4. The SIG Resource Record The SIG or "signature" resource record (RR) is the fundamental way that data is authenticated in the secure DNS. As such it is the heart of the security provided. The SIG RR unforgably authenticates other RRs of a particular type, class, and name and binds them to a time interval and the signer's fully qualified domain name. This is done using cryptographic techniques and the signer's private key. The signer is frequently the owner of the zone from which the RR originated. 4.1 SIG RDATA Format The RDATA portion of a SIG RR is as shown below. The integrity of the RDATA information is protected by the signature field. 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | type covered | algorithm | labels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | original TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | signature expiration | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | time signed | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | key footprint | / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ signer's name / / / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / +- signature / / / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The value of the SIG RR type is 24. The "type covered" is the type of the other RRs covered by this SIG. The algorithm version number is an octet specifying the digital signature algorithm used. The MD5/RSA algorithm described in this draft is version 1. Version numbers 2 through 253 are available for assignment should sufficient reason arise to allocate them. However, the designation of a new version could have a major impact on the interoperability of the global DNS systems and requires an IETF standards action. Version 254 is reserved for private use and will Eastlake, Kaufman [Page 15] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 never be assigned a specific algorithm. For version 254, the "signature" area shown above will actually begin with an Object Identified (OID) indicating the private algorithm in use and the remainder of the signature area is whatever is required by that algorithm. Version numbers 0 and 255 are reserved. The "labels" octet is an unsigned count of how many labels there are in the original SIG RR owner name not counting the null label for root and not counting any initial "*" for a wildcard. If, on retrieval, the RR appears to have a longer name, the resolver can tell it is the result of wildcard substitution. If the RR owner name appears to be shorter than the labels count, the SIG RR should be considered corrupt and ignored. The maximum number of labels possible in the current DNS is 127 but the entire octet is reserved and would be required should DNS names ever be expanded to 255 labels. If a secured retrieval is the result of wild card substitution, it is necessary for the resolver to use the original form of the name in verifying the digital signature. The field helps optimize the determination of the original form reducing the effort in authentication signed data. The following table give some examples. The value of "labels" is at the top, the retrieved owner name on the left, and the table entry is the name to use in signature verification except that "bad" means the RR is corrupt. labels= | 0 | 1 | 2 | 3 | 4 | --------+-----+------+--------+----------+----------+ .| . | bad | bad | bad | bad | d.| *. | d. | bad | bad | bad | c.d.| *. | *.d. | c.d. | bad | bad | b.c.d.| *. | *.d. | *.c.d. | b.c.d. | bad | a.b.c.d.| *. | *.d. | *.c.d. | *.b.c.d. | a.b.c.d. | The "original TTL" field is included in the RDATA portion to avoid authentication problems that caching servers would otherwise cause by decrementing the real TTL field and security problems that unscrupulous servers could otherwise cause by manipulating the real TTL field. This original TTL is protected by the signature while the current TTL field is not. NOTE: The "original TTL" must be restored into the covered RRs when the signature is verified. This implies that the RRs need to all have the same TTL to start with. The SIG is valid until the "signature expiration" time which is an unsigned number of seconds since the start of 1 January 1970. The "time signed" field is an unsigned number of seconds since the start of 1 January 1970. The "key footprint" is a 16 bit quantity that is used to help Eastlake, Kaufman [Page 16] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 efficiently select between multiple keys which may be applicable and as a quick check that a public key about to be used for the computationally expensive effort to check the signature is possibly valid. Its exact meaning is algorithm dependent. For the MD5/RSA algorithm, it is the next to the bottom two octets of the public key modulus needed to decode the signature field. That is to say, the most significant 16 of the lest significant 24 bits of this quantity in network order. The "signer's name" field is the fully qualified domain name of the signer generating the SIG RR. This is frequently the zone which contained the RR(s) being authenticated. The structured of the "signature" field depends on the algorithm chosen and is described below for the MD5/RSA algorithm. 4.1.1 Signature Format The actual signature portion of the SIG RR binds RDATA to all of the "type covered" RRs with that owner name. These covered RRs are thereby authenticated. To accomplish this, a data sequence is constructed as follows: data = RDATA | RR(s)... where | is concatenation and RR(s) are all the expanded (no name abbreviation) RR(s) of the type covered with the same owner name and class as the SIG RR in canonical order. The canonical order for RRs is to sort them in ascending order as left justified unsigned octet sequences where a missing octet sorts before a zero octet. How this data sequence is processed into the signature is algorithm dependent. For the MD5/RSA algorithm, the signature is as follows hash = MD5 ( data ) signature = ( 01 | FF* | 00 | hash ) ** e (mod n) where "|" is concatenation, "e" is the secret key exponent of the signer, and "n" is the public modulus that is the signer's public key. 01, FF, and 00 are fixed octets of the corresponding hexadecimal value. The FF octet is repeated the maximum number of times such that the value of the quantity being exponentiated is one octet shorter than the value of n. The size of n, including most and least significant bits (which will Eastlake, Kaufman [Page 17] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 be 1) SHALL be not less than 512 bits and not more than 2552 bits. n and e MUST be chosen such that the public exponent is less than 2**24 - 1 and SHOULD be chosen such that the public exponent is small. The above specifications are similar to Public Key Cryptographic Standard #1 [PKCS1]. (A public exponent of 3 minimizes the effort needed to decode a signature. Use of 3 as the public exponent may be weak for confidentiality uses since, if the same data can be collected encrypted under three different keys with an exponent of 3 then, using the Chinese Remainder Theorem, the original plain text can be easily recovered. This weakness is not significant for DNS because we seek only authentication, not confidentiality.) 4.1.2 SIG RRs Covering Type ANY The SIG RR described above protects all the RRs with a particular owner name, class, and type. Thus a server must supply them all to convince a security aware resolver. However, an unscrupulous server could claim there were no RRs of a particular type and class under an owner name while presenting signed RRs of other types. To provide a means of protection against this, one or more SIG RR is added for each owner name that covers the type ANY. It is calculated as indicated above except that all RRs for that owner name and SIG key, except the SIG RR covering type ANY itself, are included in the data string which is processed into the signature. To allow for dynamic update, the zone key signed ANY SIG RR covers only zone signed RRs. If RRs are added to a zone authenticated by an entity or user key, then an ANY SIG RR signed by that key covering the RRs signed by that key should be added. 4.1.3 Zone Transfer (AXFR) SIG The above SIG mechanisms assure the authentication of all the RRs of a particular name, class and type and all the RRs of a particular name, class and any type. However, to secure complete zone transfers, a SIG RR owned by the zone name must be created with a type covered of AXFR that covers all other zone signed RRs. It will be calculated by hashing together all other static zone RRs, including SIGs. The RRs are ordered and concatenated for hashing as described in Section 4.1.1. This SIG, other than having to be calculated last of all zone key signed SIGs in the zone, is the same as any other SIG. Eastlake, Kaufman [Page 18] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 Dynamic zone RRs which might be added by some future dynamic zone update protocol and signed by an end entity or user key rather than a zone key (see Section 3.2) are not included. They originate in the network and will not, in general, be migrated to the recommended off line zone signing procedure (see Section 8.2). Thus such dynamic RRs are not directly signed by the zone and are not generally protected against omission during zone transfers. 4.1.4 Transaction SIGs A response message from a security aware server may optionally contain a special SIG as the last item in the additional information section to authenticate the transaction. This SIG has a "type covered" field of zero, which is not a valid RR type. It is calculated by using a "data" (see section 4.1.1) of the entire preceding DNS reply message, including header, concatenated with the entire DNS query message that produced this response, including the query's header. That is data = full response (less trailing message SIG) | full query Verification of the message SIG (which is signed by the server host key, not the zone key) by the requesting resolver shows that the query and response were not tampered with in transit and that the response corresponds to the intended query. 4.2 SIG RRs in the Construction of Responses Security aware servers MUST, for every authoritative RR the query will return, attempt to send the available SIG RRs which authenticate the requested RR. If multiple such SIGs are available, there may be insufficient space in the response to include them all. In this case, SIGs whose signer is the zone containing the RR MUST be given highest priority and retained even if SIGs with other signers must be dropped. Sending SIGs to authenticate non-authoritative data (glue records and NS RRs for subzones) is optional and should be avoided if it will lead to UDP DNS response truncation. If a SIG covers any RR that would be in the answer section of the response, its automatic inclusion MUST be the answer section. If it covers an RR that would appear in the authority section, its automatic inclusion MUST be in the authority section. If it covers an RR that would appear in the additional information section it MUST Eastlake, Kaufman [Page 19] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 appear in the additional information section. Optionally, DNS transactions may be authenticated by a SIG RR at the end of the response in the additional information section (section 4.1.4). Such SIG RRs are signed by the DNS server originating the response. Although the signer field must be the name of the originating server host, the owner name, class, TTL, and original TTL, are meaningless. The class and TTL fields can be zero. To save space, the name should be root (a single zero octet). [There may be a problem with SIG and NXD RR's associated with domain names that are CNAMEs. The DNS RFCs prohibit other types of RRs appearing with a CNAME RR. This problem is being ignored until it is clear if DNS servers will really have a problem with this.] 4.3 Processing Responses with SIG RRs If SIG RRs are received in response to a query explicitly specifying the SIG type, no special processing is required but a security aware client may wish to authenticate them by checking the signature and applying consistency checks. If SIG RRs are received in any other response, a security aware client should check them using the public key of the signer. The result should then be verified against the appropriate other RRs retrieved. If the message does not pass reasonable checks or the SIG does not check against the signed RRs, the SIG RR is invalid and should be ignored. The time of receipt of the SIG RR must be in the inclusive range of the time signed and the signature expiration but the SIG can be retained and remains locally valid until the expiration time plus the authenticated TTL. If the SIG RR is the last RR in a response in the additional information section and has a type covered of zero, it is a transaction signature of the the response and the query that produced the response. It may be optionally checked and the message rejected if the checks fail. But even it the checks succeed, such a transaction authentication SIG does NOT authenticate any RRs in the message. Only proper direct or hashed RR signets signed by the zone can authenticate RRs. If a resolver does not implement transaction SIGs, it MUST at least ignore them without error. If all reasonable checks indicate that the SIG RR is valid then RRs verified by it should be considered authenticated and all other RRs in the response should be considered with suspicion. Eastlake, Kaufman [Page 20] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 4.4 File Representation of SIG RRs A SIG RR can be represented as a single logical line in a zone data file [RFC1033] but there are some special problems as described below. (It does not make sense to include a transaction authenticating SIG RR in a file as it is a transient authentication that must be calculated in real time by the DNS server.) There is no particular problem with the signer, covered type, and times. The time fields appears in the form YYYYMMDDHHMMSS where YYYY is the year, the first MM is the month number (01-12), DD is the day of the month (01-31), HH is the hour in 24 hours notation (00-23), the second MM is the minute (00-59), and SS is the second (00-59). The original TTL and algorithm fields appears as unsigned integers. The "labels" field does not appear in the file representation as it can be calculated from the owner name. The key footprint appears as an eight digit unsigned hexadecimal number. However, the signature itself can be very long. It is the last data field and is represented in base 64 (see Appendix) and may be divided up into any number of white space separated substrings, down to single base 64 digits, which are concatenated to obtain the full signature. These substrings can be split between lines using the standard parenthesis. Eastlake, Kaufman [Page 21] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 5. Non-existent Names The SIG RR mechanism described in section 4 above provides strong authentication of RRs that exist in a zone. But is it not immediately clear how to authenticatably deny the existence of a name in a zone. The nonexistence of a name in a zone is indicates by the NXD RR for a name interval containing the nonexistent name. An NXD RR and its SIG are returned in the additional information section, along with the error, if the resolver is security aware. NXD RRs can also be returned if an explicit query is made for the NXD type. The existence of a complete set of NXD records in a zone means that any query for any name to a security aware server serving the zone should result in an reply containing at least one signed RR. 5.1 The NXD Resource Record The NXD resource record is used to securely indicate that no RRs with an owner name in a certain name interval exist in a zone. The owner name of the NXD RR is an existing name in the zone. It's RDATA is another existing name in the zone. The presence of the NXD RR means that no name between its owner name and the name in its RDATA area exists. This implies a canonical ordering of all domain names in a zone. The ordering is to sort labels as unsigned left justified octet strings where the absence of a byte sorts before a zero byte. Names are then sorted by sorting on the highest level label and then, within those names with the same highest level label by the next lower label, etc. Since we are talking about a zone, the zone name itself always exists and all other names are the zone name with some prefix of lower level labels. Thus the zone name itself always sorts first. There is a slight problem with the last NXD in a zone as it wants to have an owner name which is the last existing name in sort order, which is easy, but it is not obvious what name to put in its RDATA to indicate the entire remainder of the name space. This is handled by treating the name space as circular and putting the zone name in the RDATA of the last NXD. There are additional complexities due to interaction with wildcards as explained below. The NXD RRs for a zone can be automatically calculated and added to Eastlake, Kaufman [Page 22] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 the zone by the same recommended off-line process that signs the zone. The NXD RR's TTL should not exceed the zone minimum TTL. The type number for the NXD RR is xxx. 5.2 NXD RDATA Format The RDATA for an NXD RR consists simply of a domain name. 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | next domain name / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5.3 Example Assume a zone has entries for big.foo.bar, medium.foo.bar. small.foo.bar. tiny.foo.bar. Then a query to a security aware server for huge.foo.bar would produce an error reply with the additional information section containing big.foo.bar. NXD medium.foo.bar. and the corresponding SIG RR. 5.4 Interaction of NXD RRs and Wildcard RRs As a wildcard RR causes all possible names in an interval to exist, there should not be an NXD record that would cover any part of this interval. Thus if *.X.ZONE exists you would expect an NXD RR that ends at X.ZONE and one that starts with the last name covered by *.X.ZONE. However, this "last name covered" is something very ugly and long like \255\255\255....X.zone. So the NXD for the interval following is simply given the owner name *.X.zone. This "*" type name is not expanded when the NXD is returned as additional information in connection with a query for a non-existent name and Eastlake, Kaufman [Page 23] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 type. If there could be any wildcard RRs in a zone and thus wildcard NXDs, care must be taken in interpreting the results of explicit NXD retrievals as the owner name may be a wildcard expansion. The existence of one or more wildcard RRs covering a name interval makes it possible for a malicious server to hide any more specificly named RRs in the internal. The server can just falsely return the wildcard match NXD instead of the more specificly named RRs. If there is a zone wide wildcard, there will be only one NXD RR whose owner name and RDATA are both the zone name. In this case a server could conceal the existence of any more specific RRs in the zone. (It would be possible to make a more complex NXD feature, taking into account the types of RRs that did not exist in a name interval, and the like, which would eliminate this possibility. But it would be more complex and would be so constraining as to make any future dynamic update feature that could create new names very difficult (see Section 3.2).) 5.5 Blocking NXD Pseudo-Zone Transfers In a secure zone, a resolver can query for the initial NXD associated with the zone name. Using the RDATA field from that RR, it can query for the next NXD RR. By repeating this, it can walk through all the NXDs in the zone. If there are no wildcards, it can use this technique to find all names in a zone. If it does type ANY queries, it can incrementally get all information in the zone and perhaps defeat attempts to administratively block zone transfers. If there are any wildcards, this NXD walking technique will not find any more specific RR names in the part of the name space the wildcard covers. By doing explicit retrievals for wildcard names, a resolver could determine what intervals are covered by wildcards but still could not, with these techniques, find any names inside such intervals except by trying every name. If it is desired to block NXD walking, the recommended method is to add a zone wide wildcard of the KEY type with the no key bit on and with no type (zone, entity, or user) bit on. This will cause there to be only one NXD RR in the zone for the zone name and leak no information about what real names exist in the zone. This protection from pseudo-zone transfers is bought at the expense of eliminating the data origin authentication of the non-existence of names that NXD RRs can provide. If an entire zone is covered by a wildcard, a malicious server can return an RR produced by matching the resulting wildcard NXD and can thus hide all the real data and delegations with more specific names in the zone. Eastlake, Kaufman [Page 24] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 6. How to Resolve Securely Retrieving or resolving authentic data from the DNS involves starting with one or more trusted public keys and, in general, progressing securely from them through the DNS zone structure to the zone of interest. Such trusted public keys would normally be configured in a manner similar to that described in section 6.1. However, as a practical matter, a security aware resolver would still gain some confidence in the results it returns even if it was not configured with any keys but trusted what it got from a local well known server as a starting point. 6.1 Boot File Format The recommended format for a boot file line to configure starting keys is as follows: pubkey name object flags algorithm [exponent modulus] for a public key. "object" is the domain name of the thing the key is associated with and "name" is the owner name if the line is translated into a KEY RR). Flags indicates the type of key and is the same as the flag byte in the KEY RR. In particular, if the "no key" bit is on in flags, then all fields after flags may be omitted. Algorithm is the algorithm in use where one is the MD5/RSA algorithm and 254 indicates a private algorithm. The material after the algorithm is algorithm dependent and, for private algorithms, starts with the algorithm's identifying OID. For the RSA algorithm, it is the public key exponent as a decimal number between 3 and 16777215, and the modulus in base 64 (see Appendix). While it might seem logical for everyone to start with the key for the root zone, this has problems. The logistics of updating every DNS resolver in the world when the root key changes would be excessive. It may be some time before there even is a root key. Furthermore, many organizations will explicitly wish their "interior" DNS implementations to completely trust only their own zone. These interior resolvers can then go through the organization's zone server to access data outsize the organization's domain. 6.2 Chaining Through Zones Starting with one trusted zone key, it is possible to retrieve signed keys for subzones which have a key. Every secure zone (except root) should also include the KEY RR for its super-zone signed by the secure zone and with the owner name of the secure zone and object Eastlake, Kaufman [Page 25] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 name of the super-zone. This makes it possible to climb the tree of zones if one starts below root. A secure sub-zone is indicated by a KEY RR appearing with the NS RRs for the sub-zone and with the same owner and object names. These make it possible to descend within the tree of zones. A resolver should keep track of the number of successive secure zones traversed from a starting point to any secure zone it can reach. In general, the lower such a distance number is, the greater the confidence in the data. Data configured via a boot file should be given a distance number of zero. Should a query encounter different data with different distance values, that with a larger value should be ignored. A security conscious resolver should completely refuse to step from a secure zone into a non-secure zone unless the non-secure zone is certified to be non-secure or only experimentally secure by the presence of an authenticated KEY RR for the non-secure zone with a no key flag or the presence of a KEY RR with the experimental bit set. Otherwise the resolver is probably getting completely bogus or spoofed data. If legitimate non-secure zones are encountered in traversing the DNS tree, then no zone can be trusted as secure that can be reached only via information from such non-secure zones. Since the non-secure zone data could have been spoofed, the "secure" zone reach via it could be counterfeit. The "distance" to data in such zones or zones reached via such zones could be set to 512 or more as this exceeds the largest possible distance through secure zones in the DNS. Nevertheless, continuing to apply secure checks within "secure" zones reached via non-secure zones will, as a practical matter, provide some increase in security. The syntax of KEY RRs, with an arbitrary object name, provides for cross-certification. Although the syntax permits the owner name of a cross-certification KEY RR to be any name, by convention and to avoid an undue concentration of such KEY RRs under any particular name, their owner name should be the zone name prefixed with the destination object name (truncated an integral number of labels from the front if necessary due to DNS name restrictions). Thus a key for isoc.org would appear in the mit.edu zone with the owner name isoc.org.mit.edu and object name isoc.org. The existence of cross certifications adds further policy questions. Assume we have a zone B.A and a zone Y.X. Many possibilities exist for a secure resolver configured with the B.A key to get to Y.X. If all the zones along the way are secure, it could climb to root and then descend the other side, a total of four hops (B.A -> A -> . -> X -> Y.X). If the B.A administrator had installed a cross certified key for Y.X in the B.A zone, using that would be a shorter and Eastlake, Kaufman [Page 26] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 presumably more secure way to find Y.X's key which would be immune to the non-security or even compromise of the servers for A or root or X. But what if some less trusted subzone of B.A, say flakey.B.A installed a cross certified key for Y.X? If there is a conflict, should this be preferred to a hierarhically derived key obtained by climbing to root and descending? Such questions are entirely a matter of local resolver policy. 6.3 Secure Time Coordinated interpretation of the time fields in SIG RRs requires that reasonably consistent time be available to the hosts implementing the DNS security extensions. A variety of time synchronization protocols exist including the Network Time Protocol (NTP, RFC1305). If such protocols are used, they should be used securely so that time can not be spoofed. Otherwise, for example, a host could get its clock turned back and might then believe old SIG and KEY RRs which were valid but no longer are. Eastlake, Kaufman [Page 27] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 7. Operational Considerations This section discusses a variety of considerations in secure operation of DNS using these proposed protocol extensions. 7.1 Key Size Considerations There are a number of factors that effect public key size choice for use in the DNS security extension. Unfortunately, these factors usually do not all point in the same direction. Choice of a key size should generally be made by the zone administrator depending on their local conditions. For most schemes, larger keys are more secure but slower. Verification (the most common operation) for the MD5/RSA algorithm will vary roughly with the square of the modulus length, signing will vary with the cube of the modulus length, and key generation (the least common operation) will vary with the fourth power of the modulus length. The current best algorithms for factoring a modulus and breaking RSA security vary roughly with the square of the modulus itself. Thus going from a 640 bit modulus to a 1280 bit modulus only increases the verification time by a factor of 4 but vastly increases the work factor of breaking the key. [RSA FAQ] However, larger keys increase size of the KEY and SIG RRs. This increases the chance of UDP packet overflow and the possible necessity for using higher overhead TCP. The recommended minimum RSA algorithm modulus size, 640 bits, is believed by the authors to be secure at this time and for some years but high level zones in the DNS tree may wish to set a higher minimum, perhaps 1000 bits, for security reasons. (Since the United States National Security Agency generally permits export of encryption systems using an RSA modulus of up to 512 bits, use of that small a modulus, i.e. n, must be considered weak.) For a key used only to secure data and not to secure other keys, 640 bits should be entirely adequate. 7.2 Key Storage It is strongly recommended that zone private keys and the zone file master copy be kept and used in off-line non-network connected physically secure machines only. Periodically an application can be run to re-sign the RRs in a zone by adding NXD and SIG RRs. Then the augmented file can be transferred, perhaps by sneaker-net, to the Eastlake, Kaufman [Page 28] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 networked zone primary server machine. The idea is to have a one way information flow to the network to avoid the possibility of tampering from the network. Keeping the zone master file on-line on the network and simply cycling it through an off-line signer does not do this. The on-line version could still be tampered with if the host it resides on is compromised. The master copy of the zone file should be off net and should not be updated based on an unsecured network mediated communication. Non-zone private keys, such as host or user keys, may have to be kept on line to be used for real-time purposes such a IP secure session set-up or secure mail. 7.3 Key Generation Careful key generation is a sometimes over looked but absolutely essential element in any cryptographically secure system. The strongest algorithms used with the longest keys are still of no use if an adversary can guess enough to lower the size of the likely key space so that it can be exhaustively searched. Suggestions will be found in draft-ietf-security-randomness-*.txt. It is strongly recommended that key generation also occur off-line, perhaps on the machine used to sign zones (see Section 7.2). 7.4 Key Lifetimes No key should be used forever. The longer a key is in use, the greater the probability that it will have been compromised through carelessness, accident, espionage, or cryptanalysis. No zone key should have a lifetime significantly over five years. The recommended maximum lifetime for zone keys that are kept off-line and carefully guarded is 13 months with the intent that they be replaced every year. The recommended maximum lifetime for end entity keys that are used for IP-security or the like and are kept on line is 36 days with the intent that they be replaced monthly or more often. In some cases, an entity key lifetime of a little over a day may be reasonable. Key lifetimes significantly over a year increase the risk that, when the time comes up change the key, no one at the site will remember how to do it. Eastlake, Kaufman [Page 29] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 7.5 Signature Lifetime Signature expiration times must be set far enought in the future that it is quite certain that new signatures can be generated before the old ones expire. However, setting expiration too far into the future could, if bad data or signatures were ever generated, mean a long time to flush such badness. It is recommended that signature lifetime be a small multiple of the TTL but not less than a reasonable re-signing interval. 7.6 Root It should be noted that in DNS the root is a zone unto itself. Thus the root zone key should only be see signing itself or signing RRs with names one level below root, such as .aq, .edu, or .arpa. Implementations MAY reject as bogus any purported root signature of records with a name more than one level below root. Eastlake, Kaufman [Page 30] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 8. Conformance Several levels of server and resolver conformance are defined. 8.1 Server Conformance Three levels of server conformance are defined as follows: Basic server compliance is the ability to store and retrieve (including zone transfer) SIG, KEY, and NXD RRs. Secondaries for a secure zone must be at least basicly compliant. Medium server compliance adds the following to basic compliance: (1) ability to read SIG, KEY, and NXD RRs in zone files and (2) ability, given a zone file and private key, to add appropriate SIG and NXD RRs, possibly via a separate application. Primary servers for secure zones must be at least minimally compliant. Full server compliance is ability to automatically include SIG, KEY, and NXD RRs in responses as appropriate, as well as meeting minimal compliance. 8.2 Resolver Conformance Two levels of resolver compliance are defined: A basic compliance resolver can handle SIG, KEY, and NXD RRs when they are explicitly requested. A fully compliant resolver understands KEY, SIG, and NXD RRs, maintains appropriate information in its local caches and database to indicate which RRs have been authenticated and to what extent they have been authenticated, and performs additional queries as necessary to obtain KEY, SIG, or NXD RRs from non-security aware servers. Eastlake, Kaufman [Page 31] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 9. Security Considerations This document concerns technical details of extensions to the Domain Name System (DNS) protocol to provide data integrity and data origin authentication, public key distribution, and optional transaction security. If should be noted that, at most, these extensions guarantee the validity of resource records, including KEY resource records, retrieved from the DNS. They do not magically solve other security problems. For example, using secure DNS you can have high confidence in the IP address you retrieve for a host; however, this does not stop someone for substituting an unauthorized host at that address or capturing packets sent to that address and responding with packets apparently from that address. Any reasonably complete security system will require the protection of many other facets of the Internet. References [PKCS1] - PKCS #1: RSA Encryption Standard, RSA Data Security, Inc., 3 June 1991, Version 1.4. [RFC1032] - Domain Administrators Guide, M. Stahl, November 1987 [RFC1033] - Domain Administrators Operations Guide, M. Lottor, November 1987 [RFC1034] - Domain Names - Concepts and Facilities, P. Mockapetris, November 1987 [RFC1035] - Domain Names - Implementation and Specifications [RFC1321] - The MD5 Message-Digest Algorithm, R. Rivest, April 16 1992. [RSA FAQ] - RSADSI Frequently Asked Questions periodic posting. Eastlake, Kaufman [Page 32] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 Authors Addresses Donald E. Eastlake, 3rd Digital Equipment Corporation 550 King Street, LKG2-1/BB3 Littleton, MA 01460 Telephone: +1 508 486 6577(w) +1 508 287 4877(h) EMail: dee@lkg.dec.com Charles W. Kaufman Iris Associates 1 Technology Park Drive Westford, MA 01886 Telephone: +1 508-392-5276 EMail: charlie_kaufman@iris.com Expiration and File Name This draft expires 23 June 1995. Its file name is draft-ietf-dnssec-secext-03.txt. Eastlake, Kaufman [Page 33] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 Appendix: Base 64 Encoding The following encoding technique is taken from RFC 1521 by Borenstein and Freed. It is reproduced here in a slightly edited form for convenience. A 65-character subset of US-ASCII is used, enabling 6 bits to be represented per printable character. (The extra 65th character, "=", is used to signify a special processing function.) The encoding process represents 24-bit groups of input bits as output strings of 4 encoded characters. Proceeding from left to right, a 24-bit input group is formed by concatenating 3 8-bit input groups. These 24 bits are then treated as 4 concatenated 6-bit groups, each of which is translated into a single digit in the base64 alphabet. Each 6-bit group is used as an index into an array of 64 printable characters. The character referenced by the index is placed in the output string. Table 1: The Base64 Alphabet Value Encoding Value Encoding Value Encoding Value Encoding 0 A 17 R 34 i 51 z 1 B 18 S 35 j 52 0 2 C 19 T 36 k 53 1 3 D 20 U 37 l 54 2 4 E 21 V 38 m 55 3 5 F 22 W 39 n 56 4 6 G 23 X 40 o 57 5 7 H 24 Y 41 p 58 6 8 I 25 Z 42 q 59 7 9 J 26 a 43 r 60 8 10 K 27 b 44 s 61 9 11 L 28 c 45 t 62 + 12 M 29 d 46 u 63 / 13 N 30 e 47 v 14 O 31 f 48 w (pad) = 15 P 32 g 49 x 16 Q 33 h 50 y Special processing is performed if fewer than 24 bits are available at the end of the data being encoded. A full encoding quantum is always completed at the end of a quantity. When fewer than 24 input bits are available in an input group, zero bits are added (on the right) to form an integral number of 6-bit groups. Padding at the end of the data is performed using the '=' character. Since all base64 input is an integral number of octets, only the following cases can arise: (1) the final quantum of encoding input is an integral multiple of 24 bits; here, the final unit of encoded output Eastlake, Kaufman [Page 34] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 will be an integral multiple of 4 characters with no "=" padding, (2) the final quantum of encoding input is exactly 8 bits; here, the final unit of encoded output will be two characters followed by two "=" padding characters, or (3) the final quantum of encoding input is exactly 16 bits; here, the final unit of encoded output will be three characters followed by one "=" padding character. Eastlake, Kaufman [Page 35] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 Status of This Document....................................1 Abstract...................................................2 Acknowledgements...........................................2 Table of Contents..........................................3 1. Introduction............................................5 2. Brief Overview of the Extensions.......................6 2.1 Services Not Provided..................................6 2.2 Key Distribution.......................................6 2.3 Data Origin Authentication and Integrity...............7 2.3.2 The SIG Resource Record..............................7 2.3.3 Authenticating Name Non-existence....................8 2.3.5 Special Problems With Time-to-Live...................8 2.3.5 Signers Other Than The Zone..........................9 2.3 DNS Transaction Authentication.........................9 3. The KEY Resource Record................................10 3.1 KEY RDATA format......................................10 3.2 Object Types and DNS Names and Keys...................10 3.3 The KEY RR Flag Octet.................................11 3.4 The KEY Algorithm Version and MD5/RSA Algorithm.......12 3.5 KEY RRs in the Construction of Responses..............13 3.6 File Representation of KEY RRs........................14 4. The SIG Resource Record................................15 4.1 SIG RDATA Format......................................15 4.1.1 Signature Format....................................17 4.1.2 SIG RRs Covering Type ANY...........................18 4.1.3 Zone Transfer (AXFR) SIG............................18 4.1.4 Transaction SIGs....................................19 4.2 SIG RRs in the Construction of Responses..............19 4.3 Processing Responses with SIG RRs.....................20 4.4 File Representation of SIG RRs........................21 5. Non-existent Names.....................................22 5.1 The NXD Resource Record...............................22 5.2 NXD RDATA Format......................................23 5.3 Example...............................................23 5.4 Interaction of NXD RRs and Wildcard RRs...............23 5.5 Blocking NXD Pseudo-Zone Transfers....................24 6. How to Resolve Securely................................25 6.1 Boot File Format......................................25 6.2 Chaining Through Zones................................25 6.3 Secure Time...........................................27 7. Operational Considerations.............................28 Eastlake, Kaufman [Page 36] INTERNET-DRAFT DNS Protocol Security Extensions December 1994 7.1 Key Size Considerations...............................28 7.2 Key Storage...........................................28 7.3 Key Generation........................................29 7.4 Key Lifetimes.........................................29 7.5 Signature Lifetime....................................30 7.6 Root..................................................30 8. Conformance............................................31 8.1 Server Conformance....................................31 8.2 Resolver Conformance..................................31 9. Security Considerations................................32 References................................................32 Authors Addresses.........................................33 Expiration and File Name..................................33 Appendix: Base 64 Encoding................................34 Eastlake, Kaufman [Page 37]   Received: from sol.tis.com by magellan.TIS.COM id aa19729; 27 Dec 94 12:20 EST Received: from fnal.fnal.gov(131.225.9.1) by relay via smap (V1.3) id sma008780; Tue Dec 27 12:22:12 1994 Received: from munin.fnal.gov by FNAL.FNAL.GOV (PMDF V4.2-12 #3998) id <01HL4X40B1PC00OXIT@FNAL.FNAL.GOV>; Tue, 27 Dec 1994 11:21:49 CDT Received: from LOCALHOST.fnal.gov by munin.fnal.gov (4.1/SMI-4.1-m) id AA05487; Tue, 27 Dec 94 11:21:13 CST Date: Tue, 27 Dec 1994 11:21:12 -0600 From: Matt Crawford Subject: Comments Re: updated draft In-Reply-To: Your message of Sat, 24 Dec 94 03:07:19 EST. <9412240807.AA14806@skidrow.tay.dec.com> Sender: crawdad@munin.fnal.gov To: "Donald E. Eastlake 3rd (Beast)" Cc: dns-security@tis.com Message-Id: <9412271721.AA05487@munin.fnal.gov> Content-Transfer-Encoding: 7BIT > or even different names, but this is strongly discouraged. In > particular, the use of a zone key as a non-zone key will usually > require that the key be kept on line and thereby become much more > vulnerable. ^ private If the spec for AAAA RRs is out as an RFC before the next version of this draft goes in, I urge you to change all references to type A RRs to include type AAAA. That will save an addendum later. > > The SIG is valid until the "signature expiration" time which is an > unsigned number of seconds since the start of 1 January 1970. > > The "time signed" field is an unsigned number of seconds since the > start of 1 January 1970. Could you mention the time zone GMT or UCT or whatever its proper name is? > be 1) SHALL be not less than 512 bits and not more than 2552 bits. n > and e MUST be chosen such that the public exponent is less than 2**24 > - 1 and SHOULD be chosen such that the public exponent is small. Comparison with section 3.6 indicates that "less than or equal to" was meant here. > 4.1.4 Transaction SIGs > [...] > This SIG has a "type covered" field of zero, which is not a valid RR > type. It is calculated by using a "data" (see section 4.1.1) of the > entire preceding DNS reply message, including header, concatenated You can't possibly mean the IP header with its variable TTL field, so could you write "including DNS header" here? > 4.3 Processing Responses with SIG RRs > [...] > message. Only proper direct or hashed RR signets signed by the zone > can authenticate RRs. Is this reference to direct and hashed signets a bit of legacy terminology from earlier versions? > Full server compliance is ability to automatically include SIG, > KEY, and NXD RRs in responses as appropriate, as well as meeting > minimal compliance. Was that "minimal" supposed to be "medium"? _________________________________________________________ Matt Crawford crawdad@fnal.gov Fermilab   Received: from sol.tis.com by magellan.TIS.COM id aa18895; 1 Jan 95 20:08 EST Received: from inet-gw-2.pa.dec.com(16.1.0.23) by relay via smap (V1.3) id sma009459; Sun Jan 1 20:10:57 1995 Received: from skidrow.tay.dec.com by inet-gw-2.pa.dec.com (5.65/10Aug94) id AA27731; Sun, 1 Jan 95 17:09:56 -0800 Received: by skidrow.tay.dec.com (5.65/MS-081993); id AA13977; Sun, 1 Jan 1995 20:14:43 -0500 Message-Id: <9501020114.AA13977@skidrow.tay.dec.com> To: Matt Crawford Cc: dns-security@tis.com Subject: Re: Comments Re: updated draft In-Reply-To: Your message of "Tue, 27 Dec 94 11:21:12 CST." <9412271721.AA05487@munin.fnal.gov> Date: Sun, 01 Jan 95 20:14:42 -0500 From: "Donald E. Eastlake 3rd (Beast)" X-Mts: smtp Matt, Thanks for all your excellent suggestions. I've incorporated them along with some other comments I've gotten and will now submit this draft-ietf-dnssec-secext-03.txt to internet-drafts. From: Matt Crawford In-Reply-To: Your message of Sat, 24 Dec 94 03:07:19 EST. <9412240807.AA14806@skidrow.tay.dec.com> Sender: crawdad@munin.fnal.gov To: "Donald E. Eastlake 3rd (Beast)" Cc: dns-security@tis.com Content-Transfer-Encoding: 7BIT >> or even different names, but this is strongly discouraged. In >> particular, the use of a zone key as a non-zone key will usually >> require that the key be kept on line and thereby become much more >> vulnerable. ^ > private Good clarification. >If the spec for AAAA RRs is out as an RFC before the next version of >this draft goes in, I urge you to change all references to type A >RRs to include type AAAA. That will save an addendum later. I went ahead and made this change where I noticed it. I don't see that it is necessary to wait for AAAA RRs to be RFCified. If the AAAA RFC is not out when this draft is to be submitted as an RFC, I can alway take them out. >> >> The SIG is valid until the "signature expiration" time which is an >> unsigned number of seconds since the start of 1 January 1970. >> >> The "time signed" field is an unsigned number of seconds since the >> start of 1 January 1970. > >Could you mention the time zone GMT or UCT or whatever its proper >name is? GMT. Good point. >> be 1) SHALL be not less than 512 bits and not more than 2552 bits. n >> and e MUST be chosen such that the public exponent is less than 2**24 >> - 1 and SHOULD be chosen such that the public exponent is small. > >Comparison with section 3.6 indicates that "less than or equal to" >was meant here. Right. >> 4.1.4 Transaction SIGs >> [...] >> This SIG has a "type covered" field of zero, which is not a valid RR >> type. It is calculated by using a "data" (see section 4.1.1) of the >> entire preceding DNS reply message, including header, concatenated > >You can't possibly mean the IP header with its variable TTL field, so >could you write "including DNS header" here? I didn't consider that a "DNS reply message" had much to do with the transport envelope around it but I'll make the change you suggest for clarity. >> 4.3 Processing Responses with SIG RRs >> [...] >> message. Only proper direct or hashed RR signets signed by the zone >> can authenticate RRs. > >Is this reference to direct and hashed signets a bit of legacy >terminology from earlier versions? Right. I've changed it to just say SIG RR. >> Full server compliance is ability to automatically include SIG, >> KEY, and NXD RRs in responses as appropriate, as well as meeting >> minimal compliance. > >Was that "minimal" supposed to be "medium"? Yes, this is also and artifact of changing the names of the conformance levels. >_________________________________________________________ >Matt Crawford crawdad@fnal.gov Fermilab Thanks again, Donald   Received: from sol.tis.com by magellan.TIS.COM id aa02586; 4 Jan 95 14:27 EST Received: from kerby.ocsg.com(192.156.168.6) by relay via smap (V1.3) id sma020188; Wed Jan 4 14:29:20 1995 Received: (uucp@localhost) by kerby.ocsg.com (8.6.9/8.6.4 + 8.6.9, dpg hack 5dec94) with UUCP id LAA08875; Wed, 4 Jan 1995 11:19:34 -0800 Received: by war04.ocsg.com (NX5.67d/NX3.0M, dpg hack 15dec93) id AA03528; Wed, 4 Jan 95 10:45:03 -0800 Date: Wed, 4 Jan 95 10:45:03 -0800 From: Dennis Glatting Message-Id: <9501041845.AA03528@war04.ocsg.com> Received: by NeXT.Mailer (1.100) Received: by NeXT Mailer (1.100) To: bind-workers@vix.com, dns-security@tis.com Subject: Looking for a Public Domain implementation of the DNS Security Extensions Reply-To: dpg@ocsg.com Is there a public domain implementation of the DNS Security Extensions (draft-ietf-dnssec-secext-03.txt)? Where can I get hold of a copy? -dpg   Received: from sol.tis.com by magellan.TIS.COM id aa02751; 4 Jan 95 14:51 EST Received: from sol.tis.com(192.33.112.100) by relay via smap (V1.3) id sma021017; Wed Jan 4 14:54:02 1995 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA19799; Wed, 4 Jan 95 14:51:08 EST Message-Id: <9501041951.AA19799@tis.com> Reply-To: James M Galvin To: dpg@ocsg.com Cc: bind-workers@vix.com, dns-security@tis.com Subject: Re: Looking for a Public Domain implementation of the DNS Security Extensions In-Reply-To: Dennis Glatting's message of Wed, 04 Jan 1995 10:45:03 PST. <9501041845.AA03528@war04.ocsg.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <22427.789249140.1@tis.com> Date: Wed, 04 Jan 1995 14:52:21 -0500 From: James M Galvin Is there a public domain implementation of the DNS Security Extensions (draft-ietf-dnssec-secext-03.txt)? Where can I get hold of a copy? TIS is developing a version of the extensions you cite, which we expect to be openly available to the Internet community. They are not currently available. We expect to begin beta testing sometime during first quarter 95. We'll let these lists know about our progress and the availability of the software from time to time. Jim   Received: from sol.tis.com by magellan.TIS.COM id aa12931; 5 Jan 95 13:08 EST Received: from ietf.cnri.reston.va.us(132.151.1.35) by relay via smap (V1.3) id sma015974; Thu Jan 5 13:10:15 1995 Received: from [127.0.0.1] by IETF.CNRI.Reston.VA.US id aa06265; 5 Jan 95 12:45 EST Mime-Version: 1.0 Content-Type: Multipart/Mixed; Boundary="NextPart" To: IETF-Announce: ;, tis.com@magellan.TIS.COM MMDF-Warning: Parse error in original version of preceding line at magellan.TIS.COM Cc: dns-security@tis.com From: Internet-Drafts@cnri.reston.va.us Reply-To: Internet-Drafts@cnri.reston.va.us Subject: I-D ACTION:draft-ietf-dnssec-secext-03.txt Date: Thu, 05 Jan 95 12:45:56 -0500 Sender: cclark@cnri.reston.va.us Message-Id: <9501051245.aa06265@IETF.CNRI.Reston.VA.US> --NextPart A Revised Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the DNS Security Working Group of the IETF. Title : Domain Name System Protocol Security Extensions Author(s) : D. Eastlake, C. Kaufman Filename : draft-ietf-dnssec-secext-03.txt Pages : 35 Date : 01/04/1995 The Domain Name System (DNS) has become a critical operational part of the Internet infrastructure yet it has no strong security mechanisms to assure data integrity or authentication. Extensions to the DNS are described that provide these services to security aware resolvers or applications through the use of cryptographic digital signatures. These digital signatures are included in secured zones as resource records. Security can still be provided even through non-security aware DNS servers. The extensions also provide for the storage of authenticated public keys in the DNS. This storage of keys can support a general public key distribution service as well as DNS security. The stored keys enable security aware resolvers to learn the authenticating key of zones in addition to keys for which they are initially configured. Keys associated with DNS names can be retrieved to support other protocols. Provision is made for a variety of key types and algorithms. In addition, the security extensions provide for the optional authentication of DNS protocol transactions. Internet-Drafts are available by anonymous FTP. Login with the username "anonymous" and a password of your e-mail address. After logging in, type "cd internet-drafts" and then "get draft-ietf-dnssec-secext-03.txt". A URL for the Internet-Draft is: ftp://ds.internic.net/internet-drafts/draft-ietf-dnssec-secext-03.txt Internet-Drafts directories are located at: o Africa Address: ftp.is.co.za (196.4.160.2) o Europe Address: nic.nordu.net (192.36.148.17) o Pacific Rim Address: munnari.oz.au (128.250.1.21) o US East Coast Address: ds.internic.net (198.49.45.10) o US West Coast Address: ftp.isi.edu (128.9.0.32) Internet-Drafts are also available by mail. Send a message to: mailserv@ds.internic.net. In the body type: "FILE /internet-drafts/draft-ietf-dnssec-secext-03.txt". NOTE: The mail server at ds.internic.net can return the document in MIME-encoded form by using the "mpack" utility. To use this feature, insert the command "ENCODING mime" before the "FILE" command. To decode the response(s), you will need "munpack" or a MIME-compliant mail reader. Different MIME-compliant mail readers exhibit different behavior, especially when dealing with "multipart" MIME messages (i.e., documents which have been split up into multiple messages), so check your local documentation on how to manipulate these messages. For questions, please mail to Internet-Drafts@cnri.reston.va.us. Below is the data which will enable a MIME compliant mail reader implementation to automatically retrieve the ASCII version of the Internet-Draft. --NextPart Content-Type: Multipart/Alternative; Boundary="OtherAccess" --OtherAccess Content-Type: Message/External-body; access-type="mail-server"; server="mailserv@ds.internic.net" Content-Type: text/plain Content-ID: <19950104174616.I-D@CNRI.Reston.VA.US> ENCODING mime FILE /internet-drafts/draft-ietf-dnssec-secext-03.txt --OtherAccess Content-Type: Message/External-body; name="draft-ietf-dnssec-secext-03.txt"; site="ds.internic.net"; access-type="anon-ftp"; directory="internet-drafts" Content-Type: text/plain Content-ID: <19950104174616.I-D@CNRI.Reston.VA.US> --OtherAccess-- --NextPart--   Received: from sol.tis.com by magellan.TIS.COM id ab05178; 10 Jan 95 22:35 EST Received: from inet-gw-1.pa.dec.com(16.1.0.22) by relay via smap (V1.3) id sma021894; Tue Jan 10 18:13:15 1995 Received: from skidrow.tay.dec.com by inet-gw-1.pa.dec.com (5.65/10Aug94) id AA05289; Tue, 10 Jan 95 14:21:47 -0800 Received: by skidrow.tay.dec.com (5.65/MS-081993); id AA22223; Tue, 10 Jan 1995 17:26:44 -0500 Message-Id: <9501102226.AA22223@skidrow.tay.dec.com> To: Internet Drafts MMDF-Warning: Unable to confirm address in preceding line at magellan.TIS.COM Cc: dns-security@tis.com Subject: submission of draft-ietf-dnssec-as-map-01.txt Date: Tue, 10 Jan 95 17:26:44 -0500 From: "Donald E. Eastlake 3rd (Beast)" X-Mts: smtp Please place the following updated draft in the internet drafts directories. Thanks, Donald --------------------------------------------------------------------------- Donald E. Eastlake, III DTN: 226-6577(w) dee@lkg.dec.com 550 King St, LKG2-1/BB3 1-508-486-6577(w) dee@ranger.enet.dec.com Littleton, MA 01460 USA 1-508-486-7417(fax) 1-508-287-4877(h) INTERNET-DRAFT Mapping A.S. Number into the DNS 12 January 1995 Expires 11 July 1995 Mapping Autonomous Systems Number into the Domain Name System ------- ---------- ------- ------ ---- --- ------ ---- ------ Donald E. Eastlake 3rd Status of This Document This draft, file name draft-ietf-dnssec-as-map-01.txt, is intended to be become a standards track RFC concerning DNS and routing security. Distribution of this document is unlimited. Comments should be sent to the DNS Security Working Group mailing list or to the author. This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months. Internet-Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet- Drafts as reference material or to cite them other than as a ``working draft'' or ``work in progress.'' To learn the current status of any Internet-Draft, please check the 1id-abstracts.txt listing contained in the Internet-Drafts Shadow Directories on ds.internic.net, nic.nordu.net, ftp.isi.edu, munnari.oz.au, or ftp.is.co.za. Donald E. Eastlake 3rd [Page 1] INTERNET-DRAFT Mapping A.S. Numbers into the DNS Abstract One requirement of secure routing is that independent routing entities, such as those identified by Internet Autonomous System Numbers, be able to authenticate messages to each other. Modifications currently being developed (see draft-ietf-dnssec- secext-*.txt) to the Domain Name System will enable it to be used for convenient public key distribution. This draft maps all Autonomous System numbers into DNS Domain Names so that the DNS can be used to distribute their public keys. Acknowledgements The contributions of the following persons to this draft are gratefully acknowledged: Ran Atkinson, Christian Huitema, Tony Li, Michael A. Patton. Donald E. Eastlake 3rd [Page 2] INTERNET-DRAFT Mapping A.S. Numbers into the DNS Table of Contents Status of This Document....................................1 Abstract...................................................2 Acknowledgements...........................................2 Table of Contents..........................................3 1. Introduction............................................4 2. Autonomous System Number Mapping........................5 3. Meaning of RRs..........................................6 4. Security Considerations.................................7 References.................................................7 Author's Address...........................................7 Expiration and File Name...................................7 Donald E. Eastlake 3rd [Page 3] INTERNET-DRAFT Mapping A.S. Numbers into the DNS 1. Introduction There are a number of elements that will be required to secure routing in the Internet. One of these is a way that independently operated top level routing domains be able to authenticate messages to each other. Sharing a private symmetric key between each pair of such domains is impractical. The Autonomous System numbering scheme provides for 2**16 such domains which implies approximately 2**31 pairs, an impractical number of keys to securely generate, install, and periodically replace. The solution is to use public key technology whereby each domain has a private key it can use to sign messages. Other domains that know the corresponding public key can then authenticate these messages. Such authenticated messages can be used to set up and maintain efficient symmetric keys on an as needed basis. But how do the domains securely obtain the Autonomous System number to public key mapping? Extensions currently being developed for the Domain Name System will enable it to be conveniently used for authenticated public key distribution (see draft-ietf-dnssec-secext-*.txt). All that is required is a mapping of Autonomous System numbers into domain names, which is provided by this draft. It should be noted that the public keys retrieved from DNS will likely be used primarily to authenticate initial connection set up messages. Autonomous Systems that need to converse with any frequency will probably negotiate more efficient session keys. Donald E. Eastlake 3rd [Page 4] INTERNET-DRAFT Mapping A.S. Numbers into the DNS 2. Autonomous System Number Mapping Autonomous System (A.S.) numbers are 16 bit quantities, usually written as decimal number whose maximum value would be 65,535. For example, ANS is autonomous system 690. The A.S. number is mapped into a domain name as described below. Take the thousands part of the A.S. number and the number modulo 1,000 as decimal numbers, reverse their order and put a period between them, and then append ".in-as.arpa". This mapping is analogous to the IPv4 address mapping into the in-addr.arpa DNS domain. Thus the domain name correspond to Autonomous System 690 (decimal) is 690.0.in-as.arpa. and the domain corresponding to the largest possible A.S. number is 535.65.in-as.arpa. Donald E. Eastlake 3rd [Page 5] INTERNET-DRAFT Mapping A.S. Numbers into the DNS 3. Meaning of RRs The following guidance is given for some RR types that could be stored under the names mapped from A.S. numbers. The KEY RR is given first, then the rest in alphabetic order. KEY: This type of resource record associates a public key with the Autonomous System (A.S.) designated by its name. Such a public key can be used to authenticate communications with or between A.S.s. The existence of KEY RRs in the reason for mapping A.S. names into the DNS. Under DNS security as proposed in draft-ietf-dnssec- secext-*.txt the KEY RR can be used to store any type of digital key. A: DO NOT place type A RRs at A.S. nodes. A.S. domain names are reserved for Autonomous Systems only and should NOT be used for a host or any type of end entity other than an Autonomous System. CNAME: This type of RR is an alias pointing to another domain name. An A.S. could have a CNAME pointing to a different A.S. but this is not likely to be very useful as A.S. RRs will normally be looked up when the A.S. number is actually encountered in use. MX: There is no special use for an MX RR for an A.S. name. It could point to a host that would accept mail related to that A.S. NS: The presence of NS records under an in-as.arpa name means that it has been carved out as a subzone. This gives the A.S. complete control over the zone refresh parameters and control over the creation of inferior names. No special meaning is currently assigned to such inferior names so, although this is not advised, they could be used for hosts or whatever. PTR: The part of the forward domain tree that administratively corresponds to the A.S. should be indicated by a PTR RR. It some entity, say example.net, has several A.S.s, there would be PTRs to example.net from several names in the in-as.arpa hierarchy. RP: A Responsible Person RR SHOULD appear under each A.S. name telling you who you should contact in the case of problems with that A.S. TXT: Text RRs can be used for comments, postal address, or similar notes under an A.S. name. Donald E. Eastlake 3rd [Page 6] INTERNET-DRAFT Mapping A.S. Numbers into the DNS 4. Security Considerations The entirety of this document concerns a means to map Internet Autonomous System numbers into the Domain Name System (DNS) so that secure DNS can be used to provide secure distribution of Autonomous System's public keys. References [RFC904] - Exterior Gateway Protocol Formal Specification, D. L. Mills [RFC1034] - Domain Names - Concepts and Facilities, P. Mockapetris, November 1987 [RFC1035] - Domain Names - Implementation and Specifications, P. Mockapetris Author's Address Donald E. Eastlake 3rd Digital Equipment Corporation 550 King Street, LKG2-1/BB3 Littleton, MA 01460 Telephone: +1 508 486 6577(w) +1 508 287 4877(h) EMail: dee@lkg.dec.com Expiration and File Name This draft expires 11 July 1995 Its file name is draft-ietf-dnssec-as-map-01.txt. Donald E. Eastlake 3rd [Page 7]   Received: from sol.tis.com by magellan.TIS.COM id aa09017; 11 Jan 95 9:25 EST Received: from venera.isi.edu(128.9.0.32) by relay via smap (V1.3) id sma016133; Wed Jan 11 09:21:06 1995 Received: from zed.isi.edu by venera.isi.edu (5.65c/5.61+local-20) id ; Wed, 11 Jan 1995 06:26:48 -0800 From: bmanning@isi.edu Posted-Date: Wed, 11 Jan 1995 06:26:21 -0800 (PST) Message-Id: <199501111426.AA25899@zed.isi.edu> Received: by zed.isi.edu (5.65c/4.0.3-4) id ; Wed, 11 Jan 1995 06:26:21 -0800 Subject: Re: submission of draft-ietf-dnssec-as-map-01.txt To: "Donald E. Eastlake 3rd" Date: Wed, 11 Jan 1995 06:26:21 -0800 (PST) Cc: internet-drafts@cnri.reston.va.us, dns-security@tis.com In-Reply-To: <9501102226.AA22223@skidrow.tay.dec.com> from "Donald E. Eastlake 3rd" at Jan 10, 95 05:26:44 pm X-Mailer: ELM [version 2.4 PL24] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 183 You might consider removing the .arpa zone. Recent practice has been to move these sort of zones into the .INT domain. (the inaddr domains for nasps and ipv6 come to mind) --bill   Received: from sol.tis.com by magellan.TIS.COM id aa11635; 11 Jan 95 12:57 EST Received: from inet-gw-1.pa.dec.com(16.1.0.22) by relay via smap (V1.3) id sma019664; Wed Jan 11 12:53:18 1995 Received: from skidrow.tay.dec.com by inet-gw-1.pa.dec.com (5.65/10Aug94) id AA07037; Wed, 11 Jan 95 09:51:03 -0800 Received: by skidrow.tay.dec.com (5.65/MS-081993); id AA12881; Wed, 11 Jan 1995 12:56:09 -0500 Message-Id: <9501111756.AA12881@skidrow.tay.dec.com> To: bmanning@isi.edu MMDF-Warning: Unable to confirm address in preceding line at magellan.TIS.COM Cc: dns-security@tis.com Subject: Re: submission of draft-ietf-dnssec-as-map-01.txt In-Reply-To: Your message of "Wed, 11 Jan 95 06:26:21 PST." <199501111426.AA25899@zed.isi.edu> Date: Wed, 11 Jan 95 12:56:09 -0500 From: "Donald E. Eastlake 3rd (Beast)" X-Mts: smtp I don't really care and have gotten comments both ways. My feeling was that Autonomous Systems numbers were kind of connected with IPv4 so I'm inclined to put it under .arpa. Donald From: bmanning@isi.edu Posted-Date: Wed, 11 Jan 1995 06:26:21 -0800 (PST) To: "Donald E. Eastlake 3rd" Cc: internet-drafts@cnri.reston.va.us, dns-security@tis.com In-Reply-To: <9501102226.AA22223@skidrow.tay.dec.com> from "Donald E. Eastlake 3rd" at Jan 10, 95 05:2 6:44 pm X-Mailer: ELM [version 2.4 PL24] k> >You might consider removing the .arpa zone. Recent practice has been to move these sort of >zones into the .INT domain. (the inaddr domains for nasps and ipv6 come to mind) > >--bill   Received: from sol.tis.com by magellan.TIS.COM id aa13459; 11 Jan 95 16:58 EST Received: from ietf.cnri.reston.va.us(132.151.1.35) by relay via smap (V1.3) id sma025631; Wed Jan 11 16:55:01 1995 Received: from [127.0.0.1] by IETF.CNRI.Reston.VA.US id aa10180; 11 Jan 95 16:42 EST Mime-Version: 1.0 Content-Type: Multipart/Mixed; Boundary="NextPart" To: IETF-Announce: ;, tis.com@magellan.TIS.COM MMDF-Warning: Parse error in original version of preceding line at magellan.TIS.COM Cc: dns-security@tis.com From: Internet-Drafts@cnri.reston.va.us Reply-To: Internet-Drafts@cnri.reston.va.us Subject: I-D ACTION:draft-ietf-dnssec-as-map-01.txt Date: Wed, 11 Jan 95 16:42:43 -0500 Sender: cclark@cnri.reston.va.us Message-Id: <9501111642.aa10180@IETF.CNRI.Reston.VA.US> --NextPart A Revised Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the DNS Security Working Group of the IETF. Title : Mapping Autonomous Systems Number into the Domain Name System Author(s) : D. Eastlake Filename : draft-ietf-dnssec-as-map-01.txt Pages : 7 Date : 01/10/1995 One requirement of secure routing is that independent routing entities, such as those identified by Internet Autonomous System Numbers, be able to authenticate messages to each other. Modifications currently being developed (see other draft-ietf-dnssec-*.txt) to the Domain Name System will enable it to be used for convenient public key distribution. This draft maps all Autonomous System numbers into DNS Domain Names so that the DNS can be used to distribute their public keys. Internet-Drafts are available by anonymous FTP. Login with the username "anonymous" and a password of your e-mail address. After logging in, type "cd internet-drafts" and then "get draft-ietf-dnssec-as-map-01.txt". A URL for the Internet-Draft is: ftp://ds.internic.net/internet-drafts/draft-ietf-dnssec-as-map-01.txt Internet-Drafts directories are located at: o Africa Address: ftp.is.co.za (196.4.160.2) o Europe Address: nic.nordu.net (192.36.148.17) o Pacific Rim Address: munnari.oz.au (128.250.1.21) o US East Coast Address: ds.internic.net (198.49.45.10) o US West Coast Address: ftp.isi.edu (128.9.0.32) Internet-Drafts are also available by mail. Send a message to: mailserv@ds.internic.net. In the body type: "FILE /internet-drafts/draft-ietf-dnssec-as-map-01.txt". NOTE: The mail server at ds.internic.net can return the document in MIME-encoded form by using the "mpack" utility. To use this feature, insert the command "ENCODING mime" before the "FILE" command. To decode the response(s), you will need "munpack" or a MIME-compliant mail reader. Different MIME-compliant mail readers exhibit different behavior, especially when dealing with "multipart" MIME messages (i.e., documents which have been split up into multiple messages), so check your local documentation on how to manipulate these messages. For questions, please mail to Internet-Drafts@cnri.reston.va.us. Below is the data which will enable a MIME compliant mail reader implementation to automatically retrieve the ASCII version of the Internet-Draft. --NextPart Content-Type: Multipart/Alternative; Boundary="OtherAccess" --OtherAccess Content-Type: Message/External-body; access-type="mail-server"; server="mailserv@ds.internic.net" Content-Type: text/plain Content-ID: <19950111122236.I-D@CNRI.Reston.VA.US> ENCODING mime FILE /internet-drafts/draft-ietf-dnssec-as-map-01.txt --OtherAccess Content-Type: Message/External-body; name="draft-ietf-dnssec-as-map-01.txt"; site="ds.internic.net"; access-type="anon-ftp"; directory="internet-drafts" Content-Type: text/plain Content-ID: <19950111122236.I-D@CNRI.Reston.VA.US> --OtherAccess-- --NextPart--   Received: from relay.tis.com by neptune.TIS.COM id aa05870; 7 Feb 95 16:14 GMT Received: by relay.tis.com; id LAA28677; Tue, 7 Feb 1995 11:17:44 -0500 Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (V1.3) id sma028659; Tue Feb 7 11:17:27 1995 Received: from magellan.TIS.COM by tis.com (4.1/SUN-5.64) id AA12776; Tue, 7 Feb 95 11:14:49 EST Received: from sol.tis.com by magellan.TIS.COM id aa03181; 7 Feb 95 11:15 EST Received: from magellan.tis.com by tis.com (4.1/SUN-5.64) id AA12756; Tue, 7 Feb 95 11:14:46 EST Reply-To: List Master To: dns-security@tis.com Subject: DNS-SECURITY Archives Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <3174.792173712.1@tis.com> Date: Tue, 07 Feb 1995 11:15:12 -0500 Message-Id: <3176.792173712@tis.com> From: List Master (agent: James M Galvin) The DNS-SECURITY archives are available via anonymous ftp from the host "ftp.tis.com" in the directory "/pub/ietf/dns-security". There you will find files called dns-security-YYMM.txt.Z, which are compressed text files containing all messages sent to the DNS-SECURITY list up through and including the month MM and the year YY. The most recent messages are in a file called "dns-security.mbox". This file is updated automatically as each message is sent to the list. No more waiting for me to update the archives! Yeah!! Enjoy, Jim List Maintainer   Received: from relay.tis.com by neptune.TIS.COM id aa20783; 5 Mar 95 19:13 EST Received: from cs.columbia.edu(128.59.16.20) by relay.tis.com via smap (V1.3) id sma004392; Sun Mar 5 19:17:07 1995 Received: from play.cs.columbia.edu (play.cs.columbia.edu [128.59.10.7]) by cs.columbia.edu (8.6.10/8.6.6) with ESMTP id TAA21211 for ; Sun, 5 Mar 1995 19:17:32 -0500 Received: (from jakka@localhost) by play.cs.columbia.edu (8.6.10/8.6.6) id TAA26759 for dns-security@tis.com; Sun, 5 Mar 1995 19:17:31 -0500 Date: Sun, 5 Mar 95 19:17:31 EST From: Jakka Sairamesh To: dns-security@tis.com Subject: Subscribe Message-ID: Hello, I am very interested in extensions to DNS to suppory Dynamic Updates and secure way of doing it. I would like to know more about this. Can I subscribe to this mailing list thanks a lot ramesh Center For Telecommunications Columbia University New York, NY, 10027   Received: from relay.tis.com by neptune.TIS.COM id aa27818; 6 Mar 95 17:21 EST Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (a1.4) id sma015486; Mon Mar 6 17:15:30 1995 Message-Id: <9503062215.AA07361@tis.com> Reply-To: James M Galvin To: dns-security@tis.com Subject: non-meeting in Danvers Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <27372.794528160.1@tis.com> Date: Mon, 06 Mar 1995 17:16:01 -0500 From: James M Galvin Unless someone has a strong objection, I'm not planning a meeting in Danvers. The current status is as follows. TIS has been implementing the specification. We expect to have a prototype implementation by the Danvers meeting. Eastlake/Kaufman and TIS have been interacting to resolve ambiguities and to otherwise clarify the proposal as it was last presented. The plan is for Eastlake/Kaufman to issue one more version of the specification and then to call for consensus on the mailing list to submit the document for publication as a Proposed Standard. I would expect that this working group will meet either in July or December to present a detailed status of the implementation and some relevant statistics on its operation. Comments? (Silence will be interpreted as agreement, so those who dissent should speak up.) Thanks, Jim   Received: from relay.tis.com by neptune.TIS.COM id aa28077; 6 Mar 95 18:05 EST Received: from fnal.fnal.gov(131.225.9.1) by relay.tis.com via smap (a1.4) id sma016428; Mon Mar 6 18:09:15 1995 Received: from munin.fnal.gov by FNAL.FNAL.GOV (PMDF V4.3-12 #3998) id <01HNTND3YUTS00D36E@FNAL.FNAL.GOV>; Mon, 06 Mar 1995 17:09:40 -0500 (CDT) Received: from LOCALHOST.fnal.gov by munin.fnal.gov (4.1/SMI-4.1-m) id AA14449; Mon, 6 Mar 95 17:08:38 CST Date: Mon, 06 Mar 1995 17:08:37 -0600 From: Matt Crawford Subject: Re: non-meeting in Danvers In-reply-to: Your message of Mon, 06 Mar 95 17:16:01 EST. <9503062215.AA07361@tis.com> Sender: crawdad@munin.fnal.gov To: James M Galvin Cc: dns-security@tis.com Message-id: <9503062308.AA14449@munin.fnal.gov> Content-transfer-encoding: 7BIT X-Face: /RKQi"kntyd}7l)d8n%'Dum<~(aMW3,5g&'NiH5I4Jj|wT:j;Qa$!@A<~/*C:{:MmAQ:o%S /KKi}G4_.||4I[9!{%3]Hd"a*E{ Message-Id: <9503070357.AA11046@necom830.cc.titech.ac.jp> Subject: Re: non-meeting in Danvers To: galvin@tis.com Date: Tue, 7 Mar 95 12:57:32 JST Cc: dns-security@tis.com In-Reply-To: <9503062215.AA07361@tis.com>; from "James M Galvin" at Mar 6, 95 5:16 pm X-Mailer: ELM [version 2.3 PL11] > Unless someone has a strong objection, I'm not planning a meeting in > Danvers. The current status is as follows. > > TIS has been implementing the specification. We expect to have a > prototype implementation by the Danvers meeting. I really wanted to see a promised working implementation well before the meeting. I'm afraid it's too late now, though. > Eastlake/Kaufman and TIS have been interacting to resolve ambiguities > and to otherwise clarify the proposal as it was last presented. Resolve ambiguities and clarify? As the proposal still contains several technical defects, fix them. As Doland himself havs recently said: :IETF is much more likely to implement before standardizing and that, :in some areas, IETF standards are much more successful than those :promulgated by other organizations. it's good to be able to clearly demonstrate the defects with not-working implementations. Otherwise, defects are too subtle to be understood by those who does not have a lot of experience on name server coding. Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa29192; 10 Mar 95 8:53 EST Received: from mailhub.tis.com(192.33.112.100) by relay.tis.com via smap (a1.4) id sma001569; Fri Mar 10 08:57:04 1995 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA26454; Fri, 10 Mar 95 08:57:03 EST Message-Id: <9503101357.AA26454@tis.com> Reply-To: James M Galvin To: Masataka Ohta Cc: dns-security@tis.com Subject: Re: non-meeting in Danvers In-Reply-To: Masataka Ohta's message of Tue, 07 Mar 1995 12:57:32 +0200. <9503070357.AA11046@necom830.cc.titech.ac.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <20479.794843790.1@tis.com> Date: Fri, 10 Mar 1995 08:56:31 -0500 From: James M Galvin > Eastlake/Kaufman and TIS have been interacting to resolve ambiguities > and to otherwise clarify the proposal as it was last presented. Resolve ambiguities and clarify? As the proposal still contains several technical defects, fix them. We, TIS, are not aware of any technical defects. We've really had very little trouble implementing the specifications as written. Thanks, Jim   Received: from relay.tis.com by neptune.TIS.COM id aa15044; 12 Mar 95 21:42 EST Received: from unknown(131.112.32.132) by relay.tis.com via smap (a1.4) id sma017821; Sun Mar 12 21:45:25 1995 Received: by necom830.cc.titech.ac.jp (5.65+/necom-mx-rg); Mon, 13 Mar 95 11:44:26 +0900 From: Masataka Ohta Message-Id: <9503130244.AA10698@necom830.cc.titech.ac.jp> Subject: Re: non-meeting in Danvers To: galvin@tis.com Date: Mon, 13 Mar 95 11:44:24 JST Cc: dns-security@tis.com In-Reply-To: <9503101357.AA26454@tis.com>; from "James M Galvin" at Mar 10, 95 8:56 am X-Mailer: ELM [version 2.3 PL11] > > Eastlake/Kaufman and TIS have been interacting to resolve ambiguities > > and to otherwise clarify the proposal as it was last presented. > > Resolve ambiguities and clarify? > > As the proposal still contains several technical defects, fix > them. > > We, TIS, are not aware of any technical defects. It is not surprising that you, who can't understand why non-authoritative delegation can't be authenticated, can't detect other defects. > We've really had very > little trouble implementing the specifications as written. The defect is not in cryptographic part on which TIS people have a lot of expertise, but in DNS part. Give the large amount of delay, I suspect there yet exist no implementation with sufficient functionality on DNS protocols. Let us check your implementation. Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa11942; 31 Mar 95 13:06 EST Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (a1.4) id sma010241; Fri Mar 31 13:10:52 1995 Received: by callandor.cybercash.com; id RAA18786; Thu, 30 Mar 1995 17:29:14 -0500 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (V1.3) id sma018782; Thu Mar 30 17:28:49 1995 Received: by cybercash.com (4.1/SMI-4.1) id AA05003; Fri, 31 Mar 95 13:08:26 EST Date: Fri, 31 Mar 95 13:08:26 EST From: "Donald E. Eastlake" Message-Id: <9503311808.AA05003@cybercash.com> To: dns-security@tis.com Subject: preliminary version of next dnssec draft DNS Security Working Group Donald E. Eastlake, 3rd INTERNET-DRAFT CyberCash Charles W. Kaufman Iris Expires: 1 Oct 1995 31 Mar 1995 Domain Name System Protocol Security Extensions ------ ---- ------ -------- -------- ---------- Status of This Document This draft, file name draft-ietf-dnssec-secext-04.txt, is intended to be become a Proposed Standard RFC. Distribution of this document is unlimited. Comments should be sent to the DNS Security Working Group mailing list or to the authors. This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months. Internet-Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet- Drafts as reference material or to cite them other than as a ``working draft'' or ``work in progress.'' To learn the current status of any Internet-Draft, please check the 1id-abstracts.txt listing contained in the Internet-Drafts Shadow Directories on ds.internic.net, nic.nordu.net, ftp.isi.edu, munnari.oz.au, or ftp.is.co.za. Eastlake, Kaufman [Page 1] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 Abstract The Domain Name System (DNS) has become a critical operational part of the Internet infrastructure yet it has no strong security mechanisms to assure data integrity or authentication. Extensions to the DNS are described that provide these services to security aware resolvers or applications through the use of cryptographic digital signatures. These digital signatures are included in secured zones as resource records. Security can still be provided even through non-security aware DNS servers. The extensions also provide for the storage of authenticated public keys in the DNS. This storage of keys can support a general public key distribution service as well as DNS security. The stored keys enable security aware resolvers to learn the authenticating key of zones in addition to keys for which they are initially configured. Keys associated with DNS names can be retrieved to support other protocols. Provision is made for a variety of key types and algorithms. In addition, the security extensions provide for the optional authentication of DNS protocol transactions. Acknowledgements The significant contributions of the following persons (in alphabetic order) to this draft are gratefully acknowledged: Madelyn Badger, Matt Crawford, James M. Galvin, Olafur Gudmundsson, Sandy Murphy, Masataka Ohta, Michael A. Patton, Jeffrey I. Schiller. Eastlake, Kaufman [Page 2] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 Table of Contents Status of This Document....................................1 Abstract...................................................2 Acknowledgements...........................................2 Table of Contents..........................................3 1. Overview of Contents....................................5 2. Brief Overview of the Extensions.......................6 2.1 Services Not Provided..................................6 2.2 Key Distribution.......................................6 2.3 Data Origin Authentication and Integrity...............7 2.3.2 The SIG Resource Record..............................7 2.3.3 Authenticating Name Non-existence....................8 2.3.4 Special Problems With Time-to-Live...................8 2.3.5 Signers Other Than The Zone..........................9 2.4 DNS Transaction Authentication.........................9 3. The KEY Resource Record................................10 3.1 KEY RDATA format......................................10 3.2 Object Types and DNS Names and Keys...................10 3.3 The KEY RR Flag Octet.................................11 3.4 The KEY Algorithm Number and the MD5/RSA Algorithm....12 3.5 KEY RRs in the Construction of Responses..............13 3.6 File Representation of KEY RRs........................14 4. The SIG Resource Record................................15 4.1 SIG RDATA Format......................................15 4.1.1 Signature Format....................................17 4.1.2 SIG RRs Covering Type ANY...........................18 4.1.3 Zone Transfer (AXFR) SIG............................19 4.1.4 Transaction SIGs....................................19 4.2 SIG RRs in the Construction of Responses..............20 4.3 Processing Responses and SIG RRs......................20 4.4 Signature Expiration, TTLs, and Validity..............21 4.5 File Representation of SIG RRs........................22 5. Non-existent Names.....................................23 5.1 The NXD Resource Record...............................23 5.2 NXD RDATA Format......................................24 5.3 Example...............................................24 5.4 Interaction of NXD RRs and Wildcard RRs...............24 5.5 Blocking NXD Pseudo-Zone Transfers....................25 6. How to Resolve Securely................................27 6.1 Boot File Format......................................27 6.2 Chaining Through Zones................................28 Eastlake, Kaufman [Page 3] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 6.3 Secure Time...........................................29 6.4 Resolver Response Code................................29 7. Operational Considerations.............................31 7.1 Key Size Considerations...............................31 7.2 Key Storage...........................................31 7.3 Key Generation........................................32 7.4 Key Lifetimes.........................................32 7.5 Signature Lifetime....................................33 7.6 Root..................................................33 8. Conformance............................................34 8.1 Server Conformance....................................34 8.2 Resolver Conformance..................................34 9. Security Considerations................................35 References................................................35 Authors Addresses.........................................36 Expiration and File Name..................................36 Appendix: Base 64 Encoding................................37 Eastlake, Kaufman [Page 4] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 1. Overview of Contents This draft describes extensions of the Domain Name System (DNS) protocol to support DNS security and public key distribution. It assumes that the reader is familiar with the Domain Name System, particularly as described in RFCs 1034 and 1035. Section 2 provides an overview of the extensions and the key distribution, data origin authentication, and transaction security they provide. Section 3 discusses the KEY resource record, its structure, use in DNS responses, and file representation. These resource records represent the pubic keys of entities name in the DNS and are used for key distribution. Section 4 discusses the SIG digital signature resource record, its structure, use in DNS responses, and file representation. These resource records are used to authenticate other resource records in the DNS and optionally to authenticate DNS transactions. Section 5 discusses the NXD resource record and its use in DNS responses. The NXD RR permits authenticated denial of the existence of a name in the DNS. Section 6 discusses how a resolver can be configured with a starting key or keys and proceed to securely resolve DNS requests. New response statuscodes needed to reflect the security component of responses to security aware applications are also enumerated. Section 7 reviews a variety of operational considerations including key generation, lifetime, and storage. Section 8 defines levels of conformance for resolvers and servers. Section 9 provides a few paragraphs on overall security considerations. Eastlake, Kaufman [Page 5] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 2. Brief Overview of the Extensions The DNS protocol security extensions provide three distinct services: key distribution as described in section 2.2 below, data origin authentication as described in section 2.3 below, and transaction authentication, described in section 2.4 below. 2.1 Services Not Provided It is part of the design philosophy of the DNS that the data in it is public and that the DNS gives the same answers to all inquirers. Following this philosophy, no attempt has been made to include any sort of access control lists or other means to differentiate inquirers. In addition, no effort has been made to provide for any confidentiality for queries or responses. (This service may be available via a network level security protocol for which there is current an IETF working group.) 2.2 Key Distribution Resource records are defined to associate keys with DNS names. This permits the DNS to be used as a general public key distribution mechanism in support of the data origin authentication and transaction authentication DNS services as well as other security services such as network level security. The syntax of a KEY resource record is described in Section 3. It includes the name of the entity the key is associated with (frequently but not always the KEY resource record owner name), an algorithm identifier, flags indicating the type of entity the key is associated with and/or asserting that there is no key associated with that entity, and the actual public key parameters. Under conditions described in Section 3, security aware DNS servers will automatically attempt to return KEY resources as additional information, along with those resource records actually requested, to minimize the number of queries needed. Eastlake, Kaufman [Page 6] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 2.3 Data Origin Authentication and Integrity Security is provided by associating with resource records in the DNS cryptographically generated digital signatures. Commonly, there will be a single private key that signs for an entire zone. If a security aware resolver reliably learns the public key of the zone, it can verify, for any data read from that zone, that it was properly authorized and is reasonably current. The expected implementation is for the zone private key to be kept off-line and used to re-sign all of the records in the zone periodically. The data origin authentication key belongs to the zone and not to the servers that store copies of the data. That means compromise of a server or even all servers for a zone will not necessarily affect the degree of assurance that a resolver has that the data is genuine. A resolver can learn the public key of a zone either by reading it from DNS or by having it staticly configured. To reliably learn the public key by reading it from DNS, the key itself must be signed. Thus, to provide a reasonable degree of security, the resolver must be configured with at least the public key of one zone. From that, it can securely read the public keys of other zones if the intervening zones in the DNS tree are secure. It is in principle more secure to have the resolver manually configured with the public keys of multiple zones, since then the compromise of a single zone would not permit the faking of information from other zones. It is also more administratively cumbersome, however, particularly when public keys change. Adding origin authentication and integrity requires no change to the "on-the-wire" DNS protocol beyond the addition of the signature resource types (and, as a practical matter, the key resource type needed for key distribution). This service can be supported by existing resolver and server implementations so long as they can support the additional resource types (see Section 8). If signatures are always separately retrieved and verified when retrieving the information they authenticate, there will be more trips to the server and performance will suffer. To avoid this, security aware servers mitigate that degradation by automatically sending exactly the signature(s) needed where possible. 2.3.2 The SIG Resource Record The syntax of a SIG resource record (signature) is described in Section 4. It includes the type of the RR(s) being signed, the name of the signer, the time at which the signature was created, the time it expires (when it is no longer to be believed), its original time Eastlake, Kaufman [Page 7] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 to live (which may be longer than its current time to live but cannot be shorter), the cryptographic algorithm in use, and the actual signature. Every name in a zone supporting signed data will have associated with it at least one SIG resource record for each resource type under that name. A security aware server supporting the performance enhanced version of the DNS protocol security extensions will attempt to return, with all records retrieved, the corresponding SIGs. If a server does not support the protocol, the resolver must retrieve all the SIG records for a name and select the one or ones that sign the resource record(s) that resolver is interested in. 2.3.3 Authenticating Name Non-existence The above security mechanism provides only a way to sign existing RRs in a zone. Data origin authentication is not obviously provided for the non-existence of a domain name in a zone. This gap is filled by the NXD RR which authenticatably asserts a range of non-existent names in a zone. The owner of the NXD RR is the start of such a ranger and its RDATA is the end of the range; however, there are additional complexities due to wildcards. Section 6 below covers the NXD RR. 2.3.4 Special Problems With Time-to-Live A digital signature will fail to verify if any change has occurred to the data between the time it was originally signed and the time the signature is verified. This conflicts with our desire to have the time-to-live field tick down when resource records are cached. This could be avoided by leaving the time-to-live out of the digital signature, but that would allow unscrupulous secondaries to set arbitrarily long time to live values undetected. Instead, we include the "original" time-to-live in the signature and communicate that data in addition to the current time-to-live. Unscrupulous servers under this scheme can manipulate the time to live but a security aware resolver will bound the TTL value it uses at the original signed value. Separately, signatures include a time signed and an expiration time. A resolver that knows an absolute time can determine securely whether a signature has expired. It is not possible to rely solely on the signature expiration as a substitute for the TTL, however, since non-security aware servers must still be supported. Eastlake, Kaufman [Page 8] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 2.3.5 Signers Other Than The Zone There are two general cases where a SIG resource record is signed by other than the zone private key. One is for future support of dynamic update where an entity is permitted to authenticate/update its own records. The public key of the entity must be present in the DNS and be appropriately signed but the other RR(s) may be signed with the entity's key. The other is for support of transaction authentication as described in Section 2.4 below. 2.4 DNS Transaction Authentication The data origin authentication service described above protects resource records but provides no protection for DNS message headers. If header bits are falsely set by a server, there is little that can be done. However, it is possible to add transaction authentication. Such authentication means that a resolver can be sure it is getting messages from the server it thinks it queried and that the response is from the query it sent and that these messages have not been diddled in transit. This is accomplished by optionally adding a special SIG resource record to the end of the reply which digitally signs the concatenation of the server's response and the resolver's query. The private key used belongs to the host composing the reply, not to the zone being queried. The corresponding public key is stored in and retrieved from the DNS. Because replies are highly variable, message authentication SIGs can not be pre-calculated. Thus it will be necessary to keep the private key on-line, for example in software or in a directly connected piece of hardware. DNS level transaction authentication would be unnecessary if a lower level (i.e., IP level) end-to-end security protocol were available. However, such a protocol is not yet standardized and when it is, there will be a significant time during which there will be systems on which it will be hard to add IPSEC but relatively easy to replace the DNS components. Eastlake, Kaufman [Page 9] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 3. The KEY Resource Record The KEY RR is used to document a key that is associated with a DNS name. It will be a public key as only public keys are stored in the DNS. This can be the public key of a zone owner, of a host or other end entity, or a user. A KEY RR is, like any other RR, authenticated by a SIG RR. Security aware DNS implementations should be designed to handle at least two simultaneously valid keys of the same type associated with a name. The type number for the KEY RR is 25. 3.1 KEY RDATA format The RDATA for a KEY RR consists of an object name, flags, the algorithm number, and the public key itself. The format is as follows: 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / +- object name +---------------+---------------+ / | flags | algorithm | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / + - public key / / / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-/ The object name and flags octets are described in Sections 3.2 and 3.3 below respectively. The flags must be examined before any following data as they control the format and even whether there is any following data. The algorithm and public key fields are described in Section 3.4. The format of the public key is algorithm dependent. 3.2 Object Types and DNS Names and Keys The public key in a KEY RR belongs to the object named in the object name field. Frequently this will also be the owner name of the KEY RR. But they will be different in the case of the key or keys stored under a zone's name for the zone's superzone or keys that are stored for cross certification of other zones. The object name may be compressed with standard DNS name compression when being transmitted over the network. Eastlake, Kaufman [Page 10] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 The DNS object name may refer to up to three different things. For example, dee.cybercash.com could be (1) a zone, (2) a host or other end entity , and (3) the mapping into a DNS name of the user or account dee@cybercash.com . Thus, there are flags in the KEY RR to indicate with which of these roles the object name and public key are associated as described below. Except for the case of cross certification, where the object name isn't in the zone at all, the object name and owner name of a KEY RR will be the same. The inclusion of a superzone's key in its subzone is a special case of cross certification. Although the same name can be used for up to all three of these contexts, such overloading of a name is discouraged. It is also possible to use the same key for different things with the same name or even different names, but this is strongly discouraged. In particular, the use of a zone key as a non-zone key will usually require that the private key be kept on line and thereby become much more vulnerable. It would be desirable for the growth of DNS to be managed so that additional possible simultaneous uses for names are NOT added. New uses should be distinguished by exclusive domains. For example, all IP autonomous system numbers have been mapped into the in-as.arpa domain [draft-ietf-dnssec-as-map-*.txt] and all telephone numbers in the world have been mapped into the tpc.int domain [RFC 1530]. This is much preferable to having the same name possibly be an autonomous system number, telephone number, and/or host as well as a zone and a user. In addition to the name type bits, there are additional control bits, the "no key" bit, the "experimental" bit, and the "signatory" field, as described below. 3.3 The KEY RR Flag Octet In the "flags" field: Bit 0 is the "no key" bit. If this bit is on, there is no key information and the RR stops with the flags octet. By the use of this bit, a signed KEY RR can authenticatably assert that, for example, a zone is not secured. Bit 1 is the "experimental" bit. Keys may be associated with zones, entities, or users for experimental, trial, or optional use, in which case this bit will be one. If this bit is a zero, it means that the use or availability of security based on the key is "mandatory". Thus, if this bit is off for a zone, the zone should be assumed secured by SIG RRs and any responses indicating the zone is Eastlake, Kaufman [Page 11] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 not secured should be considered bogus. If this bit is a one for a host or end entity, it might sometimes operate in a secure mode and at other times operate without security. The experimental bit, like all other aspects of the KEY RR, is only effective if the KEY RR is appropriately signed by a SIG RR. The experimental bit must be zero for safe secure operation and should only be a one for a minimal transition period. Bits 2-4 are the "signatory" field. If non-zero, it indicates that the key can validly sign RRs of the same name. If the owner name is a wildcard, then RRs with any name which is in the wildcard's scope can be signed including NS and corresponding zone KEY RRs to carve out a subzone. Seven different non-zero values are possible for this field and any differences in their meaning are reserved for definition in connection with possible future DNS dynamic update or other new DNS commands. This field is meaningless for zone keys which always have authority to sign any RRs in the zone. The signatory field, like all other aspects of the KEY RR, is only effective if the KEY RR is appropriately signed by a SIG RR. Bit 5 on indicates that this is a key associated with a "user" or "account" at an end entity, usually a host. The coding of the owner name is that used for the responsible individual mailbox in the SOA record: The owner name is the user name as the name of a node under the entity name. For example, "j.random_user" on host.subdomain.domain could have a public key associated through a KEY RR with name j\.random_user.host.subdomain.domain. It could be used in an security protocol where authentication of a user was desired. This key would be useful in IP or other security for a user level service such a telnet, ftp, rlogin, etc. Bit 6 on indicates that this is a key associated with the non- zone entity whose name is the RR owner name. This will commonly be a host but could, in some parts of the DNS tree, be some other type of entity such as an Autonomous System [draft-ietf-dnssec-as-map-*.txt]. This is the public key used in connection with the optional DNS transaction authentication service that can be used if the owner name is a DNS server host. It could also be used in an IP-security protocol where authentication of a host was desired. Bit 7 on indicates that this is a zone key for the zone whose name is the KEY RR owner name. This is the fundamental type of DNS data origin authentication public key. 3.4 The KEY Algorithm Number and the MD5/RSA Algorithm This octet is the key algorithm parallel to the same field for the SIG resource. The MD5/RSA algorithm described in this draft is Eastlake, Kaufman [Page 12] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 number 1. Numbers 2 through 253 are available for assignment should sufficient reason arise. However, the designation of a new algorithm could have a major impact on interoperability and requires an IETF standards action. Number 254 is reserved for private use and will never be assigned a specific algorithm. For number 254, the public key area shown in the packet diagram above will actually begin with an Object Identifier (OID) indicating the private algorithm in use and the remainder of the area is whatever is required by that algorithm. Algorithms 0 and 255 are reserved. If the no key bit is zero and the algorithm field is 1, indicating the MD5/RSA algorithm, the public key filed is structured as follows: 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | public key exponent | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ / | / +- modulus / | / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-/ The public key exponent is a 24 bit unsigned integer. The public key modulus field is a multiprecision unsigned integer. The length of the modulus can be determined from the RDLENGTH and the preceding RDATA fields. Leading zero bytes are prohibited in the modulus. 3.5 KEY RRs in the Construction of Responses An explicit request for KEY RRs does not cause any special additional information processing except, of course, for the corresponding SIG RR from a security aware server. Security aware DNS servers will include KEY RRs as additional information in responses where appropriate including the following: (1) On the retrieval of NS RRs, the zone key KEY RR(s) for the zone served by these name servers will be included. If not all additional info will fit, the KEY RR(s) have lower priority than type A or AAAA glue RRs. (2) On retrieval of type A or AAAA RRs, the end entity KEY RR(s) will be included. On inclusion of A or AAAA RRs as additional information, their KEY RRs will also be included but with lower priority than the relevant A or AAAA RRs. Eastlake, Kaufman [Page 13] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 3.6 File Representation of KEY RRs KEY RRs may appear as lines in a zone data file. In the RDATA portion, the object name appears first. The flag octet and algorithm number octets are then represented as unsigned integers; however, if the "no key" flag is on in the flags, nothing appears after the flag octet. The public key is represented in base 64 (see Appendix) and may be divided up into any number of white space separated substrings, down to single base 64 digits, which are concatenated to obtain the full signature. These substrings can span lines using the standard parenthesis. Note that the public key may have internal sub-fields but these do not appear in the master file representation. For example, with algorithm 1 there is a public exponent and then a modulus and with algorithm 254, there will be an OID followed by algorithm dependent information. Eastlake, Kaufman [Page 14] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 4. The SIG Resource Record The SIG or "signature" resource record (RR) is the fundamental way that data is authenticated in the secure DNS. As such it is the heart of the security provided. The SIG RR unforgably authenticates other RRs of a particular type, class, and name and binds them to a time interval and the signer's fully qualified domain name. This is done using cryptographic techniques and the signer's private key. The signer is frequently the owner of the zone from which the RR originated. 4.1 SIG RDATA Format The RDATA portion of a SIG RR is as shown below. The integrity of the RDATA information is protected by the signature field. 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | type covered | algorithm | labels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | original TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | signature expiration | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | time signed | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | key footprint | / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ signer's name / / / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / +- signature / / / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The value of the SIG RR type is 24. The "type covered" is the type of the other RRs covered by this SIG. The algorithm number is an octet specifying the digital signature algorithm used. The MD5/RSA algorithm described in this draft is number 1. Numbers 2 through 253 are available for assignment should sufficient reason arise to allocate them. However, the designation of a new algorithm could have a major impact on the interoperability of the global DNS systems and requires an IETF standards action. Number 254 is reserved for private use and will not be assigned a Eastlake, Kaufman [Page 15] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 specific algorithm. For number 254, the "signature" area shown above will actually begin with an Object Identified (OID) indicating the private algorithm in use and the remainder of the signature area is whatever is required by that algorithm. Numbers 0 and 255 are reserved. The "labels" octet is an unsigned count of how many labels there are in the original SIG RR owner name not counting the null label for root and not counting any initial "*" for a wildcard. If a secured retrieval is the result of wild card substitution, it is necessary for the resolver to use the original form of the name in verifying the digital signature. This field helps optimize the determination of the original form reducing the effort in authenticating signed data. If, on retrieval, the RR appears to have a longer name than indicated by "labels", the resolver can tell it is the result of wildcard substitution. If the RR owner name appears to be shorter than the labels count, the SIG RR should be considered corrupt and ignored. The maximum number of labels possible in the current DNS is 127 but the entire octet is reserved and would be required should DNS names ever be expanded to 255 labels. The following table give some examples. The value of "labels" is at the top, the retrieved owner name on the left, and the table entry is the name to use in signature verification except that "bad" means the RR is corrupt. labels= | 0 | 1 | 2 | 3 | 4 | --------+-----+------+--------+----------+----------+ .| . | bad | bad | bad | bad | d.| *. | d. | bad | bad | bad | c.d.| *. | *.d. | c.d. | bad | bad | b.c.d.| *. | *.d. | *.c.d. | b.c.d. | bad | a.b.c.d.| *. | *.d. | *.c.d. | *.b.c.d. | a.b.c.d. | The "original TTL" field is included in the RDATA portion to avoid (1) authentication problems that caching servers would otherwise cause by decrementing the real TTL field and (2) security problems that unscrupulous servers could otherwise cause by manipulating the real TTL field. This original TTL is protected by the signature while the current TTL field is not. NOTE: The "original TTL" must be restored into the covered RRs when the signature is verified. This implies that the RRs need to all have the same TTL to start with. The SIG is valid until the "signature expiration" time which is an unsigned number of seconds since the start of 1 January 1970, GMT, ignoring leap seconds, but see also section 4.4. The "time signed" field is an unsigned number of seconds since the Eastlake, Kaufman [Page 16] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 start of 1 January 1970, GMT, ignoring leap seconds. The "key footprint" is a 16 bit quantity that is used to help efficiently select between multiple keys which may be applicable and as a quick check that a public key about to be used for the computationally expensive effort to check the signature is possibly valid. Its exact meaning is algorithm dependent. For the MD5/RSA algorithm, it is the next to the bottom two octets of the public key modulus needed to decode the signature field. That is to say, the most significant 16 of the lest significant 24 bits of this quantity in network order. The "signer's name" field is the fully qualified domain name of the signer generating the SIG RR. This is frequently the zone which contained the RR(s) being authenticated. The signer's name may be compressed with standard DNS name compression when being transmitted over the network. The structured of the "signature" field depends on the algorithm chosen and is described below for the MD5/RSA algorithm. 4.1.1 Signature Format The actual signature portion of the SIG RR binds the other RDATA fields to all of the "type covered" RRs with that owner name. These covered RRs are thereby authenticated. To accomplish this, a data sequence is constructed as follows: data = RDATA | RR(s)... where | is concatenation, RDATA is all the RDATA fields in the SIG RR itself before the signature, and RR(s) are all the RR(s) of the type covered with the same owner name and class as the SIG RR in canonical form and order. For purposes of DNS security, the canonical form for an RR is the RR with domain names (1) fully expanded (no name compression via pointers) and (2) all domain name letters set to lower case. For purposes of DNS security, the canonical order for RRs is to sort them in ascending order as left justified unsigned octet sequences in network (transmission) order where a missing octet sorts before a zero octet. How this data sequence is processed into the signature is algorithm dependent. For the MD5/RSA algorithm, the signature is as follows Eastlake, Kaufman [Page 17] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 hash = MD5 ( data ) signature = ( 01 | FF* | 00 | hash ) ** e (mod n) where MD5 is the message digest algorithm documented in RFC 1321, "|" is concatenation, "e" is the secret key exponent of the signer, and "n" is the public modulus that is the signer's public key. 01, FF, and 00 are fixed octets of the corresponding hexadecimal value. The FF octet is repeated the maximum number of times such that the value of the quantity being exponentiated is one octet shorter than the value of n. The size of n, including most and least significant bits (which will be 1) SHALL be not less than 512 bits and not more than 2552 bits. n and e MUST be chosen such that the public exponent is less than or equal to 2**24 - 1 and SHOULD be chosen such that the public exponent is small. Leading zeros bytes are not permitted in the MD5/RSA algorithm signature. The above specifications are similar to Public Key Cryptographic Standard #1 [PKCS1]. A public exponent of 3 minimizes the effort needed to decode a signature. Use of 3 as the public exponent may be weak for confidentiality uses since, if the same data can be collected encrypted under three different keys with an exponent of 3 then, using the Chinese Remainder Theorem, the original plain text can be easily recovered. This weakness is not significant for DNS because we seek only authentication, not confidentiality. 4.1.2 SIG RRs Covering Type ANY The SIG RR described above protects all of the set of RRs with a particular owner name, class, and type. Thus a server must supply all of such RRs to convince a security aware resolver. However, an unscrupulous server could claim there were no RRs of a particular type and class under an owner name while presenting signed RRs of the same name and class but other types. To provide a means of protection against this, one or more SIG RRs that cover the type ANY are added for each owner name. They are calculated as indicated above except that all RRs for the owner name, class, and SIG key, except any SIG RRs covering type ANY itself, are included in the data string which is processed into the signature. To allow for dynamic update, the zone key signed ANY SIG RR covers only zone signed RRs. If RRs are added to a zone authenticated by an Eastlake, Kaufman [Page 18] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 entity or user key, they are not covered by an ANY SIG. 4.1.3 Zone Transfer (AXFR) SIG The above SIG mechanisms assure the authentication of all zone signed RRs of a particular name, class and type and of a particular name, class and any type. However, to secure complete zone transfers, a SIG RR owned by the zone name must be created with a type covered of AXFR that covers all other zone signed RRs. It will be calculated by hashing together all other static zone RRs, including SIGs. The RRs are ordered and concatenated for hashing as described in Section 4.1.1 except that the type ANY SIGs are placed at the end of all other types for the same owner name. The AXFR SIG must be calculated last of all zone key signed SIGs in the zone. It really belongs to the zone as a whole, not the the zone name, and is not included in the calculation of any SIG covering type ANY. The AXFR SIG is only retrieved as part of a zone transfer. Dynamic zone RRs which might be added by some future dynamic zone update protocol and signed by an end entity or user key rather than a zone key (see Section 3.2) are not included. They originate in the network and will not, in general, be migrated to the recommended off line zone signing procedure (see Section 8.2). Thus such dynamic RRs are not directly signed by the zone and are not generally protected against omission during zone transfers. 4.1.4 Transaction SIGs A response message from a security aware server may optionally contain a special SIG as the last item in the additional information section to authenticate the transaction. This SIG has a "type covered" field of zero, which is not a valid RR type. It is calculated by using a "data" (see section 4.1.1) of the entire preceding DNS reply message, including DNS header, concatenated with the entire DNS query message that produced this response, including the query's DNS header. That is data = full response (less trailing message SIG) | full query Verification of the message SIG (which is signed by the server host key, not the zone key) by the requesting resolver shows that the query and response were not tampered with in transit and that the response corresponds to the intended query. Eastlake, Kaufman [Page 19] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 4.2 SIG RRs in the Construction of Responses Security aware servers MUST, for every authoritative RR the query will return, attempt to send the available SIG RRs which authenticate the requested RR. If multiple such SIGs are available, there may be insufficient space in the response to include them all. In this case, SIGs whose signer is the zone containing the RR MUST be given highest priority and retained even if SIGs with other signers must be dropped. Sending SIGs to authenticate non-authoritative data (glue records and NS RRs for subzones) is optional and should be avoided if it would lead to UDP DNS response truncation. Note that KEYs for subzones are authoritative. If a SIG covers any RR that would be in the answer section of the response, its automatic inclusion MUST be the answer section. If it covers an RR that would appear in the authority section, its automatic inclusion MUST be in the authority section. If it covers an RR that would appear in the additional information section it MUST appear in the additional information section. Optionally, DNS transactions may be authenticated by a SIG RR at the end of the response in the additional information section (section 4.1.4). Such SIG RRs are signed by the DNS server originating the response. Although the signer field must be the name of the originating server host, the owner name, class, TTL, and original TTL, are meaningless. The class and TTL fields can be zero. To save space, the owner name should be root (a single zero octet). [There may be a problem with SIG and NXD RR's associated with domain names that are CNAMEs. The DNS RFCs prohibit other types of RRs appearing with a CNAME RR. This problem is being ignored until it is clear if DNS servers will really have a problem with this.] 4.3 Processing Responses and SIG RRs If SIG RRs are received in response to a query initiated outside the resolver explicitly specifying the SIG type, no special processing is required. A security aware client MAY, in this case, wish to authenticate them by checking the signature and applying consistency checks. If SIG RRs are received in any other response (i.e., SIGs sent spontaneously by a security aware server or requested for security purposes from a non-security aware server by a security aware resolver), a security aware resolver MUST check them using the public key of the signer. The result should then be verified against the Eastlake, Kaufman [Page 20] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 appropriate other RRs retrieved. If the message does not pass reasonable checks or the SIG does not check against the signed RRs, the SIG RR is invalid and should be ignored. If all of the SIG RR(s) purporting to authenticate a set of RRs are invalid, then the set of RR(s) is not authenticated and should generally be ignored. If the SIG RR is the last RR in a response in the additional information section and has a type covered of zero, it is a transaction signature of the response and the query that produced the response. It MAY be optionally checked and the message rejected if the checks fail. But even it the checks succeed, such a transaction authentication SIG does NOT authenticate any RRs in the message. Only a proper SIG RR signed by the zone can authenticate RRs. If a resolver does not implement transaction SIGs, it MUST at least ignore them without error. If all reasonable checks indicate that the SIG RR is valid then RRs verified by it should be considered authenticated. If a response, other than a query initiated outside the resolver explicitly specifying the SIG type which fails, is received without SIGs, the resolver should act as follows: if the zone is secure, the resolver should spontaneously initiate a query to the same resolver for the SIGs covering any retrieved RRs and hold those RRs in a neither valid nor invalid state pending the results of this query; if the zone is insecure, the RRs should be accepted but marked as not authenticated. 4.4 Signature Expiration, TTLs, and Validity Security aware servers should not consider SIG RRs to be authentic after their expiration time and not consider any RR to be valid after its signatures have expired. Within that constraint, servers should continue to follow DNS TTL aging. Thus authoritative servers should continue to follow the zone refresh and expire parameters and a non- authoritative server should count down the TTL and discard RRs when the TTL is zero. In addition, when RRs are transmitted in a query response, the TTL should be trimmed so that current time plus the TTL does not extend beyond the signature expiration time. Thus, in general, the TTL on an transmitted RR would be min(sigExpTim,max(zoneMinTTL,min(originalTTL,currentTTL))) Eastlake, Kaufman [Page 21] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 4.5 File Representation of SIG RRs A SIG RR can be represented as a single logical line in a zone data file [RFC1033] but there are some special problems as described below. (It does not make sense to include a transaction authenticating SIG RR in a file as it is a transient authentication that must be calculated in real time by the DNS server.) There is no particular problem with the signer, covered type, and times. The time fields appears in the form YYYYMMDDHHMMSS where YYYY is the year, the first MM is the month number (01-12), DD is the day of the month (01-31), HH is the hour in 24 hours notation (00-23), the second MM is the minute (00-59), and SS is the second (00-59). The original TTL and algorithm fields appears as unsigned integers. The "labels" field does not appear in the file representation as it can be calculated from the owner name. The key footprint appears as an unsigned decimal number. However, the signature itself can be very long. It is the last data field and is represented in base 64 (see Appendix) and may be divided up into any number of white space separated substrings, down to single base 64 digits, which are concatenated to obtain the full signature. These substrings can be split between lines using the standard parenthesis. Eastlake, Kaufman [Page 22] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 5. Non-existent Names The SIG RR mechanism described in section 4 above provides strong authentication of RRs that exist in a zone. But is it not immediately clear how to authenticatably deny the existence of a name in a zone. The nonexistence of a name in a zone is indicated by the NXD RR for a name interval containing the nonexistent name. An NXD RR and its SIG are returned in the authority section, along with the error, if the server is security aware. NXD RRs will also be returned if an explicit query is made for the NXD type. The existence of a complete set of NXD records in a zone means that any query for any name to a security aware server serving the zone should result in an reply containing at least one signed RR. NXD RRs do not appear in zone master files since they can be derived from the rest of the zone. 5.1 The NXD Resource Record The NXD resource record is used to securely indicate that no RRs with an owner name in a certain name interval exist in a zone. The owner name of the NXD RR is an existing name in the zone. It's RDATA is another existing name in the zone. The presence of the NXD RR means that no name between its owner name and the name in its RDATA area exists. This implies a canonical ordering of all domain names in a zone. The ordering is to sort labels as unsigned left justified octet strings where the absence of a byte sorts before a zero byte. Names are then sorted by sorting on the highest level label and then, within those names with the same highest level label by the next lower label, etc. Since we are talking about a zone, the zone name itself always exists and all other names are the zone name with some prefix of lower level labels. Thus the zone name itself always sorts first. There is a slight problem with the last NXD in a zone as it wants to have an owner name which is the last existing name in sort order, which is easy, but it is not obvious what name to put in its RDATA to indicate the entire remainder of the name space. This is handled by treating the name space as circular and putting the zone name in the RDATA of the last NXD. There are additional complexities due to interaction with wildcards Eastlake, Kaufman [Page 23] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 as explained below. The NXD RRs for a zone can be automatically calculated and added to the zone by the same recommended off-line process that signs the zone. The NXD RR's TTL should not exceed the zone minimum TTL. 5.2 NXD RDATA Format The RDATA for an NXD RR consists simply of a domain name. The type number for the NXD RR is 30. 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | next domain name / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5.3 Example Assume a zone has entries for big.foo.bar, medium.foo.bar. small.foo.bar. tiny.foo.bar. Then a query to a security aware server for huge.foo.bar would produce an error reply with the authority section data including big.foo.bar. NXD medium.foo.bar. and the corresponding SIG RR. 5.4 Interaction of NXD RRs and Wildcard RRs As a wildcard RR causes all possible names in an interval to exist, there should not be an NXD record that would cover any part of this interval. Thus if *.X.ZONE exists you would expect an NXD RR that ends at X.ZONE and one that starts with the last name covered by *.X.ZONE. However, this "last name covered" is something very ugly and long like \255\255\255....X.zone. So the NXD for the interval following is simply given the owner name *.X.ZONE. This "*" type name is not expanded when the NXD is returned as authority Eastlake, Kaufman [Page 24] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 information in connection with a query for a non-existent name and type. If there could be any wildcard RRs in a zone and thus wildcard NXDs, care must be taken in interpreting the results of explicit NXD retrievals as the owner name may be a wildcard expansion. The existence of one or more wildcard RRs covering a name interval makes it possible for a malicious server to hide any more specificly named RRs in the internal. The server can just falsely return the wildcard match NXD instead of the more specificly named RRs. If there is a zone wide wildcard, there will be only one NXD RR whose owner name and RDATA are both the zone name. In this case a server could conceal the existence of any more specific RRs in the zone. (It would be possible to design a more complex NXD feature, taking into account the types of RRs that did not exist in a name interval, and the like, which would eliminate this possibility. But it would be more complex and would be so constraining as to make any future dynamic update feature that could create new names very difficult (see Section 3.2).) 5.5 Blocking NXD Pseudo-Zone Transfers In a secure zone, a resolver can query for the initial NXD associated with the zone name. Using the RDATA field from that RR, it can query for the next NXD RR. By repeating this, it can walk through all the NXDs in the zone. If there are no wildcards, it can use this technique to find all names in a zone. If it does type ANY queries, it can incrementally get all information in the zone and perhaps defeat attempts to administratively block zone transfers. If there are any wildcards, this NXD walking technique will not find any more specific RR names in the part of the name space the wildcard covers. By doing explicit retrievals for wildcard names, a resolver could determine what intervals are covered by wildcards but still could not, with these techniques, find any names inside such intervals except by trying every name. If it is desired to block NXD walking, the recommended method is to add a zone wide wildcard of the KEY type with the no key bit on and with no type (zone, entity, or user) bit on. This will cause there to be only one NXD RR in the zone for the zone name and leak no information about what real names exist in the zone. This protection from pseudo-zone transfers is bought at the expense of eliminating the data origin authentication of the non-existence of names that NXD RRs can provide. If an entire zone is covered by a wildcard, a malicious server can return an RR produced by matching the resulting wildcard NXD and can thus hide all the real data and delegations with Eastlake, Kaufman [Page 25] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 more specific names in the zone. Eastlake, Kaufman [Page 26] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 6. How to Resolve Securely Retrieving or resolving authentic data from the DNS involves starting with one or more trusted public keys. With trusted keys, it is possible to progress securely through the secure DNS zone structure to the zone of interest as described in section 6.2. Such trusted public keys would normally be configured in a manner similar to that described in section 6.1. However, as a practical matter, a security aware resolver would still gain some confidence in the results it returns even if it was not configured with any keys but trusted what it got from a local well known server as a starting point. The proper validation of signatures requires a reasonably secure shared opinion of the absolute time between resolvers and servers. In getting to the data of interest to respond to a query, a secure resolver may encounter genuine non-secure zones. It may proceed through such zones but should report this as described in section 6.4. 6.1 Boot File Format The recommended format for a boot file line to configure starting keys is as follows: pubkey name object flags algorithm key-data for a public key. "object" is the domain name of the thing the key is associated with and "name" is the owner name (if the line is translated into a KEY RR). Flags indicates the type of key and is the same as the flag byte in the KEY RR. In particular, if the "no key" bit is on in flags, then all fields after flags may be omitted. Algorithm is the algorithm in use where one is the MD5/RSA algorithm and 254 indicates a private algorithm. The material after the algorithm is algorithm dependent and, for private algorithms, starts with the algorithm's identifying OID. It is encoded in base 64 (see Appendix). While it might seem logical for everyone to start with the key for the root zone, this has problems. The logistics of updating every DNS resolver in the world when the root key changes would be excessive. It may be some time before there even is a root key. Furthermore, many organizations will explicitly wish their "interior" DNS implementations to completely trust only their own zone. These interior resolvers can then go through the organization's zone server to access data outsize the organization's domain. Eastlake, Kaufman [Page 27] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 6.2 Chaining Through Zones Starting with one or more trusted keys for a zone, it is possible to retrieve signed keys for its subzones and superzone which have a key. Every secure zone (except root) should also include the KEY RR for its super-zone signed by the secure zone and with the owner name of the secure zone and object name of the super-zone. This makes it possible to climb the tree of zones if one starts below root. A secure sub-zone is indicated by a KEY RR appearing with the NS RRs for the sub-zone and with the same owner and object names. These make it possible to descend within the tree of zones. A resolver should keep track of the number of successive secure zones traversed from a starting point to any secure zone it can reach. In general, the lower such a distance number is, the greater the confidence in the data. Data configured via a boot file should be given a distance number of zero. Should a query encounter different data for the same query with different distance values, that with a larger value should be ignored. (This can happen due to cross- certification as described below.) A security conscious resolver should completely refuse to step from a secure zone into a non-secure zone unless the non-secure zone is certified to be non-secure or only experimentally secure by the presence of an authenticated KEY RR for the non-secure zone with a no key flag or the presence of a KEY RR with the experimental bit set. Otherwise the resolver is probably getting completely bogus or spoofed data. If legitimate non-secure zones are encountered in traversing the DNS tree, then no zone can be trusted as secure that can be reached only via information from such non-secure zones. Since the non-secure zone data could have been spoofed, the "secure" zone reach via it could be counterfeit. The "distance" to data in such zones or zones reached via such zones could be set to 512 or more as this exceeds the largest possible distance through secure zones in the DNS. Nevertheless, continuing to apply secure checks within "secure" zones reached via non-secure zones will, as a practical matter, provide some increase in security. The syntax of KEY RRs, with an arbitrary object name, provides for cross-certification. Although the syntax permits the owner name of a cross-certification KEY RR to be any name, by convention and to avoid an undue concentration of such KEY RRs under any particular name, their owner name should be the zone name prefixed with the destination object name (truncated an integral number of labels from the front if necessary due to DNS name restrictions). Thus a key for isoc.org would appear in the mit.edu zone with the owner name isoc.org.mit.edu and object name isoc.org. Eastlake, Kaufman [Page 28] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 The existence of cross certifications adds further policy questions. Assume we have a zone BB.AA and a zone YY.XX. Many possibilities exist for a secure resolver configured with the BB.AA key to get to YY.XX. If all the zones along the way are secure, it could climb to root and then descend the other side, a total of four hops (BB.AA -> AA -> . -> XX -> YY.XX). If the BB.AA administrator had installed a cross certified key for YY.XX in the BB.AA zone, using that would be a shorter and presumably more secure way to find YY.XX's key which would be immune to the non-security or even compromise of the servers for AA or root or XX. But what if some less trusted subzone of BB.AA, say Flakey.BB.AA installed a cross certified key for YY.XX? If there is a conflict, should this be preferred to a hierarhically derived key obtained by climbing to root and descending? Such questions are entirely a matter of local resolver policy and no universal answer can be given. 6.3 Secure Time Coordinated interpretation of the time fields in SIG RRs requires that reasonably consistent time be available to the hosts implementing the DNS security extensions. A variety of time synchronization protocols exist including the Network Time Protocol (NTP, RFC1305). If such protocols are used, they should be used securely so that time can not be spoofed. Otherwise, for example, a host could get its clock turned back and might then believe old SIG and KEY RRs which were valid but no longer are. 6.4 Resolver Response Code Without security, a DNS resolver has three basic response codes it can give: Success - with data. Transient failure - no server reachable or responding, etc. Solid failure - an authoritative answer that the data does not exist. With security, a second dimension can be added to these responses: Null - resolver is not secure. Verified - response has been securely verified. Eastlake, Kaufman [Page 29] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 Verification Not Available - queried zone is known to be insecure zone. Verification Not Possible - queried zone is secure but verification was not possible due to chaining through one or more insecure zones. Verification Failed - queried zone is secure but response signature failed to verify. In general, it is desireable for there to be local options on the treatment of various combinations of these two sets of response codes. A trusted security aware application should get both the basic and security response codes. A high security resolver might wish to refuse to supply any non-verified DNS data to applications and translate confirmed absence of security or failed verification into a solid failure indication. A low security resolver might wish to provide whatever information it can along with an indication of its security. However, under no circumstances should Verification Failed information be made available to a non-security aware application. Stub resolvers will generally not be security aware. They will partake of the security policy of the recursive resolver they make use of. Eastlake, Kaufman [Page 30] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 7. Operational Considerations This section discusses a variety of considerations in secure operation of DNS using these proposed protocol extensions. 7.1 Key Size Considerations There are a number of factors that effect public key size choice for use in the DNS security extension. Unfortunately, these factors usually do not all point in the same direction. Choice of zone key size should generally be made by the zone administrator depending on their local conditions. For most schemes, larger keys are more secure but slower. Given a small public exponent, verification (the most common operation) for the MD5/RSA algorithm will vary roughly with the square of the modulus length, signing will vary with the cube of the modulus length, and key generation (the least common operation) will vary with the fourth power of the modulus length. The current best algorithms for factoring a modulus and breaking RSA security vary roughly with the square of the modulus itself. Thus going from a 640 bit modulus to a 1280 bit modulus only increases the verification time by a factor of 4 but increases the work factor of breaking the key by over 2^3000. [RSA FAQ] An upper bound of 2552 bit has been established for the MD4/RSA DNS security algorithm for interoperability purposes. However, larger keys increase size of the KEY and SIG RRs. This increases the chance of UDP packet overflow and the possible necessity for using higher overhead TCP. The recommended minimum RSA algorithm modulus size, 640 bits, is believed by the authors to be secure at this time and for some years but high level zones in the DNS tree may wish to set a higher minimum, perhaps 1000 bits, for security reasons. (Since the United States National Security Agency generally permits export of encryption systems using an RSA modulus of up to 512 bits, use of that small a modulus, i.e. n, must be considered weak.) For a key used only to secure data and not to secure other keys, 640 bits should be entirely adequate. 7.2 Key Storage It is strongly recommended that zone private keys and the zone file master copy be kept and used in off-line non-network connected Eastlake, Kaufman [Page 31] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 physically secure machines only. Periodically an application can be run to re-sign the RRs in a zone by adding NXD and SIG RRs. Then the augmented file can be transferred, perhaps by sneaker-net, to the networked zone primary server machine. The idea is to have a one way information flow to the network to avoid the possibility of tampering from the network. Keeping the zone master file on-line on the network and simply cycling it through an off-line signer does not do this. The on-line version could still be tampered with if the host it resides on is compromised. For maximum security, the master copy of the zone file should be off net and should not be updated based on an unsecured network mediated communication. Non-zone private keys, such as host or user keys, may have to be kept on line to be used for real-time purposes such a IP secure session set-up or secure mail. 7.3 Key Generation Careful key generation is a sometimes over looked but absolutely essential element in any cryptographically secure system. The strongest algorithms used with the longest keys are still of no use if an adversary can guess enough to lower the size of the likely key space so that it can be exhaustively searched. Suggestions will be found in RFC 1750. It is strongly recommended that key generation also occur off-line, perhaps on the machine used to sign zones (see Section 7.2). 7.4 Key Lifetimes No key should be used forever. The longer a key is in use, the greater the probability that it will have been compromised through carelessness, accident, espionage, or cryptanalysis. Furthermore, if key rollover is a rare event, there is an increased risk that, when the time does come up change the key, no one at the site will remember how to do it or other problems will have developed in the procedures. While key lifetime is a matter of local policy, these considerations suggest that no zone key should have a lifetime significantly over four years. A reasonable maximum lifetime for zone keys that are kept off-line and carefully guarded is 13 months with the intent that they be replaced every year. A reasonable maximum lifetime for end entity keys that are used for IP-security or the like and are kept on Eastlake, Kaufman [Page 32] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 line is 36 days with the intent that they be replaced monthly or more often. In some cases, an entity key lifetime of somewhat over a day may be reasonable. 7.5 Signature Lifetime Signature expiration times must be set far enough in the future that it is quite certain that new signatures can be generated before the old ones expire. However, setting expiration too far into the future could, if bad data or signatures were ever generated, mean a long time to flush such badness. It is recommended that signature lifetime be a small multiple of the TTL but not less than a reasonable re-signing interval. 7.6 Root It should be noted that in DNS the root is a zone unto itself. Thus the root zone key should only be seen signing itself or signing RRs with names one level below root, such as .aq, .edu, or .arpa. Implementations MAY reject as bogus any purported root signature of records with a name more than one level below root. Eastlake, Kaufman [Page 33] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 8. Conformance Several levels of server and resolver conformance are defined. 8.1 Server Conformance Three levels of server conformance are defined as follows: Basic server compliance is the ability to store and retrieve (including zone transfer) SIG, KEY, and NXD RRs. Secondaries for a secure zone must be at least basicly compliant. Medium server compliance adds the following to basic compliance: (1) ability to read SIG, KEY, and NXD RRs in zone files and (2) ability, given a zone file and private key, to add appropriate SIG and NXD RRs, possibly via a separate application. Primary servers for secure zones must be at least minimally compliant. Full server compliance is ability to automatically include SIG, KEY, and NXD RRs in responses as appropriate, as well as meeting medium compliance. 8.2 Resolver Conformance Two levels of resolver compliance are defined: A basic compliance resolver can handle SIG, KEY, and NXD RRs when they are explicitly requested. A fully compliant resolver understands KEY, SIG, and NXD RRs, maintains appropriate information in its local caches and database to indicate which RRs have been authenticated and to what extent they have been authenticated, and performs additional queries as necessary to obtain KEY, SIG, or NXD RRs from non-security aware servers. Eastlake, Kaufman [Page 34] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 9. Security Considerations This document concerns technical details of extensions to the Domain Name System (DNS) protocol to provide data integrity and data origin authentication, public key distribution, and optional transaction security. If should be noted that, at most, these extensions guarantee the validity of resource records, including KEY resource records, retrieved from the DNS. They do not magically solve other security problems. For example, using secure DNS you can have high confidence in the IP address you retrieve for a host; however, this does not stop someone for substituting an unauthorized host at that address or capturing packets sent to that address and responding with packets apparently from that address. Any reasonably complete security system will require the protection of many other facets of the Internet. References [PKCS1] - PKCS #1: RSA Encryption Standard, RSA Data Security, Inc., 3 June 1991, Version 1.4. [RFC1032] - Domain Administrators Guide, M. Stahl, November 1987 [RFC1033] - Domain Administrators Operations Guide, M. Lottor, November 1987 [RFC1034] - Domain Names - Concepts and Facilities, P. Mockapetris, November 1987 [RFC1035] - Domain Names - Implementation and Specifications [RFC1305] - Network Time Protocol (v3), D. Mills, April 9 1992. [RFC1321] - The MD5 Message-Digest Algorithm, R. Rivest, April 16 1992. [RFC1750] - Randomness Requirements for Security, D. Eastlake, S. Crocker, J. Schiller, December 1994. [RSA FAQ] - RSADSI Frequently Asked Questions periodic posting. Eastlake, Kaufman [Page 35] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 Authors Addresses Donald E. Eastlake, 3rd CyberCash, Inc. 318 Acton Street Carlisle, MA 01741 USA Telephone: +1 508 287 4877(w/h) EMail: dee@cybercash.com Charles W. Kaufman Iris Associates 1 Technology Park Drive Westford, MA 01886 USA Telephone: +1 508-392-5276 EMail: charlie_kaufman@iris.com Expiration and File Name This draft expires 1 October 1995. Its file name is draft-ietf-dnssec-secext-04.txt. Eastlake, Kaufman [Page 36] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 Appendix: Base 64 Encoding The following encoding technique is taken from RFC 1521 by Borenstein and Freed. It is reproduced here in an edited form for convenience. A 65-character subset of US-ASCII is used, enabling 6 bits to be represented per printable character. (The extra 65th character, "=", is used to signify a special processing function.) The encoding process represents 24-bit groups of input bits as output strings of 4 encoded characters. Proceeding from left to right, a 24-bit input group is formed by concatenating 3 8-bit input groups. These 24 bits are then treated as 4 concatenated 6-bit groups, each of which is translated into a single digit in the base64 alphabet. Each 6-bit group is used as an index into an array of 64 printable characters. The character referenced by the index is placed in the output string. Table 1: The Base64 Alphabet Value Encoding Value Encoding Value Encoding Value Encoding 0 A 17 R 34 i 51 z 1 B 18 S 35 j 52 0 2 C 19 T 36 k 53 1 3 D 20 U 37 l 54 2 4 E 21 V 38 m 55 3 5 F 22 W 39 n 56 4 6 G 23 X 40 o 57 5 7 H 24 Y 41 p 58 6 8 I 25 Z 42 q 59 7 9 J 26 a 43 r 60 8 10 K 27 b 44 s 61 9 11 L 28 c 45 t 62 + 12 M 29 d 46 u 63 / 13 N 30 e 47 v 14 O 31 f 48 w (pad) = 15 P 32 g 49 x 16 Q 33 h 50 y Special processing is performed if fewer than 24 bits are available at the end of the data being encoded. A full encoding quantum is always completed at the end of a quantity. When fewer than 24 input bits are available in an input group, zero bits are added (on the right) to form an integral number of 6-bit groups. Padding at the end of the data is performed using the '=' character. Since all base64 input is an integral number of octets, only the following cases can arise: (1) the final quantum of encoding input is an integral multiple of 24 bits; here, the final unit of encoded output will be an integral multiple of 4 characters with no "=" padding, (2) Eastlake, Kaufman [Page 37] INTERNET-DRAFT DNS Protocol Security Extensions March 1995 the final quantum of encoding input is exactly 8 bits; here, the final unit of encoded output will be two characters followed by two "=" padding characters, or (3) the final quantum of encoding input is exactly 16 bits; here, the final unit of encoded output will be three characters followed by one "=" padding character. Eastlake, Kaufman [Page 38]   Received: from relay.tis.com by neptune.TIS.COM id aa15926; 23 May 95 10:09 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0) id sma006572; Tue, 23 May 95 10:13:52 -0400 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA17288; Tue, 23 May 95 10:13:29 EDT Message-Id: <9505231413.AA17288@tis.com> Reply-To: dns-security@TIS.COM To: dns-security@TIS.COM Subject: meeting in Stockholm?? Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <17368.801238419.1@tis.com> Date: Tue, 23 May 1995 10:13:41 -0400 From: James M Galvin Hello everybody. What a wonderfully quiet list we have! However, wearing my Chair's hat, it's time to think about a meeting in Stockholm. I'm soliciting for comments on whether to meet in Stockholm. Here's our current status to help you decide. 1. Eastlake/Kaufman are almost done with the last revision of the current specification. 2. TIS is almost done with an alpha implementation of the specification. The implementation is alpha because we have'nt implemented everything in the spec, yet, but what we have done is complete. I expect both of these things to come to closure very soon now. When E/K are done with the specification, we'll post it as an internet-draft and immediately start a working group two week last call. After that, it will go to our area director for consideration to be published as a proposed standard. TIS will release our alpha software when the specification is released. This version of the software will be provided by request only. Future versions will be available via anonymous FTP. For now, it will only be available to a US or Canadian site. (Sorry, that's the law. We will resolve international distribution before we're done.) If you want the software, now would be a good time to let me know. Send a note to me at "galvin@tis.com". (REPLYING TO THIS MESSAGE WILL NOT WORK.) In the past, it was requested that the discussions that E/K and TIS be visible to the community. I will be posting the collected works to our anonymous FTP server, probably next week, for those who want to indulge. The problem I have is creating an agenda for a meeting in Stockholm. There might be some interesting operational issues to discuss. In addition, there are some issues related to dynamic update that are probably worth discussing. However, all of these things we could do on the mailing list and thus involve more people. So, I'm leaning towards not having a meeting but I'm interested in what other people think. Comments? Jim   Received: from relay.tis.com by neptune.TIS.COM id aa16598; 23 May 95 11:14 EDT Received: from necom830.cc.titech.ac.jp(131.112.32.132) by relay.tis.com via smap (g3.0) id sma008038; Tue, 23 May 95 11:19:13 -0400 Received: by necom830.cc.titech.ac.jp (8.6.11/necom-mx-rg); Wed, 24 May 1995 00:17:38 +0900 From: Masataka Ohta Message-Id: <199505231517.AAA14152@necom830.cc.titech.ac.jp> Subject: Re: meeting in Stockholm?? To: dns-security@TIS.COM Date: Wed, 24 May 95 0:17:36 JST In-Reply-To: <9505231413.AA17288@tis.com>; from "James M Galvin" at May 23, 95 10:13 am X-Mailer: ELM [version 2.3 PL11] > Hello everybody. What a wonderfully quiet list we have! However, > wearing my Chair's hat, it's time to think about a meeting in Stockholm. > > I'm soliciting for comments on whether to meet in Stockholm. Here's our > current status to help you decide. > > 1. Eastlake/Kaufman are almost done with the last revision of the current > specification. In Danvers, I talked with Donald. To my surprize, he, then, could have understood several issues of why his protocol does NOT work, which is too complex DNS issue that people without real coding experience have the least chance to understand. Later, he send me a mail on the way on how to avoid some of the issues. But, unfortunately, he doesn't understand the issue well that it does not work. So, I'm quite sure that > 2. TIS is almost done with an alpha implementation of the specification. > The implementation is alpha because we have'nt implemented everything > in the spec, yet, but what we have done is complete. your implementation is broken. > TIS will release our alpha software when the specification is released. > This version of the software will be provided by request only. Future > versions will be available via anonymous FTP. For now, it will only be > available to a US or Canadian site. (Sorry, that's the law. We will > resolve international distribution before we're done.) Then, WG, including me, can't evaluate the code, which is equivalent to having no code. > The problem I have is creating an agenda for a meeting in Stockholm. > There might be some interesting operational issues to discuss. Sure. The E/K spec has several defects, which might have been revealed with some operational experience. > However, all of these things we could do on > the mailing list and thus involve more people. Distribute some working code. You are about a year late. > I expect both of these things to come to closure very soon now. When > E/K are done with the specification, we'll post it as an internet-draft > and immediately start a working group two week last call. After that, > it will go to our area director for consideration to be published as a > proposed standard. Wasn't that agreed in Tronto that the draft should be made as a proposed standard after working code appears, which was scheduled to be before San Jose? Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa17110; 23 May 95 12:03 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0) id sma008753; Tue, 23 May 95 12:08:09 -0400 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA01095; Tue, 23 May 95 12:07:46 EDT Message-Id: <9505231607.AA01095@tis.com> Reply-To: James M Galvin To: Masataka Ohta Cc: dns-security@TIS.COM Subject: Re: meeting in Stockholm?? In-Reply-To: Masataka Ohta's message of Wed, 24 May 1995 00:17:36 +0200. <199505231517.AAA14152@necom830.cc.titech.ac.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <17696.801245273.1@tis.com> Date: Tue, 23 May 1995 12:07:54 -0400 From: James M Galvin In Danvers, I talked with Donald. To my surprize, he, then, could have understood several issues of why his protocol does NOT work, which is too complex DNS issue that people without real coding experience have the least chance to understand. Please do describe what you believe is broken. It is important that we all understand and we resolve any problems. your implementation is broken. While there may be scenarios in which in doesn't work, owing to our not testing all possible operational environments, it does, in fact, work at this time. It is far from broken in all of the cases in which we have tested it. For a protocol as important as DNS, we agree with you that real, operational testing is essential. We're going to begin that process soon. > For now, it will only be > available to a US or Canadian site. Then, WG, including me, can't evaluate the code, which is equivalent to having no code. You are correct, the situation is a bit lop-sided at the moment. However, I don't believe it is as bad as having no code. There are a set of folks who will get to see the code and test it, in the short-term. You, too, will eventually have access. Unfortunately, this situation is not under our control so there is nothing I or you can do about it. > The problem I have is creating an agenda for a meeting in Stockholm. > There might be some interesting operational issues to discuss. Sure. The E/K spec has several defects, which might have been revealed with some operational experience. As I suggested above, please do describe your defects. In our experience, what we've implemented works fine. > However, all of these things we could do on > the mailing list and thus involve more people. Distribute some working code. You are about a year late. You're exaggerating Ohtason, since we've only been working on this for a year. In any case, we're distributing code now. > I expect both of these things to come to closure very soon > now. When E/K are done with the specification, we'll post it > as an internet-draft and immediately start a working group two > week last call. After that, it will go to our area director > for consideration to be published as a proposed standard. Wasn't that agreed in Tronto that the draft should be made as a proposed standard after working code appears, which was scheduled to be before San Jose? I don't remember it that way but I could be wrong. What I remember is simply stating, as a TIS person not the Chair, that we would have some code very soon. We had hoped to have a demo in San Jose but didn't have enough pieces implemented to justify it. As we got further along in the implementation some questions came up which we resolved with the authors of the specs. Had there not been any questions we would have had code some time ago, well in advance of the specification release. As Chair, I know there is no requirement for working code for a proposed standard. There is for a draft standard, however. In any case, the working group can aspire to a higher standard and insist on working code before the spec is published as a proposed standard. What do others think? Jim   Received: from relay.tis.com by neptune.TIS.COM id aa28227; 24 May 95 8:58 EDT Received: from necom830.cc.titech.ac.jp(131.112.32.132) by relay.tis.com via smap (g3.0) id sma017096; Wed, 24 May 95 09:03:01 -0400 Received: by necom830.cc.titech.ac.jp (8.6.11/necom-mx-rg); Wed, 24 May 1995 22:00:50 +0859 From: Masataka Ohta Message-Id: <199505241301.WAA01875@necom830.cc.titech.ac.jp> Subject: Re: meeting in Stockholm?? To: galvin@TIS.COM Date: Wed, 24 May 95 22:00:48 JST Cc: dns-security@TIS.COM In-Reply-To: <9505231607.AA01095@tis.com>; from "James M Galvin" at May 23, 95 12:07 pm X-Mailer: ELM [version 2.3 PL11] > In Danvers, I talked with Donald. To my surprize, he, then, could have > understood several issues of why his protocol does NOT work, which is > too complex DNS issue that people without real coding experience have > the least chance to understand. > > Please do describe what you believe is broken. I did several times. > It is important that we all understand and we resolve any problems. The problem is that you, Jim, can't understand. For example, at the last meeting, it was discussed why glue records can not be and does not have to be authenticated. People with some DNS experience could have understood the issue and the agreement was reached. But, judging from the meeting summary you wrote, you didn't understand it at all. And now, dynamic update draft is combined with secure DNS in wrong way related to glue record and can't work. Sue was able to understand the issue when I talked with her personally at Danvers. But I doubt she realized the seriousness of the defect (because dynamic update draft has other problems). > your implementation is broken. > > While there may be scenarios in which in doesn't work, owing to our not > testing all possible operational environments, it does, in fact, work at > this time. It's not a problem of operational environment but just a wrong specification. > For a protocol as important as DNS, we agree with you that real, > operational testing is essential. It is inessential to have real operational test on protocols which is known to be broken in advance. > Then, WG, including me, can't evaluate the code, which is equivalent > to having no code. > > You are correct, the situation is a bit lop-sided at the moment. > However, I don't believe it is as bad as having no code. Agreed. It is worse than having no code. > You, too, will eventually have access. Unfortunately, this > situation is not under our control so there is nothing I or you can do > about it. Fine. You can't say operational code is reviewd by WG. And, can't I do nothing? Don't you remember that I said, at the last meeting, my secure name server is running? It's export control free. > As I suggested above, please do describe your defects. In our > experience, what we've implemented works fine. Read WG log. Cryptographic part should work just fine but not more than that. > Distribute some working code. You are about a year late. > > You're exaggerating Ohtason, since we've only been working on this for a > year. Not, as I spent only a week or two about a year ago to make my mostly complete secure name server run. > In any case, we're distributing code now. You aren't. > As Chair, I know there is no requirement for working code for a proposed > standard. No. But it's an agreement of the WG and is also a personal opinion of Donald. Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa29264; 24 May 95 10:22 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0) id sma018473; Wed, 24 May 95 10:26:59 -0400 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA10999; Wed, 24 May 95 10:26:40 EDT Message-Id: <9505241426.AA10999@tis.com> Reply-To: James M Galvin To: Masataka Ohta Cc: dns-security@TIS.COM Subject: Re: meeting in Stockholm?? In-Reply-To: Masataka Ohta's message of Wed, 24 May 1995 22:00:48 +0200. <199505241301.WAA01875@necom830.cc.titech.ac.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <974.801325596.1@tis.com> Date: Wed, 24 May 1995 10:26:38 -0400 From: James M Galvin And now, dynamic update draft is combined with secure DNS in wrong way related to glue record and can't work. Sue was able to understand the issue when I talked with her personally at Danvers. But I doubt she realized the seriousness of the defect (because dynamic update draft has other problems). The next version of the Secure DNS draft should say more about glue records, to clarify the issue of concern with respect to Secure DNS. We haven't looked carefully at the relationship to dynamic update, yet. > As I suggested above, please do describe your defects. In our > experience, what we've implemented works fine. Read WG log. Cryptographic part should work just fine but not more than that. I don't understand this comment. > As Chair, I know there is no requirement for working code for > a proposed standard. No. But it's an agreement of the WG and is also a personal opinion of Donald. As always, the working group may aspire to a higher standard. I don't remember the working group agreeing to working code before any publication but I've no problem being corrected if others in the working group agree with you. Also, I suspect you are misinterpreting Donald's preference. Although I won't attempt to speak for him or to his rationale, I do know that he's in agreement with me with respect to publishing the specification as soon as the revision is ready, in parallel with software release. Jim   Received: from relay.tis.com by neptune.TIS.COM id aa29511; 24 May 95 10:40 EDT Received: from necom830.cc.titech.ac.jp(131.112.32.132) by relay.tis.com via smap (g3.0) id sma018849; Wed, 24 May 95 10:44:58 -0400 Received: by necom830.cc.titech.ac.jp (8.6.11/necom-mx-rg); Wed, 24 May 1995 23:43:17 +0900 From: Masataka Ohta Message-Id: <199505241443.XAA02444@necom830.cc.titech.ac.jp> Subject: Re: meeting in Stockholm?? To: galvin@TIS.COM Date: Wed, 24 May 95 23:43:16 JST Cc: dns-security@TIS.COM In-Reply-To: <9505241426.AA10999@tis.com>; from "James M Galvin" at May 24, 95 10:26 am X-Mailer: ELM [version 2.3 PL11] > And now, dynamic update draft is combined with secure DNS in > wrong way related to glue record and can't work. Sue was able to > understand the issue when I talked with her personally at > Danvers. But I doubt she realized the seriousness of the defect > (because dynamic update draft has other problems). > > The next version of the Secure DNS draft should say more about glue > records, What's wrong is not wording, but protocol. > to clarify the issue of concern with respect to Secure DNS. As Donald still does not understand it to be able to propose a solution, it is worthless. And, of course, there are several other wrongness in the specification. > We > haven't looked carefully at the relationship to dynamic update, yet. You don't have to. > > As I suggested above, please do describe your defects. In our > > experience, what we've implemented works fine. > > Read WG log. Cryptographic part should work just fine but not > more than that. > > I don't understand this comment. Don't you know that secure DNS consists of cryptography and DNS? DNS part is subtly but fatally broken. > As always, the working group may aspire to a higher standard. I don't > remember the working group agreeing to working code before any > publication but I've no problem being corrected if others in the working > group agree with you. Read WG log. Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa00431; 24 May 95 11:38 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0) id sma019877; Wed, 24 May 95 11:43:28 -0400 Received: by callandor.cybercash.com; id WAA09098; Mon, 22 May 1995 22:50:25 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (V1.3) id sma009090; Mon May 22 22:50:20 1995 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA09566; Wed, 24 May 95 11:38:23 EDT Date: Wed, 24 May 1995 11:38:22 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: Masataka Ohta Cc: dns-security@TIS.COM Subject: Re: meeting in Stockholm?? In-Reply-To: <199505241443.XAA02444@necom830.cc.titech.ac.jp> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Ohta San, I believe that the next version of the draft, which I plan to have out next week, will address most of your concerns. While it is true that in the past, even when you spoke to me in person at Danvers, I did not fully understand these, I believe that I do now. Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa00590; 24 May 95 11:54 EDT Received: from kerby.ocsg.com(192.156.168.6) by relay.tis.com via smap (g3.0) id sma020099; Wed, 24 May 95 11:58:42 -0400 Received: from sickly.cybersafe.com (sickly.cybersafe.com [192.156.168.11]) by kerby.ocsg.com (8.6.12/8.6.11, dpg hack 11mar95) with SMTP id IAA22971; Wed, 24 May 1995 08:58:50 -0700 Received: by sickly.cybersafe.com (NX5.67d/NX3.0S) id AA05817; Wed, 24 May 95 08:58:40 -0700 Date: Wed, 24 May 95 08:58:40 -0700 From: Dennis Glatting Message-Id: <9505241558.AA05817@sickly.cybersafe.com> Received: by NeXT.Mailer (1.100) Received: by NeXT Mailer (1.100) To: Masataka Ohta Subject: Re: meeting in Stockholm?? Cc: galvin@TIS.COM, dns-security@TIS.COM Reply-To: dennis.glatting@cybersafe.com It would help if detailed descriptions of the problems are posted rather than terse, inconclusive statements. -dpg   Received: from relay.tis.com by neptune.TIS.COM id aa00586; 24 May 95 11:54 EDT Received: from necom830.cc.titech.ac.jp(131.112.32.132) by relay.tis.com via smap (g3.0) id sma020074; Wed, 24 May 95 11:56:17 -0400 Received: by necom830.cc.titech.ac.jp (8.6.11/necom-mx-rg); Thu, 25 May 1995 00:53:59 +0859 From: Masataka Ohta Message-Id: <199505241554.AAA02799@necom830.cc.titech.ac.jp> Subject: Re: meeting in Stockholm?? To: "Donald E. Eastlake 3rd" Date: Thu, 25 May 95 0:53:58 JST Cc: dns-security@TIS.COM In-Reply-To: ; from "Donald E. Eastlake 3rd" at May 24, 95 11:38 am X-Mailer: ELM [version 2.3 PL11] > I believe that the next version of the draft, which I plan to have out > next week, will address most of your concerns. While it is true that > in the past, even when you spoke to me in person at Danvers, I did not > fully understand these, I believe that I do now. I really hope so. But, as the implementation is said to be still partial, I, quite righteously from my experience, can't believe you completely. :-) Anyway, I'm looking forward to see the next version. Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa05982; 30 May 95 15:35 EDT From: hugo@watson.ibm.com MMDF-Warning: Parse error in original version of preceding line at neptune.TIS.COM Message-Id: <199505301939.PAA09411@relay.tis.com> Received: from watson.ibm.com(129.34.139.4) by relay.tis.com via smap (g3.0) id sma009407; Tue, 30 May 95 15:39:33 -0400 Received: from YKTVMV by watson.ibm.com (IBM VM SMTP V2R3) with BSMTP id 8925; Tue, 30 May 95 15:40:14 EDT Date: Tue, 30 May 95 15:39:03 EDT To: dns-security@TIS.COM Subject: meeting in Stockholm?? Ref: Your note of Tue, 23 May 1995 10:13:41 -0400 (attached) Charles, I do not remember if you're subscribed to this list (dns-sec). Let me know if you are, so I do not forward these messages. This one seems important fyi. Hugo ----------------------------- Note follows ------------------------------ Received: from TIS.COM by watson.ibm.com (IBM VM SMTP V2R3) with TCP; Tue, 23 May 95 11:08:08 EDT Received: from neptune.tis.com by neptune.TIS.COM id aa15930; 23 May 95 10:15 EDT Received: from relay.tis.com by neptune.TIS.COM id aa15926; 23 May 95 10:09 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0) id sma006572; Tue, 23 May 95 10:13:52 -0400 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA17288; Tue, 23 May 95 10:13:29 EDT Message-Id: <9505231413.AA17288@tis.com> Reply-To: dns-security@TIS.COM To: dns-security@TIS.COM Subject: meeting in Stockholm?? Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <17368.801238419.1@tis.com> Date: Tue, 23 May 1995 10:13:41 -0400 From: James M Galvin Hello everybody. What a wonderfully quiet list we have! However, wearing my Chair's hat, it's time to think about a meeting in Stockholm. I'm soliciting for comments on whether to meet in Stockholm. Here's our current status to help you decide. 1. Eastlake/Kaufman are almost done with the last revision of the current specification. 2. TIS is almost done with an alpha implementation of the specification. The implementation is alpha because we have'nt implemented everything in the spec, yet, but what we have done is complete. I expect both of these things to come to closure very soon now. When E/K are done with the specification, we'll post it as an internet-draft and immediately start a working group two week last call. After that, it will go to our area director for consideration to be published as a proposed standard. TIS will release our alpha software when the specification is released. This version of the software will be provided by request only. Future versions will be available via anonymous FTP. For now, it will only be available to a US or Canadian site. (Sorry, that's the law. We will resolve international distribution before we're done.) If you want the software, now would be a good time to let me know. Send a note to me at "galvin@tis.com". (REPLYING TO THIS MESSAGE WILL NOT WORK.) In the past, it was requested that the discussions that E/K and TIS be visible to the community. I will be posting the collected works to our anonymous FTP server, probably next week, for those who want to indulge. The problem I have is creating an agenda for a meeting in Stockholm. There might be some interesting operational issues to discuss. In addition, there are some issues related to dynamic update that are probably worth discussing. However, all of these things we could do on the mailing list and thus involve more people. So, I'm leaning towards not having a meeting but I'm interested in what other people think. Comments? Jim   Received: from relay.tis.com by neptune.TIS.COM id aa09088; 15 Jun 95 16:32 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id sma019858; Thu, 15 Jun 95 16:34:56 -0400 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA04346; Thu, 15 Jun 95 16:36:24 EDT Message-Id: <9506152036.AA04346@tis.com> Reply-To: James M Galvin To: dns-security@TIS.COM Subject: no meeting in Stockholm Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <2025.803248582.1@tis.com> Date: Thu, 15 Jun 1995 16:36:23 -0400 From: James M Galvin Looks like the right thing to do is not have a meeting in Stockholm. I expect to propose an agenda for this mailing list before then, following the next (final?) version of the specification, whichever is later. Thanks, Jim   Received: from relay.tis.com by neptune.TIS.COM id aa02546; 19 Jun 95 23:32 EDT Received: from necom830.cc.titech.ac.jp(131.112.32.132) by relay.tis.com via smap (g3.0.1) id sma025897; Mon, 19 Jun 95 23:35:13 -0400 Received: by necom830.cc.titech.ac.jp (8.6.11/necom-mx-rg); Tue, 20 Jun 1995 12:34:56 +0859 From: Masataka Ohta Message-Id: <199506200335.MAA04182@necom830.cc.titech.ac.jp> Subject: Re: no meeting in Stockholm To: galvin@TIS.COM Date: Tue, 20 Jun 95 12:34:53 JST Cc: dns-security@TIS.COM In-Reply-To: <9506152036.AA04346@tis.com>; from "James M Galvin" at Jun 15, 95 4:36 pm X-Mailer: ELM [version 2.3 PL11] > Looks like the right thing to do is not have a meeting in Stockholm. Agreed. It's not meaningful to have discussion on an incomplete and defective draft. > I > expect to propose an agenda for this mailing list before then, following > the next (final?) version of the specification, whichever is later. I hope, someday for the first time, we can have a discussion on DNS-affinity issues of proposals, which you couldn't have understood the importance and actively obstructed at the last meeting. Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa13447; 28 Jun 95 15:45 EDT Received: from ietf.cnri.reston.va.us(132.151.1.35) by relay.tis.com via smap (g3.0.1) id xma014166; Wed, 28 Jun 95 15:47:08 -0400 Received: from [127.0.0.1] by IETF.CNRI.Reston.VA.US id aa04911; 28 Jun 95 15:29 EDT Mime-Version: 1.0 Content-Type: Multipart/Mixed; Boundary="NextPart" To: IETF-Announce: ;, tis.com@TIS.COM MMDF-Warning: Parse error in original version of preceding line at neptune.TIS.COM cc: dns-security@TIS.COM From: Internet-Drafts@cnri.reston.va.us Reply-to: Internet-Drafts@cnri.reston.va.us Subject: I-D ACTION:draft-ietf-dnssec-secext-04.txt Date: Wed, 28 Jun 95 15:29:31 -0400 Sender: cclark@cnri.reston.va.us Message-ID: <9506281529.aa04911@IETF.CNRI.Reston.VA.US> --NextPart A Revised Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the Domain Name System Security Working Group of the IETF. Title : Domain Name System Security Extensions Author(s) : D. Eastlake, C. Kaufman Filename : draft-ietf-dnssec-secext-04.txt Pages : 41 Date : 06/26/1995 The Domain Name System (DNS) has become a critical operational part of the Internet infrastructure yet it has no strong security mechanisms to assure data integrity or authentication. Extensions to the DNS are described that provide these services to security aware resolvers or applications through the use of cryptographic digital signatures. These digital signatures are included in secured zones as resource records. Security can still be provided even through non-security aware DNS servers in many cases. The extensions also provide for the storage of authenticated public keys in the DNS. This storage of keys can support general public key distribution service as well as DNS security. The stored keys enable security aware resolvers to learn the authenticating key of zones in addition to keys for which they are initially configured. Keys associated with DNS names can be retrieved to support other protocols. Provision is made for a variety of key types and algorithms. In addition, the security extensions provide for the optional authentication of DNS protocol transactions. Internet-Drafts are available by anonymous FTP. Login with the username "anonymous" and a password of your e-mail address. After logging in, type "cd internet-drafts" and then "get draft-ietf-dnssec-secext-04.txt". A URL for the Internet-Draft is: ftp://ds.internic.net/internet-drafts/draft-ietf-dnssec-secext-04.txt Internet-Drafts directories are located at: o Africa Address: ftp.is.co.za (196.4.160.2) o Europe Address: nic.nordu.net (192.36.148.17) Address: ftp.nis.garr.it (192.12.192.10) o Pacific Rim Address: munnari.oz.au (128.250.1.21) o US East Coast Address: ds.internic.net (198.49.45.10) o US West Coast Address: ftp.isi.edu (128.9.0.32) Internet-Drafts are also available by mail. Send a message to: mailserv@ds.internic.net. In the body type: "FILE /internet-drafts/draft-ietf-dnssec-secext-04.txt". NOTE: The mail server at ds.internic.net can return the document in MIME-encoded form by using the "mpack" utility. To use this feature, insert the command "ENCODING mime" before the "FILE" command. To decode the response(s), you will need "munpack" or a MIME-compliant mail reader. Different MIME-compliant mail readers exhibit different behavior, especially when dealing with "multipart" MIME messages (i.e., documents which have been split up into multiple messages), so check your local documentation on how to manipulate these messages. For questions, please mail to Internet-Drafts@cnri.reston.va.us. Below is the data which will enable a MIME compliant mail reader implementation to automatically retrieve the ASCII version of the Internet-Draft. --NextPart Content-Type: Multipart/Alternative; Boundary="OtherAccess" --OtherAccess Content-Type: Message/External-body; access-type="mail-server"; server="mailserv@ds.internic.net" Content-Type: text/plain Content-ID: <19950626104131.I-D@CNRI.Reston.VA.US> ENCODING mime FILE /internet-drafts/draft-ietf-dnssec-secext-04.txt --OtherAccess Content-Type: Message/External-body; name="draft-ietf-dnssec-secext-04.txt"; site="ds.internic.net"; access-type="anon-ftp"; directory="internet-drafts" Content-Type: text/plain Content-ID: <19950626104131.I-D@CNRI.Reston.VA.US> --OtherAccess-- --NextPart--   Received: from relay.tis.com by neptune.TIS.COM id aa16038; 24 Jul 95 11:18 EDT Received: from necom830.cc.titech.ac.jp(131.112.32.132) by relay.tis.com via smap (g3.0.1) id xma009916; Mon, 24 Jul 95 11:10:50 -0400 Received: by necom830.cc.titech.ac.jp (8.6.11/necom-mx-rg); Tue, 25 Jul 1995 00:14:10 +0900 From: Masataka Ohta Message-Id: <199507241514.AAA07143@necom830.cc.titech.ac.jp> Subject: Re: meeting in Stockholm?? To: "Donald E. Eastlake 3rd" Date: Tue, 25 Jul 95 0:14:09 JST Cc: dns-security@TIS.COM In-Reply-To: ; from "Donald E. Eastlake 3rd" at May 24, 95 11:38 am X-Mailer: ELM [version 2.3 PL11] Donald; > Ohta San, > > I believe that the next version of the draft, which I plan to have out > next week, will address most of your concerns. While it is true that > in the past, even when you spoke to me in person at Danvers, I did not > fully understand these, I believe that I do now. I haven't had enough time to review all the part of your draft. But, at least, your draft ignores the WG consensus at the last meeting that non-authoritative delegation RRs do not have to and should not be authenticated by parent zones. As discussed in the meeting, the ignorance makes delegation packets unnecessarily lengthy so that 512 bytes won't be enough. I'd like to propose that, instead of seeking your own way only to make secure DNS complex, you should merge your partially implemented proposal with mine whose implementation of export-free, almost-complete nameserver has been running for these 8 monthes after my 2 weeks of hacking. Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa22108; 24 Jul 95 18:22 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma015751; Mon, 24 Jul 95 18:14:40 -0400 Received: by callandor.cybercash.com; id SAA22522; Mon, 24 Jul 1995 18:16:37 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma022520; Mon, 24 Jul 95 18:16:32 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA10570; Mon, 24 Jul 95 18:19:31 EDT Date: Mon, 24 Jul 1995 18:19:30 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: Masataka Ohta Cc: dns-security@TIS.COM Subject: Re: meeting in Stockholm?? In-Reply-To: <199507241514.AAA07143@necom830.cc.titech.ac.jp> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Tue, 25 Jul 1995, Masataka Ohta wrote: > Donald; > > > Ohta San, > > > > I believe that the next version of the draft, which I plan to have out > > next week, will address most of your concerns. While it is true that > > in the past, even when you spoke to me in person at Danvers, I did not > > fully understand these, I believe that I do now. > > I haven't had enough time to review all the part of your draft. > > But, at least, your draft ignores the WG consensus at the > last meeting that non-authoritative delegation RRs do not > have to and should not be authenticated by parent zones. I think the draft follows the consensus. See sections 2.3.4 which says that only the KEY RR (for which the parent zone is authoritative) should be signed by the parent (and the NXT RR but you don't see that on "delegation packets"). > As discussed in the meeting, the ignorance makes delegation packets > unnecessarily lengthy so that 512 bytes won't be enough. > > I'd like to propose that, instead of seeking your own way only > to make secure DNS complex, you should merge your partially It's my opinion that, while the original proposal by myself and Charlie Kaufman was more complex than yours, our current proposal is simpler. > implemented proposal with mine whose implementation of > export-free, almost-complete nameserver has been running for > these 8 monthes after my 2 weeks of hacking. I am not doing the implementation so I don't have any ability to make decisions concerning "merging" of implementations. > Masataka Ohta Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa03050; 25 Jul 95 9:29 EDT Received: from holmes.umd.edu(129.2.128.24) by relay.tis.com via smap (g3.0.1) id xma022342; Tue, 25 Jul 95 09:22:12 -0400 Received: from UMDD (umdd.umd.edu [128.8.170.13]) by holmes.umd.edu(8.6.12/94Mar10) with SMTP id JAA32106; Tue, 25 Jul 1995 09:29:37 -0400 Message-Id: <199507251329.JAA32106@holmes.umd.edu> Received: by UMDD.UMD.EDU id 3964 ; 25 Jul 95 09:29:39 EDT Received: by UMDD (Mailer R2.10 ptf000) id 3964; Tue, 25 Jul 95 09:29:39 EDT Date: Tue, 25 Jul 95 09:13:43 EDT From: Bruce Crabill Subject: comments on NXT RR To: DNS-SECURITY@TIS.COM I've been reading draft-ietf-dnssec-secext-04.txt and have a few comments about section 5, the section dealing with the NXT RR. I realize that the NXT RR is realitively new (used to be the NXD RR but was renamed when the bitmap was added), but the documentation for the RR needs to be made a bit clearer. You don't really say what the bitmap is a bitmap of (you get the impression that it is a bitmap of RR types (as in the WKS bitmap of protocols), but this isn't clearly stated, nor is the structure of the bitmap defined. The example on the bottom of page 27 implies that the bitmap has a value of 130. I'm not sure how to interept this. If it is decimal, then you are saying that it applies to DNS RR types 0 and 6. Also, has the FTP site for the archives changed? The last archive on FTP.TIS.COM is 9411 and I can't seem to find any place where the NXT RR was discussed. Bruce   Received: from relay.tis.com by neptune.TIS.COM id aa00572; 26 Jul 95 17:32 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma016332; Wed, 26 Jul 95 17:25:26 -0400 Received: from magellan.tis.com by tis.com (4.1/SUN-5.64) id AA06086; Wed, 26 Jul 95 17:31:41 EDT Message-Id: <9507262131.AA06086@tis.com> Reply-To: James M Galvin To: dns-security@TIS.COM Subject: ANNOUNCE: TIS/DNSSEC Version 1.0 alpha is now available Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <26084.806794299.1@tis.com> Date: Wed, 26 Jul 1995 17:31:43 -0400 From: James M Galvin Trusted Information Systems is pleased to announce the availability of a secure DNS: TIS/DNSSEC Version 1.0 alpha. It provides integrity and authentication services for DNS resource records using digital signature technology. It is being made available for alpha testing on the following basis. o TIS/DNSSEC is available via anonymous FTP in source code form. All modules have been written in the C programming language and it is known to run on many UNIX-derived operating systems. o This version of TIS/DNSSEC depends on a specialized version of TIS/MOSS, which is currently included in the distribution. o This version of TIS/DNSSEC is not available outside the United States or Canada, nor can you give it to anyone who is not a U.S. or Canadian citizen and does not have a U.S. "green card." (These are U.S. State and Commerce Department requirements because of the use of TIS/MOSS. We hope to be able to remove this restriction in a future version.) This version of TIS/DNSSEC is an alpha implementation because it does not implement the entire specification. As soon as we complete the implementation it will be a beta distribution until the code stabilizes. TIS/DNSSEC is a product of Trusted Information Systems that may be used free of charge during the alpha test period. Instructions on how to retrieve TIS/DNSSEC Version 1.0 alpha may be found in the file "/pub/DNSSEC/README" on the host "ftp.tis.com" which may be retrieved via anonymous ftp. If you have any questions or comments please send email to "tisdnssec-support@tis.com".   Received: from relay.tis.com by neptune.TIS.COM id aa00632; 26 Jul 95 17:38 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma016403; Wed, 26 Jul 95 17:31:30 -0400 Received: from magellan.tis.com by tis.com (4.1/SUN-5.64) id AA06321; Wed, 26 Jul 95 17:37:45 EDT Message-Id: <9507262137.AA06321@tis.com> Reply-To: James M Galvin To: dns-security@TIS.COM Subject: WG Last Call: draft-ietf-dnssec-secext-04.txt Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <26111.806794666.1@tis.com> Date: Wed, 26 Jul 1995 17:37:47 -0400 From: James M Galvin Speaking as chair of the DNS Security Working Group, I would like to announce a working group last call on the following document: draft-ietf-dnssec-secext-04.txt This document will be submitted to the IESG on or after August 16 (3 weeks from now) for consideration as a Proposed Standard unless it is found to be technically flawed. Speak now (on technical flaws) or forever hold your peace. Jim   Received: from relay.tis.com by neptune.TIS.COM id aa28048; 2 Aug 95 3:25 EDT Received: from necom830.cc.titech.ac.jp(131.112.32.132) by relay.tis.com via smap (g3.0.1) id xma011675; Wed, 2 Aug 95 03:17:18 -0400 Received: by necom830.cc.titech.ac.jp (8.6.11/necom-mx-rg); Wed, 2 Aug 1995 16:19:36 +0900 From: Masataka Ohta MMDF-Warning: Unable to confirm address in preceding line at neptune.TIS.COM Message-Id: <199508020719.QAA06514@necom830.cc.titech.ac.jp> Subject: Re: meeting in Stockholm?? To: "Donald E. Eastlake 3rd" Date: Wed, 2 Aug 95 16:19:35 JST Cc: dns-security@TIS.COM In-Reply-To: ; from "Donald E. Eastlake 3rd" at Jul 24, 95 6:19 pm X-Mailer: ELM [version 2.3 PL11] > > > I believe that the next version of the draft, which I plan to have out > > > next week, will address most of your concerns. While it is true that > > > in the past, even when you spoke to me in person at Danvers, I did not > > > fully understand these, I believe that I do now. > > > > I haven't had enough time to review all the part of your draft. > > > > But, at least, your draft ignores the WG consensus at the > > last meeting that non-authoritative delegation RRs do not > > have to and should not be authenticated by parent zones. > > I think the draft follows the consensus. See sections 2.3.4 which > says that only the KEY RR (for which the parent zone is authoritative) > should be signed by the parent (and the NXT RR but you don't see that > on "delegation packets"). I'm afraid you still misunderstand what "authoritative" means. > > As discussed in the meeting, the ignorance makes delegation packets > > unnecessarily lengthy so that 512 bytes won't be enough. And this issue remains unsolved. > > I'd like to propose that, instead of seeking your own way only > > to make secure DNS complex, you should merge your partially > > It's my opinion that, while the original proposal by myself and > Charlie Kaufman was more complex than yours, our current proposal is > simpler. It is no excuse that you made a bad proposal less bad, especially in the face of a good proposal. > > implemented proposal with mine whose implementation of > > export-free, almost-complete nameserver has been running for > > these 8 monthes after my 2 weeks of hacking. > > I am not doing the implementation so I don't have any ability to make > decisions concerning "merging" of implementations. I'm talking not about implementations but about specifications, only one of which is implemented. Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa00737; 2 Aug 95 7:20 EDT Received: from necom830.cc.titech.ac.jp(131.112.32.132) by relay.tis.com via smap (g3.0.1) id xma013007; Wed, 2 Aug 95 07:12:44 -0400 Received: by necom830.cc.titech.ac.jp (8.6.11/necom-mx-rg); Wed, 2 Aug 1995 20:16:49 +0859 From: Masataka Ohta Message-Id: <199508021117.UAA08574@necom830.cc.titech.ac.jp> Subject: Re: WG Last Call: draft-ietf-dnssec-secext-04.txt To: galvin@TIS.COM Date: Wed, 2 Aug 95 20:16:48 JST Cc: dns-security@TIS.COM In-Reply-To: <9507262137.AA06321@tis.com>; from "James M Galvin" at Jul 26, 95 5:37 pm X-Mailer: ELM [version 2.3 PL11] > Speaking as chair of the DNS Security Working Group, I would like to > announce a working group last call on the following document: > > draft-ietf-dnssec-secext-04.txt I don't think we are ready to proceed. > This document will be submitted to the IESG on or after August 16 (3 > weeks from now) for consideration as a Proposed Standard unless it is > found to be technically flawed. Why didn't you have a meeting or two at Stockholm, if you want to have an intense discussion? Yes, it is technically flawed. If you don't think so, give a full implementation. Moreover, E&K proposal is not compared to the alternative proposal of mine, because, at the last meeting, you forced your wrong view that the difference is merely on the number of RR types. > Speak now (on technical flaws) or forever hold your peace. While your misjudgement was understandable at the time of the last meeting, I really hope you not repeat it again. Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa14120; 2 Aug 95 21:44 EDT Received: from big-screw.mit.edu(18.72.0.176) by relay.tis.com via smap (g3.0.1) id xma026175; Wed, 2 Aug 95 21:36:16 -0400 Received: by big-screw id AA15630; Wed, 2 Aug 95 21:44:19 -0400 Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 2 Aug 1995 21:44:31 -0400 To: dns-security@TIS.COM From: "Jeffrey I. Schiller" Subject: Re: WG Last Call: draft-ietf-dnnsec-secext-04.txt I will re-iterate a comment I made in private in Stockholm. I would strongly suggest that the signature computation be exactly compatible with that performed by the RSAREF toolkit (not to mention other toolkits, PEM and PGP which all conform to the PKCS standard for signatures). The current documented version is only "close." -Jeff   Received: from relay.tis.com by neptune.TIS.COM id aa27990; 3 Aug 95 14:30 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma006281; Thu, 3 Aug 95 14:21:47 -0400 Received: by callandor.cybercash.com; id OAA08504; Thu, 3 Aug 1995 14:19:50 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma008500; Thu, 3 Aug 95 14:19:42 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA04174; Thu, 3 Aug 95 14:23:10 EDT Date: Thu, 3 Aug 1995 14:23:09 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: James M Galvin Cc: dns-security@TIS.COM Subject: Re: WG Last Call: draft-ietf-dnssec-secext-04.txt In-Reply-To: <9507262137.AA06321@tis.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Wed, 26 Jul 1995, James M Galvin wrote: > Speaking as chair of the DNS Security Working Group, I would like to > announce a working group last call on the following document: > > draft-ietf-dnssec-secext-04.txt > > This document will be submitted to the IESG on or after August 16 (3 > weeks from now) for consideration as a Proposed Standard unless it is > found to be technically flawed. > > Speak now (on technical flaws) or forever hold your peace. > > Jim I would like to make the following minor changes. I do not believe these have any techncial effect. (1) As suggested by Jeff Schiller, change the RSA algorithm signature to be exactly PKCS1. (see his message below) This mostly involved adding the MD5 OID algorithm identifier to the MD5 message digest before encrypting with the private key. It would make it possible to implement DNSSEC with RSAREF. (2) Since MOSS has now gone to Proposed Standard, I want to reserve bit 9 in the KEY RR flags to indicate MOSS. (3) Due to the message sent by Bruce Crabill below, I would like to add the following clarifying text to section 5 and to change the examle to use a list of RR type mnemonics. "The NXT RR type bit map is one bit per RR type present for the owner name similar to the WKS socket bit map. The first bit represents RR type zero (an illegal type which should not be present.) A one bit indicates that at least one RR of that type is present for the owner name. A zero indicates that no such RR is present. All bits not specified because they are beyond the end of the bit map are assumed to be zero. Note that bit 30, for NXT, will always be on so the minimum bit map length is actually four octets. The NXT bit map should be printed as a list of type mnemonics or decimal numbers similar to the WKS RR." I believe these changes are not of a type that would require delaying forwarding the draft to the IESG. Donald From jis@mit.eduThu Aug 3 13:13:13 1995 Date: Wed, 2 Aug 1995 21:44:31 -0400 From: "Jeffrey I. Schiller" To: dns-security@TIS.COM Subject: Re: WG Last Call: draft-ietf-dnnsec-secext-04.txt I will re-iterate a comment I made in private in Stockholm. I would strongly suggest that the signature computation be exactly compatible with that performed by the RSAREF toolkit (not to mention other toolkits, PEM and PGP which all conform to the PKCS standard for signatures). The current documented version is only "close." -Jeff From BRUCE@umdd.umd.eduThu Aug 3 13:23:50 1995 Date: Tue, 25 Jul 95 09:13:43 EDT From: Bruce Crabill To: DNS-SECURITY@TIS.COM Subject: comments on NXT RR I've been reading draft-ietf-dnssec-secext-04.txt and have a few comments about section 5, the section dealing with the NXT RR. I realize that the NXT RR is realitively new (used to be the NXD RR but was renamed when the bitmap was added), but the documentation for the RR needs to be made a bit clearer. You don't really say what the bitmap is a bitmap of (you get the impression that it is a bitmap of RR types (as in the WKS bitmap of protocols), but this isn't clearly stated, nor is the structure of the bitmap defined. The example on the bottom of page 27 implies that the bitmap has a value of 130. I'm not sure how to interept this. If it is decimal, then you are saying that it applies to DNS RR types 0 and 6. ... ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa10721; 8 Aug 95 12:16 EDT Received: from ietf.cnri.reston.va.us(132.151.1.35) by relay.tis.com via smap (g3.0.1) id xmad01879; Tue, 8 Aug 95 12:07:20 -0400 Received: from [127.0.0.1] by IETF.CNRI.Reston.VA.US id aa14163; 8 Aug 95 12:04 EDT Mime-Version: 1.0 Content-Type: Multipart/Mixed; Boundary="NextPart" To: IETF-Announce: ;, tis.com@TIS.COM MMDF-Warning: Parse error in original version of preceding line at neptune.TIS.COM cc: dns-security@TIS.COM From: Internet-Drafts@cnri.reston.va.us Reply-to: Internet-Drafts@cnri.reston.va.us Subject: I-D ACTION:draft-ietf-dnssec-as-map-02.txt Date: Tue, 08 Aug 95 12:04:40 -0400 Sender: cclark@cnri.reston.va.us Message-ID: <9508081204.aa14163@IETF.CNRI.Reston.VA.US> --NextPart A Revised Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the Domain Name System Security Working Group of the IETF. Title : Mapping Autonomous Systems Number into the Domain Name System Author(s) : D. Eastlake Filename : draft-ietf-dnssec-as-map-02.txt Pages : 9 Date : 08/07/1995 One requirement of secure routing is that independent routing entities, such as those identified by Internet Autonomous System Numbers, be able to authenticate messages to each other. Modifications currently being developed (see draft-ietf-dnssec-secext-*.txt) to the Domain Name System will enable it to be used for authenticated public key distribution. This draft maps all Autonomous System numbers into DNS Domain Names so that the DNS can be used to distribute their public keys. Internet-Drafts are available by anonymous FTP. Login with the username "anonymous" and a password of your e-mail address. After logging in, type "cd internet-drafts" and then "get draft-ietf-dnssec-as-map-02.txt". A URL for the Internet-Draft is: ftp://ds.internic.net/internet-drafts/draft-ietf-dnssec-as-map-02.txt Internet-Drafts directories are located at: o Africa Address: ftp.is.co.za (196.4.160.8) o Europe Address: nic.nordu.net (192.36.148.17) Address: ftp.nis.garr.it (192.12.192.10) o Pacific Rim Address: munnari.oz.au (128.250.1.21) o US East Coast Address: ds.internic.net (198.49.45.10) o US West Coast Address: ftp.isi.edu (128.9.0.32) Internet-Drafts are also available by mail. Send a message to: mailserv@ds.internic.net. In the body type: "FILE /internet-drafts/draft-ietf-dnssec-as-map-02.txt". NOTE: The mail server at ds.internic.net can return the document in MIME-encoded form by using the "mpack" utility. To use this feature, insert the command "ENCODING mime" before the "FILE" command. To decode the response(s), you will need "munpack" or a MIME-compliant mail reader. Different MIME-compliant mail readers exhibit different behavior, especially when dealing with "multipart" MIME messages (i.e., documents which have been split up into multiple messages), so check your local documentation on how to manipulate these messages. For questions, please mail to Internet-Drafts@cnri.reston.va.us. Below is the data which will enable a MIME compliant mail reader implementation to automatically retrieve the ASCII version of the Internet-Draft. --NextPart Content-Type: Multipart/Alternative; Boundary="OtherAccess" --OtherAccess Content-Type: Message/External-body; access-type="mail-server"; server="mailserv@ds.internic.net" Content-Type: text/plain Content-ID: <19950807171114.I-D@CNRI.Reston.VA.US> ENCODING mime FILE /internet-drafts/draft-ietf-dnssec-as-map-02.txt --OtherAccess Content-Type: Message/External-body; name="draft-ietf-dnssec-as-map-02.txt"; site="ds.internic.net"; access-type="anon-ftp"; directory="internet-drafts" Content-Type: text/plain Content-ID: <19950807171114.I-D@CNRI.Reston.VA.US> --OtherAccess-- --NextPart--   Received: from relay.tis.com by neptune.TIS.COM id aa21112; 11 Aug 95 14:28 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma020516; Fri, 11 Aug 95 14:20:07 -0400 Received: by callandor.cybercash.com; id OAA19114; Fri, 11 Aug 1995 14:22:28 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma019108; Fri, 11 Aug 95 14:22:14 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA14106; Fri, 11 Aug 95 14:26:08 EDT Date: Fri, 11 Aug 1995 14:26:07 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: dns-security@TIS.COM Subject: Re: WG Last Call: draft-ietf-dnssec-secext-04.txt In-Reply-To: Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Since there have not been any particular objections, I have incorporated the changes listed in my 3 August message with exact wording indicated below interspersed with my original message. In addition, I would like to make the following minor clarifications in the next few days in connection with dynamic update. (1) Add an explicit statement that a SIG RR with an expiration date before the date signed is ineffective. (2) Add an explicit statement that SIG RRs should not have a date signed significantly in the future. and (3) Add an explicit statement that, to prevent misordering of network request to update a zone dynamically, monotonically increasing "time signed" dates are necessary. Donald On Thu, 3 Aug 1995, Donald E. Eastlake 3rd wrote: > On Wed, 26 Jul 1995, James M Galvin wrote: > > Speaking as chair of the DNS Security Working Group, I would like to > > announce a working group last call on the following document: > > > > draft-ietf-dnssec-secext-04.txt > > > > This document will be submitted to the IESG on or after August 16 (3 > > weeks from now) for consideration as a Proposed Standard unless it is > > found to be technically flawed. > > > > Speak now (on technical flaws) or forever hold your peace. > > > > Jim > > I would like to make the following minor changes. I do not > believe these have any techncial effect. > > (1) As suggested by Jeff Schiller, change the RSA algorithm signature > to be exactly PKCS1. (see his message below) This mostly involved > adding the MD5 OID algorithm identifier to the MD5 message digest > before encrypting with the private key. It would make it possible to > implement DNSSEC with RSAREF. -- exact source changed/reordered .in +3 .ne 3 hash = MD5 ( data ) signature = ( 01 | FF* | 00 | prefix | hash ) ** e (mod n) .in -3 where MD5 is the message digest algorithm documented in RFC 1321, "|" is concatenation, "e" is the secret key exponent of the signer, and "n" is the public modulus of the signer's public key. 01, FF, and 00 are fixed octets of the corresponding hexadecimal value. "prefix" is the ASN.1 BER MD5 algorithm designator prefix specified in PKCS1, that is, .br .ti +5 hex 3020300c06082a864886f70d020505000410 [NETSEC]. .br The FF octet is repeated the maximum number of times such that the value of the quantity being exponentiated is one octet shorter than the value of n. The above specifications are exactly Public Key Cryptographic Standard #1 [PKCS1]. The size of n, including most and least significant bits (which will be 1) SHALL be not less than 512 bits and not more than 2552 bits. n and e SHOULD be chosen such that the public exponent is small. Leading zeros bytes are not permitted in the MD5/RSA algorithm signature. -- end exact source changed/reordered > (2) Since MOSS has now gone to Proposed Standard, I want to reserve > bit 9 in the KEY RR flags to indicate MOSS. -- begin exact changed source Bit 8 is reserved to be the "IPSEC" bit and indicate that this key is valid for use in conjunction with the IP level security standard. This key could be used in connection with secured communication on behalf of an end entity or user whose name is the owner name of the KEY RR if the entity or user bits are on. The presence of a KEY resource with the IPSEC and entity bits on and experimental and no-key bits off is a guarantee that the host speaks IPSEC. .ti +5 Bit 9 is reserved to be the "MOSS" bit and indicate that this key is valid for use in conjunction with MIME object security standard. This key could be used in connection with secured communication on behalf of an end entity or user whose name is the owner name of the KEY RR if the entity or user bits are on. The presence of a KEY resource with the MOSS and entity bits on and experimental and no-key bits off is a guarantee that the host speaks MOSS. .ti +5 Bits 10-11 are reserved and must be zero. -- end exact changed source > (3) Due to the message sent by Bruce Crabill below, I would like to > add the following clarifying text to section 5 and to change the > examle to use a list of RR type mnemonics. > "The NXT RR type bit map is one bit per RR type present for the owner > name similar to the WKS socket bit map. The first bit represents RR > type zero (an illegal type which should not be present.) A one bit > indicates that at least one RR of that type is present for the owner > name. A zero indicates that no such RR is present. All bits not > specified because they are beyond the end of the bit map are assumed > to be zero. Note that bit 30, for NXT, will always be on so the > minimum bit map length is actually four octets. The NXT bit map > should be printed as a list of type mnemonics or decimal numbers > similar to the WKS RR." Exact text above added and example line changed to the following: big.foo.bar. NXT medium.foo.bar. A, MX, SIG, NXT > I believe these changes are not of a type that would require delaying > forwarding the draft to the IESG. > > Donald > > > >From jis@mit.eduThu Aug 3 13:13:13 1995 > Date: Wed, 2 Aug 1995 21:44:31 -0400 > From: "Jeffrey I. Schiller" > To: dns-security@TIS.COM > Subject: Re: WG Last Call: draft-ietf-dnnsec-secext-04.txt > > I will re-iterate a comment I made in private in Stockholm. I would > strongly suggest that the signature computation be exactly compatible with > that performed by the RSAREF toolkit (not to mention other toolkits, PEM > and PGP which all conform to the PKCS standard for signatures). The current > documented version is only "close." > > -Jeff > > > >From BRUCE@umdd.umd.eduThu Aug 3 13:23:50 1995 > Date: Tue, 25 Jul 95 09:13:43 EDT > From: Bruce Crabill > To: DNS-SECURITY@TIS.COM > Subject: comments on NXT RR > > I've been reading draft-ietf-dnssec-secext-04.txt and have a few comments > about section 5, the section dealing with the NXT RR. I realize that the > NXT RR is realitively new (used to be the NXD RR but was renamed when the > bitmap was added), but the documentation for the RR needs to be made a bit > clearer. You don't really say what the bitmap is a bitmap of (you get the > impression that it is a bitmap of RR types (as in the WKS bitmap of > protocols), but this isn't clearly stated, nor is the structure of the > bitmap defined. The example on the bottom of page 27 implies that the > bitmap has a value of 130. I'm not sure how to interept this. If it is > decimal, then you are saying that it applies to DNS RR types 0 and 6. > ... > > ===================================================================== > Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com > 318 Acton Street +1 508-371-7148(fax) dee@world.std.com > Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA) > ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa17255; 13 Aug 95 9:52 EDT Received: from necom830.cc.titech.ac.jp(131.112.32.132) by relay.tis.com via smap (g3.0.1) id xma002889; Sun, 13 Aug 95 09:43:14 -0400 Received: by necom830.cc.titech.ac.jp (8.6.11/necom-mx-rg); Sun, 13 Aug 1995 22:47:47 +0859 From: Masataka Ohta Message-Id: <199508131348.WAA25745@necom830.cc.titech.ac.jp> Subject: Re: WG Last Call: draft-ietf-dnssec-secext-04.txt To: "Donald E. Eastlake 3rd" Date: Sun, 13 Aug 95 22:47:46 JST Cc: dns-security@TIS.COM In-Reply-To: ; from "Donald E. Eastlake 3rd" at Aug 11, 95 2:26 pm X-Mailer: ELM [version 2.3 PL11] > Since there have not been any particular objections, I have incorporated > the changes listed in my 3 August message with exact wording indicated > below interspersed with my original message. Why are you so much interested in revising your proposal which is proven to be broken to unnecessarily cause UDP packet size overflow? Masataka Ohta   Received: from relay.tis.com by neptune.TIS.COM id aa22870; 13 Aug 95 22:09 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma005112; Sun, 13 Aug 95 21:59:55 -0400 Received: by callandor.cybercash.com; id WAA03832; Sun, 13 Aug 1995 22:02:17 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma003830; Sun, 13 Aug 95 22:02:17 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA21607; Sun, 13 Aug 95 22:06:14 EDT Date: Sun, 13 Aug 1995 22:06:13 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: dns-security@TIS.COM Subject: Re: WG Last Call: draft-ietf-dnssec-secext-04.txt In-Reply-To: <199508131348.WAA25745@necom830.cc.titech.ac.jp> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Ohta-san, On Sun, 13 Aug 1995, Masataka Ohta wrote: > > Since there have not been any particular objections, I have incorporated > > the changes listed in my 3 August message with exact wording indicated > > below interspersed with my original message. > > Why are you so much interested in revising your proposal which > is proven to be broken to unnecessarily cause UDP packet size > overflow? I have suggest six very minor changes to the draft and I think the reasons for each should have been clear. In the initial batch of three, one was specifically requested by the Security Area Head so that DNS RSA signatures could be calculated by RSAREF, on was simply a clarification requested by a mailing list participant, and one was the reservation of an additional KEY RR bit because MOSS has gone to Proposed Standard. The second batch were all requested by the editor of the DNS Dyanmic Update Draft. On Wed, 2 Aug 1995, Masataka Ohta wrote: > [responding to a posting by Jim Galvin, DNSSEC WG Chair:] > > Speaking as chair of the DNS Security Working Group, I would like to > > announce a working group last call on the following document: > > > > draft-ietf-dnssec-secext-04.txt > > I don't think we are ready to proceed. I believe the consensus is that we are ready. > > This document will be submitted to the IESG on or after August 16 (3 > > weeks from now) for consideration as a Proposed Standard unless it is > > found to be technically flawed. > > Why didn't you have a meeting or two at Stockholm, if you want to have > an intense discussion? > > Yes, it is technically flawed. If you don't think so, give a full > implementation. If you believe the current proposal has flaws, that you can not persuade other of, but will be shown by implementation, you need only sit back and these will become aparent, will they not? > Moreover, E&K proposal is not compared to the alternative proposal of > mine, because, at the last meeting, you forced your wrong view that > the difference is merely on the number of RR types. If you beieve that you were not treated fairly at the last DNS SEC working group meeting, you have had ample time to post to the mailing list. I have seen very few postings from you and none addressing this point. > > Speak now (on technical flaws) or forever hold your peace. > > While your misjudgement was understandable at the time of > the last meeting, I really hope you not repeat it again. It seems to me that, very roughly, there are two possible levels of problem. One relates to such matters as efficiency, how many retrievals will overflow the UDP packet maximum, etc., but does not generally touch on correct operation of the protocol. It is clear that in this area you have your own opinions but they differ from the working group consensus. You have not persuaded the working group to your opinion and I do not think you will be able to do so at this point. There is also a second level of problem which would be a clear case where the protocol, as described, acted incorrectly. By this I do not mean, for example, the problems with securing CNAME RRs in old servers, becasue that problem is documented in the draft. I mean some case of incorrect operation that has not been considered or documented. If you know of a problem of this second type, it should be possible for you to describe an exact, clear, and complete exmaple which would produce such incorrect (not just "inefficient") results, and I would suggest that you do so. > Masataka Ohta Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa25392; 19 Aug 95 23:25 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma006386; Sat, 19 Aug 95 23:16:03 -0400 Received: by callandor.cybercash.com; id XAA28185; Sat, 19 Aug 1995 23:18:23 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma028180; Sat, 19 Aug 95 23:18:01 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA27047; Sat, 19 Aug 95 23:22:25 EDT Date: Sat, 19 Aug 1995 23:22:24 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: dns-security@TIS.COM Subject: Re: WG Last Call: draft-ietf-dnssec-secext-04.txt (fwd) Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Since there was no objection to the changes listed below, I have incorporated them. Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA) ---------- Forwarded message ---------- Date: Fri, 11 Aug 1995 14:26:07 -0400 (EDT) From: Donald E. Eastlake 3rd To: dns-security@TIS.COM Subject: Re: WG Last Call: draft-ietf-dnssec-secext-04.txt ... In addition, I would like to make the following minor clarifications in the next few days in connection with dynamic update. (1) Add an explicit statement that a SIG RR with an expiration date before the date signed is ineffective. (2) Add an explicit statement that SIG RRs should not have a date signed significantly in the future. and (3) Add an explicit statement that, to prevent misordering of network request to update a zone dynamically, monotonically increasing "time signed" dates are necessary. Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa06944; 23 Aug 95 8:29 EDT Received: from sun4nl.nl.net(193.78.240.1) by relay.tis.com via smap (g3.0.1) id xma017473; Wed, 23 Aug 95 08:19:49 -0400 Received: from baltzer.nl by sun4nl.NL.net with SMTP id AA16480 (5.65b/CWI-3.3); Wed, 23 Aug 1995 14:15:32 +0200 Date: Wed, 23 Aug 1995 14:15:32 +0200 Message-Id: <9508231215.AA16480@sun4nl.NL.net> X-Sender: Pbaltzer@sun4nl.nluug.nl Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: From: Baltzer Science Publishers Subject: WIRELESS NETWORKS - CONTENTS CONTENTS WIRELESS NETWORKS, ISSN 1022-0038, Co-published with the ACM (Association for Computing Machinery) The journal of mobile communication, computation and information Editor-in-Chief: I. Chlamtac, Department of Electrical and Computer Engineering, University of Massachusetts, Amherst MA 01003, USA Aims & Scope: The wireless communication revolution is bringing fundamental changes to communication and computing. From wide-area cellular systems to wireless LANs, mobile and wireless networks are on the verge of providing fully distributed and ubiquitous mobile computing and communications any time, anywhere.Through a seamless integration with fixed network infrastructures the future promises a universal communication grid, bringing an end to the tyranny of geography. A parallel evolution and proliferation of services for the mobile user are changing the scope of communication and the nature of user and machine interaction paradigms. Wireless Networks will serve as the publication vehicle for high-quality, in-depth original articles addressing networks, systems, algorithms, and applications that support the symbiosis of portable computers, wireless networks, mobile communication and computation, and their integration into the global network of the future. Regularly addressed topics will include: Network architectures for nomadic LAN to WAN communication and computation; mobile and wireless communications protocols, media access control algorithms, algorithms for mobility and mobility management including hand-off, registration, location, tracking, and routing; performance evaluation of mobile/wireless networks; systems topology design including cell architectures, capacity allocation and coverage issues, mobility, bandwidth, or intermittent connectivity related communication and computing issues; network management, control and signaling; security, scalability and reliability issues; database design and management for mobility; software principles, operating systems and resource management for nomadic computing; service integration and interworking of wired and wireless networks; applications, computing services and service algorithms in the mobile environment; enabling technologies for wireless and mobile communication including wireless signal propagation studies, portable hardware technologies, energy efficient and low-power design and components; network demonstrations, experimentation, and testbeds. Contents Volume 1, No. II pp. 129-138, J.P.M.G. Linnartz, On the performance of packet switched cellular networks for wireless data communication pp. 139-146, Z. Haas and S. Paul, Limited lifetime shared access in mobile systems pp. 147-160, I Rubin and S. Shambayati, Performance evaluation of a reservation random access scheme for packetized wireless systems with call control and hand-off loading pp. 161-174, K.Y. Eng, M.J. Karol, M. Veeraraghavan, E. Ayanoglu, C.B. Woodworth, and R.A. Valenzuela, A wireless broadband ad-hoc ATM local-area network pp. 175-186, A. Bar-Noy, I. Kessler and M. Sidi, Mobile users: To update or not to update? pp. 187-196, I. Akyildiz and J. S.M. Ho, Dynamic mobile user location update for wireless PCS networks pp. 197-210, R. Jain and Yi-Bing Lin, An auxiliary user location strategy employing forward pointers to reduce network impacts of PCS pp. 211-220, C. Rose and R. Yates, Minimizing the average cost of paging under delay constraints pp. 221-226, A. Farago, On the complexity of finding sparsest and densest parts in wireless networks pp. 227-239, M. Zorzi, Mobile radio slotted ALOHA with capture and diversity Submissions of articles and proposals for special issues are to be addressed to the Editor-in-Chief: I. Chlamtac Requests for FREE SPECIMEN copies and orders for Wireless Networks are to be sent to: E-mail: publish@baltzer.nl or see our homepage http://www.NL.net/~baltzer/ .   Received: from relay.tis.com by neptune.TIS.COM id aa13417; 24 Aug 95 13:57 EDT Received: from ietf.cnri.reston.va.us(132.151.1.35) by relay.tis.com via smap (g3.0.1) id xma010567; Thu, 24 Aug 95 13:47:26 -0400 Received: from [127.0.0.1] by IETF.CNRI.Reston.VA.US id aa15334; 24 Aug 95 13:46 EDT Mime-Version: 1.0 Content-Type: Multipart/Mixed; Boundary="NextPart" To: IETF-Announce: ;, tis.com@TIS.COM MMDF-Warning: Parse error in original version of preceding line at neptune.TIS.COM cc: dns-security@TIS.COM From: Internet-Drafts@cnri.reston.va.us Reply-to: Internet-Drafts@cnri.reston.va.us Subject: I-D ACTION:draft-ietf-dnssec-secext-05.txt Date: Thu, 24 Aug 95 13:46:57 -0400 Sender: cclark@cnri.reston.va.us Message-ID: <9508241346.aa15334@IETF.CNRI.Reston.VA.US> --NextPart A Revised Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the Domain Name System Security Working Group of the IETF. Title : Domain Name System Security Extensions Author(s) : D. Eastlake, C. Kaufman Filename : draft-ietf-dnssec-secext-05.txt Pages : 41 Date : 08/23/1995 The Domain Name System (DNS) has become a critical operational part of the Internet infrastructure yet it has no strong security mechanisms to assure data integrity or authentication. Extensions to the DNS are described that provide these services to security aware resolvers or applications through the use of cryptographic digital signatures. These digital signatures are included in secured zones as resource records. Security can still be provided even through non-security aware DNS servers in many cases. The extensions also provide for the storage of authenticated public keys in the DNS. This storage of keys can support general public key distribution service as well as DNS security. The stored keys enable security aware resolvers to learn the authenticating key of zones in addition to keys for which they are initially configured. Keys associated with DNS names can be retrieved to support other protocols. Provision is made for a variety of key types and algorithms. In addition, the security extensions provide for the optional authentication of DNS protocol transactions. Internet-Drafts are available by anonymous FTP. Login with the username "anonymous" and a password of your e-mail address. After logging in, type "cd internet-drafts" and then "get draft-ietf-dnssec-secext-05.txt". A URL for the Internet-Draft is: ftp://ds.internic.net/internet-drafts/draft-ietf-dnssec-secext-05.txt Internet-Drafts directories are located at: o Africa Address: ftp.is.co.za (196.4.160.8) o Europe Address: nic.nordu.net (192.36.148.17) Address: ftp.nis.garr.it (192.12.192.10) o Pacific Rim Address: munnari.oz.au (128.250.1.21) o US East Coast Address: ds.internic.net (198.49.45.10) o US West Coast Address: ftp.isi.edu (128.9.0.32) Internet-Drafts are also available by mail. Send a message to: mailserv@ds.internic.net. In the body type: "FILE /internet-drafts/draft-ietf-dnssec-secext-05.txt". NOTE: The mail server at ds.internic.net can return the document in MIME-encoded form by using the "mpack" utility. To use this feature, insert the command "ENCODING mime" before the "FILE" command. To decode the response(s), you will need "munpack" or a MIME-compliant mail reader. Different MIME-compliant mail readers exhibit different behavior, especially when dealing with "multipart" MIME messages (i.e., documents which have been split up into multiple messages), so check your local documentation on how to manipulate these messages. For questions, please mail to Internet-Drafts@cnri.reston.va.us. Below is the data which will enable a MIME compliant mail reader implementation to automatically retrieve the ASCII version of the Internet-Draft. --NextPart Content-Type: Multipart/Alternative; Boundary="OtherAccess" --OtherAccess Content-Type: Message/External-body; access-type="mail-server"; server="mailserv@ds.internic.net" Content-Type: text/plain Content-ID: <19950823133519.I-D@CNRI.Reston.VA.US> ENCODING mime FILE /internet-drafts/draft-ietf-dnssec-secext-05.txt --OtherAccess Content-Type: Message/External-body; name="draft-ietf-dnssec-secext-05.txt"; site="ds.internic.net"; access-type="anon-ftp"; directory="internet-drafts" Content-Type: text/plain Content-ID: <19950823133519.I-D@CNRI.Reston.VA.US> --OtherAccess-- --NextPart--   Received: from relay.tis.com by neptune.TIS.COM id aa08603; 25 Aug 95 13:59 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma026169; Fri, 25 Aug 95 13:49:23 -0400 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA20300; Fri, 25 Aug 95 13:57:58 EDT Message-Id: <9508251757.AA20300@tis.com> Reply-To: James M Galvin To: dns-security@TIS.COM Cc: Jeffrey I Schiller Subject: Re: WG Last Call: draft-ietf-dnssec-secext-04.txt In-Reply-To: "Donald E. Eastlake 3rd"'s message of Sat, 19 Aug 1995 23:22:24 EDT. Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <18936.809373492.1@tis.com> Date: Fri, 25 Aug 1995 13:58:17 -0400 From: James M Galvin The Last Call period officially ended last week and a new version of the document has been issued with the suggested changes. Since no technical problems have been found with the specification, I'm declaring the working group consensus to be to move the document forward. With this note I'm officially forwarding the document: draft-ietf-dnssec-secext-05.txt as a product of this working group to the Security Area Director to be considered for publication as a Proposed Standard. Jim   Received: from relay.tis.com by neptune.TIS.COM id aa11593; 25 Aug 95 16:32 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma028781; Fri, 25 Aug 95 16:22:21 -0400 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA06423; Fri, 25 Aug 95 16:30:56 EDT Message-Id: <9508252030.AA06423@tis.com> Reply-To: James M Galvin From: James M Galvin To: dns-security@TIS.COM Subject: ANNOUNCE: TIS/DNSSEC Version 1.1 alpha is now available Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <23285.809382675.1@tis.com> Date: Fri, 25 Aug 1995 16:31:16 -0400 Sender: galvin@TIS.COM Trusted Information Systems is pleased to announce the availability of a secure DNS: TIS/DNSSEC Version 1.1 alpha. It provides integrity and authentication services for DNS resource records using digital signature technology. It is being made available for alpha testing on the following basis. o TIS/DNSSEC is available via anonymous FTP in source code form. All modules have been written in the C programming language and it is known to run on many UNIX-derived operating systems. o This version of TIS/DNSSEC depends on a specialized version of TIS/MOSS, which is currently included in the distribution. The next version will depend exclusively on RSAREF. o This version of TIS/DNSSEC is not available outside the United States or Canada, nor can you give it to anyone who is not a U.S. or Canadian citizen and does not have a U.S. "green card." (These are U.S. State and Commerce Department requirements because of the use of TIS/MOSS. We hope to be able to remove this restriction in a future version.) This version of TIS/DNSSEC is an alpha implementation because it does not implement the entire specification. As soon as we complete the implementation it will be a beta distribution until the code stabilizes. TIS/DNSSEC is a product of Trusted Information Systems that may be used free of charge during the alpha test period. Instructions on how to retrieve TIS/DNSSEC Version 1.1 alpha may be found in the file "/pub/DNSSEC/README" on the host "ftp.tis.com" which may be retrieved via anonymous ftp. If you have any questions or comments please send email to "tisdnssec-support@tis.com".   Received: from relay.tis.com by neptune.TIS.COM id aa26562; 26 Aug 95 15:06 EDT Received: from big-screw.mit.edu(18.72.0.176) by relay.tis.com via smap (g3.0.1) id xma006296; Sat, 26 Aug 95 14:56:58 -0400 Received: by big-screw id AA28751; Sat, 26 Aug 95 15:06:51 -0400 X-Sender: jis@e40-po.mit.edu (Unverified) Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sat, 26 Aug 1995 15:07:02 -0400 To: James M Galvin From: "Jeffrey I. Schiller" Subject: Re: WG Last Call: draft-ietf-dnssec-secext-04.txt Cc: dns-security@TIS.COM, Jeffrey I Schiller At 13:58 8/25/95, James M Galvin wrote: >The Last Call period officially ended last week and a new version of the >document has been issued with the suggested changes. > >Since no technical problems have been found with the specification, I'm >declaring the working group consensus to be to move the document >forward. > >With this note I'm officially forwarding the document: > > draft-ietf-dnssec-secext-05.txt > >as a product of this working group to the Security Area Director to be >considered for publication as a Proposed Standard. OK. I'll review it and get back to you (which shouldn't take too long as I have already read through it once). -Jeff   Received: from relay.tis.com by neptune.TIS.COM id aa12901; 27 Aug 95 17:26 EDT Received: from watson.ibm.com(129.34.139.4) by relay.tis.com via smap (g3.0.1) id xma012100; Sun, 27 Aug 95 17:17:04 -0400 Received: from WATSON by watson.ibm.com (IBM VM SMTP V2R3) with BSMTP id 1199; Sun, 27 Aug 95 17:27:02 EDT Received: from YKTVMV by watson.vnet.ibm.com with "VAGENT.V1.02 on VAGENT2" id 5395; Sun, 27 Aug 1995 17:27:02 EDT Received: from gimili.watson.ibm.com by yktvmv.watson.ibm.com (IBM VM SMTP V2Rx) with TCP; Sun, 27 Aug 95 17:27:02 EDT Received: by gimili.watson.ibm.com (AIX 3.2/UCB 5.64/930311) id AA36586; Sun, 27 Aug 1995 17:26:42 -0400 Date: Sun, 27 Aug 1995 17:26:42 -0400 From: "S.Kutten" Message-Id: <9508272126.AA36586@gimili.watson.ibm.com> To: dns-security@TIS.COM Subject: Call for papers: special issue on security and mobility Call for Papers For the new journal published in cooperation with the ACM: WIRELESS NETWORKS Special Issue: Mobility and Security Scope: Mobility introduces a new dimension to the problem of secure computing and communication. The securing becomes harder and often more important. This is sometimes due to the mobility of the communication devices, sometimes due to the mobility of users (without mobile device), or the mobility of objects, or that of the attackers. Papers are sought that address the requirements, designs, algorithms and implementation experience for securing networks, distributed systems, information, and applications in environments that can support mobility. Possible topics include, but are not limited to: Securing communication and distributed systems, such as: - Internet (TCP/IP, mobile IP, DNS, DHCP) - ATM - CDPD - GSM - SNA - Wireless LAN Cryptographic protocols, such as: - key distribution - authentication - payments - anonymity and privacy Cryptographic functions, such as: - encryption - message authentication - message digest - signatures Computer viruses and worms Security for intelligent and mobile objects and agents Secure electronic commerce Cryptographic hardware Security and cryptography for wireless communication systems. The authors should send 6 copies of their paper to one of the guest editors by November 15, 1995. The following time-table shall be followed: Manuscript Submission Deadline: November 15, 1995 Acceptance Notification: May 15, 1996 Final Manuscript Submission Deadline: July 15, 1996 Expected Publication Date: Last Quarter 1996 E-mail submissions are encouraged (post-script only). Set subject to `Submission to WINET special issue'. Guest Editors: Amir Herzberg IBM T.J. Watson Research Center P.O. Box 704 #H3-D18 Yorktown Heights, NY 10598 Telephone: (914) 784-6981 Facsimile: (914) 784-6205 Internet: amir@watson.ibm.com Shay Kutten IBM T.J. Watson Research Center P.O. Box 704 #H3-D38 Yorktown Heights, NY 10598 Telephone: (914) 784-7346 Facsimile: (914) 784-6205 Internet: kutten@watson.ibm.com   Received: from relay.tis.com by neptune.TIS.COM id aa08897; 11 Sep 95 10:25 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma026865; Mon, 11 Sep 95 10:14:07 -0400 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA26161; Mon, 11 Sep 95 10:24:01 EDT Message-Id: <9509111424.AA26161@tis.com> Reply-To: James M Galvin To: dns-security@TIS.COM Subject: ANNOUNCEMENT: TIS/DNSSEC Version 1.2 alpha Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <13577.810829467.1@tis.com> Date: Mon, 11 Sep 1995 10:24:28 -0400 From: James M Galvin A new version of TIS/DNSSEC is now available. This version is distinguished from the previous version as follows. in sync with bind Beta26 uses RSAREF For information on how to acquire TIS/DNSSEC retrieve the file /pub/DNSSEC/README on the host ftp.tis.com via anonymous FTP. If you have any questions or problems please send a note to tisdnssec-support@tis.com. Enjoy, Jim   Received: from relay.tis.com by neptune.TIS.COM id aa21608; 20 Sep 95 18:49 EDT Received: from ns.novell.com(137.65.1.1) by relay.tis.com via smap (g3.0.1) id xma018222; Wed, 20 Sep 95 18:35:00 -0400 Received: from na.SJF.Novell.COM ([130.57.6.3]) by ns.Novell.COM (4.1/SMI-4.1) id AA09207; Wed, 20 Sep 95 16:46:39 MDT Received: by na.SJF.Novell.COM (4.1/SMI-4.1) id AA03331; Wed, 20 Sep 95 15:43:52 PDT From: Alex Alten Message-Id: <9509202243.AA03331@na.SJF.Novell.COM> Subject: comments on secure DNS spec To: dee@cybercash.com, charlie_kaufman@iris.com Date: Wed, 20 Sep 1995 15:43:51 -0700 (PDT) Cc: dns-security@TIS.COM X-Mailer: ELM [version 2.4 PL22] Content-Type: text Content-Length: 4399 Hello Charles and Donald, I have some comments about the latest secure DNS draft dated Aug. 16. Overall I think the paper is good. It does a clean job of fitting a secure framework over the existing DNS infrastructure. 1. On page 15 the MD5/RSA algorithm is specified as 1. I'd recommend that MD5 not be explicitly specified. The algorithm octet should only specify an (asymmetric) encryption algorithm. For example specify the following on page 21: hash = MD5 ( data ) signature ( 01 | FF* | 00 | prefix | implicit tag | hash ) ** e (mod n) Where 'implicit tag' = A0 10 for MD5 A1 14 for SHA1 The first byte the hex 'A' means an ASN.1 Context specific Class i.e. this document, Constructed constructor i.e. a non-atomic data type (similer a C struct definition). The '0' or '1' are the tag numbers for each hash type. The 2nd byte is simply the number of bytes that will follow it. The ASN.1 grammar notation is as follows: HashMd5 ::= [0] IMPLICIT OCTET STRING (SIZE (16)) HashSha ::= [1] IMPLICIT OCTET STRING (SIZE (20)) The reason I recommend this is for two reasons: A. To allow other protocols to interoperate with this specification. A proposed draft for secure SNMP uses this to specify MD5 and SHA1 hashes. I would like to see secure Telnet and FTP adhere to this as well. This is more a coordination issue among the major Internet protocols, since they may be using secure DNS as a key management server. B. To allow more than one hash to be used. If improved hashes are designed or needed this allows a simple mechanism to upgrade hashes without modifying the algorithm number. 2. Why not use ElGamal instead of RSA for keys and signatures? This is a practical issue. Why not specify ElGamal instead of RSA? the RSA patent has 5 more years before it expires. ElGamal is unpatented and its underlying patent, Diffie-Hellman, expires in 1.5 years. I believe ElGamal is just as strong as RSA and has undergone over a decade of cryptanalysis. It is being used as the foundation of the US Digital Signature Standard. 3. Why not double encrypt the hash during DNS transactions? (pages 10, 22) This requires that a security aware resolver has a public/private key. Basically the resolver generates a SIG by hashing its request, then encrypting it with its own private key, and finally encrypting it with the DNS server's public key. When the server responds it encrypts its SIG hash with its own private key and then with the resolver's public key. The resolver's public key does not have to be stored on the DNS server, it could be sent as part of the request (KEY). Doing this would reduce the possibility of an intermediate gateway from replaying the response to multiple resolvers. Also it prevents the resolver's request from getting modified without detection. 4. Why not securely encapsulate the DNS packet? (pages 10, 22) Why not fully encapsulate the DNS packet, by using an authentication header and having the DNS packet as the data payload. This would simplify authentication machinery. A nice side benefit is that existing DNS servers could be retrofited without rewriting code. You have to fool them into thinking they are receiving the old DNS packet, when in fact the encapsulation machinery first receives, then verifies the authentication header, then strips the header off and finally passes the rest into the old DNS protocol machinery. The old DNS parotocol machinery never has to be recompiled, relinked, etc. The double encryption of the hash from #3 could be used here as well. 4. Why not use a larger key footprint? (page 20) I noticed that you use a "key footprint" of 16 bits. Other protocols that I seen typically use more bits. For example 64 bits (8 bytes). Would this larger size make more sense since DNS is distributed world-wide and there could eventually be millions of keys (assuming it will also be a key management server). Sincerely, - Alex -- Alexander I. Alten Alten@Na.Sjf.Novell.Com (408) 577-8224 Novell, Inc. Member of Technical Staff Mail Stop F1-42-D2 2180 Fortune Drive San Jose, CA 95131 USA   Received: from relay.tis.com by neptune.TIS.COM id aa23675; 20 Sep 95 22:00 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma020172; Wed, 20 Sep 95 21:46:06 -0400 Received: by callandor.cybercash.com; id VAA15057; Wed, 20 Sep 1995 21:51:49 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma015048; Wed, 20 Sep 95 21:51:27 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA12101; Wed, 20 Sep 95 22:00:19 EDT Date: Wed, 20 Sep 1995 22:00:17 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: Alex Alten Cc: charlie_kaufman@iris.com, "Donald E. Eastlake" , dns-security@TIS.COM Subject: Re: comments on secure DNS spec In-Reply-To: <9509202243.AA03331@na.SJF.Novell.COM> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Wed, 20 Sep 1995, Alex Alten wrote: > Hello Charles and Donald, > I have some comments about the latest secure DNS draft dated Aug. 16. > Overall I think the paper is good. It does a clean job of fitting > a secure framework over the existing DNS infrastructure. > 1. On page 15 the MD5/RSA algorithm is specified as 1. I'd > recommend that MD5 not be explicitly specified. The algorithm > octet should only specify an (asymmetric) encryption algorithm. > > For example specify the following on page 21: > > hash = MD5 ( data ) > > signature ( 01 | FF* | 00 | prefix | implicit tag | hash ) ** e (mod n) > > Where 'implicit tag' = A0 10 for MD5 > A1 14 for SHA1 > > The first byte the hex 'A' means an ASN.1 Context specific Class i.e. > this document, Constructed constructor i.e. a non-atomic data type > (similer a C struct definition). The '0' or '1' are the tag numbers > for each hash type. The 2nd byte is simply the number of bytes that > will follow it. > > The ASN.1 grammar notation is as follows: > > HashMd5 ::= [0] IMPLICIT OCTET STRING (SIZE (16)) > HashSha ::= [1] IMPLICIT OCTET STRING (SIZE (20)) Your idea seems pretty simiple. I don't know why you clutter it up with all this ASN.1 cruft. In fact, your material above is yet another good example of how ASN.1 makes something very simple much harder to understand and a little more complex to implement. *If* we put this in, I would like just a one byte hash selector field. > The reason I recommend this is for two reasons: > > A. To allow other protocols to interoperate with this specification. > A proposed draft for secure SNMP uses this to specify MD5 and SHA1 > hashes. I would like to see secure Telnet and FTP adhere to this > as well. This is more a coordination issue among the major Internet > protocols, since they may be using secure DNS as a key management > server. SNMP long ago made the error of using ASN.1, something regretted by many of those involved. We don't need to duplicate that error. I think secure Telnet and FTP and the plethora of other point to point security protocols in the Internet should go away and be replaced by IPSEC. If the decision were up to me, I'd seriously consider an embargo on any "improvements" to these other point-to-point protocols to encourage development and deployment of IPSEC. (These comments do not apply to store-and-forward security such as DNS and email.) > B. To allow more than one hash to be used. If improved hashes > are designed or needed this allows a simple mechanism to > upgrade hashes without modifying the algorithm number. I don't see how this additional complexity of two numbers to specify the full algorithm makes things simpler. True, it allows easier combinations of different algorithms and hashes. But we are talking about the DNS here, a fundamental global naming system of the Internet, not just some point-to-point Telnet connections or something. If people switch to secure DNS in significant numbers, and some people wanted to add SHA as an alternative hash algorithm, I think it should take a standards action and, unless it is an emergency, a *lot* of advance notice. MD5 is the Internet standard for now. I'm included to leave things as they are and see how it goes. This change seems to invite the proliferation of non-interoperable options. It could always be added later. > 2. Why not use ElGamal instead of RSA for keys and signatures? > > This is a practical issue. Why not specify ElGamal instead of RSA? > the RSA patent has 5 more years before it expires. ElGamal is > unpatented and its underlying patent, Diffie-Hellman, expires in > 1.5 years. I believe ElGamal is just as strong as RSA and has > undergone over a decade of cryptanalysis. It is being used as the > foundation of the US Digital Signature Standard. Some of your points are good but RSA is the standard for use in the Internet now. Defining additional key types, such a ElGamal and Diffie-Hellman is reasonable for storage in the DNS but a variety of SIGs in DNS raises interoperability questions unless everyone implements every algorithm. > 3. Why not double encrypt the hash during DNS transactions? (pages 10, 22) > > This requires that a security aware resolver has a public/private key. > Basically the resolver generates a SIG by hashing its request, then > encrypting it with its own private key, and finally encrypting it > with the DNS server's public key. When the server responds it > encrypts its SIG hash with its own private key and then with the > resolver's public key. The resolver's public key does not have to > be stored on the DNS server, it could be sent as part of the > request (KEY). Doing this would reduce the possibility of an > intermediate gateway from replaying the response to multiple > resolvers. Also it prevents the resolver's request from getting > modified without detection. You are talking one hell of a lot of expensive public key operations at a busy DNS server for no gain that I can see. An intermediate gateway (like a caching server?) replaying the response to multiple servers sounds like a good thing if it's data that the servers want. If it's not, then it's not much different from other denial of service attacks. It would take a lot less work for many DNS servers to just answer a tampered with request rather than figure out its bad. And if the optional transaction security is in use, the requester knows if the query was tampered with anyway, if they can't tell from the data in the response. A fundamental WG assumption is that DNS queries and data are public. Why bother signing the query when you can tell if it got through by just checking the sig on the response if transaction security is being used? If you want a secure private pipe to your DNS server, use IPSEC. > 4. Why not securely encapsulate the DNS packet? (pages 10, 22) > > Why not fully encapsulate the DNS packet, by using an authentication > header and having the DNS packet as the data payload. This would > simplify authentication machinery. A nice side benefit is that > existing DNS servers could be retrofited without rewriting code. > You have to fool them into thinking they are receiving the old DNS > packet, when in fact the encapsulation machinery first receives, > then verifies the authentication header, then strips the header off > and finally passes the rest into the old DNS protocol machinery. > The old DNS parotocol machinery never has to be recompiled, relinked, > etc. The double encryption of the hash from #3 could be used here > as well. Now that IPSEC is a Proposed Standard, I think the last think people need is yet another point to point transport level security protocol. There is never a need to authenticate the source of an DNS request since a fundamental WG assumption is that DNS gives the same answer to everyone so it does not matter where a request came from. I don't see that it is of much use securing a DNS response unless it's to an insecure resolver from a secure DNS server. Just putting authentication on all or any large subset of the DNS point to point transmissions would have approximately no effect on DNS security. If might help for some small network if you maintained host access control lists and only ran DNS components on trusted machines, which seems pretty unrealistic and uninteresting to me. The transaction security optionally provided in dnssec seems to answer the need of a stub resolver for secure communications with a secure recursive resolver. It was an interim measure pending IPSEC and should be re-evaluated when IPSEC is significantly deployed. It may still be a saving since it secures two packets with one sig. > 4. Why not use a larger key footprint? (page 20) > > I noticed that you use a "key footprint" of 16 bits. Other protocols > that I seen typically use more bits. For example 64 bits (8 bytes). > Would this larger size make more sense since DNS is distributed > world-wide and there could eventually be millions of keys (assuming > it will also be a key management server). The key footprint is used only to help pick between and to provide a really trivial insecure first level validity check on the keys associated with a particular DNS name. I doubt there will be millions of keys assoicated with any single DNS name. > Sincerely, > > - Alex > > -- > > Alexander I. Alten > Alten@Na.Sjf.Novell.Com > (408) 577-8224 > > Novell, Inc. > Member of Technical Staff > Mail Stop F1-42-D2 > 2180 Fortune Drive > San Jose, CA 95131 > USA Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa12897; 21 Sep 95 18:35 EDT Received: from ns.novell.com(137.65.1.1) by relay.tis.com via smap (g3.0.1) id xma005307; Thu, 21 Sep 95 18:20:38 -0400 Received: from na.SJF.Novell.COM ([130.57.6.3]) by ns.Novell.COM (4.1/SMI-4.1) id AA15904; Thu, 21 Sep 95 16:37:27 MDT Received: by na.SJF.Novell.COM (4.1/SMI-4.1) id AA09178; Thu, 21 Sep 95 15:35:34 PDT From: Alex Alten Message-Id: <9509212235.AA09178@na.SJF.Novell.COM> Subject: Re: comments on secure DNS spec To: "Donald E. Eastlake 3rd" Date: Thu, 21 Sep 1995 15:35:33 -0700 (PDT) Cc: alten@novell.com, charlie_kaufman@iris.com, dee@cybercash.com, dns-security@TIS.COM In-Reply-To: from "Donald E. Eastlake 3rd" at Sep 20, 95 10:00:17 pm X-Mailer: ELM [version 2.4 PL22] Content-Type: text Content-Length: 4417 Don, Thanks for replying so promptly. I agree with most of your answers. >> hash = MD5 ( data ) >> >> signature ( 01 | FF* | 00 | prefix | implicit tag | hash ) ** e (mod n) >> >> Where 'implicit tag' = A0 10 for MD5 >> A1 14 for SHA1 >> >> The first byte the hex 'A' means an ASN.1 Context specific Class i.e. >> this document, Constructed constructor i.e. a non-atomic data type >> (similer a C struct definition). The '0' or '1' are the tag numbers >> for each hash type. The 2nd byte is simply the number of bytes that >> will follow it. >> >> The ASN.1 grammar notation is as follows: >> >> HashMd5 ::= [0] IMPLICIT OCTET STRING (SIZE (16)) >> HashSha ::= [1] IMPLICIT OCTET STRING (SIZE (20)) > >Your idea seems pretty simiple. I don't know why you clutter it up >with all this ASN.1 cruft. In fact, your material above is yet >another good example of how ASN.1 makes something very simple much >harder to understand and a little more complex to implement. > >*If* we put this in, I would like just a one byte hash selector field. > Good point. I'm so used to ASN.1 from my work with SNMP that I usually don't think twice about it. Speaking of ASN.1 I noticed in your document that you do have an ASN.1 construct called the "prefix" (p 21). It is as follows: prefix = hex 3020300c06082a864886f70d020505000410 signature = ( 01 | FF* | 00 | prefix | hash ) ** e (mod n) Why are you bothering with this "cruft"? Why not just pad out the hash with random numbers? Or at least pseudo-random numbers if the secure DNS server can't generate true random numbers. Wouldn't this strengthen the resulting signature? When we decrypt the signature we already know that the hash is in the last 16 bytes of the buffer. Or if you use the hash selector byte then place it and the hash in the front and pad with random bytes to the end of the buffer. >I think secure Telnet and FTP and the plethora of other point to point >security protocols in the Internet should go away and be replaced by >IPSEC. If the decision were up to me, I'd seriously consider an >embargo on any "improvements" to these other point-to-point protocols >to encourage development and deployment of IPSEC. (These comments do >not apply to store-and-forward security such as DNS and email.) > I'm afraid that I must disagree with you about Telnet and FTP. These protocols depend on user authentication. IP level authentication is not enough to distinguish between users on a multi-user system. Some protocols like SNMP are also used over other non-Internet protocols, such as Appletalk and IPX. From an overall design perspective I doubt IPSEC will be able to adequately deal with the security needs of all higher level protocols. I'm finding out that each one has its individual needs which cannot always be covered by a "one size fits all" solution. >> 2. Why not use ElGamal instead of RSA for keys and signatures? >> >> This is a practical issue. Why not specify ElGamal instead of RSA? >> the RSA patent has 5 more years before it expires. ElGamal is >> unpatented and its underlying patent, Diffie-Hellman, expires in >> 1.5 years. I believe ElGamal is just as strong as RSA and has >> undergone over a decade of cryptanalysis. It is being used as the >> foundation of the US Digital Signature Standard. > >Some of your points are good but RSA is the standard for use in the >Internet now. Defining additional key types, such a ElGamal and >Diffie-Hellman is reasonable for storage in the DNS but a variety of >SIGs in DNS raises interoperability questions unless everyone >implements every algorithm. Unless I missed it, RSA has not been specified as a proposed standard RFC. RSA has a major drawback, its licensing costs. This is not a trivial point, many people will object to this. I'm asking you and the WG to seriously consider using ElGamal instead of RSA for signatures because we will avoid many years of licensing costs. I sincerely believe that this will enhance the acceptance of secure DNS in the Internet community by removing a financial constraint during the first half decade of its deployment. - Alex -- Alexander I. Alten Alten@Na.Sjf.Novell.Com (408) 577-8224 Novell, Inc. Member of Technical Staff Mail Stop F1-42-D2 2180 Fortune Drive San Jose, CA 95131 USA   Received: from relay.tis.com by neptune.TIS.COM id aa22506; 22 Sep 95 7:17 EDT Received: from ctrvx1.vanderbilt.edu(129.59.1.21) by relay.tis.com via smap (g3.0.1) id xma011300; Fri, 22 Sep 95 07:02:03 -0400 Received: from ctrvax.Vanderbilt.Edu by ctrvax.Vanderbilt.Edu (PMDF V5.0-5 #11488) id <01HVKB8537OG8WVYQ9@ctrvax.Vanderbilt.Edu> for listys@ctrvax.Vanderbilt.Edu; Fri, 22 Sep 1995 04:44:43 -0500 (CDT) Date: Fri, 22 Sep 1995 04:44:43 -0500 (CDT) From: BEZALEL GAVISH Subject: CFP 4th International Conference on Telecommunication Systems To: listys: ;, tis.com@ctrvax.vanderbilt.edu MMDF-Warning: Parse error in original version of preceding line at neptune.TIS.COM Message-id: <01HVKB853HBM8WVYQ9@ctrvax.Vanderbilt.Edu> X-VMS-To: IN%"listys" X-VMS-Cc: GAVISHB MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Content-transfer-encoding: 7BIT TSMCFP96 Below you will find a copy of the call for papers for the 4th international conference on telecommunication systems which will be held March 21-24, 1996 in Nashville, TN. If you appear on multiple mailing lists or exploders, you might receive multiple copies of this message. I hope it does not cause you too much trouble, you have my apologies for it. ********************************************************************* C A L L for P A P E R S 4th International Conference on Telecommunication Systems Modelling and Analysis March 21-24, 1996 Nashville, TN Sponsored by: Bell South Telecommunications INFORMS Technical Section on Telecommunications INFORMS College of Information Systems Owen Graduate School of Management The 4th International Conference on Telecommunication Systems - Modelling and Analysis will be held in Nashville, Tennessee on March 21-24, 1996. The conference location will be the Bell South Tower in downtown Nashville. The conference will build on the tradition of the earlier conferences with a few changes in format due to the new conference location. The general idea is to limit the number of participants, concentrate on a few topics, present new problems and problem areas, encouraging informal interaction and exchanges of ideas. The objective is to advance the state of the modelling and analysis in telecommunications by stimulating research activity on new and important problems. The conference will be divided into segments with each segment devoted to a specific topic. This will allow for little conflict between segments. All papers will be screened by the program committee to ensure the quality of presentations. A decentralized paper handling process will be used, the Program Committee has been divided along geographical areas with a separate Program Subcommittee assigned to each area. Abstracts and papers should be submitted directly to Program Committee Chair of the appropriate area. It is expected that this will expedite the paper review process. In response to suggestions made by last year's participants, social and cultural activities will be included in the 1996 agenda. Lead Speakers and Keynote speakers include: Leonard Kleinrock, "Nomadic Computing and its Implications for Network Support" Alan Konheim, "A Monitor for Controlling Peak and Average ATM Input Traffic" Bezalel Gavish, "Low Earth Orbit Satellite Based Communication Systems - Research Issues" The Chairmen of the geographic Program Committees are: ---Australia, New Zealand and South East Asia: Prof. Richard Harris Department of Communication and Electronic Engineering Royal Melbourne Institute of Technology GPO Box 2476V Tel: 61 3660 2457 Melbourne, 3001 FAX: 61 3660 1060 Australia Email: richard@catt.citri.edu.au ---Europe: Prof. Guy Pujolle Laboratoire PRiSM Universite de Versailles - Saint-Quentin 45, avenue des Etats-Unis Tel: 33 1 39 25 40 61 78 035 Versailles Cedex FAX: 33 1 39 25 40 57 France Email: guy.pujolle@prism.uvsq.fr ---North America: Prof. Andre Girard INRS-Telecommunications 16, place du Commerce Tel: 514-765-7832 Verdun, Quebec FAX: 514-765-8785 Canada H3E 1H6 Email: andre@inrs-telecom.uquebec.ca ---North East Asia: Prof. Yutaka Takahashi Department of Applied Mathematics and Physics Faculty of Engineering Kyoto University Tel: 81 757535493 Yoshida-Honmachi, Sakyo-ku, Kyoto 606 FAX: Japan Email: yutaka@kuamp.kyoto-u.ac.jp ---South and Central America: Dr. Ernesto Santibanez-Gonzalez School of Industrial Engineering Catholic University of Valparaiso Tel: 56 32 257331 Av. Brasil 2147 FAX: 56 32 214823 Chile Email: esantiba@aix1.ucv.cl and Prof. Henrique Pacca L. Luna Department of Computer Science Federal University of Minas Gerais Tel: 31270-901 Belo Horizonte - MG FAX: Brazil Email: pacca@dcc.ufmg.br ---Chairman of the Economics track: Prof. Jeffrey Mackie-Mason Department of Economics Tel: 313-764-7438 University of Michigan FAX: 313-763-9181 Ann Arbor, MI 48109-1220 Email: jmm@umich.edu and Prof. William W. Sharkey ---All other geographic areas: Prof. Bezalel Gavish Owen Graduate School of Management Vanderbilt University Tel: 615-322-3659 401 21st Avenue South FAX: 615-343-7177 Nashville, TN 37203 Email: gavishb@ctrvax.vanderbilt.edu Listed below are some of the potential segments: -- Configuration of ATM networks -- Internet and its impact on commerce -- Topological Design and Network Configuration Problems -- Design and Analysis of Local Access Networks and Outside Plant Problems -- Low Earth Orbit Satellite communication systems -- Cellular Systems and PCS Modelling and Configuration -- Time Dependent Expansion of Telecommunication Systems -- Designing Networks for Reliability and Availability -- Network Design Problems in Gigabit and Terabit Networks -- LAN, WAN Global Network Interconnection -- ATM, ISDN, BISDN Modeling and Analysis Issues -- Artificial Intelligence/Heuristics in Telecommunication Systems -- Quantitative Methods in Network Management -- Pricing and Economic Analysis of Telecommunications -- Impact of Telecommunications on Industrial Organization -- Performance Evaluation of Telecommunication Systems -- Distributed Computing and Distributed Data Bases -- Security and Privacy issues in Telecommunications -- Virtual reality, Multimedia and their impact The Program Committee is open to any ideas you might have regarding additional topics or format of the conference. The intention is to limit the number of parallel sessions to two. The conference is scheduled over a weekend so as to reduce teaching conflicts for academic participants, take advantage of weekend hotel and airfare rates and of the many events that take place in the downtown area. Due to the limit on the number of participants early registration is recommended. To ensure your participation, please use the following steps: 1. Send to the appropriate Program Committee Chair by October 1, 1995, a paper (preferable), or titles and abstracts for potential presentations to be considered for the conference. Sending more than one abstract is encouraged, enabling the Program Committee to have a wider choice in terms of assigning talks to segments. Use E-mail to expedite the submission of titles and abstracts. 2. Use the form at the end of this message to preregister for the conference. Let us also know if you would like to have a formal duty during the conference as: Session Chair, or Discussant. 3. You will be notified by December 1, 1995, which abstract/s has been selected for the conference. Detailed instructions on how to prepare camera ready copies will be sent to authors of accepted presentations. January 30, 1996, is the deadline for sending a final version of the paper. Participants will receive copies of the collection of papers to be presented. All papers submitted to the conference will be considered for publication in the "Telecommunication Systems" Journal. The Program Committee looks forward to receiving your feedback/ideas. Feel free to volunteer any help you can offer. If you have suggestions for Segment Leaders (i.e., individuals who will have a longer time to give an overview/state of the art talk on their segment subject) please E-mail them to Prof Gavish. Also, if there are individuals whose participation you view as important, please send their names and E-mail addresses to the Program Committee Chairman, or forward to them a copy of this message. I look forward to a very successful conference. Sincerely yours, Bezalel Gavish ------------------------------------------------------------------------------- Cut Here ------------------------------------------------------------------------------- Fourth International Conference on Telecommunication Systems Modelling and Analysis REGISTRATION FORM Date: __________________ Location: Nashville, TN Dates: March 21, 1996 (afternoon) to March 24, 1996 Name: ________________________________________ Title: __________________ Affiliation: __________________________________________________________________ Address: __________________________________________________________________ __________________________________________________________________ Phone: ____________________________ FAX: _______________________________ E-mail: __________________________________________________________________ Potential Title of Paper(s): __________________________________________________ ____________________________________________________________________ I would like to Volunteer as Comments A Session Chair : Yes No ________________________________________________ A Discussant : Yes No ________________________________________________ Organize a Session: Yes No ________________________________________________ ________________________________________________ REGISTRATION RATES and DEADLINES Last Applicable Participant Type Date Academic Industry ---------------- -------- -------- 1. Preregistration Until Dec. 1, 1996 $ 350 $ 450 2. Registration Until Feb. 1, 1996 $ 400 $ 500 3. Registration After Feb. 1, 1996 $ 450 $ 650 Mail your registration form and check to: Mrs. Dru Lundeng Owen Graduate School of Management Vanderbilt University 401 21st Avenue, South Nashville, TN 37203, USA The check should be addressed to: 4th Int'l. Telecomm Systems Conference Refund Policy: Half refund, for requests received by February 1, 1996. No refund after February 1, 1996. If you have any questions regarding the conference, please contact Dru Lundeng at 615-322-3694 or through E-mail at lundeng@ctrvax.vanderbilt.edu. ------------------------------------------------------------------------------- Bezalel Gavish Owen Graduate School of Management Vanderbilt University Nashville, TN, 37203 Bitnet: GAVISHB@VUCTRVAX Internet: GAVISHB@CTRVAX.VANDERBILT.EDU Tel: (615) 322-3659 Home: (615) 370-0813 FAX: (615) 343-7177 -------------------------------------------------------------------------------   Received: from relay.tis.com by neptune.TIS.COM id aa24595; 22 Sep 95 9:14 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma012498; Fri, 22 Sep 95 08:58:58 -0400 Received: by callandor.cybercash.com; id JAA28410; Fri, 22 Sep 1995 09:05:25 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma028407; Fri, 22 Sep 95 09:05:07 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA26602; Fri, 22 Sep 95 09:14:03 EDT Date: Fri, 22 Sep 1995 09:14:03 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: Alex Alten Cc: charlie_kaufman@iris.com, "Donald E. Eastlake" , dns-security@TIS.COM Subject: Re: comments on secure DNS spec In-Reply-To: <9509212235.AA09178@na.SJF.Novell.COM> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Thu, 21 Sep 1995, Alex Alten wrote: > Don, > > Thanks for replying so promptly. I agree with most of your answers. > > >> hash = MD5 ( data ) > >> > >> signature ( 01 | FF* | 00 | prefix | implicit tag | hash ) ** e (mod n) > >> > >> Where 'implicit tag' = A0 10 for MD5 > >> A1 14 for SHA1 > >> > >> The first byte the hex 'A' means an ASN.1 Context specific Class i.e. > >> this document, Constructed constructor i.e. a non-atomic data type > >> (similer a C struct definition). The '0' or '1' are the tag numbers > >> for each hash type. The 2nd byte is simply the number of bytes that > >> will follow it. > >> > >> The ASN.1 grammar notation is as follows: > >> > >> HashMd5 ::= [0] IMPLICIT OCTET STRING (SIZE (16)) > >> HashSha ::= [1] IMPLICIT OCTET STRING (SIZE (20)) > > > >Your idea seems pretty simiple. I don't know why you clutter it up > >with all this ASN.1 cruft. In fact, your material above is yet > >another good example of how ASN.1 makes something very simple much > >harder to understand and a little more complex to implement. > > > >*If* we put this in, I would like just a one byte hash selector field. > > Good point. I'm so used to ASN.1 from my work with SNMP that I usually > don't think twice about it. > > Speaking of ASN.1 I noticed in your document that you do have an ASN.1 > construct called the "prefix" (p 21). It is as follows: > > prefix = hex 3020300c06082a864886f70d020505000410 > > signature = ( 01 | FF* | 00 | prefix | hash ) ** e (mod n) > > Why are you bothering with this "cruft"? Why not just pad out the hash > with random numbers? Or at least pseudo-random numbers if the secure > DNS server can't generate true random numbers. Wouldn't this strengthen > the resulting signature? When we decrypt the signature we already know > that the hash is in the last 16 bytes of the buffer. Or if you use the > hash selector byte then place it and the hash in the front and pad with > random bytes to the end of the buffer. We are bothering with this silly cruft for exactly one reason: it is required to implement on top of RSAREF, the royalty free reference implementation that you have to use in the USA for non-commercial use to avoid either infringing or paying a license fee. We were requested to make this change by the IETF Security Area Head. As for the FF*, this is a signature, not encyption. Producing random numbers is an effort that buys you nothing in this case. You have the public key so you are supposed to be able to decyrpt the sig. It is a benefit, not a bug, if two sigs by the same authenticator over the same data to be authentiated are identical. The situation is entirely different if you are encyrpting in which case I agree fully that you need random padding. > >I think secure Telnet and FTP and the plethora of other point to point > >security protocols in the Internet should go away and be replaced by > >IPSEC. If the decision were up to me, I'd seriously consider an > >embargo on any "improvements" to these other point-to-point protocols > >to encourage development and deployment of IPSEC. (These comments do > >not apply to store-and-forward security such as DNS and email.) > > I'm afraid that I must disagree with you about Telnet and FTP. These > protocols depend on user authentication. IP level authentication is > not enough to distinguish between users on a multi-user system. Some > protocols like SNMP are also used over other non-Internet protocols, > such as Appletalk and IPX. From an overall design perspective I doubt > IPSEC will be able to adequately deal with the security needs of all > higher level protocols. I'm finding out that each one has its individual > needs which cannot always be covered by a "one size fits all" solution. This is not the place to discuss IPSEC, whose key management is not yet a standard, but you can bet it will provide user level authentication, multi-level secure level authentication, etc., as well as host/interface level authentication. I never claimed that IPSEC would answer all needs, just almost all point-to-point needs. > >> 2. Why not use ElGamal instead of RSA for keys and signatures? > >> > >> This is a practical issue. Why not specify ElGamal instead of RSA? > >> the RSA patent has 5 more years before it expires. ElGamal is > >> unpatented and its underlying patent, Diffie-Hellman, expires in > >> 1.5 years. I believe ElGamal is just as strong as RSA and has > >> undergone over a decade of cryptanalysis. It is being used as the > >> foundation of the US Digital Signature Standard. > > > >Some of your points are good but RSA is the standard for use in the > >Internet now. Defining additional key types, such a ElGamal and > >Diffie-Hellman is reasonable for storage in the DNS but a variety of > >SIGs in DNS raises interoperability questions unless everyone > >implements every algorithm. > > Unless I missed it, RSA has not been specified as a proposed standard RFC. > RSA has a major drawback, its licensing costs. This is not a trivial > point, many people will object to this. As far as I am aware, every Internet standard that specified a public key algorithm specifies RSA and none specify ElGamal. That's enough of a standard for me for this first pass at a standard for DNS security. ElGamal is not free of licensing costs as of this date. > I'm asking you and the WG to seriously consider using ElGamal instead of > RSA for signatures because we will avoid many years of licensing costs. I > sincerely believe that this will enhance the acceptance of secure DNS in > the Internet community by removing a financial constraint during the > first half decade of its deployment. > - Alex > -- > Alexander I. Alten > Alten@Na.Sjf.Novell.Com > (408) 577-8224 > > Novell, Inc. > Member of Technical Staff > Mail Stop F1-42-D2 > 2180 Fortune Drive > San Jose, CA 95131 > USA Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa25035; 22 Sep 95 9:41 EDT Received: from itd.nrl.navy.mil(132.250.80.2) by relay.tis.com via smap (g3.0.1) id xma012854; Fri, 22 Sep 95 09:26:30 -0400 Received: by itd.nrl.navy.mil (4.1/SMI-4.1) id AA20247; Fri, 22 Sep 95 09:42:25 EDT Date: Fri, 22 Sep 95 09:42:25 EDT From: Ran Atkinson Message-Id: <9509221342.AA20247@itd.nrl.navy.mil> To: alten@novell.com Subject: IP security Cc: dns-security@TIS.COM Don Eastlake wrote: >I think secure Telnet and FTP and the plethora of other point to point >security protocols in the Internet should go away and be replaced by >IPSEC. If the decision were up to me, I'd seriously consider an >embargo on any "improvements" to these other point-to-point protocols >to encourage development and deployment of IPSEC. (These comments do >not apply to store-and-forward security such as DNS and email.) Alex Alten responded: % I'm afraid that I must disagree with you about Telnet and FTP. % These protocols depend on user authentication. IP level % authentication is not enough to distinguish between users on a % multi-user system. The above comment tells me that you must not have read RFC-1825 thru RFC-1827 carefully enough. The IPsec Proposed Standards _require_ that implementations support user-oriented keying so that one _can_ distinguish between users on a multi-user system with cryptographic assurances. The NRL IPsec implementation does support keying on a per-socket basis NOW. (We have a BSD based implementation, so sockets are the appropriate term; one could do the same thing with TLI/XTI though the implementation details would differ). % Some protocols like SNMP are also used over other non-Internet protocols, % such as Appletalk and IPX. True, though at last report ALL security was being removed from SNMPv2 by the working group. Also, Don did not say that there were no applications needing application security, just that most applications did not need application layer security. % From an overall design perspective I doubt IPSEC will be able to % adequately deal with the security needs of all higher level protocols. % I'm finding out that each one has its individual needs which cannot % always be covered by a "one size fits all" solution. I agree with Don that IPsec can fully handle the security needs of MOST higher level protocols and that we probably ought not keep stuffing security into EVERY upper-layer protocol. DNS and PEM are good examples of higher level protocols that really need application layer security. Ran rja@cs.nrl.navy.mil [Followups probably belong on the IPsec list or in private email rather than on the DNS Security list...]   Received: from relay.tis.com by neptune.TIS.COM id aa06095; 22 Sep 95 20:05 EDT Received: from gw.home.vix.com(192.5.5.1) by relay.tis.com via smap (g3.0.1) id xma023883; Fri, 22 Sep 95 19:49:46 -0400 Received: by gw.home.vix.com id AA23694; Fri, 22 Sep 95 17:05:50 -0700 Date: Fri, 22 Sep 95 17:05:50 -0700 X-Btw: vix.com is also gw.home.vix.com and vixie.sf.ca.us To: dns-security@TIS.COM From: Paul A Vixie Subject: Re: comments on secure DNS spec Organization: Vixie Enterprises Message-Id: References: <9509212235.AA09178@na.SJF.Novell.COM> Nntp-Posting-Host: wisdom.home.vix.com In-Reply-To: alten@novell.com's message of 21 Sep 1995 16:13:57 -0700 >>> This is a practical issue. Why not specify ElGamal instead of RSA? >>> the RSA patent has 5 more years before it expires. ElGamal is >>> unpatented and its underlying patent, Diffie-Hellman, expires in >>> 1.5 years. I believe ElGamal is just as strong as RSA and has >>> undergone over a decade of cryptanalysis. It is being used as the >>> foundation of the US Digital Signature Standard. >> >> Some of your points are good but RSA is the standard for use in the >> Internet now. Defining additional key types, such a ElGamal and >> Diffie-Hellman is reasonable for storage in the DNS but a variety of >> SIGs in DNS raises interoperability questions unless everyone >> implements every algorithm. > > Unless I missed it, RSA has not been specified as a proposed standard RFC. > RSA has a major drawback, its licensing costs. This is not a trivial > point, many people will object to this. Not just "object". DNSSEC cannot go to "recommended standard" until we have a signed license agreement from RSA in favour of ISOC. RFC 1601 or 1602 (my memory is lapsing) pretty much requires this. I recommend that you send mail to the IETF Security Area Director(s) explaining your concerns; perhaps they will let you (or all of us?) know the status of their work with RSA on this point. Note that I do not expect RSA to give away _everything_; they'll likely want licenses with vendors and individual users who _generate_ signatures, but to merely _verify_ one is something that we can't require users to pay for or DNSSEC will not catch on. > I'm asking you and the WG to seriously consider using ElGamal instead of > RSA for signatures because we will avoid many years of licensing costs. I > sincerely believe that this will enhance the acceptance of secure DNS in > the Internet community by removing a financial constraint during the > first half decade of its deployment. I strongly agree with this, but from my own efforts in this area I have learned that RSA is the 600-pound gorilla in this picture, it will sit anywhere it wants to. Your objection will no doubt be noted, along with mine. -- Paul Vixie La Honda, CA "Illegitimi non carborundum." pacbell!vixie!paul (dont let the bastards grind you down)   Received: from relay.tis.com by neptune.TIS.COM id aa07238; 22 Sep 95 21:59 EDT From: smb@research.att.com MMDF-Warning: Parse error in original version of preceding line at neptune.TIS.COM Message-Id: <199509230144.VAA24795@relay.tis.com> Received: from research.att.com(192.20.225.3) by relay.tis.com via smap (g3.0.1) id xma024793; Fri, 22 Sep 95 21:43:53 -0400 Received: by gryphon; Fri Sep 22 21:59:40 EDT 1995 To: Paul A Vixie cc: dns-security@TIS.COM Subject: Re: comments on secure DNS spec Date: Fri, 22 Sep 95 21:59:40 EDT I strongly agree with this, but from my own efforts in this area I have learned that RSA is the 600-pound gorilla in this picture, it will sit anywhere it wants to. Your objection will no doubt be noted, along with mine. Note that the world has changed. A few days ago, an arbitration panel *dissolved* PKP. The so-called Stanford patents, most notably Diffie- Hellman, reverted to Cylink; the others reverted to RSA. The press releases from RSA and Cylink are flat-out contradictory on what licenses one needs for which algorithms -- but there's no doubt that RSA is in a much weaker position than it was, since Bidzos no longer controls the Diffie-Hellman patent. Not, of course, that this necessarily makes our life any easier, just different...   Received: from relay.tis.com by neptune.TIS.COM id aa07354; 22 Sep 95 22:06 EDT Received: from oahu.cs.umass.edu(128.119.40.142) by relay.tis.com via smap (g3.0.1) id xma024883; Fri, 22 Sep 95 21:51:23 -0400 Received: (from ramesh@localhost) by oahu.cs.umass.edu (8.6.11/8.6.9) id WAA05189; Fri, 22 Sep 1995 22:08:57 -0400 Date: Fri, 22 Sep 1995 22:08:57 -0400 From: Ramesh Sitaraman Message-Id: <199509230208.WAA05189@oahu.cs.umass.edu> To: arpanet-bboard@mc.lcs.mit.edu, atm@bbn.com, cnom@meatro.bellcore.com, dbworld@cs.wisc.edu, dns-security@TIS.COM, end2end-interest@isi.edu, f-troup@aurora.cis.upenn.edu, globecom@signet.com.sig, hipparch@sophia.inria.fr, ietf-announce@cnri.reston.va.us, ipsec@ans.net, mobile-ip@tadpole.com, ost237-transport@comp.lancs.ac.uk, rdd@cc.bellcore.com, rem-conf-request@es.net, rem-conf@es.net, reres@laas.fr, sigmedia@bellcore.com, www-security@ns2.rutgers.edu, xtp-relay@cs.concordia.ca Subject: CFP: Special Issue of Wireless Networks; Deadline Oct 1st. ******************************************************************* ***********************CALL FOR PAPERS***************************** ******************************************************************* The ACM journal on WIRELESS NETWORKS, published in cooperation with Baltzer Science publishers announces a special issue on, MOBILITY MANAGEMENT IN WIRELESS NETWORKS with guest editors, Prof. Christopher Rose Prof. Ramesh Sitaraman Director of Mobility Studies Department of Computer Science Rutgers University, WINLAB University of Massachusetts, Amherst OVERVIEW: Our highly mobile society and its increasing demand for immediate access to knowledge will require that future information networks gracefully accommodate mobility of both users and services. For example, a particular user might wish to gain network access through any number of different ports or connection media. Likewise, a network service might reside on one of many possible processors. Under such a scenario, where both users and network services change location, the distinction between the ``fixed'' and ``mobile'' network blurs; all networks are mobile networks. The overall costs of maintaining accurate location records are at present only poorly understood. However, recent work indicates that simply for telephone traffic, the excess network signaling load expense would be much larger than that required for classical fixed traffic. If migrant services and databases are included, the aggregate signaling load can only be greater. In addition, for wireless systems, the relevant signaling events require use of radio channels and such use must be minimized owing to the scarcity of bandwidth. Thus, either from the standpoint of modifying existing fixed network signaling structures or designing wireless network paging/registration strategies, it is important to understand, quantify and devise methods for handling the impact of location uncertainty on signaling. SCOPE: This special issue will concentrate on the problems associated with acquiring and maintaining mobile unit location information in the wireless environment. A representative sampling of topics is provided below: - Mobility modeling - Location prediction - Empirical measurements for user profiles - Location tracking and mobile network topology - Location tracking for handoff - Paging/Registration cost minimization - Multi-unit paging techniques - Performance Analysis of location management strategies PUBLICATION SCHEDULE: MANUSCRIPT DUE: October 1, 1995 ACCEPTANCE NOTIFICATION: January 1, 1996 FINAL MANUSCRIPT DUE: March 1 1996 Publication Date: Summer 1996. SUBMISSION GUIDELINES: Authors should email an electronic Postscript copy of their paper to winet_mobility@cs.umass.edu by October 1, 1995. The editors will acknowledge the receipt of the paper within a few days. Submissions should be limited to 20 pages, excluding figures and references. If email submission is inconvenient, then six (6) copies of their paper (double-sided if possible) should be sent by the due date to Christopher Rose P.O. Box 909 Piscataway, N.J. 08855-0909 VOICE: (908) 445-5250 FAX: (908) 445-2820 EMAIL: winet_mobility@cs.umass.edu We look forward to your participation in providing a stimulating special issue on an important topic.   Received: from relay.tis.com by neptune.TIS.COM id aa12420; 25 Sep 95 12:14 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma013527; Mon, 25 Sep 95 11:57:45 -0400 Received: by callandor.cybercash.com; id MAA24472; Mon, 25 Sep 1995 12:05:05 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma024467; Mon, 25 Sep 95 12:04:41 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA22387; Mon, 25 Sep 95 12:13:46 EDT Date: Mon, 25 Sep 1995 12:13:45 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: Paul A Vixie Cc: dns-security@TIS.COM Subject: Re: comments on secure DNS spec In-Reply-To: Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Humm...., I suppose if PKP is really disolved then the RFC from them which guarantees reasonable and non-discriminatory licensing is no longer in effect and no IETF standards using RSA can proceed until new assurances are in place. In this regard, RSA and ElGamal are in the same boat right now. Donald On Fri, 22 Sep 1995, Paul A Vixie wrote: > >>> This is a practical issue. Why not specify ElGamal instead of RSA? > >>> the RSA patent has 5 more years before it expires. ElGamal is > >>> unpatented and its underlying patent, Diffie-Hellman, expires in > >>> 1.5 years. I believe ElGamal is just as strong as RSA and has > >>> undergone over a decade of cryptanalysis. It is being used as the > >>> foundation of the US Digital Signature Standard. > >> > >> Some of your points are good but RSA is the standard for use in the > >> Internet now. Defining additional key types, such a ElGamal and > >> Diffie-Hellman is reasonable for storage in the DNS but a variety of > >> SIGs in DNS raises interoperability questions unless everyone > >> implements every algorithm. > > > > Unless I missed it, RSA has not been specified as a proposed standard RFC. > > RSA has a major drawback, its licensing costs. This is not a trivial > > point, many people will object to this. > > Not just "object". DNSSEC cannot go to "recommended standard" until we > have a signed license agreement from RSA in favour of ISOC. RFC 1601 or > 1602 (my memory is lapsing) pretty much requires this. I recommend that > you send mail to the IETF Security Area Director(s) explaining your > concerns; perhaps they will let you (or all of us?) know the status of > their work with RSA on this point. Doesn't need any actual license. Just a guarantee that licenses will be available on a reasonable and non-discriminatory basis. > Note that I do not expect RSA to give away _everything_; they'll likely > want licenses with vendors and individual users who _generate_ signatures, > but to merely _verify_ one is something that we can't require users to > pay for or DNSSEC will not catch on. > > > I'm asking you and the WG to seriously consider using ElGamal instead of > > RSA for signatures because we will avoid many years of licensing costs. I > > sincerely believe that this will enhance the acceptance of secure DNS in > > the Internet community by removing a financial constraint during the > > first half decade of its deployment. > > I strongly agree with this, but from my own efforts in this area I have > learned that RSA is the 600-pound gorilla in this picture, it will sit > anywhere it wants to. Your objection will no doubt be noted, along with > mine. > -- > Paul Vixie > La Honda, CA "Illegitimi non carborundum." > > pacbell!vixie!paul (dont let the bastards grind you down) Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa13356; 25 Sep 95 13:17 EDT Received: from south-station-annex.mit.edu(18.72.1.2) by relay.tis.com via smap (g3.0.1) id xma014455; Mon, 25 Sep 95 13:01:15 -0400 Received: from DCL.MIT.EDU by MIT.EDU with SMTP id AA19481; Mon, 25 Sep 95 13:17:44 EDT Received: by dcl.MIT.EDU (5.0/4.7) id AA07610; Mon, 25 Sep 1995 13:18:07 -0400 Date: Mon, 25 Sep 1995 13:18:07 -0400 From: Theodore Ts'o Message-Id: <9509251718.AA07610@dcl.MIT.EDU> To: "Donald E. Eastlake 3rd" Cc: Paul A Vixie , dns-security@TIS.COM In-Reply-To: Donald E. Eastlake 3rd's message of Mon, 25 Sep 1995 12:13:45 -0400 (EDT), Subject: Re: comments on secure DNS spec Address: 1 Amherst St., Cambridge, MA 02139 Phone: (617) 253-8091 Content-Length: 909 Date: Mon, 25 Sep 1995 12:13:45 -0400 (EDT) From: "Donald E. Eastlake 3rd" I suppose if PKP is really disolved then the RFC from them which guarantees reasonable and non-discriminatory licensing is no longer in effect and no IETF standards using RSA can proceed until new assurances are in place. In this regard, RSA and ElGamal are in the same boat right now. In the RSAREF license, RSADSI indemnified the users of the RSAREF license against "any claim, suit or proceeding against you on the basis of infringement of any United States patent in the field of cryptography by the unmodified Program". Hence, users of RSAREF have nothing to fear, since RSADSI has promised to defend (or at its option settle) any patent claims brought against those users from Cylink. Another Good Reason for making the dns-sec patent formats compatible with RSAREF. - Ted   Received: from relay.tis.com by neptune.TIS.COM id aa25281; 26 Sep 95 1:54 EDT Received: from servo.qualcomm.com(129.46.128.14) by relay.tis.com via smap (g3.0.1) id xma023910; Tue, 26 Sep 95 01:38:46 -0400 Received: (karn@localhost) by servo.qualcomm.com (8.6.12/QC-BSD-2.5.1) id WAA18552; Mon, 25 Sep 1995 22:53:01 -0700 Date: Mon, 25 Sep 1995 22:53:01 -0700 From: Phil Karn Message-Id: <199509260553.WAA18552@servo.qualcomm.com> To: dee@cybercash.com CC: alten@novell.com, charlie_kaufman@iris.com, dee@cybercash.com, dns-security@TIS.COM In-reply-to: (dee@cybercash.com) Subject: Re: comments on secure DNS spec >It is a >benefit, not a bug, if two sigs by the same authenticator over the >same data to be authentiated are identical. Is this true? I thought the consensus among the cryptographers was that you should never sign something unless you control part of the message to be signed. Phil   Received: from relay.tis.com by neptune.TIS.COM id aa25512; 26 Sep 95 2:14 EDT Received: from sonicsys.sonicsys.stph.net(196.12.54.2) by relay.tis.com via smap (g3.0.1) id xma024038; Tue, 26 Sep 95 01:58:03 -0400 Received: from [196.12.54.11] (vasu.sonicsys.stph.net [196.12.54.11]) by sonicsys.sonicsys.stph.net (8.6.9/8.6.9) with SMTP id MAA00655 for ; Tue, 26 Sep 1995 12:01:38 +0500 Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Tue, 26 Sep 1995 12:02:56 +0000 To: dns-security@TIS.COM From: VASUDEV Subject: un subscribe un subscribe E-MAIL:   Received: from relay.tis.com by neptune.TIS.COM id aa03355; 26 Sep 95 11:03 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma029301; Tue, 26 Sep 95 10:47:49 -0400 Received: by callandor.cybercash.com; id KAA06253; Tue, 26 Sep 1995 10:55:10 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma006246; Tue, 26 Sep 95 10:54:47 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA02872; Tue, 26 Sep 95 11:03:54 EDT Date: Tue, 26 Sep 1995 11:03:54 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: Phil Karn Cc: alten@novell.com, dns-security@TIS.COM Subject: Re: comments on secure DNS spec In-Reply-To: <199509260553.WAA18552@servo.qualcomm.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Well, you never want to sign something, especially with RSA, that someone else gives you because they might be secretly getting you to decrypt something or the like. But signing a hash of what they give you should be fine. If they can control what you are signing then, it means they can invert the hash function in which case you are sunk anyway and your signatures provide no security. Donald On Mon, 25 Sep 1995, Phil Karn wrote: > >It is a > >benefit, not a bug, if two sigs by the same authenticator over the > >same data to be authentiated are identical. > > Is this true? I thought the consensus among the cryptographers was > that you should never sign something unless you control part of the > message to be signed. > > Phil > ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa05356; 26 Sep 95 12:57 EDT Received: from newton.ncsa.uiuc.edu(141.142.2.2) by relay.tis.com via smap (g3.0.1) id xma001555; Tue, 26 Sep 95 12:40:31 -0400 Received: from [141.142.150.60] (aslan.ncsa.uiuc.edu [141.142.150.60]) by newton.ncsa.uiuc.edu (8.6.11/8.6.12) with SMTP id LAA23891; Tue, 26 Sep 1995 11:55:59 -0500 X-Sender: kerowe@newton Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Tue, 26 Sep 1995 11:55:23 -0800 To: "Donald E. Eastlake 3rd" From: "Kenneth E. Rowe" Subject: Re: comments on secure DNS spec Cc: Phil Karn , alten@novell.com, dns-security@TIS.COM At 11:03 AM 9/26/95, Donald E. Eastlake 3rd wrote: >Well, you never want to sign something, especially with RSA, that >someone else gives you because they might be secretly getting you to >decrypt something or the like. But signing a hash of what they give >you should be fine. If they can control what you are signing then, it >means they can invert the hash function in which case you are sunk >anyway and your signatures provide no security. > The first problem is an argument for using SHA/DSA instead of RSA. I don't understand the concern with the hash function. Is it invertable?! Can you be a little more descriptive than "sunk"? Ken, ------------------------------------------------------------- Kenneth E. Rowe (kerowe@ncsa.uiuc.edu) Senior Security Engineer (217) 244-5270 (Office) / Security Coordinator (217) 244-0710 (NCSA IRST) National Center for Supercomputing Applications *** email ncsa-irst@ncsa.uiuc.edu for computer incident response ***   Received: from relay.tis.com by neptune.TIS.COM id aa09105; 26 Sep 95 16:17 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma005175; Tue, 26 Sep 95 16:01:34 -0400 Received: by callandor.cybercash.com; id QAA10010; Tue, 26 Sep 1995 16:05:14 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma010007; Tue, 26 Sep 95 16:04:49 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA05930; Tue, 26 Sep 95 16:13:56 EDT Date: Tue, 26 Sep 1995 16:13:56 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: "Kenneth E. Rowe" Cc: Phil Karn , alten@novell.com, dns-security@TIS.COM Subject: Re: comments on secure DNS spec In-Reply-To: Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Tue, 26 Sep 1995, Kenneth E. Rowe wrote: > At 11:03 AM 9/26/95, Donald E. Eastlake 3rd wrote: > >Well, you never want to sign something, especially with RSA, that > >someone else gives you because they might be secretly getting you to > >decrypt something or the like. But signing a hash of what they give > >you should be fine. If they can control what you are signing then, it > >means they can invert the hash function in which case you are sunk > >anyway and your signatures provide no security. > > The first problem is an argument for using SHA/DSA instead of RSA. The point about RSA is the signing is encrypting under the private key which is decrypting under the public key. Yes, this is an argument for other signature algorithms, but not a very stong one if you use proper procedures. > I don't understand the concern with the hash function. Is it invertable?! > Can you be a little more descriptive than "sunk"? If someone can invert a hash function and easily come up with things that hash to a particular hash value, they can probably find something that you wouldn't sign with the same hash as what you did sign so they can forge messages your signature will appear to sign. That's what I meant by sunk. There is no particular reason to think MD5 is weak in this regard. > Ken, > ------------------------------------------------------------- > Kenneth E. Rowe (kerowe@ncsa.uiuc.edu) > Senior Security Engineer (217) 244-5270 (Office) > / Security Coordinator (217) 244-0710 (NCSA IRST) > National Center for Supercomputing Applications > *** email ncsa-irst@ncsa.uiuc.edu for computer incident response *** Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa10624; 26 Sep 95 17:29 EDT Received: from ns.novell.com(137.65.1.1) by relay.tis.com via smap (g3.0.1) id xma006862; Tue, 26 Sep 95 17:12:51 -0400 Received: from na.SJF.Novell.COM ([130.57.6.3]) by ns.Novell.COM (4.1/SMI-4.1) id AA22106; Tue, 26 Sep 95 15:29:46 MDT Received: by na.SJF.Novell.COM (4.1/SMI-4.1) id AA11965; Tue, 26 Sep 95 14:24:58 PDT From: Alex Alten Message-Id: <9509262124.AA11965@na.SJF.Novell.COM> Subject: Re: comments on secure DNS spec To: "Donald E. Eastlake 3rd" Date: Tue, 26 Sep 1995 14:24:57 -0700 (PDT) Cc: paul@vix.com, dns-security@TIS.COM In-Reply-To: from "Donald E. Eastlake 3rd" at Sep 25, 95 12:13:45 pm X-Mailer: ELM [version 2.4 PL22] Content-Type: text Content-Length: 4390 After thinking about this for a while, I've come to the conclusion that the Internet community needs to settle on a public key standard. The situation right now is untenable, defacto standards like PGP are implemented with homegrown RSA, RFC1824 (TESS) specifies ElGamal, many drafts are specifing RSAREF. Managing and distributing keys among all these protocols will be difficult, if not impossible. We need to issue a RFC that secure DNS, secure SNMP, and others can reference. Certainly RSA is a fine algorithm, albeit expensive over the next 5 years. We need to seriously consider other algorithms, such as ElGamal, for the standard. I think the choice should be one that has withstood years of cryptanalysis, it is reasonable to implement and use, and it will be unencumbered with patents, etc., as soon as possible. At this point in time I tend to favor ElGamal as having the best mix of these properties, it will be unencumbered in 1.5 years. - Alex > > Humm...., > > I suppose if PKP is really disolved then the RFC from them which > guarantees reasonable and non-discriminatory licensing is no longer > in effect and no IETF standards using RSA can proceed until new > assurances are in place. In this regard, RSA and ElGamal are in > the same boat right now. > > Donald > > On Fri, 22 Sep 1995, Paul A Vixie wrote: > > > >>> This is a practical issue. Why not specify ElGamal instead of RSA? > > >>> the RSA patent has 5 more years before it expires. ElGamal is > > >>> unpatented and its underlying patent, Diffie-Hellman, expires in > > >>> 1.5 years. I believe ElGamal is just as strong as RSA and has > > >>> undergone over a decade of cryptanalysis. It is being used as the > > >>> foundation of the US Digital Signature Standard. > > >> > > >> Some of your points are good but RSA is the standard for use in the > > >> Internet now. Defining additional key types, such a ElGamal and > > >> Diffie-Hellman is reasonable for storage in the DNS but a variety of > > >> SIGs in DNS raises interoperability questions unless everyone > > >> implements every algorithm. > > > > > > Unless I missed it, RSA has not been specified as a proposed standard RFC. > > > RSA has a major drawback, its licensing costs. This is not a trivial > > > point, many people will object to this. > > > > Not just "object". DNSSEC cannot go to "recommended standard" until we > > have a signed license agreement from RSA in favour of ISOC. RFC 1601 or > > 1602 (my memory is lapsing) pretty much requires this. I recommend that > > you send mail to the IETF Security Area Director(s) explaining your > > concerns; perhaps they will let you (or all of us?) know the status of > > their work with RSA on this point. > > Doesn't need any actual license. Just a guarantee that licenses will be > available on a reasonable and non-discriminatory basis. > > > Note that I do not expect RSA to give away _everything_; they'll likely > > want licenses with vendors and individual users who _generate_ signatures, > > but to merely _verify_ one is something that we can't require users to > > pay for or DNSSEC will not catch on. > > > > > I'm asking you and the WG to seriously consider using ElGamal instead of > > > RSA for signatures because we will avoid many years of licensing costs. I > > > sincerely believe that this will enhance the acceptance of secure DNS in > > > the Internet community by removing a financial constraint during the > > > first half decade of its deployment. > > > > I strongly agree with this, but from my own efforts in this area I have > > learned that RSA is the 600-pound gorilla in this picture, it will sit > > anywhere it wants to. Your objection will no doubt be noted, along with > > mine. > > -- > > Paul Vixie > > La Honda, CA "Illegitimi non carborundum." > > > > pacbell!vixie!paul (dont let the bastards grind you down) > > Donald > ===================================================================== > Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com > 318 Acton Street +1 508-371-7148(fax) dee@world.std.com > Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA) > > -- Alexander I. Alten Alten@Na.Sjf.Novell.Com (408) 577-8224 Novell, Inc. Member of Technical Staff Mail Stop F1-42-D2 2180 Fortune Drive San Jose, CA 95131 USA   Received: from relay.tis.com by neptune.TIS.COM id aa14714; 26 Sep 95 22:27 EDT Received: from ns.novell.com(137.65.1.1) by relay.tis.com via smap (g3.0.1) id xma010060; Tue, 26 Sep 95 22:02:00 -0400 Received: from na.SJF.Novell.COM ([130.57.6.3]) by ns.Novell.COM (4.1/SMI-4.1) id AA23612; Tue, 26 Sep 95 20:18:55 MDT Received: by na.SJF.Novell.COM (4.1/SMI-4.1) id AA14608; Tue, 26 Sep 95 19:14:01 PDT From: Alex Alten Message-Id: <9509270214.AA14608@na.SJF.Novell.COM> Subject: Re: IP security To: Ran Atkinson Date: Tue, 26 Sep 1995 19:14:00 -0700 (PDT) Cc: alten@novell.com, dns-security@TIS.COM In-Reply-To: <9509221342.AA20247@itd.nrl.navy.mil> from "Ran Atkinson" at Sep 22, 95 09:42:25 am X-Mailer: ELM [version 2.4 PL22] Content-Type: text Content-Length: 5406 > > > Don Eastlake wrote: > >I think secure Telnet and FTP and the plethora of other point to point > >security protocols in the Internet should go away and be replaced by > >IPSEC. If the decision were up to me, I'd seriously consider an > >embargo on any "improvements" to these other point-to-point protocols > >to encourage development and deployment of IPSEC. (These comments do > >not apply to store-and-forward security such as DNS and email.) > > Alex Alten responded: > % I'm afraid that I must disagree with you about Telnet and FTP. > % These protocols depend on user authentication. IP level > % authentication is not enough to distinguish between users on a > % multi-user system. > > The above comment tells me that you must not have read RFC-1825 thru > RFC-1827 carefully enough. The IPsec Proposed Standards _require_ > that implementations support user-oriented keying so that one _can_ > distinguish between users on a multi-user system with cryptographic > assurances. The NRL IPsec implementation does support keying on a > per-socket basis NOW. (We have a BSD based implementation, so sockets > are the appropriate term; one could do the same thing with TLI/XTI > though the implementation details would differ). > I read 1825 and 1826. While these documents do comment on supporting user authentication, it is not clear to me how this information is actually percolated between IP, UDP/TCP, and the application protocols. IP can certainly communicate authentication information with UDP and TCP but without redesigning those protocols how does the information get to the application layer? For example how could FTP command and data sessions insert user authentication info into the IPSEC AH header? How does the IP layer coordinate with the FTP layer to verify an incoming packet? It seems this all becomes rather difficult unless you are willing to break the modularity of each layer. The NRL implementation must be reaching around the UDP and TCP headers in order to insert the user keys into the IPSEC AH header. If I have two FTP users establishing command sessions with a distant FTP server, how does that server's IP stack know which key belongs to which incoming packet? It would have to look into the TCP header to find out what is going on and then somehow look up the correct key associated with that incoming port number and IP address. What if an FTP client disconnects and then reconnects with a new command session source port number? Key management based on IP and port number (a socket) will be a challenge. Interoperability at the socket level between various vendors will be even more of a challenge. I believe that IP security should only concern itself with the IP layer e.g. authenticating IP addresses, etc. Nothing more, nothing less. > % Some protocols like SNMP are also used over other non-Internet protocols, > % such as Appletalk and IPX. > > True, though at last report ALL security was being removed from SNMPv2 > by the working group. Also, Don did not say that there were no > applications needing application security, just that most applications > did not need application layer security. > This is correct, I was one of those who recommended that it be dropped from the current round. We hope to continue with an effort focused only on security. > % From an overall design perspective I doubt IPSEC will be able to > % adequately deal with the security needs of all higher level protocols. > % I'm finding out that each one has its individual needs which cannot > % always be covered by a "one size fits all" solution. > > I agree with Don that IPsec can fully handle the security needs of MOST > higher level protocols and that we probably ought not keep stuffing > security into EVERY upper-layer protocol. DNS and PEM are good examples > of higher level protocols that really need application layer security. > I disagree with this statement for the following reasons: 1. If IPSEC fails to be accepted by the Internet community, then there is no alternative mechanism (except SSL?). An example of this is the failure of the old SNMP security design. I think it is important for application protocols to develop their own security mechanisms. 2. For the forseeable future IPSEC will not be uniformly deployed throughout the world. Thus one cannot be assured that data can be sent securely anywhere using only IPSEC. A company may be able to ensure that its employees can use a secure application level protocol since it can control it's host machines. But it may not be able to control intermediate gateways to guarentee end-to-end IP security. 3. An IP stack may not be under user control, therefore there is no assurance that user data is always safe. Security will depend on the trustworthiness of an administrator of the stack. Or the transport stack could be poorly implemented, allowing others to crack or retrieve keys (like the recent snafu with Netscape). > Ran > rja@cs.nrl.navy.mil > > [Followups probably belong on the IPsec list or in private email > rather than on the DNS Security list...] Please tell me how to register with the IPsec list. - Alex -- Alexander I. Alten Alten@Na.Sjf.Novell.Com (408) 577-8224 Novell, Inc. Member of Technical Staff Mail Stop F1-42-D2 2180 Fortune Drive San Jose, CA 95131 USA   Received: from relay.tis.com by neptune.TIS.COM id aa15109; 26 Sep 95 23:03 EDT Received: from optima.cs.arizona.edu(192.12.69.5) by relay.tis.com via smap (g3.0.1) id xma010456; Tue, 26 Sep 95 22:47:15 -0400 Received: from uncial.CS.Arizona.EDU by optima.cs.arizona.edu (5.65c/15) via SMTP id AA05404; Tue, 26 Sep 1995 20:04:21 MST Received: by uncial.CS.Arizona.EDU; (5.65/1.1.8.2/08Nov94-0446PM) id AA02359; Tue, 26 Sep 1995 20:04:19 -0700 Date: Tue, 26 Sep 1995 20:04:19 -0700 From: Hilarie Orman Message-Id: <9509270304.AA02359@uncial.CS.Arizona.EDU> To: alten@novell.com Cc: dns-security@TIS.COM, ipsec@ans.net In-Reply-To: Yourmessage <9509270214.AA14608@na.SJF.Novell.COM> Subject: Re: IP security The RFCs in question address IP message protection and authentication, not much more nor less, just as one would wish. Can there exist an interface to higher levels that provide authentication at the granularity of a "user" (whatever such an entity may be)? It appears so to several people, and the binding between security association identifiers and users is the central to the feasibility. The mechanism of that binding and the interface to it hasn't been defined in detail yet. So we have a network level mechanism with the informal claim that it covers almost all transport level uses, given an appropriate interface definition. One important use that the RFC's don't define is a way of providing message protection at a granularity smaller than one IP message. If this is crucial to one's need for security, then another mechanism will be required. Multipart secure messages seem like a useful thing for many applications, of course. So I think there is a legitimate argument that is brewing where the application layer security people clash with the ESP people on which territory is more rightfully theirs.   Received: from relay.tis.com by neptune.TIS.COM id aa22591; 28 Sep 95 14:43 EDT Received: from watson.ibm.com(129.34.139.4) by relay.tis.com via smap (g3.0.1) id xma005651; Thu, 28 Sep 95 14:27:12 -0400 Received: from WATSON by watson.ibm.com (IBM VM SMTP V2R3) with BSMTP id 7213; Thu, 28 Sep 95 14:44:04 EDT Received: from YKTVMV by watson.vnet.ibm.com with "VAGENT.V1.02 on VAGENT2" id 5371; Thu, 28 Sep 1995 14:44:04 EDT Received: from gimili.watson.ibm.com by yktvmv.watson.ibm.com (IBM VM SMTP V2Rx) with TCP; Thu, 28 Sep 95 14:44:03 EDT Received: by gimili.watson.ibm.com (AIX 3.2/UCB 5.64/950830) id AA33730; Thu, 28 Sep 1995 14:43:42 -0400 Date: Thu, 28 Sep 1995 14:43:42 -0400 From: "S.Kutten" Message-Id: <9509281843.AA33730@gimili.watson.ibm.com> To: dns-security@TIS.COM Subject: call for papers Call for Papers For the new journal published in cooperation with the ACM: WIRELESS NETWORKS Special Issue: Mobility and Security Scope: Mobility introduces a new dimension to the problem of secure computing and communication. The securing becomes harder and often more important. This is sometimes due to the mobility of the communication devices, sometimes due to the mobility of users (without mobile device), or the mobility of objects, or that of the attackers. Papers are sought that address the requirements, designs, algorithms and implementation experience for securing networks, distributed systems, information, and applications in environments that can support mobility. Possible topics include, but are not limited to: Securing communication and distributed systems, such as: - Internet (TCP/IP, mobile IP, DNS, DHCP) - ATM - CDPD - GSM - SNA - Wireless LAN Cryptographic protocols, such as: - key distribution - authentication - payments - anonymity and privacy Cryptographic functions, such as: - encryption - message authentication - message digest - signatures Computer viruses and worms Security for intelligent and mobile objects and agents Secure electronic commerce Cryptographic hardware Security and cryptography for wireless communication systems. The authors should send 6 copies of their paper to one of the guest editors by November 15, 1995. The following time-table shall be followed: Manuscript Submission Deadline: November 15, 1995 Acceptance Notification: May 15, 1996 Final Manuscript Submission Deadline: July 15, 1996 Expected Publication Date: Last Quarter 1996 E-mail submissions are encouraged (post-script only). Set subject to `Submission to WINET special issue'. Guest Editors: Amir Herzberg IBM T.J. Watson Research Center P.O. Box 704 #H3-D18 Yorktown Heights, NY 10598 Telephone: (914) 784-6981 Facsimile: (914) 784-6205 Internet: amir@watson.ibm.com Shay Kutten IBM T.J. Watson Research Center P.O. Box 704 #H3-D38 Yorktown Heights, NY 10598 Telephone: (914) 784-7346 Facsimile: (914) 784-6205 Internet: kutten@watson.ibm.com   Received: from relay.tis.com by neptune.TIS.COM id aa27953; 3 Oct 95 17:02 EDT Received: from unknown.tycho.ncsc.mil(144.51.3.1) by relay.tis.com via smap (g3.0.1) id xma006398; Tue, 3 Oct 95 16:45:17 -0400 Received: by tarius.tycho.ncsc.mil (4.1/SMI-4.1) id AA08390; Tue, 3 Oct 95 17:02:56 EDT Date: Tue, 3 Oct 95 17:02:56 EDT From: "Scott J. Carlson" Message-Id: <9510032102.AA08390@tarius.tycho.ncsc.mil> To: dns-security@TIS.COM Subject: freebsd compilation Hey there, I am currently working with Your DNS Security Implementation Package sec_bind493-b26-v1.2.tar.gz I was curious if you have had anyone successfully compile this package under freebsd v2.0.5 Rel #7? If so, could you please point me in their direction or send me the diffs for the things they had to change in order to get it to compile. I am having problems myself, and am just about to get ready to edit some of the makefiles and stuff, but if someone else has done it first, I may as well as use their work. Thanks a lot Scott Carlson National Security Agency sjc@tycho.ncsc.mil   Received: from relay.tis.com by neptune.TIS.COM id aa01883; 3 Oct 95 21:52 EDT Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma009037; Tue, 3 Oct 95 21:35:43 -0400 Received: by callandor.cybercash.com; id VAA18817; Tue, 3 Oct 1995 21:52:10 -0400 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.1) id xma018814; Tue, 3 Oct 95 21:51:47 -0400 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA10656; Tue, 3 Oct 95 21:51:54 EDT Date: Tue, 3 Oct 1995 21:51:52 -0400 (EDT) From: "Donald E. Eastlake 3rd" To: dns-security@TIS.COM Cc: jis@mit.edu, yakov@cisco.com, Susan Thomson in WG hat , Randy Bush Subject: "Null" SIGs, NXT ordering, SIG orig TTL Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII I have made some minor edits and one significant change to the last posted version of the DNS Security draft. I do not plan to send this latest version in to Internet-Drafts until waiting a bit for comments. The significant change is to define Algorithm 253 as the null security algorithm. That is to say, KEY algorithm type 253 has null key information and SIG algorithm type 253 has a null signature part. The primary reason for this SIG type is so that DNS dynamic updates can be done without any security overhead in the same way as secure dynamic updates can be done. (Presumably one would only do this inside a secure subnet where all hosts were trusted...) The DNS dynamic update uses the date signed field in the SIG and that, along with all of the other RDATA fields, except signature, is still present in algorithm type 253 SIGs. An algorithm type 253 KEY is necessary so that you can authoritatively declare that algorithm type 253 SIGs can be used in a zone. Secure DNS resover and similar software should normally treate a zone authoritatively secured by algorithm type 253 as if it were a zone authoritatively declared to be insecure. Such software needs, in any case, to know which algoirthms or possibly even key lengths it will consider secure and which it will consider insecure. The minor changes consist of fixing some typos (pubic -> public, etc.), changing referenced to dynamic update to the present tense, etc., and also (1) providing that the ordering of labels for NXT purposes is as if all letters were lower case (to follow the hash ordering rules) and (2) providing that the original TTL field for a SIG can be omitted in a master file if it is the same at the TTL of the SIG itself. I will append the new version (draft-ietf-dnssec-secext-06.txt) below. People are welcome to do diffs with the previous version, comment, or whatever. Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA) DNS Security Working Group Donald E. Eastlake, 3rd INTERNET-DRAFT CyberCash UPDATES RFC 1034, 1035 Charles W. Kaufman Iris Expires: 2 April 1996 3 October 1995 Domain Name System Security Extensions ------ ---- ------ -------- ---------- Status of This Document This draft, file name draft-ietf-dnssec-secext-06.txt, is intended to be become a Proposed Standard RFC. Distribution of this document is unlimited. Comments should be sent to the DNS Security Working Group mailing list or to the authors. This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months. Internet-Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet- Drafts as reference material or to cite them other than as a ``working draft'' or ``work in progress.'' To learn the current status of any Internet-Draft, please check the 1id-abstracts.txt listing contained in the Internet-Drafts Shadow Directories on ds.internic.net, ftp.isi.edu, nic.nordu.net, ftp.nis.garr.it, munnari.oz.au, or ftp.is.co.za. Eastlake, Kaufman [Page 1] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 Abstract The Domain Name System (DNS) has become a critical operational part of the Internet infrastructure yet it has no strong security mechanisms to assure data integrity or authentication. Extensions to the DNS are described that provide these services to security aware resolvers or applications through the use of cryptographic digital signatures. These digital signatures are included in secured zones as resource records. Security can still be provided even through non-security aware DNS servers in many cases. The extensions also provide for the storage of authenticated public keys in the DNS. This storage of keys can support general public key distribution service as well as DNS security. The stored keys enable security aware resolvers to learn the authenticating key of zones in addition to keys for which they are initially configured. Keys associated with DNS names can be retrieved to support other protocols. Provision is made for a variety of key types and algorithms. In addition, the security extensions provide for the optional authentication of DNS protocol transactions. Acknowledgements The significant contributions of the following persons (in alphabetic order) to this draft are gratefully acknowledged: Madelyn Badger Matt Crawford James M. Galvin Olafur Gudmundsson Sandy Murphy Masataka Ohta Michael A. Patton Jeffrey I. Schiller Eastlake, Kaufman [Page 2] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 Table of Contents Status of This Document....................................1 Abstract...................................................2 Acknowledgements...........................................2 Table of Contents..........................................3 1. Overview of Contents....................................5 2. Overview of the Extensions.............................6 2.1 Services Not Provided..................................6 2.2 Key Distribution.......................................6 2.3 Data Origin Authentication and Integrity...............7 2.3.1 The SIG Resource Record..............................8 2.3.2 Authenticating Name and Type Non-existence...........8 2.3.3 Special Considerations With Time-to-Live.............8 2.3.4 Special Considerations at Delegation Points..........9 2.3.5 Special Considerations with CNAME RRs................9 2.3.6 Signers Other Than The Zone.........................10 2.4 DNS Transaction Authentication........................10 3. The KEY Resource Record................................11 3.1 KEY RDATA format......................................11 3.2 Object Types, DNS Names, and Keys.....................11 3.3 The KEY RR Flag Field.................................12 3.4 The Protocol Octet....................................14 3.5 The KEY Algorithm Number and the MD5/RSA Algorithm....14 3.6 Interaction of Flags, Algorithm, and Protocol Bytes...15 3.7 KEY RRs in the Construction of Responses..............16 3.8 File Representation of KEY RRs........................16 4. The SIG Resource Record................................18 4.1 SIG RDATA Format......................................18 4.1.1 Signature Data......................................20 4.1.2 MD5/RSA Algorithm Signature Calculation.............21 4.1.3 Zone Transfer (AXFR) SIG............................22 4.1.4 Transaction SIGs....................................22 4.2 SIG RRs in the Construction of Responses..............23 4.3 Processing Responses and SIG RRs......................24 4.4 Signature Expiration, TTLs, and Validity..............25 4.5 File Representation of SIG RRs........................25 5. Non-existent Names and Types...........................27 5.1 The NXT Resource Record...............................27 5.2 NXT RDATA Format......................................28 5.3 Example...............................................28 5.4 Interaction of NXT RRs and Wildcard RRs...............29 5.5 Blocking NXT Pseudo-Zone Transfers....................30 Eastlake, Kaufman [Page 3] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 5.6 Special Considerations at Delegation Points...........30 6. The AD and CD Bits and How to Resolve Securely.........31 6.1 The AD and CD Header Bits.............................31 6.2 Boot File Format......................................32 6.3 Chaining Through Zones................................33 6.4 Secure Time...........................................34 7. Operational Considerations.............................35 7.1 Key Size Considerations...............................35 7.2 Key Storage...........................................36 7.3 Key Generation........................................36 7.4 Key Lifetimes.........................................36 7.5 Signature Lifetime....................................37 7.6 Root..................................................37 8. Conformance............................................38 8.1 Server Conformance....................................38 8.2 Resolver Conformance..................................38 9. Security Considerations................................39 References................................................39 Authors Addresses.........................................41 Expiration and File Name..................................41 Appendix: Base 64 Encoding................................42 Eastlake, Kaufman [Page 4] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 1. Overview of Contents This draft describes extensions of the Domain Name System (DNS) protocol to support DNS security and public key distribution. It assumes that the reader is familiar with the Domain Name System, particularly as described in RFCs 1034 and 1035. Section 2 provides an overview of the extensions and the key distribution, data origin authentication, and transaction security they provide. Section 3 discusses the KEY resource record, its structure, use in DNS responses, and file representation. These resource records represent the public keys of entities named in the DNS and are used for key distribution. Section 4 discusses the SIG digital signature resource record, its structure, use in DNS responses, and file representation. These resource records are used to authenticate other resource records in the DNS and optionally to authenticate DNS transactions. Section 5 discusses the NXT resource record and its use in DNS responses. The NXT RR permits authenticated denial in the DNS of the existence of a name or of a particular type for an existing name. Section 6 discusses how a resolver can be configured with a starting key or keys and proceed to securely resolve DNS requests. Interactions between resolvers and servers are discussed for all combinations of security aware and security non-aware. Two additional query header bits are defined for signaling between resolvers and servers. Section 7 reviews a variety of operational considerations including key generation, lifetime, and storage. Section 8 defines levels of conformance for resolvers and servers. Section 9 provides a few paragraphs on overall security considerations. An Appendix is provided that gives some details of base64 encoding which is used in the file representation of some RR's defined in this draft. Eastlake, Kaufman [Page 5] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 2. Overview of the Extensions The Domain Name System (DNS) protocol security extensions provide three distinct services: key distribution as described in Section 2.2 below, data origin authentication as described in Section 2.3 below, and transaction authentication, described in Section 2.4 below. Special considerations related to time to live, CNAMEs, and delegation points are also discussed in Section 2.3. 2.1 Services Not Provided It is part of the design philosophy of the DNS that the data in it is public and that the DNS gives the same answers to all inquirers. Following this philosophy, no attempt has been made to include any sort of access control lists or other means to differentiate inquirers. In addition, no effort has been made to provide for any confidentiality for queries or responses. (This service may be available via IPSEC. [put refs to IPSEC RFCs here if available]) 2.2 Key Distribution Resource records (RRs) are defined to associate keys with DNS names. This permits the DNS to be used as a general public key distribution mechanism in support of the data origin authentication and transaction authentication DNS services as well as other security services. The syntax of a KEY resource record (RR) is described in Section 3. It includes an algorithm identifier, flags indicating the type of entity the key is associated with and/or asserting that there is no key associated with that entity, and the actual public key parameters. Under conditions described in Section 3, security aware DNS servers may automatically attempt to return KEY resources as additional information, along with those resource records actually requested, to minimize the number of queries needed. Eastlake, Kaufman [Page 6] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 2.3 Data Origin Authentication and Integrity Authentication is provided by associating with resource records in the DNS cryptographically generated digital signatures. Commonly, there will be a single private key that signs for an entire zone. If a security aware resolver reliably learns the public key of the zone, it can verify, for any data read from that zone, that it was properly authorized and is reasonably current. The expected implementation is for the zone private key to be kept off-line and used to re-sign all of the records in the zone periodically. This data origin authentication key belongs to the zone and not to the servers that store copies of the data. That means compromise of a server or even all servers for a zone will not necessarily affect the degree of assurance that a resolver has that it can determine whether data is genuine. A resolver can learn the public key of a zone either by reading it from DNS or by having it staticly configured. To reliably learn the public key by reading it from DNS, the key itself must be signed. Thus, to provide a reasonable degree of security, the resolver must be configured with at least the public key of one zone that it can use to authenticate signatures. From that, it can securely read the public keys of other zones if the intervening zones in the DNS tree are secure. (It is in principle more secure to have the resolver manually configured with the public keys of multiple zones, since then the compromise of a single zone would not permit the faking of information from other zones. It is also more administratively cumbersome, however, particularly when public keys change.) Adding data origin authentication and integrity requires no change to the "on-the-wire" DNS protocol beyond the addition of the signature resource types and, as a practical matter, the key resource type needed for key distribution. This service can be supported by existing resolver and server implementations so long as they can support the additional resource types (see Section 8) with the one exception that CNAME referals can not be authenticated if they are from non-security aware servers (see Section 2.3.5). If signatures are always separately retrieved and verified when retrieving the information they authenticate, there will be more trips to the server and performance will suffer. To avoid this, security aware servers mitigate that degradation by always sending the signature(s) needed. Eastlake, Kaufman [Page 7] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 2.3.1 The SIG Resource Record The syntax of a SIG resource record (signature) is described in Section 4. It includes the type of the RR(s) being signed, the name of the signer, the time at which the signature was created, the time it expires (when it is no longer to be believed), its original time to live (which may be longer than its current time to live but cannot be shorter), the cryptographic algorithm in use, and the actual signature. Every name in a secured zone will have associated with it at least one SIG resource record for each resource type under that name. A security aware server supporting the performance enhanced version of the DNS protocol security extensions will attempt to return, with all records retrieved, the corresponding SIGs. If a server does not support the protocol, the resolver must retrieve all the SIG records for a name and select the one or ones that sign the resource record(s) that resolver is interested in. 2.3.2 Authenticating Name and Type Non-existence The above security mechanism provides only a way to sign existing RRs in a zone. "Data origin" authentication is not obviously provided for the non-existence of a domain name in a zone or the non-existence of a type for an existing name. This gap is filled by the NXT RR which authenticatably asserts a range of non-existent names in a zone and the non-existence types for the initial name in that range. Section 5 below covers the NXT RR. 2.3.3 Special Considerations With Time-to-Live A digital signature will fail to verify if any change has occurred to the data between the time it was originally signed and the time the signature is verified. This conflicts with our desire to have the time-to-live field tick down when resource records are cached. This could be avoided by leaving the time-to-live out of the digital signature, but that would allow unscrupulous servers to set arbitrarily long time to live values undetected. Instead, we include the "original" time-to-live in the signature and communicate that data in addition to the current time-to-live. Unscrupulous servers under this scheme can manipulate the time to live but a security aware resolver will bound the TTL value it uses at the original signed value. Separately, signatures include a time signed and an expiration time. A resolver that knows the absolute time can Eastlake, Kaufman [Page 8] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 determine securely whether a signature has expired. It is not possible to rely solely on the signature expiration as a substitute for the TTL, however, since non-security aware servers must still be supported. 2.3.4 Special Considerations at Delegation Points DNS security would like to view each zone as a unit of data completely under the control of the zone owner and signed by the zone's key. But the operational DNS views the leaf nodes in a zone which are also the apex nodes of a subzone (i.e., delegation points) as "really" belonging to the subzone. These nodes occur in two master files and will have RRs signed by both the upper and lower zone's keys. A retrieval could get a mixture of these RRs and SIGs, especially since one server could be serving both the zone above and below a delegation point. In general, the KEY RR from the superzone is authoritative while for all other RRs, the data from the subzone is more authoritative. To avoid conflicts, only the KEY RR in the superzone should be signed and the NS and any A (glue) RRs should only be signed in the subzone along with the SOA and any other RRs that have the zone name as owner. The only exception is the NXT RR type that will always appear differently and authoritatively in both the superzone and subzone, if both are secure, as described in Section 5. 2.3.5 Special Considerations with CNAME RRs There is a significant problem with security related RRs with the same owner name as a CNAME RR when retrieved from a non-security- aware server. In particular, an initial retrieval for the CNAME or any other type will not retrieve an associated signature, key, or NXT RR. For types other than CNAME it will retrieve that type at the target name of the CNAME (or chain of CNAMEs) and will return the CNAME as additional info. In particular, a specific retrieval for type SIG will not get the SIG, if any, at the original domain name but rather an SIG at the target name. In general, security aware servers must be used to securely CNAME in DNS. Security aware servers must (1) allow KEY, SIG, and NXT RRs along with CNAME RRs, (2) suppress CNAME processing on retrieval of these types as well as on retrieval of the type CNAME, and (3) automatically return SIG RRs authenticating the CNAME or CNAMEs encountered in resolving a query. Eastlake, Kaufman [Page 9] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 2.3.6 Signers Other Than The Zone There are two cases where a SIG resource record is signed by other than the zone private key. One is for support of dynamic update where an entity is permitted to authenticate/update its own records. The public key of the entity must be present in the DNS and be appropriately signed but the other RR(s) may be signed with the entity's key. The other is for support of transaction authentication as described in Section 2.4 below. 2.4 DNS Transaction Authentication The data origin authentication service described above protects resource records but provides no protection for DNS message headers. If header bits are falsely set by a server, there is little that can be done. However, it is possible to add transaction authentication. Such authentication means that a resolver can be sure it is at least getting messages from the server it thinks it queried, that the response is from the query it sent, and that these messages have not been diddled in transit. This is accomplished by optionally adding a special SIG resource record to the end of the reply which digitally signs the concatenation of the server's response and the resolver's query. The private key used belongs to the host composing the reply, not to the zone being queried. The corresponding public key is stored in and retrieved from the DNS. Because replies are highly variable, message authentication SIGs can not be pre-calculated. Thus it will be necessary to keep the private key on-line, for example in software or in a directly connected piece of hardware. DNS level transaction authentication will be unnecessary when IPSEC end-to-end security protocol is generally available [refernce IPSEC RFCs when RFC numbers assigned]. However, there will be a significant time during which there will be systems on which it will be hard to add such a protocol but relatively easy to replace the DNS components. Eastlake, Kaufman [Page 10] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 3. The KEY Resource Record The KEY resource record (RR) is used to document a key that is associated with a Domain Name System (DNS) name. It will be a public key as only public keys are stored in the DNS. This can be the public key of a zone, of a host or other end entity, or a user. A KEY RR is, like any other RR, authenticated by a SIG RR. Security aware DNS implementations MUST be designed to handle at least two simultaneously valid keys of the same type associated with a name. The type number for the KEY RR is 25. 3.1 KEY RDATA format The RDATA for a KEY RR consists of flags, a protocol octet, the algorithm number, and the public key itself. The format is as follows: 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | flags | protocol | algorithm | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / / public key / / / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-| The meaning of the KEY RR owner name, flags, and protocol octet are described in Sections 3.2, 3.3 and 3.4 below respectively. The flags and protocol must be examined before any following data as they control the format and even whether there is any following data. The algorithm and public key fields are described in Section 3.5. The format of the public key is algorithm dependent. 3.2 Object Types, DNS Names, and Keys The public key in a KEY RR belongs to the object named in the owner name. This DNS name may refer to up to three different things. For example, dee.cybercash.com could be (1) a zone, (2) a host or other end entity , and (3) the mapping into a DNS name of the user or account dee@cybercash.com . Thus, there are flags in the KEY RR to indicate with which of these roles the owner name and public key are associated as described below. Eastlake, Kaufman [Page 11] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 Although the same name can be used for up to all three of these contexts, such overloading of a name is discouraged. It is also possible to use the same key for different things with the same name or even different names, but this is strongly discouraged. In particular, the use of a zone key as a non-zone key will usually require that the private key be kept on line and thereby become much more vulnerable. It would be desirable for the growth of DNS to be managed so that additional possible simultaneous uses for names are NOT added. New uses should be distinguished by exclusive domains. For example, all IP autonomous system numbers have been mapped into the in-as.arpa domain [draft-ietf-dnssec-as-map-*.txt] and all telephone numbers in the world have been mapped into the tpc.int domain [RFC 1530]. This is much preferable to having the same name possibly be an autonomous system number, telephone number, and/or host as well as a zone and a user. In addition to the name type bits, there are additional control bits, the "no key" bit, the "experimental" bit, the "signatory" field, etc., as described below. 3.3 The KEY RR Flag Field In the "flags" field: Bit 0 is the "no key" bit. If this bit is on, there is no key information and the RR stops after the algorithm octet. By the use of this bit, a signed KEY RR can authenticatably assert that, for example, a zone is not secured. Bit 1 is the "experimental" bit. It is ignored if the "no key" bit is on and the following description assumes the "no key" bit to be off. Keys may be associated with zones, entities, or users for experimental, trial, or optional use, in which case this bit will be one. If this bit is a zero, it means that the use or availability of security based on the key is "mandatory". Thus, if this bit is off for a zone key, the zone should be assumed secured by SIG RRs and any responses indicating the zone is not secured should be considered bogus. If this bit is a one for a host or end entity, it might sometimes operate in a secure mode and at other times operate without security. The experimental bit, like all other aspects of the KEY RR, is only effective if the KEY RR is appropriately signed by a SIG RR. The experimental bit must be zero for safe secure operation and should only be a one for a minimal transition period. Bits 2-4 are reserved and must be zero. Eastlake, Kaufman [Page 12] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 Bit 5 on indicates that this is a key associated with a "user" or "account" at an end entity, usually a host. The coding of the owner name is that used for the responsible individual mailbox in the SOA record: The owner name is the user name as the name of a node under the entity name. For example, "j.random_user" on host.subdomain.domain could have a public key associated through a KEY RR with name j\.random_user.host.subdomain.domain. It could be used in an security protocol where authentication of a user was desired. This key would be useful in IP or other security for a user level service such a telnet, ftp, rlogin, etc. Bit 6 on indicates that this is a key associated with the non- zone "entity" whose name is the RR owner name. This will commonly be a host but could, in some parts of the DNS tree, be some other type of entity such as a telephone number [RFC 1530]. This is the public key used in connection with the optional DNS transaction authentication service that can be used if the owner name is a DNS server host. It could also be used in an IP-security protocol where authentication of a host was desired such as routing, NTP, etc. Bit 7 is the "zone" bit and indicates that this is a zone key for the zone whose name is the KEY RR owner name. This is the fundamental type of DNS data origin authentication public key. Bit 8 is reserved to be the IPSEC bit and indicate that this key is valid for use in conjunction with the IP level security standard. This key could be used in connection with secured communication on behalf of an end entity or user whose name is the owner name of the KEY RR if the entity or user bits are on. The presence of a KEY resource with the IPSEC and entity bits on and experimental and no- key bits off is a guarantee that the host speaks IPSEC. Bit 9 is reserved to be the "email" bit and indicate that this key is valid for use in conjunction with MIME security multiparts. This key could be used in connection with secured communication on behalf of an end entity or user whose name is the owner name of the KEY RR if the entity or user bits are on. Bits 10-11 are reserved and must be zero. Bits 12-15 are the "signatory" field. If non-zero, it indicates that the key can validly sign RRs of the same name. If the owner name is a wildcard, then RRs with any name which is in the wildcard's scope can be signed. Fifteen different non-zero values are possible for this field and any differences in their meaning are reserved for definition in connection with DNS dynamic update or other new DNS commands. This field is meaningless for zone keys which always have authority to sign any RRs in the zone. The signatory field, like all other aspects of the KEY RR, is only effective if the KEY RR is appropriately signed by a SIG RR. Eastlake, Kaufman [Page 13] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 3.4 The Protocol Octet It is anticipated that keys stored in DNS will be used in conjunction with Internet protocols other than DNS (keys with zone bit or signatory field non-zero) and IPSEC (keys with IPSEC bit set). The protocol octet is provided to indicate that a key is valid for such use and, for end entity keys or the host part of user keys, that the secure version of that protocol is implemented on that entity or host. Values between 1 and 191 decimal inclusive are available for assignment by IANA for such protocols. The 63 values between 192 and 254 inclusive will not be assigned to a specific protocol and are available for experimental use under bilateral agreement. Value 0 indicates, for a particular key, that it is not valid for any particular additional protocol beyond those indicated in the flag field. And value 255 indicates that the key is valid for all assigned protocols (those in the 1 to 191 range). It is intended that new uses of DNS stored keys would initially be implemented, and operational experience gained, using the experimental range of the protocol octet. If demand for widespread deployment for the indefinite future warrants, a value in the assigned range would then be designated for the protocol. Finally, (1) should the protocol become so widespread in conjunction with other protocols which are indicated via the protocol octet and with which it shares key values that duplicate RRs are a serious burden and (2) should the protocol provide substantial facilities not available in any protocol for which a flags field bit has been allocated, then a flag field bit may be allocated to the protocol. Then a key can be simultaneously indicated as valid for that protocol and the entity or host can be simultaneously flagged as implementing the secure version of that protocol, along with other protocols for which flag field bits have been assigned. Note that the IPSEC protocol being developed may provide facilities adequate for all point to point IP communication meaning that additional flag field bits would only be assigned, when appropriate as indicated above, to protocols with a store-and-forward nature (other than DNS) or otherwise not subsumed into a point-to-point paradigm. 3.5 The KEY Algorithm Number and the MD5/RSA Algorithm This octet is the key algorithm parallel to the same field for the SIG resource. The MD5/RSA algorithm described in this draft is number 1. Numbers 2 through 252 are available for assignment should sufficient reason arise. However, the designation of a new algorithm Eastlake, Kaufman [Page 14] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 could have a major impact on interoperability and requires an IETF standards action. Number 254 is reserved for private use and will never be assigned a specific algorithm. For number 254, the public key area shown in the packet diagram above will actually begin with an Object Identifier (OID) indicating the private algorithm in use and the remainder of the area is whatever is required by that algorithm. Number 253 is reserved for use where the date or other labeling fields of SIGs are desired withouth any actual security. For number 253, the public key area is null. Values 0 and 255 are reserved. If the no key bit is zero and the algorithm field is 1, indicating the MD5/RSA algorithm, the public key field is structured as follows: 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | pub exp length| public key exponent / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / +- modulus / | / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-/ To promote interoperability, the exponent and modulus are each limited to 2552 bits in length. The public key exponent is a variable length unsigned integer. Its length in octets is represented as one octet if it is in the range of 1 to 255 and by a zero octet followed by a two octet unsigned length if it is longer than 255 bytes. The public key modulus field is a multiprecision unsigned integer. The length of the modulus can be determined from the RDLENGTH and the preceding RDATA fields including the exponent. Leading zero bytes are prohibited in the exponent and modulus. 3.6 Interaction of Flags, Algorithm, and Protocol Bytes Various combinations of the no-key bit, algorithm byte, protocol byte, and any protocol indicating flags (such as the reserved IPSEC flag) are possible. (Note that the zone flag bit being on or the signatory field being non-zero is effectively a DNS protocol flag on.) The meaning of these combinations is indicated below: Eastlake, Kaufman [Page 15] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 NK = no key flag AL = alogrithm byte PR = protocols indicated by protocol byte or protocol flags x represents any valid non-zero value. AL PR NK Meaning 0 0 0 Illegal, claims key but has bad algorithm field. 0 0 1 Specifies total lack of security for owner. 0 x 0 Illegal, claims key but has bad algorithm field. 0 x 1 Specified protocols insecure, others may be secure. x 0 0 Useless. Gives key but no protocols to use it. x 0 1 Useless. Denies key but for no protocols. x x 0 Specifies key for protocols and certifies that those protocols are implemented with security. x x 1 Algorithm not understood for protocol. (remember, in reference to the above table, that a protocol byte of 255 means all protocols with protocol bytes assigned) 3.7 KEY RRs in the Construction of Responses An explicit request for KEY RRs does not cause any special additional information processing except, of course, for the corresponding SIG RR from a security aware server. Security aware DNS servers will include KEY RRs as additional information in responses where appropriate including the following: (1) On the retrieval of NS RRs, the zone key KEY RR(s) for the zone served by these name servers will be included as additional information. If not all additional info will fit, the KEY RR(s) have higher priority than type A (or AAAA) glue RRs. (2) On retrieval of type A (or AAAA) RRs, the end entity KEY RR(s) will be included. On inclusion of A (or AAAA) RRs as additional information, their KEY RRs will also be included but with lower priority than the relevant A (or AAAA) RRs. 3.8 File Representation of KEY RRs KEY RRs may appear as lines in a zone data file. The flag field, protocol, and algorithm number octets are then represented as unsigned integers. Note that if the "no key" flag is on in the flags or the algorithm specified is 253, nothing appears Eastlake, Kaufman [Page 16] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 after the algorithm octet. The remaining public key portion is represented in base 64 (see Appendix) and may be divided up into any number of white space separated substrings, down to single base 64 digits, which are concatenated to obtain the full signature. These substrings can span lines using the standard parenthesis. Note that the public key may have internal sub-fields but these do not appear in the master file representation. For example, with algorithm 1 there is a public exponent and then a modulus and with algorithm 254, there will be an OID followed by algorithm dependent information. Eastlake, Kaufman [Page 17] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 4. The SIG Resource Record The SIG or "signature" resource record (RR) is the fundamental way that data is authenticated in the secure Domain Name System (DNS). As such it is the heart of the security provided. The SIG RR unforgably authenticates other RRs of a particular type, class, and name and binds them to a time interval and the signer's domain name. This is done using cryptographic techniques and the signer's private key. The signer is frequently the owner of the zone from which the RR originated. 4.1 SIG RDATA Format The RDATA portion of a SIG RR is as shown below. The integrity of the RDATA information is protected by the signature field. 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | type covered | algorithm | labels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | original TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | signature expiration | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | time signed | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | key footprint | / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ signer's name / / / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | / +- signature / / / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The value of the SIG RR type is 24. The "type covered" is the type of the other RRs covered by this SIG. The algorithm number is an octet specifying the digital signature algorithm used parallel to the algorithm octet for the KEY RR. The MD5/RSA algorithm described in this draft is number 1. Numbers 2 through 252 are available for assignment should sufficient reason arise to allocate them. However, the designation of a new algorithm could have a major impact on the interoperability of the global DNS systems and requires an IETF standards action. Number 254 is Eastlake, Kaufman [Page 18] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 reserved for private use and will not be assigned a specific algorithm. For number 254, the "signature" area shown above will actually begin with an Object Identifier (OID) indicating the private algorithm in use and the remainder of the signature area is whatever is required by that algorithm. Number 253 is used when the time fields or other non-signature fields of the SIG are desired without any actual security. For number 253, the signature field will be null. Values 0 and 255 are reserved. The "labels" octet is an unsigned count of how many labels there are in the original SIG RR owner name not counting the null label for root and not counting any initial "*" for a wildcard. If a secured retrieval is the result of wild card substitution, it is necessary for the resolver to use the original form of the name in verifying the digital signature. This field helps optimize the determination of the original form reducing the effort in authenticating signed data. If, on retrieval, the RR appears to have a longer name than indicated by "labels", the resolver can tell it is the result of wildcard substitution. If the RR owner name appears to be shorter than the labels count, the SIG RR should be considered corrupt and ignored. The maximum number of labels possible in the current DNS is 127 but the entire octet is reserved and would be required should DNS names ever be expanded to 255 labels. The following table gives some examples. The value of "labels" is at the top, the retrieved owner name on the left, and the table entry is the name to use in signature verification except that "bad" means the RR is corrupt. labels= | 0 | 1 | 2 | 3 | 4 | --------+-----+------+--------+----------+----------+ .| . | bad | bad | bad | bad | d.| *. | d. | bad | bad | bad | c.d.| *. | *.d. | c.d. | bad | bad | b.c.d.| *. | *.d. | *.c.d. | b.c.d. | bad | a.b.c.d.| *. | *.d. | *.c.d. | *.b.c.d. | a.b.c.d. | The "original TTL" field is included in the RDATA portion to avoid (1) authentication problems that caching servers would otherwise cause by decrementing the real TTL field and (2) security problems that unscrupulous servers could otherwise cause by manipulating the real TTL field. This original TTL is protected by the signature while the current TTL field is not. NOTE: The "original TTL" must be restored into the covered RRs when the signature is verified. This implies that the RRs for a particular type need to all have the same TTL to start with. The SIG is valid until the "signature expiration" time which is an unsigned number of seconds since the start of 1 January 1970, GMT, Eastlake, Kaufman [Page 19] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 ignoring leap seconds. (See also Section 4.4.) SIG RRs should not have a date signed significantly in the future. To prevent misordering of network request to update a zone dynamically, monotonically increasing "time signed" dates are necessary. The "time signed" field is an unsigned number of seconds since the start of 1 January 1970, GMT, ignoring leap seconds. A SIG RR with an expiration date before the date signed is ineffective. The "key footprint" is a 16 bit quantity that is used to help efficiently select between multiple keys which may be applicable and as a quick check that a public key about to be used for the computationally expensive effort to check the signature is possibly valid. Its exact meaning is algorithm dependent. For the MD5/RSA algorithm, it is the next to the bottom two octets of the public key modulus needed to decode the signature field. That is to say, the most significant 16 of the lest significant 24 bits of this quantity in network order. The "signer's name" field is the domain name of the signer generating the SIG RR. This is frequently the zone which contained the RR(s) being authenticated. The signer's name may be compressed with standard DNS name compression when being transmitted over the network. The structure of the "signature" field is described below. 4.1.1 Signature Data Except for algorithm number 253 where it is null, the actual signature portion of the SIG RR binds the other RDATA fields to all of the "type covered" RRs with that owner name. These covered RRs are thereby authenticated. To accomplish this, a data sequence is constructed as follows: data = RDATA | RR(s)... where | is concatenation, RDATA is all the RDATA fields in the SIG RR itself before the signature, and RR(s) are all the RR(s) of the type covered with the same owner name and class as the SIG RR in canonical form and order. For purposes of DNS security, the canonical form for an RR is the RR with domain names (1) fully expanded (no name compression via pointers) and (2) all domain name letters set to lower case. Eastlake, Kaufman [Page 20] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 For purposes of DNS security, the canonical order for RRs is to sort them in ascending order by name, then by type, as left justified unsigned octet sequences in network (transmission) order where a missing octet sorts before a zero octet. (See also ordering discussion in Section 5.1.) Within any particular name and type they are similarly sorted by RDATA as a left justified unsigned octet sequence. EXCEPT that the type SIG RR(s) covering any particular type appear immediately after the other RRs of that type. Thus if at name a.b there is one A RR and one KEY RR, their order with SIGs for concatenating the "data" to be signed would be as follows: a.b. A .... a.b. SIG A ... a.b. KEY ... a.b. SIG KEY ... (SIGs on type ANY should not be included in a zone.) How this data sequence is processed into the signature is algorithm dependent. 4.1.2 MD5/RSA Algorithm Signature Calculation For the MD5/RSA algorithm, the signature is as follows hash = MD5 ( data ) signature = ( 01 | FF* | 00 | prefix | hash ) ** e (mod n) where MD5 is the message digest algorithm documented in RFC 1321, "|" is concatenation, "e" is the secret key exponent of the signer, and "n" is the public modulus of the signer's public key. 01, FF, and 00 are fixed octets of the corresponding hexadecimal value. "prefix" is the ASN.1 BER MD5 algorithm designator prefix specified in PKCS1, that is, hex 3020300c06082a864886f70d020505000410 [NETSEC]. The FF octet is repeated the maximum number of times such that the value of the quantity being exponentiated is one octet shorter than the value of n. The above specifications are exactly Public Key Cryptographic Standard #1 [PKCS1]. The size of n, including most and least significant bits (which will be 1) SHALL be not less than 512 bits and not more than 2552 bits. n and e SHOULD be chosen such that the public exponent is small. Leading zeros bytes are not permitted in the MD5/RSA algorithm Eastlake, Kaufman [Page 21] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 signature. A public exponent of 3 minimizes the effort needed to decode a signature. Use of 3 as the public exponent may be weak for confidentiality uses since, if the same data can be collected encrypted under three different keys with an exponent of 3 then, using the Chinese Remainder Theorem, the original plain text can be easily recovered. This weakness is not significant for DNS because we seek only authentication, not confidentiality. 4.1.3 Zone Transfer (AXFR) SIG The above SIG mechanisms assure the authentication of all zone signed RRs of a particular name, class and type. However, to efficiently secure complete zone transfers, a SIG RR owned by the zone name must be created with a type covered of AXFR that covers all zone signed RRs other than the SIG AXFR itself. It will be calculated by hashing together all other static zone RRs, including SIGs. The RRs are ordered and concatenated for hashing as described in Section 4.1.1. (See also ordering discussion in Section 5.1.) The AXFR SIG must be calculated last of all zone key signed SIGs in the zone. It really belongs to the zone as a whole, not to the zone name. The AXFR SIG is only retrieved as part of a zone transfer. After validation of the AXFR SIG, the zone may be considered valid without verification of all the internal zone SIGs in the zone; however, any SIGs signed by entity keys or the like must still be validated. The AXFR SIG is transmitted first in a zone transfer so the receiver can tell immediately that they may be able to avoid verifying other zone signed SIGs. Dynamic zone RRs which might be added by a dynamic zone update protocol and signed by an end entity or user key rather than a zone key (see Section 3.2) are not included in the AXFR SIG. They originate in the network and will not, in general, be migrated to the recommended off line zone signing procedure (see Section 8.2). Thus such dynamic RRs are not directly signed by the zone, are not included in the AXFR SIG, and are not generally protected against omission from zone transfers. 4.1.4 Transaction SIGs A response message from a security aware server may optionally contain a special SIG as the last item in the additional information section to authenticate the transaction. Eastlake, Kaufman [Page 22] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 This SIG has a "type covered" field of zero, which is not a valid RR type. It is calculated by using a "data" (see Section 4.1.2) of the entire preceding DNS reply message, including DNS header, concatenated with the entire DNS query message that produced this response, including the query's DNS header. That is data = full response (less final transaction SIG) | full query Verification of the transaction SIG (which is signed by the server host key, not the zone key) by the requesting resolver shows that the query and response were not tampered with in transit, that the response corresponds to the intended query, and that the response comes from the queried server. 4.2 SIG RRs in the Construction of Responses Security aware servers MUST, for every authoritative RR the query will return, attempt to send the available SIG RRs which authenticate the requested RR. The following rules apply to the inclusion of SIG RRs in responses: 1. when an RR is placed in a response, its SIG RR has a higher priority for inclusion than other RRs that may need to be included. If space does not permit its inclusion, the response MUST be considered truncated. 2. when a SIG RR is present for an RR to be included in the additional information section, the response MUST NOT be considered truncated if space does not permit the inclusion of the SIG RR. Sending SIGs to authenticate non-authoritative data (glue records and NS RRs for subzones) is unnecessary and must be avoided. Note that KEYs for subzones are authoritative. If a SIG covers any RR that would be in the answer section of the response, its automatic inclusion MUST be the answer section. If it covers an RR that would appear in the authority section, its automatic inclusion MUST be in the authority section. If it covers an RR that would appear in the additional information section it MUST appear in the additional information section. Optionally, DNS transactions may be authenticated by a SIG RR at the end of the response in the additional information section (Section 4.1.4). Such SIG RRs are signed by the DNS server originating the response. Although the signer field must be the name of the originating server host, the owner name, class, TTL, and original TTL, are meaningless. The class and TTL fields can be zero. To Eastlake, Kaufman [Page 23] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 conserve space, the owner name SHOULD be root (a single zero octet). If transaction authentication is desired, that SIG RR must be considered higher priority for inclusion than any other RR in the answer. 4.3 Processing Responses and SIG RRs The following rules apply to the processing of SIG RRs included in a response: 1. a security aware resolver that receives a response from what it believes to be a security aware server via a communication path that it believes to be secure with the AD bit (see Section 6.1) set, MAY choose to accept the RRs as received without verifying the SIG RRs. 2. in other cases, a security aware resolver SHOULD verify the SIG RRs for the RRs of interest. This may involve initiating additional queries for SIG or KEY RRs, at least in the case of getting a response from an insecure server. (As explained in 4.2 above, it will not be possible to secure CNAMEs being served up by non-secure resolvers.) NOTE: Implementors might expect the above SHOULD to be a MUST. However, local policy or the calling application may not require the security services. 3. If SIG RRs are received in response to a user query explicitly specifying the SIG type, no special processing is required. If the message does not pass reasonable checks or the SIG does not check against the signed RRs, the SIG RR is invalid and should be ignored. If all of the SIG RR(s) purporting to authenticate a set of RRs are invalid, then the set of RR(s) is not authenticated. If the SIG RR is the last RR in a response in the additional information section and has a type covered of zero, it is a transaction signature of the response and the query that produced the response. It MAY be optionally checked and the message rejected if the checks fail. But even if the checks succeed, such a transaction authentication SIG does NOT authenticate any RRs in the message. Only a proper SIG RR signed by the zone can authenticate RRs. If a resolver does not implement transaction SIGs, it MUST at least ignore them without error. If all reasonable checks indicate that the SIG RR is valid then RRs verified by it should be considered authenticated. Eastlake, Kaufman [Page 24] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 4.4 Signature Expiration, TTLs, and Validity Security aware servers must not consider SIG RRs to be authentic after their expiration time and not consider any RR to be authenticated after its signatures have expired. Within that constraint, servers should continue to follow DNS TTL aging. Thus authoritative servers should continue to follow the zone refresh and expire parameters and a non-authoritative server should count down the TTL and discard RRs when the TTL is zero. In addition, when RRs are transmitted in a query response, the TTL should be trimmed so that current time plus the TTL does not extend beyond the signature expiration time. Thus, in general, the TTL on an transmitted RR would be min(sigExpTim,max(zoneMinTTL,min(originalTTL,currentTTL))) 4.5 File Representation of SIG RRs A SIG RR can be represented as a single logical line in a zone data file [RFC1033] but there are some special considerations as described below. (It does not make sense to include a transaction authenticating SIG RR in a file as it is a transient authentication that covers data including an ephemeral transaction number so it must be calculated in real time by the DNS server.) There is no particular problem with the signer, covered type, and times. The time fields appears in the form YYYYMMDDHHMMSS where YYYY is the year, the first MM is the month number (01-12), DD is the day of the month (01-31), HH is the hour in 24 hours notation (00-23), the second MM is the minute (00-59), and SS is the second (00-59). The original TTL and algorithm fields appear as unsigned integers. If the original TTL, which applies to the type signed, is the same as the TTL of the SIG RR itself, it may be omitted. The date field which follows it is larger than the maximum possible TTL so there is no ambiguity. The "labels" field does not appear in the file representation as it can be calculated from the owner name. The key footprint appears as an unsigned decimal number. However, the signature itself can be very long. It is the last data field and is represented in base 64 (see Appendix) and may be divided up into any number of white space separated substrings, down to single base 64 digits, which are concatenated to obtain the full signature. These substrings can be split between lines using the Eastlake, Kaufman [Page 25] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 standard parenthesis. Eastlake, Kaufman [Page 26] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 5. Non-existent Names and Types The SIG RR mechanism described in Section 4 above provides strong authentication of RRs that exist in a zone. But is it not immediately clear how to authenticatably deny the existence of a name in a zone or a type for an existent name. The nonexistence of a name in a zone is indicated by the NXT ("next") RR for a name interval containing the nonexistent name. An NXT RR and its SIG are returned in the authority section, along with the error, if the server is security aware. The same is true for a non-existent type under an existing name. NXT RRs will also be returned if an explicit query is made for the NXT type. The existence of a complete set of NXT records in a zone means that any query for any name and type to a security aware server serving the zone will result in an reply containing at least one signed RR. NXT RRs do not appear in zone master files since they can be derived from the rest of the zone. 5.1 The NXT Resource Record The NXT resource record is used to securely indicate that RRs with an owner name in a certain name interval do not exist in a zone and to indicate what zone signed type RRs are present for an existing name. The owner name of the NXT RR is an existing name in the zone. It's RDATA is a "next" name and a type bit map. The presence of the NXT RR means that generally no name between its owner name and the name in its RDATA area exists and that no other types exist under its owner name. This implies a canonical ordering of all domain names in a zone. The ordering is to sort labels as unsigned left justified octet strings where the absence of a octet sorts before a zero octet and upper case letters are treated as lower case letters. Names are then sorted by sorting on the highest level label and then, within those names with the same highest level label by the next lower label, etc. Since we are talking about a zone, the zone name itself always exists and all other names are the zone name with some prefix of lower level labels. Thus the zone name itself always sorts first. There is a problem with the last NXT in a zone as it wants to have an owner name which is the last existing name in sort order, which is easy, but it is not obvious what name to put in its RDATA to indicate the entire remainder of the name space. This is handled by treating the name space as circular and putting the zone name in the RDATA of Eastlake, Kaufman [Page 27] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 the last NXT. There are special considerations due to interaction with wildcards as explained below. The NXT RRs for a zone should be automatically calculated and added to the zone by the same recommended off-line process that signs the zone. The NXT RR's TTL should not exceed the zone minimum TTL. 5.2 NXT RDATA Format The RDATA for an NXT RR consists simply of a domain name followed by a bit map. The type number for the NXT RR is 30. 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | next domain name / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | type bit map / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The NXT RR type bit map is one bit per RR type present for the owner name similar to the WKS socket bit map. The first bit represents RR type zero (an illegal type which should not be present.) A one bit indicates that at least one RR of that type is present for the owner name. A zero indicates that no such RR is present. All bits not specified because they are beyond the end of the bit map are assumed to be zero. Note that bit 30, for NXT, will always be on so the minimum bit map length is actually four octets. The NXT bit map should be printed as a list of type mnemonics or decimal numbers similar to the WKS RR. The size of the bit map can be inferred from the RDLENGTH and the length of the next domain name. 5.3 Example Assume zone foo.tld has entries for big.foo.tld, medium.foo.tld. small.foo.tld. tiny.foo.tld. Eastlake, Kaufman [Page 28] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 Then a query to a security aware server for huge.foo.tld would produce an error reply with the authority section data including something like the following: big.foo.tld. NXT medium.foo.tld. A MX SIG NXT big.foo.tld. SIG NXT 1 3 ( ;type-cov=NXT, alg=1, labels=3 19960102030405 ;signature expiration 19951211100908 ;time signed 2143658709 ;key footprint foo.tld. ;signer MxFcby9k/yvedMfQgKzhH5er0Mu/vILz45IkskceFGgiWCn/GxHhai6VAuHAoNUz4YoU 1tVfSCSqQYn6//11U6Nld80jEeC8aTrO+KKmCaY= ;signature (640 bits) ) Note that this response implies that big.foo.tld is an existing name in the zone and thus has other RR types associated with it than NXT. However, only the NXT (and its SIG) RR appear in the response to this query for huge.foo.tld, which is a non-existent name. 5.4 Interaction of NXT RRs and Wildcard RRs Since, in some sense, a wildcard RR causes all possible names in an interval to exist, there should not be an NXT RR that would cover any part of this interval. Thus if *.X.ZONE exists you would expect an NXT RR that ends at X.ZONE and one that starts with the last name covered by *.X.ZONE. However, this "last name covered" is something very ugly and long like \255\255\255....X.zone. So the NXT for the interval following is simply given the owner name *.X.ZONE. This "*" type name is not expanded when the NXT is returned as authority information in connection with a query for a non-existent name. If there could be any wildcard RRs in a zone and thus wildcard NXTs, care must be taken in interpreting the results of explicit NXT retrievals as the owner name may be a wildcard expansion. The existence of one or more wildcard RRs covering a name interval makes it possible for a malicious server to hide any more specificly named RRs in the internal. The server can just falsely return the wildcard match NXT instead of the more specificly named RRs. If there is a zone wide wildcard, there will be an NXT RR whose owner name is the wild card and whose RDATA is the zone name. In this case a server could conceal the existence of any more specific RRs in the zone. (It would be possible to design a more strict NXT feature which would eliminate this possibility. But it would be more complex and might be so constraining as to make any dynamic update feature that could create new names very difficult (see Section 3.2).) What name should be put into the RDATA of an NXT RR with an owner Eastlake, Kaufman [Page 29] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 name that is within a wild card scope? Since the "next" existing name will be one that matches the wild card, the wild card name should be used. Inclusion of such NXTs within a wild card scope is optional. 5.5 Blocking NXT Pseudo-Zone Transfers In a secure zone, a resolver can query for the initial NXT associated with the zone name. Using the next domain name RDATA field from that RR, it can query for the next NXT RR. By repeating this, it can walk through all the NXTs in the zone. If there are no wildcards, it can use this technique to find all names in a zone. If it does type ANY queries, it can incrementally get all information in the zone and perhaps defeat attempts to administratively block zone transfers. If there are any wildcards, this NXT walking technique will not find any more specific RR names in the part of the name space the wildcard covers. By doing explicit retrievals for wildcard names, a resolver could determine what intervals are covered by wildcards but still could not, with these techniques, find any names inside such intervals except by trying every name. If it is desired to block NXT walking, the recommended method is to add a zone wide wildcard of the KEY type with the no key bit on and with no type (zone, entity, or user) bit on. This will cause there to be one zone covering NXT RR and leak no information about what real names exist in the zone. This protection from pseudo-zone transfers is bought at the expense of eliminating the data origin authentication of the non-existence of names that NXT RRs can provide. If an entire zone is covered by a wildcard, a malicious server can return an RR produced by matching the resulting wildcard NXT and can thus hide all the real data and delegations with more specific names in the zone. 5.6 Special Considerations at Delegation Points A name other than root which is the head of a zone also appears as the leaf in a superzone. If both are secure, there will always be two different NXT RRs with the same name. They can be distinguished by their signers and next domain name fields. Security aware servers should return the correct NXT automatically when required to authenticate the non-existence of a name and both NXTs, if available, on explicit query for type NXT. Insecure servers will never automatically return an NXT and may only return the NXT from the subzone on explicit queries. Eastlake, Kaufman [Page 30] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 6. The AD and CD Bits and How to Resolve Securely Retrieving or resolving authentic data from the Domain Name System (DNS) involves starting with one or more trusted public keys. With trusted keys, a resolver willing to perform cryptography can progress securely through the secure DNS zone structure to the zone of interest as described in Section 6.3. Such trusted public keys would normally be configured in a manner similar to that described in Section 6.2. However, as a practical matter, a security aware resolver would still gain some confidence in the results it returns even if it was not configured with any keys but trusted what it got from a local well known server as a starting point. Data stored at a server needs security labels of Authenticated, Pending, or Insecure. There is also a fourth transient state of Bad which indicates that SIG checks have explicitly failed on the data. Such Bad data is not retained at a security aware server. Authenticated means that the data has a valid SIG under a KEY traceable via a chain of zero or more SIG and KEY RRs to a KEY configured at the resolver via its boot file. Pending data has no authenticated SIGs and at least one additional SIG the resolver is still trying to authenticate. Insecure data is data which it is known can never be either Authenticated or found Bad because it is in a zone with no key or an experimental key. Behavior in terms of control of and flagging based on such data labels is described in Section 6.1. The proper validation of signatures requires a reasonably secure shared opinion of the absolute time between resolvers and servers as described in Section 6.4. In getting to the data of interest to respond to a query, a secure resolver may encounter genuine non-secure zones. It may proceed through such zones but should report this as described in Section 6.5. 6.1 The AD and CD Header Bits Two unused bits are allocated out of the DNS query/response format header. The AD (authentic data) bit indicates in a response that the data included has been verified by the server providing it. The CD (checking disabled) bit indicates in a query that non-verified data is acceptable to the resolver sending the query. These bits are allocated from the must-be-zero Z field as follows: Eastlake, Kaufman [Page 31] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 1 1 1 1 1 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | ID | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |QR| Opcode |AA|TC|RD|RA| Z|AD|CD| RCODE | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | QDCOUNT | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | ANCOUNT | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | NSCOUNT | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | ARCOUNT | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ These bits are zero in old servers and resolvers. Thus the responses of old servers are not flagged as authenticated to security aware resolvers and queries from non-security aware resolvers do not assert the checking disabled bit and thus will be answered by security aware servers only with authenticated data. Of course security aware resolvers can not trust the AD bit unless they trust the server they are talking to and have a secure path to it. Any security aware resolver willing to do cryptography should assert the CD bit on all queries to reduce DNS latency time by allowing security aware servers to answer before they have resolved the validity of data. Security aware servers never return Bad data. For non-security aware resolvers or security aware resolvers requesting service by having the CD bit clear, security aware servers return only Authenticated or Insecure data with the AD bit set in the response. Security aware resolvers will know that if data is Insecure versus Authentic by the absence of SIG RRs. Security aware servers may return Pending data to security aware resolvers requesting the service by clearing the AD bit in the response. The AD bit may only be set on a response if the RRs in the response are either Authenticated or Insecure. 6.2 Boot File Format The format for a boot file directive to configure a starting zone key is as follows: pubkey name flags protocol algorithm key-data for a public key. "name" is the owner name (if the line is translated into a KEY RR). Flags indicates the type of key and is Eastlake, Kaufman [Page 32] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 the same as the flag octet in the KEY RR. Algorithm is the algorithm in use where one is the MD5/RSA algorithm and 254 indicates a private algorithm. The material after the algorithm is algorithm dependent and, for private algorithms, starts with the algorithm's identifying OID. If the "no key" bit is on in flags or the algorithm is specified as 253, then the key-data after algorithm may be omitted. It is treated as an octet stream and encoded in base 64 (see Appendix). A file of keys for cross certification or other purposes can be configured though the keyfile directive as follows: keyfile filename The file looks like a master file except that it can only contain KEY and SIG RRs with the SIGs signed under a key configured with the pubkey directive. While it might seem logical for everyone to start with the key for the root zone, this has problems. The logistics of updating every DNS resolver in the world when the root key changes would be excessive. It may be some time before there even is a root key. Furthermore, many organizations will explicitly wish their "interior" DNS implementations to completely trust only their own zone. These interior resolvers can then go through the organization's zone server to access data outsize the organization's domain. 6.3 Chaining Through Zones Starting with one or more trusted keys for a zone, it should be possible to retrieve signed keys for its subzones which have a key and, if the zone is not root, for some superzone. Every authoritative secure zone server should also include the KEY RR for a super-zone signed by the secure zone via a keyfile directive. This makes it possible to climb the tree of zones if one starts below root. A secure sub-zone is indicated by a KEY RR appearing with the NS RRs for the sub-zone. These make it possible to descend within the tree of zones. A resolver should keep track of the number of successive secure zones traversed from a starting point to any secure zone it can reach. In general, the lower such a distance number is, the greater the confidence in the data. Data configured via a boot file directive should be given a distance number of zero. Should a query encounter different data for the same query with different distance values, that with a larger value should be ignored. A security conscious resolver should completely refuse to step from a Eastlake, Kaufman [Page 33] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 secure zone into a non-secure zone unless the non-secure zone is certified to be non-secure, or only experimentally secure, by the presence of an authenticated KEY RR for the non-secure zone with a no key flag or the presence of a KEY RR with the experimental bit set. Otherwise the resolver is probably getting completely bogus or spoofed data. If legitimate non-secure zones are encountered in traversing the DNS tree, then no zone can be trusted as secure that can be reached only via information from such non-secure zones. Since the non-secure zone data could have been spoofed, the "secure" zone reach via it could be counterfeit. The "distance" to data in such zones or zones reached via such zones could be set to 512 or more as this exceeds the largest possible distance through secure zones in the DNS. Nevertheless, continuing to apply secure checks within "secure" zones reached via non-secure zones will, as a practical matter, provide some increase in security. 6.4 Secure Time Coordinated interpretation of the time fields in SIG RRs requires that reasonably consistent time be available to the hosts implementing the DNS security extensions. A variety of time synchronization protocols exist including the Network Time Protocol (NTP, RFC1305). If such protocols are used, they should be used securely so that time can not be spoofed. Otherwise, for example, a host could get its clock turned back and might then believe old SIG and KEY RRs which were valid but no longer are. Eastlake, Kaufman [Page 34] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 7. Operational Considerations This section discusses a variety of considerations in secure operation of the Domain Name System (DNS) using these proposed protocol extensions. 7.1 Key Size Considerations There are a number of factors that effect public key size choice for use in the DNS security extension. Unfortunately, these factors usually do not all point in the same direction. Choice of zone key size should generally be made by the zone administrator depending on their local conditions. For most schemes, larger keys are more secure but slower. Given a small public exponent, verification (the most common operation) for the MD5/RSA algorithm will vary roughly with the square of the modulus length, signing will vary with the cube of the modulus length, and key generation (the least common operation) will vary with the fourth power of the modulus length. The current best algorithms for factoring a modulus and breaking RSA security vary roughly with the square of the modulus itself. Thus going from a 640 bit modulus to a 1280 bit modulus only increases the verification time by a factor of 4 but increases the work factor of breaking the key by over 2^3000. [RSA FAQ] An upper bound of 2552 bit has been established for the MD4/RSA DNS security algorithm for interoperability purposes. However, larger keys increase the size of the KEY and SIG RRs. This increases the chance of DNS UDP packet overflow and the possible necessity for using higher overhead TCP in responses. The recommended minimum RSA algorithm modulus size, 640 bits, is believed by the authors to be secure at this time and for some years but high level zones in the DNS tree may wish to set a higher minimum, perhaps 1000 bits, for security reasons. (Since the United States National Security Agency generally permits export of encryption systems using an RSA modulus of up to 512 bits, use of that small a modulus, i.e. n, must be considered weak.) For a key used only to secure data and not to secure other keys, 640 bits should be entirely adequate. Eastlake, Kaufman [Page 35] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 7.2 Key Storage It is strongly recommended that zone private keys and the zone file master copy be kept and used in off-line non-network connected physically secure machines only. Periodically an application can be run to re-sign the RRs in a zone by adding NXT and SIG RRs. Then the augmented file can be transferred, perhaps by sneaker-net, to the networked zone primary server machine. The idea is to have a one way information flow to the network to avoid the possibility of tampering from the network. Keeping the zone master file on-line on the network and simply cycling it through an off-line signer does not do this. The on-line version could still be tampered with if the host it resides on is compromised. For maximum security, the master copy of the zone file should be off net and should not be updated based on an unsecured network mediated communication. Note, however, that secure resolvers need to be configured with some trusted on-line public key information (or a secure path to such a resolver). Non-zone private keys, such as host or user keys, may have to be kept on line to be used for real-time purposes such as DNS transaction security, IPSEC session set-up, or secure mail. 7.3 Key Generation Careful key generation is a sometimes overlooked but absolutely essential element in any cryptographically secure system. The strongest algorithms used with the longest keys are still of no use if an adversary can guess enough to lower the size of the likely key space so that it can be exhaustively searched. Suggestions will be found in RFC 1750. It is strongly recommended that key generation also occur off-line, perhaps on the machine used to sign zones (see Section 7.2). 7.4 Key Lifetimes No key should be used forever. The longer a key is in use, the greater the probability that it will have been compromised through carelessness, accident, espionage, or cryptanalysis. Furthermore, if key rollover is a rare event, there is an increased risk that, when the time does come up change the key, no one at the site will remember how to do it or other problems will have developed in the Eastlake, Kaufman [Page 36] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 procedures. While key lifetime is a matter of local policy, these considerations suggest that no zone key should have a lifetime significantly over four years. A reasonable maximum lifetime for zone keys that are kept off-line and carefully guarded is 13 months with the intent that they be replaced every year. A reasonable maximum lifetime for end entity keys that are used for IP-security or the like and are kept on line is 36 days with the intent that they be replaced monthly or more often. In some cases, an entity key lifetime of somewhat over a day may be reasonable. 7.5 Signature Lifetime Signature expiration times must be set far enough in the future that it is quite certain that new signatures can be generated before the old ones expire. However, setting expiration too far into the future could, if bad data or signatures were ever generated, mean a long time to flush such badness. It is recommended that signature lifetime be a small multiple of the TTL but not less than a reasonable re-signing interval. 7.6 Root It should be noted that in DNS the root is a zone unto itself. Thus the root zone key should only be seen signing itself or signing RRs with names one level below root, such as .aq, .edu, or .arpa. Implementations MAY reject as bogus any purported root signature of records with a name more than one level below root. Eastlake, Kaufman [Page 37] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 8. Conformance Several levels of server and resolver conformance are defined. 8.1 Server Conformance Two levels of server conformance are defined as follows: Minimal server compliance is the ability to store and retrieve (including zone transfer) SIG, KEY, and NXT RRs. Any secondary, caching, or other server for a secure zone must be at least minimally compliant and even then some things, such as secure CNAMEs, will not work. Full server compliance adds the following to basic compliance: (1) ability to read SIG, KEY, and NXT RRs in zone files and (2) ability, given a zone file and private key, to add appropriate SIG and NXT RRs, possibly via a separate application, (3) proper automatic inclusion of SIG, KEY, and NXT RRs in responses, (4) suppression of CNAME following on retrieval of the security type RRs, (5) recognize the CD query header bit and set the AD query header bit, as appropriate, and (6) proper handling of the two NXT RRs at delegation points. Primary servers for secure zones MUST be fully compliant and for completely successful secure operation, all secondary, caching, and other servers handling the zone should be fully compliant as well. 8.2 Resolver Conformance Two levels of resolver compliance are defined: A basic compliance resolver can handle SIG, KEY, and NXT RRs when they are explicitly requested. A fully compliant resolver (1) understands KEY, SIG, and NXT RRs, (2) maintains appropriate information in its local caches and database to indicate which RRs have been authenticated and to what extent they have been authenticated, (3) performs additional queries as necessary to attempt to obtain KEY, SIG, or NXT RRs from non- security aware servers, (4) normally sets the CD query header bit on its queries. Eastlake, Kaufman [Page 38] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 9. Security Considerations This document concerns technical details of extensions to the Domain Name System (DNS) protocol to provide data integrity and origin authentication, public key distribution, and optional transaction security. If should be noted that, at most, these extensions guarantee the validity of resource records, including KEY resource records, retrieved from the DNS. They do not magically solve other security problems. For example, using secure DNS you can have high confidence in the IP address you retrieve for a host name; however, this does not stop someone for substituting an unauthorized host at that address or capturing packets sent to that address and falsely responding with packets apparently from that address. Any reasonably complete security system will require the protection of many other facets of the Internet. References [NETSEC] - Network Security: PRIVATE Communications in a PUBLIC World, Charlie Kaufman, Radia Perlman, & Mike Speciner, Prentice Hall Series in Computer Networking and Distributed Communications 1995. [PKCS1] - PKCS #1: RSA Encryption Standard, RSA Data Security, Inc., 3 June 1991, Version 1.4. [RFC1032] - Domain Administrators Guide, M. Stahl, November 1987 [RFC1033] - Domain Administrators Operations Guide, M. Lottor, November 1987 [RFC1034] - Domain Names - Concepts and Facilities, P. Mockapetris, November 1987 [RFC1035] - Domain Names - Implementation and Specifications [RFC1305] - Network Time Protocol (v3), D. Mills, April 9 1992. [RFC1321] - The MD5 Message-Digest Algorithm, R. Rivest, April 16 1992. [RFC1530] - Principles of Operation for the TPC.INT Subdomain: General Principles and Policy, C. Malamud, M. Rose, October 6 1993. [RFC1750] - Randomness Requirements for Security, D. Eastlake, S. Crocker, J. Schiller, December 1994. Eastlake, Kaufman [Page 39] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 [RSA FAQ] - RSADSI Frequently Asked Questions periodic posting. Eastlake, Kaufman [Page 40] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 Authors Addresses Donald E. Eastlake, 3rd CyberCash, Inc. 318 Acton Street Carlisle, MA 01741 USA Telephone: +1 508 287 4877 EMail: dee@cybercash.com Charles W. Kaufman Iris Associates 1 Technology Park Drive Westford, MA 01886 USA Telephone: +1 508-392-5276 EMail: charlie_kaufman@iris.com Expiration and File Name This draft expires 2 April 1995. Its file name is draft-ietf-dnssec-secext-06.txt. Eastlake, Kaufman [Page 41] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 Appendix: Base 64 Encoding The following encoding technique is taken from RFC 1521 by Borenstein and Freed. It is reproduced here in an edited form for convenience. A 65-character subset of US-ASCII is used, enabling 6 bits to be represented per printable character. (The extra 65th character, "=", is used to signify a special processing function.) The encoding process represents 24-bit groups of input bits as output strings of 4 encoded characters. Proceeding from left to right, a 24-bit input group is formed by concatenating 3 8-bit input groups. These 24 bits are then treated as 4 concatenated 6-bit groups, each of which is translated into a single digit in the base64 alphabet. Each 6-bit group is used as an index into an array of 64 printable characters. The character referenced by the index is placed in the output string. Table 1: The Base64 Alphabet Value Encoding Value Encoding Value Encoding Value Encoding 0 A 17 R 34 i 51 z 1 B 18 S 35 j 52 0 2 C 19 T 36 k 53 1 3 D 20 U 37 l 54 2 4 E 21 V 38 m 55 3 5 F 22 W 39 n 56 4 6 G 23 X 40 o 57 5 7 H 24 Y 41 p 58 6 8 I 25 Z 42 q 59 7 9 J 26 a 43 r 60 8 10 K 27 b 44 s 61 9 11 L 28 c 45 t 62 + 12 M 29 d 46 u 63 / 13 N 30 e 47 v 14 O 31 f 48 w (pad) = 15 P 32 g 49 x 16 Q 33 h 50 y Special processing is performed if fewer than 24 bits are available at the end of the data being encoded. A full encoding quantum is always completed at the end of a quantity. When fewer than 24 input bits are available in an input group, zero bits are added (on the right) to form an integral number of 6-bit groups. Padding at the end of the data is performed using the '=' character. Since all base64 input is an integral number of octets, only the following cases can arise: (1) the final quantum of encoding input is an integral multiple of 24 bits; here, the final unit of encoded output will be an integral multiple of 4 characters with no "=" padding, (2) Eastlake, Kaufman [Page 42] INTERNET-DRAFT DNS Protocol Security Extensions 3 October 1995 the final quantum of encoding input is exactly 8 bits; here, the final unit of encoded output will be two characters followed by two "=" padding characters, or (3) the final quantum of encoding input is exactly 16 bits; here, the final unit of encoded output will be three characters followed by one "=" padding character. Eastlake, Kaufman [Page 43]   Received: from relay.tis.com by neptune.TIS.COM id aa03387; 6 Oct 95 12:51 EDT Received: from tce.ing.uniroma1.it(151.100.8.30) by relay.tis.com via smap (g3.0.1) id xma020436; Fri, 6 Oct 95 12:33:30 -0400 Received: from labmicrolc.ing.uniroma1.it by tce.ing.uniroma1.it (AIX 3.2/UCB 5.64/4.03) id AA12382; Fri, 6 Oct 1995 16:56:31 +0200 Message-Id: <9510061456.AA12382@tce.ing.uniroma1.it> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 6 Oct 1995 17:16:20 +0100 To: ieeetcpc@ccvm.sunysb.ed, utheorynt@vm1.nodak.edu, orcs-l@osuvm1.bitnet, tccc@cs.umass.edu, cellular@dfv.rwth-aachen.edu, performance@tay1.dec.com, glynn@leland.stanford.edu, modern-heuristics@uk.ac.mailbase, ietf-announce@cnri.reston.va.us, mobile-ip@tadpole.com, dbworld@cs.wisc.edu, end2end-interest@isi.edu, f-troup@aurora.cis.upenn.edu, rem-conf-request@es.net, cost237-transport@comp.lancs.ac.uk, reres@laas.fr, hipparch@sophia.inria.fr, xtp-relay@cs.concordia.ca, rem-conf@es.net, sigmedia@bellcore.com, www-security@ns2.Rutgers.EDU, ipsec@ans.net, dns-security@TIS.COM, mobile-ip@tadpole.com, arpanet-bboard@mc.lcs.mit.edu, atm@bbn.com, cnom@meatro.bellcore.com, globecom@signet.com.sig, ietf@isi.edu, elf@cs.washington.edu, g_f_wetzel@att.com From: Paolo Bernardi Subject: Wireless Networks Journal - CFP Herebelow it follows the call for papers for a special issue of Wireless Networks Journal. I would be very grateful if you could diffuse it according your distribution list. Thank you for your kind attention. Call for Papers WIRELESS NETWORKS JOURNAL Baltzer Science Publishers Special Issue "Exposure Hazards and Health Protection in Personal Communication Services" Scope: The rapid diffusion of electronic and telecommunication equipments and systems emitting electromagnetic waves has brought into focus the problems of electromagnetic pollution of the environment and the possible adverse health effects on human beings. In particular, over the past decade there has been a significant increase in the use of hand-held cellular telephones. Because of the proximity of the transmitting antenna to the user's head, great concerns have arose about the potential risks to human health. The problem has been made even more acute by the impending development of wireless data services and wide-band wireless local area networks. Many national and international standard organizations, governmental bodies, and health authorities have issued or are considering approval of standards, recommendations, or legistative actions to protect the public from excessive exposures. In the meantime, scientists and manufacturers are contemplating new design techniques that may reduce the exposure. The aim of this special issue is to highlight problems which are presently under consideration and to present recent progress in this area of research, with particular emphasis on scientific studies used to define exposure limits. Possible topics include, but are not limited to: Biological effects (in vitro and in vivo): - CW fields - modulated fields Dosimetry: - source characterization - electric and magnetic properties of biological materials - experiments and numerical models Epidemiology Interaction mechanisms: - at subcellular, cellular, single organ, and physiological system level Standards and Safety Issues: - cellular phones - wireless data systems and services - wireless local-area networks - Video Display Units The authors should send 4 copies of their paper to one of the Guest Editors by February 1, 1996. The following time-table shall be followed: Manuscript Submission: Deadline: February 1, 1996 Final Manuscript Submission after Revision: Deadline: July 1, 1996 Expected Publication Date: xx, xx, xx Guest Editors: Prof. Paolo Bernardi Department of Electronic Engineering Universita' di Roma "La Sapienza" Via Eudossiana 18, 00184 Roma, ITALY Tel. +39 6 4458 5 855 Fax +39 6 4742647 e-mail: bernardi@tce.ing.uniroma1.it Prof. James C. Lin The University of Illinois at Chicago College of Engineering (M/C 154) 851 South Morgan Street Chicago, Illinois 60607 - 7053 tel: +312 413 1052 fax: +312 413 0024 e-mail: u45339@uicvm.uic.edu Prof. Paolo Bernardi Department of Electronic Engineering Universita' di Roma "La Sapienza" Via Eudossiana 18, 00184 Roma ITALY Tel. +39 6 4458 5 855 Fax +39 6 4742647 E-mail bernardi@tce.ing.uniroma1.it   Received: from relay.tis.com by neptune.TIS.COM id aa10153; 10 Oct 95 9:50 EDT Received: from watson.ibm.com(129.34.139.4) by relay.tis.com via smap (g3.0.1) id xma023195; Tue, 10 Oct 95 09:33:38 -0400 Received: from WATSON by watson.ibm.com (IBM VM SMTP V2R3) with BSMTP id 2663; Tue, 10 Oct 95 09:51:45 EDT Received: from YKTVMV by watson.vnet.ibm.com with "VAGENT.V1.02 on VAGENT2" id 1919; Tue, 10 Oct 1995 09:51:43 EDT Received: from edisto.watson.ibm.com by yktvmv.watson.ibm.com (IBM VM SMTP V2Rx) with TCP; Tue, 10 Oct 95 09:51:42 EDT Received: by edisto.watson.ibm.com (AIX 3.2/UCB 5.64/900524) id AA19385; Tue, 10 Oct 1995 09:52:16 -0400 Message-Id: <9510101352.AA19385@edisto.watson.ibm.com> X-External-Networks: yes To: "Donald E. Eastlake 3rd" Cc: dns-security@TIS.COM, jis@mit.edu, yakov@cisco.com, set@thumper.bellcore.com, randy@psg.com Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-Reply-To: Your message of Tue, 03 Oct 95 21:51:52 D. Date: Tue, 10 Oct 95 09:52:16 -0500 From: "Edie E. Gunter" I have a few comments on the draft... - Section 3 says: Security aware DNS implementations MUST be designed to handle at least two simultaneously valid keys of the same type associated with a name. Why isn't the ability to handle one enough? Why MUST two valid keys be supported? Optional support of more than one is fine. (Why would anyone want more than one KEY of the same type, anyway?) - Section 3.7 refers to type AAAA RR's. What are these? - Section 4 says: The SIG RR unforgably authenticates other RRs of a particular type, class, and name and binds them to a time interval and the signer's domain name. If this is true, why isn't the SIG on a dynamic update sufficient to make that name/RR a full-fledged part of the DNS database, allowing dynamically updated data to be treated just like "static" data? If this is true, why do we even need the distinction of static versus dynamic RRs? - Section 4.1.3 says: Thus such dynamic RRs are not directly signed by the zone, are not included in the AXFR SIG, and are not generally protected against omission from zone transfers. I am quite sure this is not what anyone running a secure DNS that supports secure dynamic updates would want. It seems this section should cover how to securely include dynamic updates in a zone transfer -- if not via the method described in 4.1.3 using AXFR SIG, etc. then by some other method. - Section 4.3 says: Only a proper SIG RR signed by the zone can authenticate RRs. What about entity signed dynamic RRs? - Section 4.4 Signature Expiration When a SIG expires, the covered RR's are not removed from the database, but are kept around and the AD bit is used to indicate if the data is no longer authentic. Is that right? - Section 5.1 says: The NXT RRs for a zone should be automatically calculated and added to the zone by the same recommended off-line process that signs the zone. What about dynamic updates? Can't you get into a situation where something was added via a dynamic update and the NXT RR computed at start-up is no longer correct? It seems to me that these NXT RR's must be computed on the fly to be accurate in the face of dynamic updates. - Section 6 says: Authenticated means that the data has a valid SIG under a KEY traceable via a chain of zero or more SIG and KEY RRs to a KEY configured at the resolver via its boot file. So, if the KEY RR for a name was in the statically read master file for the zone, then RR's added dynamically and signed with the private part of that KEY are considered authenticated? - Section 6.1 says: Security aware servers never return Bad data. Is this true, given that zone transfers may omit dynamically added RR's and given that NXT RR's are calculated offline? Perhaps I don't understand the definition of Bad data here. - Section 6.3 says: A resolver should keep track of the number of successive secure zones traversed from a starting point to any secure zone it can reach. <...> Should a query encounter different data for the same query with different distance values, that with a larger value should be ignored. I don't see exactly how this is supposed to work. Are you suggesting that after sending out a query, the client waits around for multiple query responses and then picks the one with the lower distance value? In practice, wouldn't a client just take the first response with a non-empty answer section and use that? - Section 7.2 says: Periodically an application can be run to re-sign the RRs in a zone by adding NXT and SIG RRs. It seems to get dynamic updates to work within the DNSSEC framework, this period would have to be such that everything is re-signed after each dynamic update. The update becomes part of the "static" data and all the "static" data is then resigned. No, this can't be right. - Section 7.5 says: It is recommended that signature lifetime be a small multiple of the TTL but not less than a reasonable re-signing interval. In an environment where DHCP is used to hand out IP address leases and DNS is updated dynamically to reflect the lease information, the lifetime of the data will usually be that of the lease duration. In the case of mobile clients, this lease duration may be just 5 - 10 minutes. That said, what is your idea of a reasonable re-signing interval? - Also, it was mentioned to me in private email that: if you want a completely dynamic zone, you can just have the zone key sign an entity key with wildcard authority over the entire zone and then use the entity key for everything in the zone I don't see anything like this discussed in the draft -- particularly with respect to zone transfers and handling NXT records. (And if there really is this other way to do security in DNS servers that support dynamic updates, I'd really like to understand how it would work!) Edie   Received: from relay.tis.com by neptune.TIS.COM id aa11791; 10 Oct 95 11:06 EDT Received: from concorde.inria.fr(192.93.2.39) by relay.tis.com via smap (g3.0.1) id xma024184; Tue, 10 Oct 95 10:49:14 -0400 Received: from givry.inria.fr (givry.inria.fr [128.93.8.18]) by concorde.inria.fr (8.6.10/8.6.9) with ESMTP id QAA00243; Tue, 10 Oct 1995 16:00:31 +0100 Received: from givry.inria.fr (localhost.inria.fr [127.0.0.1]) by givry.inria.fr (8.6.10/8.6.6) with ESMTP id QAA03251; Tue, 10 Oct 1995 16:00:30 +0100 Message-Id: <199510101500.QAA03251@givry.inria.fr> From: Francis Dupont To: "Edie E. Gunter" cc: "Donald E. Eastlake 3rd" , dns-security@TIS.COM, jis@mit.edu, yakov@cisco.com, set@thumper.bellcore.com, randy@psg.com Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-reply-to: Your message of Tue, 10 Oct 1995 09:52:16 EST. <9510101352.AA19385@edisto.watson.ibm.com> Date: Tue, 10 Oct 1995 16:00:26 +0100 Sender: Francis.Dupont@inria.fr In your previous mail you wrote: I have a few comments on the draft... - Section 3.7 refers to type AAAA RR's. What are these? => RR for IPv6 addresses (the name is from the proposed AA RR for SIP 8 byte addresses). Regards Francis.Dupont@inria.fr PS: according to draft-ietf-ipngwg-dns-00.txt: The AAAA resource record type is a new record specific to the Inter- net class that stores a single IPv6 address. The value of the type is 28 (decimal). An IPv6 address is encoded in the data portion of an AAAA resource record in network byte order (high-order byte first). (PS: IPv6 addresses have a 16 byte length)   Received: from relay.tis.com by neptune.TIS.COM id aa01490; 11 Oct 95 10:34 EDT Received: from ietf.cnri.reston.va.us(132.151.1.35) by relay.tis.com via smap (g3.0.1) id xma008094; Wed, 11 Oct 95 10:17:07 -0400 Received: from [127.0.0.1] by IETF.CNRI.Reston.VA.US id aa10936; 11 Oct 95 9:26 EDT Mime-Version: 1.0 Content-Type: Multipart/Mixed; Boundary="NextPart" To: IETF-Announce: ;, tis.com@TIS.COM MMDF-Warning: Parse error in original version of preceding line at neptune.TIS.COM cc: dns-security@TIS.COM From: Internet-Drafts@cnri.reston.va.us Reply-to: Internet-Drafts@cnri.reston.va.us Subject: I-D ACTION:draft-ietf-dnssec-secext-06.txt Date: Wed, 11 Oct 95 09:26:09 -0400 Sender: cclark@cnri.reston.va.us Message-ID: <9510110926.aa10936@IETF.CNRI.Reston.VA.US> --NextPart A Revised Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the Domain Name System Security Working Group of the IETF. Title : Domain Name System Security Extensions Author(s) : D. Eastlake, C. Kaufman Filename : draft-ietf-dnssec-secext-06.txt Pages : 43 Date : 10/10/1995 The Domain Name System (DNS) has become a critical operational part of the Internet infrastructure yet it has no strong security mechanisms to assure data integrity or authentication. Extensions to the DNS are described that provide these services to security aware resolvers or applications through the use of cryptographic digital signatures. These digital signatures are included in secured zones as resource records. Security can still be provided even through non-security aware DNS servers in many cases. The extensions also provide for the storage of authenticated public keys in the DNS. This storage of keys can support general public key distribution service as well as DNS security. The stored keys enable security aware resolvers to learn the authenticating key of zones in addition to keys for which they are initially configured. Keys associated with DNS names can be retrieved to support other protocols. Provision is made for a variety of key types and algorithms. In addition, the security extensions provide for the optional authentication of DNS protocol transactions. Internet-Drafts are available by anonymous FTP. Login with the username "anonymous" and a password of your e-mail address. After logging in, type "cd internet-drafts" and then "get draft-ietf-dnssec-secext-06.txt". A URL for the Internet-Draft is: ftp://ds.internic.net/internet-drafts/draft-ietf-dnssec-secext-06.txt Internet-Drafts directories are located at: o Africa Address: ftp.is.co.za (196.4.160.8) o Europe Address: nic.nordu.net (192.36.148.17) Address: ftp.nis.garr.it (192.12.192.10) o Pacific Rim Address: munnari.oz.au (128.250.1.21) o US East Coast Address: ds.internic.net (198.49.45.10) o US West Coast Address: ftp.isi.edu (128.9.0.32) Internet-Drafts are also available by mail. Send a message to: mailserv@ds.internic.net. In the body type: "FILE /internet-drafts/draft-ietf-dnssec-secext-06.txt". NOTE: The mail server at ds.internic.net can return the document in MIME-encoded form by using the "mpack" utility. To use this feature, insert the command "ENCODING mime" before the "FILE" command. To decode the response(s), you will need "munpack" or a MIME-compliant mail reader. Different MIME-compliant mail readers exhibit different behavior, especially when dealing with "multipart" MIME messages (i.e., documents which have been split up into multiple messages), so check your local documentation on how to manipulate these messages. For questions, please mail to Internet-Drafts@cnri.reston.va.us. Below is the data which will enable a MIME compliant mail reader implementation to automatically retrieve the ASCII version of the Internet-Draft. --NextPart Content-Type: Multipart/Alternative; Boundary="OtherAccess" --OtherAccess Content-Type: Message/External-body; access-type="mail-server"; server="mailserv@ds.internic.net" Content-Type: text/plain Content-ID: <19951010103755.I-D@CNRI.Reston.VA.US> ENCODING mime FILE /internet-drafts/draft-ietf-dnssec-secext-06.txt --OtherAccess Content-Type: Message/External-body; name="draft-ietf-dnssec-secext-06.txt"; site="ds.internic.net"; access-type="anon-ftp"; directory="internet-drafts" Content-Type: text/plain Content-ID: <19951010103755.I-D@CNRI.Reston.VA.US> --OtherAccess-- --NextPart--   Received: from relay.tis.com by neptune.TIS.COM id aa06059; 11 Oct 95 14:55 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma011848; Wed, 11 Oct 95 14:38:24 -0400 Received: from polar.tis.com by tis.com (4.1/SUN-5.64) id AA14391; Wed, 11 Oct 95 14:55:12 EDT Message-Id: <9510111855.AA14391@tis.com> To: "Edie E. Gunter" Cc: dns-security@TIS.COM, jis@mit.edu, yakov@cisco.com, set@thumper.bellcore.com, randy@psg.com, ogud@TIS.COM Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-Reply-To: Your message of "Tue, 10 Oct 1995 09:52:16 CDT." <9510101352.AA19385@edisto.watson.ibm.com> Date: Wed, 11 Oct 1995 14:55:01 -0400 From: Olafur Gudmundsson "Edie E. Gunter" writes: > I have a few comments on the draft... > I will take a stab at few of these comments > - Section 3 says: > > Security > aware DNS implementations MUST be designed to handle at least two > simultaneously valid keys of the same type associated with a name. > > Why isn't the ability to handle one enough? Why MUST two valid > keys be supported? Optional support of more than one is fine. > (Why would anyone want more than one KEY of the same type, anyway?) Two examples: Current Key and Future Key. Current Key and Old Key. A zone may have decided to use a new key but it can not start signing with that key untill its superzone has signed the key. Superzone will have to sign two KEY RR's for the zone during KEY transition. Zone can not start signing with the new key until the superzone has signed the new key. Superzone can not stop signing the old KEY until after the zone starts signing with the New KEY. If zone knows that zonekey has been compromized it may request the superzone to only sign the NEW KEY. This will lead to service interruptions, but this is an acceptable price to pay in this rare case. Even if zone has started to use the new KEY, a server may have two sets RR's from the zone one signed by the OLD KEY and one signed by the NEW KEY, as long as the TTL and or the Signature have not expired on the RR's signed by the OLD KEY these are valid RR's. Zone may also have Key for signing zone (640bits and with exponent=3), and a second key for MOSS (2084bits and with exponent>2^20) and a third key for IPSEC (1028bits with exponent>2^12K). > - Section 4 says: > > The SIG RR unforgably authenticates other RRs of a particular type, > class, and name and binds them to a time interval and the signer's > domain name. > > If this is true, why isn't the SIG on a dynamic update sufficient > to make that name/RR a full-fledged part of the DNS database, > allowing dynamically updated data to be treated just like "static" > data? If this is true, why do we even need the distinction of > static versus dynamic RRs? Signed static RR's are covered by the SIG(AXFR). SIG(AXFR) needs to be recalculated if there are any changes (see more below). > > - Section 4.1.3 says: > > Thus > such dynamic RRs are not directly signed by the zone, are not > included in the AXFR SIG, and are not generally protected against > omission from zone transfers. > > I am quite sure this is not what anyone running a secure DNS that > supports secure dynamic updates would want. It seems this section > should cover how to securely include dynamic updates in a zone transfer -- > if not via the method described in 4.1.3 using AXFR SIG, etc. then by > some other method. IF Dynamic RR's are covered by SIG(AXFR) then the SIG(AXFR) has to be recomputed whenever a dynamic RR changes. To do this in REAL TIME the P RIVATE zonekey has to be online and available to the primary server. See section 7.2 for more details. > - Section 4.3 says: > > Only a proper SIG RR signed by the zone can authenticate RRs. > > What about entity signed dynamic RRs? > > - Section 4.4 Signature Expiration > > When a SIG expires, the covered RR's are not removed from the database, > but are kept around and the AD bit is used to indicate if the data > is no longer authentic. Is that right? Incorrect: When the SIG expires the RR's are to be purged. > > - Section 5.1 says: > > The NXT RRs for a zone should be automatically calculated and added > to the zone by the same recommended off-line process that signs the > zone. > > What about dynamic updates? Can't you get into a situation where > something was added via a dynamic update and the NXT RR computed at > start-up is no longer correct? It seems to me that these NXT RR's > must be computed on the fly to be accurate in the face of dynamic > updates. You can ONLY add types NOT names in a zone via secure dynamic update. The zone has to sign the KEY and NS RR's for the dynamic name in order for the name to be able to add/change it's RR's, This does not outlaw dynamic subzones, (subzone is indicated by ZONE KEY). > > - Section 6 says: > > Authenticated means that the data has a valid SIG under a KEY > traceable via a chain of zero or more SIG and KEY RRs to a KEY > configured at the resolver via its boot file. > > So, if the KEY RR for a name was in the statically read master > file for the zone, then RR's added dynamically and signed with > the private part of that KEY are considered authenticated? Correct if the KEY has sign bit set and the new RR are stored under the same name as the KEY. > > - Section 6.1 says: > > Security aware servers never return Bad data. > > Is this true, given that zone transfers may omit dynamically added > RR's and given that NXT RR's are calculated offline? Perhaps I > don't understand the definition of Bad data here. RR's that fail Signature check, RR's with expired Signature RR's with expired TTL... > - Section 7.2 says: > > Periodically an application can be > run to re-sign the RRs in a zone by adding NXT and SIG RRs. > > It seems to get dynamic updates to work within the DNSSEC framework, > this period would have to be such that everything is re-signed > after each dynamic update. The update becomes part of the "static" > data and all the "static" data is then resigned. No, this can't be right. Unless data that was dynamic has been added to the zone master file the dynamic data stays dynamic. Remember the only RR's signed by a zone for a dynamic name are KEY (and possibily NS) RR's. All other RR's are signed by the private key of that name. > > - Section 7.5 says: > > It is recommended that signature lifetime be a small multiple of the > TTL but not less than a reasonable re-signing interval. > > In an environment where DHCP is used to hand out IP address leases > and DNS is updated dynamically to reflect the lease information, > the lifetime of the data will usually be that of the lease duration. > In the case of mobile clients, this lease duration may be just 5 - 10 > minutes. That said, what is your idea of a reasonable re-signing interval? for static zone a day, week, 2 weeks, month, depending on local policy and requirements. If you have a signing process that you can securly send data, you can have expiration time as short as you want. But you need to lower your TTL time to be say 1 minute. > > - Also, it was mentioned to me in private email that: > > if you want a completely dynamic zone, you can just have > the zone key sign an entity key with wildcard authority over the > entire zone and then use the entity key for everything in the zone > > I don't see anything like this discussed in the draft -- > particularly with respect to zone transfers and handling > NXT records. (And if there really is this other way to do security > in DNS servers that support dynamic updates, I'd really > like to understand how it would work!) Simple you create a subzone for dynamic hosts, when ever there is a change in the zone some online process resigns the whole zone. Seriously, this is possible, and it is possible to optimize the process to only sign the changed RR and calculate the new SIG(AXFR). > > Edie Olafur   Received: from relay.tis.com by neptune.TIS.COM id aa16053; 12 Oct 95 3:15 EDT Received: from phoenix.csie.nctu.edu.tw(140.113.17.171) by relay.tis.com via smap (g3.0.1) id xma019013; Thu, 12 Oct 95 02:55:19 -0400 Received: from liny..liny (liny.csie.nctu.edu.tw [140.113.17.105]) by phoenix.csie.nctu.edu.tw (8.6.11/8.6.4) with SMTP id PAA01491 for ; Thu, 12 Oct 1995 15:12:34 +0800 Received: by liny..liny (4.1/SMI-4.1) id AA10072; Fri, 13 Oct 95 03:11:28 CST Date: Fri, 13 Oct 95 03:11:28 CST From: lin Message-Id: <9510121911.AA10072@liny..liny> To: dns-security@TIS.COM Subject: please post The ACM/Baltzer Wireless Networks Journal announces a special issue on Personal Communications Scope: Personal communications provide communication services anywhere, anytime, with anybody, and in any form. To implement the personal communications concepts, extremely sophisticated systems which integrate many diverse technologies are required. This special focuses on the research and development of advanced PCS technologies. Original contributions related to the following topics are solicited: - Small scale mobility (handover) management - Channel allocation algorithms - Large scale mobility (roaming) management - Privacy and authentication - Multi-tier system - PCS database reliability - Intelligent networks for PCS - PCS data applications - PCS backbone architecture (e.g., ATM) - Local wireless network - Wireless multimedia - Mobile IP - Modeling of PCS (measurement, analysis, and simulation) Authors are invited to submit postscript files of their papers to liny@csie.nctu.edu.tw or submit 6 copies of their papers to Professor Yi-Bing Lin, Dept. Comp. Sci. & Info. Engr., National Chiao Tung University, Hsinchu, Taiwan, R.O.C. Papers should not exceed twenty double spaced pages in length, excluding figures and diagrams. Submission deadline: April 15, 1996 Acceptance notification: July 30, 1996 Final manuscript due: October 30, 1996 Guest editors: Yi-Bing Lin Dept. Comp. Sci. & Info. Engr. National Chiao Tung University Hsinchu, Taiwan, R.O.C. Russell T. Hsing Bellcore MRE 2M199 445 South St. Morristown, NJ 07960 trh@thumper.bellcore.com   Received: from relay.tis.com by neptune.TIS.COM id aa06402; 16 Oct 95 10:44 EDT Received: from bacchus.eng.umd.edu(129.2.94.5) by relay.tis.com via smap (g3.0.1) id xma002149; Mon, 16 Oct 95 10:26:36 -0400 Received: from gutenberg.eng.umd.edu (gutenberg.eng.umd.edu [129.2.90.102]) by bacchus.eng.umd.edu (8.7/8.7) with ESMTP id KAA13058; Mon, 16 Oct 1995 10:45:30 -0400 (EDT) From: Saroj Bhandari Received: (saroj@localhost) by gutenberg.eng.umd.edu (8.7/8.6.4) id KAA21217; Mon, 16 Oct 1995 10:45:29 -0400 (EDT) Date: Mon, 16 Oct 1995 10:45:29 -0400 (EDT) Message-Id: <199510161445.KAA21217@gutenberg.eng.umd.edu> To: dns-security@TIS.COM Subject: call for papers Cc: tony@eng.umd.edu Call for Papers Hybrid and Satellite Communication Networks A special issue to be published in WIRELESS NETWORKS published in cooperation with the ACM: Scope: As attention is focused today on wireless communications, a key component of the wireless connectivity fabric is often overlooked. Satellites represent a crucial element of the global information infrastructure and are experiencing a quiet technology revolution that will multiply their capabilities significantly. The recent launches of OLYMPUS in Europe and the ACTS in the United States have proven that on-board processing, bandwidth-on-demand, switchable spot-beams, and the use of the Ka-band can convert, until now, the passive "bent-pipe" reflectors to powerful, full-fledged network nodes. The satellite advantages of ubiquitous coverage, easy access, large bandwidth, immunity to terrestrial catastrophes, and relatively low-cost add up to make satellites indispensable as parts of the worldwide information highway. The much discussed personal communication systems that are currently under development, from Motorola's Iridium to the Teledesics bold constellation concept, demonstrate one aspect of the envisioned role of future satellite systems in the mobile communication area. The main technical bottlenecks that must be overcome to permit the seamless incorporation of satellites into modern hybrid networks and their transparent interoperability with terrestrial links (whether wireless or not) include: - The mismatch of bandwidth, error-rate, and propagation delay properties between satellite and terrestrial links. - The need for seamless network protocol operation - The differences among the multiple services anticipated by such networks in the emerging multimedia markets - The congestion, access, admission control, and bandwidth allocation problems - The cost of terminal manufacturing with dual (space/terrestrial) capabilities - The regulatory, standardization, pricing, and other commercial and business issues that impact the operation of such systems. Authors are invited to send 6 copies of their papers to the guest editor on subjects that relate to the above topics. Please list contact persons, addresses, phone, fax, and e-mail information on the front page of the paper. The following schedule will be followed: Manuscript submission: February 15, 1996 Acceptance notification: June 15, 1996 Final Manuscript Due: September 15, 1996 Publication Date: 4th quarter 1997 Guest Editor: Anthony Ephremides Dept. of Electrical Engineering University of Maryland College Park, MD 20742, USA   Received: from relay.tis.com by neptune.TIS.COM id aa07004; 16 Oct 95 11:12 EDT Received: from watson.ibm.com(129.34.139.4) by relay.tis.com via smap (g3.0.1) id xma002804; Mon, 16 Oct 95 10:54:36 -0400 Received: from WATSON by watson.ibm.com (IBM VM SMTP V2R3) with BSMTP id 4367; Mon, 16 Oct 95 11:13:10 EDT Received: from YKTVMV by watson.vnet.ibm.com with "VAGENT.V1.02 on VAGENT2" id 6249; Mon, 16 Oct 1995 11:13:10 EDT Received: from edisto.watson.ibm.com by yktvmv.watson.ibm.com (IBM VM SMTP V2Rx) with TCP; Mon, 16 Oct 95 11:13:09 EDT Received: by edisto.watson.ibm.com (AIX 3.2/UCB 5.64/900524) id AA17610; Mon, 16 Oct 1995 11:12:52 -0400 Message-Id: <9510161512.AA17610@edisto.watson.ibm.com> X-External-Networks: yes To: dns-security@TIS.COM Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-Reply-To: Your message of Wed, 11 Oct 95 14:55:01 D. <9510111855.AA14391@tis.com> Date: Mon, 16 Oct 95 11:12:51 -0500 From: "Edie E. Gunter" When a SIG RR expires, is the SIG RR itself removed from the database? It seems to be understood that the covered RR's are removed, though I don't see this in the spec. My question is about the SIG RR itself. If the SIG RR is kept around, what TTL value is used when this expired SIG RR is being put into a query response? The computation in section 4.4 might lead one to think a negative TTL value is used, since sigExpTime is now in the past. Edie   Received: from relay.tis.com by neptune.TIS.COM id aa09006; 16 Oct 95 12:44 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma004526; Mon, 16 Oct 95 12:26:46 -0400 Received: from polar.tis.com.tis.com by tis.com (4.1/SUN-5.64) id AA07976; Mon, 16 Oct 95 12:44:09 EDT Date: Mon, 16 Oct 95 12:44:09 EDT From: Olafur Gudmundsson Message-Id: <9510161644.AA07976@tis.com> Received: by polar.tis.com.tis.com (4.1/SMI-4.1) id AA09257; Mon, 16 Oct 95 12:43:58 EDT To: dns-security@TIS.COM Subject: ANNOUNCEMENT: TIS/DNSSEC Version 1.3 alpha A new version of TIS/DNSSEC (alpha1.3) is now available. This version is distinguished from the previous version as follows. Supports AXFR to great extent SIG(AXFR) fails in most cases, due to incorrect transmission order of names. Change in resolver.conf to specify what nameservers to trust although this information is not used yet. First draft of man pages (comments please please) What is implemented is in sync with latest dns-sec draft (06) Number of small improvements and bug fixes, see /pub/DNSSEC/CHANGES What is missing from the current implementation Signature verification in resolver Automatic return of KEY RR with NS and Address RR's. Purging of expired SIGNATURES and RR's. Proper handling of SIG(AXFR) Transaction Signatures. (we are not going to implement this) For information on how to acquire TIS/DNSSEC retrieve the file /pub/DNSSEC/README on the host ftp.tis.com via anonymous FTP. If you have any questions or problems please send a note to tisdnssec-support@tis.com. Enjoy, Olafur   Received: from relay.tis.com by neptune.TIS.COM id aa27455; 17 Oct 95 9:42 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma017240; Tue, 17 Oct 95 09:23:56 -0400 Received: from polar.tis.com by tis.com (4.1/SUN-5.64) id AA28555; Tue, 17 Oct 95 09:41:28 EDT Message-Id: <9510171341.AA28555@tis.com> To: "Edie E. Gunter" Cc: dns-security@TIS.COM Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-Reply-To: Your message of "Mon, 16 Oct 1995 11:12:51 CDT." <9510161512.AA17610@edisto.watson.ibm.com> Date: Tue, 17 Oct 1995 09:41:16 -0400 From: Olafur Gudmundsson "Edie E. Gunter" writes: > > When a SIG RR expires, is the SIG RR itself removed from > the database? It seems to be understood that the covered > RR's are removed, though I don't see this in the spec. My > question is about the SIG RR itself. Yes it also expires when it's expiration time arrives. There is no other logical answer. > > If the SIG RR is kept around, what TTL value is used when > this expired SIG RR is being put into a query response? > The computation in section 4.4 might lead one to think > a negative TTL value is used, since sigExpTime is now in > the past. No no no, when the expiration time arrives RR's and SIG are out of date and can not be returned in an answer. Olafur > > Edie   Received: from relay.tis.com by neptune.TIS.COM id aa04052; 17 Oct 95 13:22 EDT Received: from watson.ibm.com(129.34.139.4) by relay.tis.com via smap (g3.0.1) id xma021648; Tue, 17 Oct 95 13:04:33 -0400 Received: from WATSON by watson.ibm.com (IBM VM SMTP V2R3) with BSMTP id 7175; Tue, 17 Oct 95 13:23:18 EDT Received: from YKTVMV by watson.vnet.ibm.com with "VAGENT.V1.02 on VAGENT2" id 7966; Tue, 17 Oct 1995 13:23:18 EDT Received: from edisto.watson.ibm.com by yktvmv.watson.ibm.com (IBM VM SMTP V2Rx) with TCP; Tue, 17 Oct 95 13:23:18 EDT Received: by edisto.watson.ibm.com (AIX 3.2/UCB 5.64/900524) id AA15002; Tue, 17 Oct 1995 13:23:01 -0400 Message-Id: <9510171723.AA15002@edisto.watson.ibm.com> X-External-Networks: yes To: dns-security@TIS.COM Cc: jis@mit.edu, yakov@cisco.com, set@thumper.bellcore.com, randy@psg.com, ogud@TIS.COM Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-Reply-To: Your message of Wed, 11 Oct 95 14:55:01 D. <9510111855.AA14391@tis.com> Date: Tue, 17 Oct 95 13:23:01 -0500 From: "Edie E. Gunter" >> > >> > - Section 4.1.3 says: >> > >> > Thus >> > such dynamic RRs are not directly signed by the zone, are not >> > included in the AXFR SIG, and are not generally protected against >> > omission from zone transfers. >> > >> > I am quite sure this is not what anyone running a secure DNS that >> > supports secure dynamic updates would want. It seems this section >> > should cover how to securely include dynamic updates in a zone transfer -- >> > if not via the method described in 4.1.3 using AXFR SIG, etc. then by >> > some other method. >> IF Dynamic RR's are covered by SIG(AXFR) then the SIG(AXFR) has to be >> recomputed whenever a dynamic RR changes. This would seem to be a much more desirable behavior than not covering the dynamic RRs and allowing them to be omitted in zone transfers. >> > - Section 4.4 Signature Expiration >> > >> > When a SIG expires, the covered RR's are not removed from the database, >> > but are kept around and the AD bit is used to indicate if the data >> > is no longer authentic. Is that right? >> Incorrect: When the SIG expires the RR's are to be purged. Can anyone cite the chapter/verse in the spec where this is covered? >> > >> > - Section 5.1 says: >> > >> > The NXT RRs for a zone should be automatically calculated and added >> > to the zone by the same recommended off-line process that signs the >> > zone. >> > >> > What about dynamic updates? Can't you get into a situation where >> > something was added via a dynamic update and the NXT RR computed at >> > start-up is no longer correct? It seems to me that these NXT RR's >> > must be computed on the fly to be accurate in the face of dynamic >> > updates. >> You can ONLY add types NOT names in a zone via secure dynamic update. >> The zone has to sign the KEY and NS RR's for the dynamic name in order for >> the name to be able to add/change it's RR's, If the static database contains the name APPLE and a KEY RR for that name, then an NXT RR will be computed indicating that APPLE has no A RR. If the A RR is later dyamically added, then the NXT RR computed earlier is no longer correct. The NXT RR must be recomputed after the dynamic update. >> > >> > - Also, it was mentioned to me in private email that: >> > >> > if you want a completely dynamic zone, you can just have >> > the zone key sign an entity key with wildcard authority over the >> > entire zone and then use the entity key for everything in the zone >> > >> > I don't see anything like this discussed in the draft -- >> > particularly with respect to zone transfers and handling >> > NXT records. (And if there really is this other way to do security >> > in DNS servers that support dynamic updates, I'd really >> > like to understand how it would work!) >> Simple you create a subzone for dynamic hosts, >> when ever there is a change in the zone some online process resigns the whole zone. >> Seriously, this is possible, and it is possible to optimize the process to only >> sign the changed RR and calculate the new SIG(AXFR). I don't see how this makes sense in practice. I've got a domain, watson.ibm.com. I want all the watson users to be in that domain. It seems odd to me to impose STATIC.watson.ibm.com and DYNAMIC.watson.ibm.com domains on the users. But, if static and dynamic RRs are allowed in the same zone, and if the SIG(AXFR) only covers the static RRs, then when a zone transfer is done, say to a secondary, how will that secondary know which RRs are static and which are dynamic so that is can verify the data? It must be implied that there is some new tag on the RR somewhere to indicate if the RR was added dynamically. Otherwise, the secondary is just going to recompute/verify the SIG using _all_ the RRs. No? (I suppose the secondary could go through the database and verify each and every individual SIG and thereby determine which were signed by the zone and which were not and use that to determine which RRs to include in the SIG(AXFR) verification...) Does anyone know if the TIS dnssec implementation supports dynamic updates? Edie   Received: from relay.tis.com by neptune.TIS.COM id aa16388; 23 Oct 95 8:46 EDT Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma003624; Mon, 23 Oct 95 08:27:30 -0400 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA28028; Mon, 23 Oct 95 08:45:29 EDT Message-Id: <9510231245.AA28028@tis.com> Reply-To: James M Galvin To: dns-security@TIS.COM Subject: meeting in Dallas Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <11690.814452419.1@tis.com> Date: Mon, 23 Oct 1995 08:47:00 -0400 From: James M Galvin Please note we have a meeting slot reserved for 9am, tuesday, December 5, in Dallas. We'll have document status, implementation status, and dynamic update to discuss. There may be other topics; we'll know for sure as the meeting approaches. Jim   Received: from relay.tis.com by neptune.TIS.COM id aa21798; 25 Oct 95 1:14 EDT Received: from fawlty1.eng.monash.edu.au(130.194.140.11) by relay.tis.com via smap (g3.0.1) id xma003241; Wed, 25 Oct 95 00:53:18 -0400 Received: (atiq@localhost) by fawlty1.eng.monash.edu.au (8.6.12/8.6.4) id PAA15804 for dns-security@tis.com; Wed, 25 Oct 1995 15:13:16 +1000 Message-Id: <199510250513.PAA15804@fawlty1.eng.monash.edu.au> Subject: CFP: Special issue on ATM Switching To: dns-security@TIS.COM Date: Wed, 25 Oct 1995 15:13:10 +1000 (EST) Reply-to: Mohammed Atiquzzaman From: Mohammed Atiquzzaman X-Mailer: ELM [version 2.4 PL21] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 3297 Call for Papers Special Issue of International Journal of Computer Systems Science & Engineering on ATM Switching Guest Editors: Hussein T. Mouftah, Queen's University, Canada Mohammed Atiquzzaman, Monash University, Australia. _______________________________________________________________________________ Papers are solicited for a special issue of the International Journal of Computer Systems Science & Engineering on Asynchronous Transfer Mode (ATM) Switching to be published in the third quarter of 1996. During the past decade, a considerable amount of effort has been made in studying and designing ATM switches which is believed to be the most developed aspect of ATM. The field has now become a mature area and ATM switches are becoming commercially available. This special issue will include a set of original and survey articles from both industry and academia that represents the current state-of-the-art in ATM switching. Possible topics include (but are not limited to): o Switch architectures o Fault tolerance o Buffering schemes o Congestion control and traffic management o Performance modeling o Practical experience & field trials o Buffer management o Simulation techniques for large switches o Commercial switches Five copies of complete manuscripts (not to exceed 25 double-spaced pages) should be sent to Mohammed Atiquzzaman by 1 February 1996. Please include a title page containing author(s) names and affiliations, postal addresses, e-mail addresses, telephone numbers, and fax numbers. Electronic (PostScript only) submissions are encouraged. Authors should follow the IJCSSE manuscript submission format. _______________________________________________________________________________ Guest Editors: _______________________________________________________________________________ Mohammed Atiquzzaman Hussein T. Mouftah Dept. of Elect. & Comp. Systems Engg. Department of Elect. & Comp. Engg. Monash University, Clayton 3168 Queen's University, Kingston Melbourne, Australia. Ontario, Canada K7L 3N6. Tel: +61 3 9905 5383 Tel: +1 613-545-2934 Fax: +61 3 9905 3454 Fax: +1 613-545-6615 Email: atiq@eng.monash.edu.au Email: mouftah@eleceng.ee.queensu.ca WWW: http://www.eng.monash.edu.au/~atiq _______________________________________________________________________________ Important Dates: _______________________________________________________________________________ Deadline for receipt of manuscripts: 1 February 1996 Notification of acceptance/rejection: 30 April 1996 ASCII and PostScript versions of this announcement and the author's guidelines for IJCSSE are available from http://www.eng.monash.edu.au/~atiq IJCSSE is published by CRL Publishing, London, UK. Please contact the editor-in-chief Prof. Tharam Dillon (tharam@latcs1.lat.oz.au) for queries regarding the journal and J. Thompson (100113.2636@CompuServe.com) for sample copies.   Received: from relay.tis.com by neptune.TIS.COM id aa13528; 10 Nov 95 11:49 EST Received: from gw2.att.com(192.20.239.134) by relay.tis.com via smap (g3.0.1) id xma011377; Fri, 10 Nov 95 11:27:01 -0500 Received: from elmo.lz.att.com by ig1.att.att.com id AA29266; Wed, 8 Nov 95 17:56:36 EST Received: from fireball.att.com by elmo.lz.att.com (5.x/SMI-SVR4) id AA13803; Wed, 8 Nov 1995 17:57:51 -0500 Received: by fireball.att.com (5.x/SMI-SVR4) id AA19620; Wed, 8 Nov 1995 17:56:32 -0500 Date: Wed, 8 Nov 1995 17:56:32 -0500 Message-Id: <9511082256.AA19620@fireball.att.com> From: dnssec@fireball.lz.att.com To: dns-security@TIS.COM Subject: A Simple Question I've read (most of) draft-ietf-dnssec-secext-05.txt and have either missed something, or have failed to comprehend something. I don't know if this is the right place to ask such a simple question, but here goes: So I'm a security aware resolver and I query for, say, Type A records on name A.B.C.D. I get back an A record and a SIG record: A.B.C.D IN A [some ttl] 135.24.40.12 A.B.C.D IN SIG [some ttl] [Type A SIG RDATA] How do I figure out which public KEY I'm supposed to use to authenticate the A record? If the answer to my question is something like, ``Use a KEY associated with the SIGNER'S NAME (a field in A.B.C.D's Type A SIG record),'' then how do I know that the signer is at all appropriate. For example, it would seem inappropriate to consider the A record authentic, if the SIG was generated by W.X.Y.Z (some unknown entity from another zone), even if the MD5/RSA stuff all checks out. Assuming my question is clearly addressed somewhere in the draft, then perhaps someone could just tell me which section I should read more carefully. Thanks, _________________ Matt Busche AT&T Bell Laboratories e-mail: dnssec@fireball.lz.att.com 307 Middletown-Lincroft Road Voice: 908-576-3630 Room 1E-124 FAX: 908-576-5007 Lincroft, NJ 07738-1526   Received: from relay.tis.com by neptune.TIS.COM id aa15541; 10 Nov 95 13:44 EST Received: from watson.ibm.com(129.34.139.4) by relay.tis.com via smap (g3.0.1) id xma013088; Fri, 10 Nov 95 13:23:06 -0500 Received: from WATSON by watson.ibm.com (IBM VM SMTP V2R3) with BSMTP id 8801; Fri, 10 Nov 95 13:45:17 EST Received: from YKTVMV by watson.vnet.ibm.com with "VAGENT.V1.02 on VAGENT2" id 7560; Fri, 10 Nov 1995 13:45:17 EST Received: from edisto.watson.ibm.com by yktvmv.watson.ibm.com (IBM VM SMTP V2Rx) with TCP; Fri, 10 Nov 95 13:45:16 EST Received: by edisto.watson.ibm.com (AIX 3.2/UCB 5.64/900524) id AA18042; Fri, 10 Nov 1995 13:45:01 -0500 Message-Id: <9511101845.AA18042@edisto.watson.ibm.com> X-External-Networks: yes To: dnssec@fireball.lz.att.com, dns-security@TIS.COM Subject: Re: A Simple Question In-Reply-To: Your message of Wed, 08 Nov 95 17:56:32 EST. <9511082256.AA19620@fireball.att.com> Date: Fri, 10 Nov 95 13:45:00 -0500 From: "Edie E. Gunter" > So I'm a security aware resolver and I query for, say, Type A records > on name A.B.C.D. I get back an A record and a SIG record: > > A.B.C.D IN A [some ttl] 135.24.40.12 > A.B.C.D IN SIG [some ttl] [Type A SIG RDATA] > > How do I figure out which public KEY I'm supposed to use to > authenticate the A record? The RR's for A.B.C.D can be signed by the entity A.B.C.D and/or the zone. So, if you don't have the public key for A.B.C.D and/or the zone, you'll have to query the server for those KEY RR's also (perhaps using transaction SIGs if you're really paranoid.) Now, there can be multiple keys per name. (i.e. A.B.C.D may have multiple KEY RRs for the same algorithm type.) The best explanation I've heard for handling this is to just try them all and see if any work... All KEY RR's are signed by the zone. W.X.Y.Z can't generate a SIG for A.B.C.D unless it knows either the private key for A.B.C.D or the private key for the zone (and you're allowing dynamic updates.) W.X.Y.Z should never know another name's private key. Once the private key is exposed, you're no longer secure. Edie   Received: from relay.tis.com by neptune.TIS.COM id aa26419; 13 Nov 95 5:26 EST Received: from oden.exmandato.se(192.71.33.1) by relay.tis.com via smap (g3.0.1) id xma029351; Mon, 13 Nov 95 05:04:54 -0500 Received: from li50.exmandato.se (ex125.exmandato.se [192.71.33.125]) by oden.exmandato.se (8.6.12/8.6.12) with SMTP id LAA27498; Mon, 13 Nov 1995 11:44:11 +0100 Date: Mon, 13 Nov 1995 11:44:11 +0100 Message-Id: <199511131044.LAA27498@oden.exmandato.se> X-Sender: mats@exmandato.se X-Mailer: Windows Eudora Pro Version 2.1.2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: Olafur Gudmundsson , dns-security@TIS.COM From: Mats Mellstrand Subject: Re: ANNOUNCEMENT: TIS/DNSSEC Version 1.3 alpha At 12:44 1995-10-16 EDT, Olafur Gudmundsson wrote: >A new version of TIS/DNSSEC (alpha1.3) is now available. This version is >distinguished from the previous version as follows. > > Supports AXFR to great extent SIG(AXFR) fails in most cases, > due to incorrect transmission order of names. > Change in resolver.conf to specify what nameservers to trust > although this information is not used yet. > First draft of man pages (comments please please) > What is implemented is in sync with latest dns-sec draft (06) > Number of small improvements and bug fixes, see /pub/DNSSEC/CHANGES > >What is missing from the current implementation > Signature verification in resolver > Automatic return of KEY RR with NS and Address RR's. > Purging of expired SIGNATURES and RR's. > Proper handling of SIG(AXFR) > Transaction Signatures. (we are not going to implement this) > >For information on how to acquire TIS/DNSSEC retrieve the file >/pub/DNSSEC/README on the host ftp.tis.com via anonymous FTP. > >If you have any questions or problems please send a note to >tisdnssec-support@tis.com. > >Enjoy, > >Olafur > > -------------------------------------------------------------------------- Mats Mellstrand, eXmandato AB, Box 251, 391 23 Kalmar, Sweden Tel (int):46-48012260, fax (int):46-48012280 mats@exmandato.se, http://www.exmandato.se   Received: from relay.tis.com by neptune.TIS.COM id aa26418; 13 Nov 95 5:26 EST Received: from oden.exmandato.se(192.71.33.1) by relay.tis.com via smap (g3.0.1) id xma029350; Mon, 13 Nov 95 05:04:47 -0500 Received: from li50.exmandato.se (ex125.exmandato.se [192.71.33.125]) by oden.exmandato.se (8.6.12/8.6.12) with SMTP id LAA27494; Mon, 13 Nov 1995 11:44:01 +0100 Date: Mon, 13 Nov 1995 11:44:01 +0100 Message-Id: <199511131044.LAA27494@oden.exmandato.se> X-Sender: mats@exmandato.se X-Mailer: Windows Eudora Pro Version 2.1.2 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: Olafur Gudmundsson , dns-security@TIS.COM From: Mats Mellstrand Subject: Re: ANNOUNCEMENT: TIS/DNSSEC Version 1.3 alpha At 12:44 1995-10-16 EDT, Olafur Gudmundsson wrote: >A new version of TIS/DNSSEC (alpha1.3) is now available. This version is >distinguished from the previous version as follows. > > Supports AXFR to great extent SIG(AXFR) fails in most cases, > due to incorrect transmission order of names. > Change in resolver.conf to specify what nameservers to trust > although this information is not used yet. > First draft of man pages (comments please please) > What is implemented is in sync with latest dns-sec draft (06) > Number of small improvements and bug fixes, see /pub/DNSSEC/CHANGES > >What is missing from the current implementation > Signature verification in resolver > Automatic return of KEY RR with NS and Address RR's. > Purging of expired SIGNATURES and RR's. > Proper handling of SIG(AXFR) > Transaction Signatures. (we are not going to implement this) > >For information on how to acquire TIS/DNSSEC retrieve the file >/pub/DNSSEC/README on the host ftp.tis.com via anonymous FTP. > >If you have any questions or problems please send a note to >tisdnssec-support@tis.com. > >Enjoy, > >Olafur > > -------------------------------------------------------------------------- Mats Mellstrand, eXmandato AB, Box 251, 391 23 Kalmar, Sweden Tel (int):46-48012260, fax (int):46-48012280 mats@exmandato.se, http://www.exmandato.se   Received: from relay.tis.com by neptune.TIS.COM id aa29946; 14 Nov 95 16:59 EST Received: from watson.ibm.com(129.34.139.4) by relay.tis.com via smap (g3.0.1) id xma028203; Tue, 14 Nov 95 16:38:16 -0500 Received: from WATSON by watson.ibm.com (IBM VM SMTP V2R3) with BSMTP id 7837; Tue, 14 Nov 95 16:59:23 EST Received: from YKTVMV by watson.vnet.ibm.com with "VAGENT.V1.02 on VAGENT2" id 9992; Tue, 14 Nov 1995 16:59:23 EST Received: from edisto.watson.ibm.com by yktvmv.watson.ibm.com (IBM VM SMTP V2Rx) with TCP; Tue, 14 Nov 95 16:59:22 EST Received: by edisto.watson.ibm.com (AIX 3.2/UCB 5.64/900524) id AA18904; Tue, 14 Nov 1995 16:59:10 -0500 Message-Id: <9511142159.AA18904@edisto.watson.ibm.com> X-External-Networks: yes To: dns-security@TIS.COM Subject: NSCOUNT Date: Tue, 14 Nov 95 16:59:09 -0500 From: "Edie E. Gunter" The DNSSEC draft seems to suggest that if DNS returns an NS RR in the authority section of a query response, then the SIG should also be included in the authority section of the response. Is this correct? If so, then it seems that in order for the message to be parsed correctly, the NSCOUNT field would have to be set to 2 instead of 1, to account for the SIG and the NS RR. But, the NSCOUNT field is defined (RFC 883, 1035 and elsewhere) to be the number of NS RRs in the authority section. So, it seems that the DNSSEC draft is redefining the meaning of the NSCOUNT field, though I don't see this mentioned explicitly. If the above is true, then is there is problem working with older non-security-aware servers? Are they going to fail when they get a response with an nscount of 2 but only 1 actual NS RR? Edie   Received: from relay.tis.com by neptune.TIS.COM id aa06585; 15 Nov 95 0:13 EST Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma002532; Tue, 14 Nov 95 23:51:45 -0500 Received: by callandor.cybercash.com; id AAA29300; Wed, 15 Nov 1995 00:14:47 -0500 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.3) id xma029297; Wed, 15 Nov 95 00:14:40 -0500 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA12039; Wed, 15 Nov 95 00:13:07 EST Date: Wed, 15 Nov 1995 00:13:06 -0500 (EST) From: "Donald E. Eastlake 3rd" To: "Edie E. Gunter" Cc: dns-security@TIS.COM Subject: Re: NSCOUNT In-Reply-To: <9511142159.AA18904@edisto.watson.ibm.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Edie, On Tue, 14 Nov 1995, Edie E. Gunter wrote: > The DNSSEC draft seems to suggest that if DNS returns an NS > RR in the authority section of a query response, then the > SIG should also be included in the authority section of the > response. Is this correct? Yes, the idea being that you wouldn't want additional info to cause loss of the AIG authentication the authority info (or authority info to cause loss of the SIG for the main response) due to truncation. > If so, then it seems that in order for the message to be > parsed correctly, the NSCOUNT field would have to be set to > 2 instead of 1, to account for the SIG and the NS RR. Or possibly more for multiple SIGs. Also, the NXT RR authenticating the non-existence of a name appears in the authority section. > But, the NSCOUNT field is defined (RFC 883, 1035 and elsewhere) > to be the number of NS RRs in the authority section. > So, it seems that the DNSSEC draft is redefining the > meaning of the NSCOUNT field, though I don't see this > mentioned explicitly. You are correction and I guess this should be added to the draft. > If the above is true, then is there is problem working > with older non-security-aware servers? Are they going > to fail when they get a response with an nscount of 2 > but only 1 actual NS RR? Paul Vixie has been consulted on most of these decisions. My understanding from what he has said is that older versions of BIND are quite insensitive as to what section RRs are returned in and should not have problems in these cases. > Edie Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa06862; 15 Nov 95 0:31 EST Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma002651; Wed, 15 Nov 95 00:10:15 -0500 Received: by callandor.cybercash.com; id AAA29395; Wed, 15 Nov 1995 00:33:17 -0500 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.3) id xma029393; Wed, 15 Nov 95 00:33:08 -0500 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA12149; Wed, 15 Nov 95 00:31:34 EST Date: Wed, 15 Nov 1995 00:31:32 -0500 (EST) From: "Donald E. Eastlake 3rd" To: "Edie E. Gunter" Cc: dns-security@TIS.COM, jis@mit.edu, yakov@cisco.com, set@thumper.bellcore.com Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-Reply-To: <9510171723.AA15002@edisto.watson.ibm.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sorry I've been distracted for a while by other things. Let me try to answer some of these messages... On Tue, 17 Oct 1995, Edie E. Gunter wrote: > >> > > >> > - Section 4.1.3 says: > >> > > >> > Thus > >> > such dynamic RRs are not directly signed by the zone, are not > >> > included in the AXFR SIG, and are not generally protected against > >> > omission from zone transfers. > >> > > >> > I am quite sure this is not what anyone running a secure DNS that > >> > supports secure dynamic updates would want. It seems this section > >> > should cover how to securely include dynamic updates in a zone transfer -- > >> > if not via the method described in 4.1.3 using AXFR SIG, etc. then by > >> > some other method. > >> IF Dynamic RR's are covered by SIG(AXFR) then the SIG(AXFR) has to be > >> recomputed whenever a dynamic RR changes. > > This would seem to be a much more desirable behavior than not > covering the dynamic RRs and allowing them to be omitted in > zone transfers. Edie, you have to understand that the DNSSEC document is not the Dynamic Update document. The DNSSEC document strives for maximum security with enough hooks to allow Dynamic Update. You get the most security by keeping the fixed master file off line, signing it off line, and having a one way flow of information to the primary DNS server for the zone. You are asking exactly how to implement both security and dyanmic update and I guess that should be answered by the Dynamic Update document security section which I should perhaps write something for/about. If the zone owner is content to trust a machine on line to the net, they could put the zone private key on line and resign the AXFR every update. This is not a speedly operation and might cause problems if the update rate is high. On the other hand, if they really trust this on line machine, then they should not fear that it would omit RRs from a zone transfer anyway. I would think the prefered implementation would be to have a fixed master file off line and a dynamic master file of dynamically added/changed RRs on-line. If you are willing to take the extra risk of putting the zone file on line and willing to sustain the extra computation of re-calculating the AXFR, then you can get the advantage of securiing the entirety of zone transfers no matter how many intermediate machines the zone has been transfered through. > >> > - Section 4.4 Signature Expiration > >> > > >> > When a SIG expires, the covered RR's are not removed from the database, > >> > but are kept around and the AD bit is used to indicate if the data > >> > is no longer authentic. Is that right? > >> Incorrect: When the SIG expires the RR's are to be purged. > > Can anyone cite the chapter/verse in the spec where this is covered? If a DNS server is security ignorant, it obviously does nothing when a SIG expires. If it's security aware, it shouldn't send out an RR whose SIG has expired and if it was caching it should purge them. It's not quite so clear to me if it was not cahcing but a primary or secondary server and I don't think it matters much. You clearly have a problem of not having re-signed and reloaded the zone soon enough. I don't think this case is covered in the current draft. It does not seem to matter much to me if the RR is purged or just keep around and not provided in answers (except in a zone transfer so the AXFR is right (except that it would probably be the case that if one zone signed SIG has expired, they all have, and you are totally out of it)). > >> > - Section 5.1 says: > >> > > >> > The NXT RRs for a zone should be automatically calculated and added > >> > to the zone by the same recommended off-line process that signs the > >> > zone. > >> > > >> > What about dynamic updates? Can't you get into a situation where > >> > something was added via a dynamic update and the NXT RR computed at > >> > start-up is no longer correct? It seems to me that these NXT RR's > >> > must be computed on the fly to be accurate in the face of dynamic > >> > updates. > >> You can ONLY add types NOT names in a zone via secure dynamic update. > >> The zone has to sign the KEY and NS RR's for the dynamic name in order for > >> the name to be able to add/change it's RR's, > > If the static database contains the name APPLE and a KEY RR for that > name, then an NXT RR will be computed indicating that APPLE has no > A RR. If the A RR is later dyamically added, then the NXT RR computed > earlier is no longer correct. The NXT RR must be recomputed after > the dynamic update. That's a very good point. I will change the draft to make it clear that the NXT type bits only cover zone signed types. Dynamically added types don't appear in NXTs unless the user has chosen the not-security-recommended keeping of their private key on line and has some DNS server implementation that will adjust and resign the NXT RRs... > >> > - Also, it was mentioned to me in private email that: > >> > > >> > if you want a completely dynamic zone, you can just have > >> > the zone key sign an entity key with wildcard authority over the > >> > entire zone and then use the entity key for everything in the zone > >> > > >> > I don't see anything like this discussed in the draft -- > >> > particularly with respect to zone transfers and handling > >> > NXT records. (And if there really is this other way to do security > >> > in DNS servers that support dynamic updates, I'd really > >> > like to understand how it would work!) > >> Simple you create a subzone for dynamic hosts, > >> when ever there is a change in the zone some online process resigns the whole zone. > >> Seriously, this is possible, and it is possible to optimize the process to only > >> sign the changed RR and calculate the new SIG(AXFR). > > I don't see how this makes sense in practice. I've got a domain, > watson.ibm.com. I want all the watson users to be in that domain. > It seems odd to me to impose STATIC.watson.ibm.com and > DYNAMIC.watson.ibm.com domains on the users. > > But, if static and dynamic RRs are allowed in the same zone, and > if the SIG(AXFR) only covers the static RRs, then when a zone > transfer is done, say to a secondary, how will that secondary > know which RRs are static and which are dynamic so that is can > verify the data? It must be implied that there is some new tag > on the RR somewhere to indicate if the RR was added dynamically. > Otherwise, the secondary is just going to recompute/verify the SIG > using _all_ the RRs. No? (I suppose the secondary could go > through the database and verify each and every individual SIG and > thereby determine which were signed by the zone and which were not > and use that to determine which RRs to include in the SIG(AXFR) > verification...) > > Does anyone know if the TIS dnssec implementation supports dynamic > updates? There are several things here. When a zone trasnfer is done in a world with dynamic update (which is *not* included in any DNSSEC implementation I know of), the secondary needs to caclulate the AXFR only over zone signed RRs, as you suggest. For dyanmically added RRs, it has to check the SIG that authorized it which should be traceable back to the zone key. Dyamic update can never change what names exist in a zone or, as pointed out above, the zone signed types. I suppose the minimum secure dynamic zone, say zone.tld, would have only four RRs: a dynamic update KEY RR, a NXT RR, and zone SIGs on them. They would have name *.zone.tld so they would cause all possible names to "exist" in the zone and the KEY would be authorized to create any name inferior to zone.tld. You would probably make the NS RRs hard also but they could in principle be dynamic (which would require a dynamic uypdate KEY with name zone.tld). Since a KEY can only authorize doing things with RRs that have its name or are within its name scope if it is a wildcard, the "existant names" structure of the zone can't change. I would think that most zone adminstrators would have static parts of their zones and dynamic parts. They might or might not want to use sub-zones but they certainly would not want to be forced to lose the added security they could get by keeping the static part off-line. There is no reason to have a fixed.watson.ibm.com but it names sense to have dynamic-authority1.watson.ibm.com, dynamic-authority2..., etc. why dyanmic stuff hapeens at and/or under the authorities. although in the limit you just have a bunch of names.watson.ibm.com with each of the names having a dynamic update KEY.. > Edie Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa07045; 15 Nov 95 0:43 EST Received: from rip.psg.com(147.28.0.39) by relay.tis.com via smap (g3.0.1) id xma002740; Wed, 15 Nov 95 00:21:34 -0500 Received: by rip.psg.com (Smail3.1.29.1 #1) id m0tFaca-00031sC; Tue, 14 Nov 95 21:42 PST Message-Id: Date: Tue, 14 Nov 95 21:42 PST From: Randy Bush To: "Donald E. Eastlake 3rd" Cc: namedroppers , dns-security@TIS.COM Subject: Re: NSCOUNT References: <9511142159.AA18904@edisto.watson.ibm.com> >> If the above is true, then is there is problem working >> with older non-security-aware servers? Are they going >> to fail when they get a response with an nscount of 2 >> but only 1 actual NS RR? > Paul Vixie has been consulted on most of these decisions. My understanding > from what he has said is that older versions of BIND are quite insensitive > as to what section RRs are returned in and should not have problems in > these cases. That's nice. But I thought we were talking about standards, not some implementation. There are other implementations. randy   Received: from relay.tis.com by neptune.TIS.COM id aa07369; 15 Nov 95 1:01 EST Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma002805; Wed, 15 Nov 95 00:39:45 -0500 Received: by callandor.cybercash.com; id BAA29567; Wed, 15 Nov 1995 01:02:47 -0500 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.3) id xma029565; Wed, 15 Nov 95 01:02:42 -0500 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA12347; Wed, 15 Nov 95 01:01:04 EST Date: Wed, 15 Nov 1995 01:01:03 -0500 (EST) From: "Donald E. Eastlake 3rd" To: Randy Bush Cc: namedroppers , dns-security@TIS.COM Subject: Re: NSCOUNT In-Reply-To: Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII At least for namedroppers, this is out of context. The DNS security draft calls for the inclusion of SIG RRs in the same section (authority, additional info, whatever) of the response as the data being signed. This is based on the assumption that in a secure DNS world, it is better to get less data, but have it authenticated, than more data but have it not authenticated (in the face of truncation). The rest of the email query and response discussed this and I agreed that the DNS security draft should explicitly say that the NSCOUNT field's meaning is modified from the current DNS standard RFC's to say that there may be non NS records (for example, SIGs) included in that section and count. Since the original query also asked, in one section, as below, about backward compatibility, I answered with what data I had on the subject. If people have other inputs in this area, I'm interested. Donald On Tue, 14 Nov 1995, Randy Bush wrote: > >> If the above is true, then is there is problem working > >> with older non-security-aware servers? Are they going > >> to fail when they get a response with an nscount of 2 > >> but only 1 actual NS RR? > > Paul Vixie has been consulted on most of these decisions. My understanding > > from what he has said is that older versions of BIND are quite insensitive > > as to what section RRs are returned in and should not have problems in > > these cases. > > That's nice. But I thought we were talking about standards, not some > implementation. There are other implementations. Your comment bears all the hall marks of a knee jerk response. > randy Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa08800; 15 Nov 95 3:04 EST Received: from holmes.umd.edu(128.8.10.48) by relay.tis.com via smap (g3.0.1) id xma003800; Wed, 15 Nov 95 02:42:38 -0500 Received: from UMDD (umdd.umd.edu [128.8.170.13]) by holmes.umd.edu(8.6.12/95Sep13) with SMTP id DAA10061; Wed, 15 Nov 1995 03:05:35 -0500 Message-Id: <199511150805.DAA10061@holmes.umd.edu> Received: by UMDD.UMD.EDU id 7934 ; 15 Nov 95 03:05:32 EST Received: by UMDD (Mailer R2.10 ptf000) id 7934; Wed, 15 Nov 95 03:05:32 EST Date: Wed, 15 Nov 95 03:00:16 EST From: Bruce Crabill Subject: Re: NSCOUNT In-Reply-To: Message received on Wed, 15 Nov 95 00:40:46 EST To: dns-security@TIS.COM >> If the above is true, then is there is problem working >> with older non-security-aware servers? Are they going >> to fail when they get a response with an nscount of 2 >> but only 1 actual NS RR? > >Paul Vixie has been consulted on most of these decisions. My understanding >from what he has said is that older versions of BIND are quite insensitive as >to what section RRs are returned in and should not have problems in these >cases. Thats nice, but there are other DNS implementations other than BIND in the world. Before we change something as basic as the NSCOUNT field's definition, I think we should consider the implications for more than one implementation (granted that BIND is by far the most popular). Bruce   Received: from relay.tis.com by neptune.TIS.COM id aa11322; 15 Nov 95 6:30 EST Received: from munnari.oz.au(128.250.1.21) by relay.tis.com via smap (g3.0.1) id xma004887; Wed, 15 Nov 95 06:08:30 -0500 Received: from mundamutti.cs.mu.OZ.AU by munnari.oz.au with SMTP (5.83--+1.3.1+0.50) id AA14355; Wed, 15 Nov 1995 22:31:14 +1100 (from kre@munnari.OZ.AU) To: Bruce Crabill Cc: dns-security@TIS.COM Subject: Re: NSCOUNT In-Reply-To: Your message of "Wed, 15 Nov 1995 03:00:16 EST." <199511150805.DAA10061@holmes.umd.edu> Date: Wed, 15 Nov 1995 22:30:28 +1100 Message-Id: <1817.816435028@munnari.OZ.AU> From: Robert Elz Date: Wed, 15 Nov 95 03:00:16 EST From: Bruce Crabill Message-ID: <199511150805.DAA10061@holmes.umd.edu> Before we change something as basic as the NSCOUNT field's definition, I think we should consider the implications for more than one implementation Is there anyone associated with any implementation complaining about this proposed change, or is this purely imaging what might possibly be problems for implementations they imagine might exist? The general "be liberal in what you receive" principal would tend to suggest that implementations should do no worse than logging an error message when seeing an unexpected type in the authority field. If someone could post the name of a nameserver, and a query to try, that will provoke a response with a SIG in the Auth field, then people with various implementations in use could actually try that query and see if their nameserver has any problems and report that to the list. Hypothetical speculation will get us nowhere. kre   Received: from relay.tis.com by neptune.TIS.COM id aa16331; 15 Nov 95 10:36 EST Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma008444; Wed, 15 Nov 95 10:15:11 -0500 Received: by callandor.cybercash.com; id KAA02881; Wed, 15 Nov 1995 10:38:18 -0500 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.3) id xma002878; Wed, 15 Nov 95 10:38:11 -0500 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA15441; Wed, 15 Nov 95 10:36:34 EST Date: Wed, 15 Nov 1995 10:36:34 -0500 (EST) From: "Donald E. Eastlake 3rd" To: dns-security@TIS.COM Subject: Re: NSCOUNT (fwd) Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII I looked at RFC 1035 and found that it provides in section 3.7 for servers, at their option, to include SOA RRs in the authority section and in fact an example of this is given in section 6.2.5. So it was never true that NSCOUNT was only a count of NS RRs. Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA) ---------- Forwarded message ---------- Date: Wed, 15 Nov 1995 00:13:06 -0500 (EST) From: Donald E. Eastlake 3rd To: "Edie E. Gunter" Cc: dns-security@TIS.COM Subject: Re: NSCOUNT Edie, On Tue, 14 Nov 1995, Edie E. Gunter wrote: > The DNSSEC draft seems to suggest that if DNS returns an NS > RR in the authority section of a query response, then the > SIG should also be included in the authority section of the > response. Is this correct? Yes, the idea being that you wouldn't want additional info to cause loss of the AIG authentication the authority info (or authority info to cause loss of the SIG for the main response) due to truncation. > If so, then it seems that in order for the message to be > parsed correctly, the NSCOUNT field would have to be set to > 2 instead of 1, to account for the SIG and the NS RR. Or possibly more for multiple SIGs. Also, the NXT RR authenticating the non-existence of a name appears in the authority section. > But, the NSCOUNT field is defined (RFC 883, 1035 and elsewhere) > to be the number of NS RRs in the authority section. > So, it seems that the DNSSEC draft is redefining the > meaning of the NSCOUNT field, though I don't see this > mentioned explicitly. You are correction and I guess this should be added to the draft. > If the above is true, then is there is problem working > with older non-security-aware servers? Are they going > to fail when they get a response with an nscount of 2 > but only 1 actual NS RR? Paul Vixie has been consulted on most of these decisions. My understanding from what he has said is that older versions of BIND are quite insensitive as to what section RRs are returned in and should not have problems in these cases. > Edie Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa20811; 15 Nov 95 14:46 EST Received: from holmes.umd.edu(128.8.10.48) by relay.tis.com via smap (g3.0.1) id xma013658; Wed, 15 Nov 95 14:24:54 -0500 Received: from UMDD (umdd.umd.edu [128.8.170.13]) by holmes.umd.edu(8.6.12/95Sep13) with SMTP id OAA10755; Wed, 15 Nov 1995 14:47:53 -0500 Message-Id: <199511151947.OAA10755@holmes.umd.edu> Received: by UMDD.UMD.EDU id 6604 ; 15 Nov 95 14:47:50 EST Received: by UMDD (Mailer R2.10 ptf000) id 6604; Wed, 15 Nov 95 14:47:49 EST Date: Wed, 15 Nov 95 14:44:36 EST From: Bruce Crabill Subject: Re: NSCOUNT (fwd) In-Reply-To: Message received on Wed, 15 Nov 95 11:40:14 EST To: dns-security@TIS.COM >I looked at RFC 1035 and found that it provides in section 3.7 for servers, >at their option, to include SOA RRs in the authority section and in fact an >example of this is given in section 6.2.5. So it was never true that NSCOUNT >was only a count of NS RRs. > >Donald I think you meant RFC 1034. RFC 1035 doesn't have those section numbers and defines (in section 4.1.1.) that NSCOUNT is the number of name server resource records. But you are right, RFC 1034 does add the thing about a SOA as also being a possibility. Bruce   Received: from relay.tis.com by neptune.TIS.COM id aa14730; 16 Nov 95 13:44 EST Received: from gw.home.vix.com(192.5.5.1) by relay.tis.com via smap (g3.0.1) id xma001691; Thu, 16 Nov 95 13:22:28 -0500 Received: by gw.home.vix.com id AA19980; Thu, 16 Nov 95 10:45:40 -0800 Date: Thu, 16 Nov 95 10:45:40 -0800 X-Btw: vix.com is also gw.home.vix.com and vixie.sf.ca.us To: dns-security@TIS.COM From: Paul A Vixie Subject: Re: NSCOUNT Organization: Vixie Enterprises Message-Id: References: <9511142159.AA18904@edisto.watson.ibm.com> Nntp-Posting-Host: wisdom.home.vix.com In-Reply-To: dee@cybercash.com's message of 14 Nov 1995 21:41:07 -0800 >Paul Vixie has been consulted on most of these decisions. My understanding >from what he has said is that older versions of BIND are quite insensitive as >to what section RRs are returned in and should not have problems in these >cases. BIND treats NSCOUNT as "the number of records in the authority section" and I think this is the intent of PVM's original spec -- the reason it may have been described as "the number of NS records in the authority section" is only because the authority section could only contain NS records at that time and PVM overspecified. I think it's safe to redefine this as long as we do so explicitly. -- Paul Vixie La Honda, CA "Illegitimibus non carborundum." pacbell!vixie!paul   Received: from relay.tis.com by neptune.TIS.COM id aa12610; 17 Nov 95 15:28 EST Received: from watson.ibm.com(129.34.139.4) by relay.tis.com via smap (g3.0.1) id xma028652; Fri, 17 Nov 95 15:06:16 -0500 Received: from WATSON by watson.ibm.com (IBM VM SMTP V2R3) with BSMTP id 4469; Fri, 17 Nov 95 15:29:43 EST Received: from YKTVMV by watson.vnet.ibm.com with "VAGENT.V1.02 on VAGENT2" id 8437; Fri, 17 Nov 1995 15:29:43 EST Received: from edisto.watson.ibm.com by yktvmv.watson.ibm.com (IBM VM SMTP V2Rx) with TCP; Fri, 17 Nov 95 15:29:42 EST Received: by edisto.watson.ibm.com (AIX 3.2/UCB 5.64/900524) id AA17231; Fri, 17 Nov 1995 15:29:32 -0500 Message-Id: <9511172029.AA17231@edisto.watson.ibm.com> X-External-Networks: yes To: dns-security@TIS.COM Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-Reply-To: Your message of Wed, 15 Nov 95 00:31:32 EST. Date: Fri, 17 Nov 95 15:29:32 -0500 From: "Edie E. Gunter" > If a DNS server is security ignorant, it obviously does nothing when a > SIG expires. If it's security aware, it shouldn't send out an RR > whose SIG has expired and if it was caching it should purge them. > It's not quite so clear to me if it was not cahcing but a primary or > secondary server and I don't think it matters much. You clearly have > a problem of not having re-signed and reloaded the zone soon enough. > I don't think this case is covered in the current draft. It does not > seem to matter much to me if the RR is purged or just keep around and > not provided in answers (except in a zone transfer so the AXFR is right > (except that it would probably be the case that if one zone signed SIG > has expired, they all have, and you are totally out of it)). So, what would you expect to happen when all the SIGs for a zone expire, including that for the SOA? Would the server just start rejecting every query with SERVFAIL/REFUSED? Or should the server alert the sys_admin and terminate? Or is this detail just left up to the implementation to decide? Anyone know what TIS is doing in this case? Edie   Received: from relay.tis.com by neptune.TIS.COM id aa01459; 21 Nov 95 16:30 EST Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma018053; Tue, 21 Nov 95 16:08:36 -0500 Received: by callandor.cybercash.com; id QAA11204; Tue, 21 Nov 1995 16:33:11 -0500 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.3) id xma011201; Tue, 21 Nov 95 16:33:01 -0500 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA02564; Tue, 21 Nov 95 16:30:44 EST Date: Tue, 21 Nov 1995 16:30:44 -0500 (EST) From: "Donald E. Eastlake 3rd" To: "Edie E. Gunter" Cc: dns-security@TIS.COM Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-Reply-To: <9511172029.AA17231@edisto.watson.ibm.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Things like alerting the system administrator seem like local policy issues. If all the SIGs have expired, seems like a secure server should act like it had never had any data for the zone loaded. Donald On Fri, 17 Nov 1995, Edie E. Gunter wrote: > > If a DNS server is security ignorant, it obviously does nothing when a > > SIG expires. If it's security aware, it shouldn't send out an RR > > whose SIG has expired and if it was caching it should purge them. > > It's not quite so clear to me if it was not cahcing but a primary or > > secondary server and I don't think it matters much. You clearly have > > a problem of not having re-signed and reloaded the zone soon enough. > > I don't think this case is covered in the current draft. It does not > > seem to matter much to me if the RR is purged or just keep around and > > not provided in answers (except in a zone transfer so the AXFR is right > > (except that it would probably be the case that if one zone signed SIG > > has expired, they all have, and you are totally out of it)). > > So, what would you expect to happen when all the SIGs for a > zone expire, including that for the SOA? Would the server > just start rejecting every query with SERVFAIL/REFUSED? Or > should the server alert the sys_admin and terminate? Or is > this detail just left up to the implementation to decide? > > Anyone know what TIS is doing in this case? > > Edie > ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa18217; 22 Nov 95 11:17 EST Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma000335; Wed, 22 Nov 95 10:54:22 -0500 Received: by callandor.cybercash.com; id LAA19508; Wed, 22 Nov 1995 11:19:13 -0500 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.3) id xma019504; Wed, 22 Nov 95 11:19:05 -0500 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA09168; Wed, 22 Nov 95 11:16:43 EST Date: Wed, 22 Nov 1995 11:16:42 -0500 (EST) From: "Donald E. Eastlake 3rd" To: "Edie E. Gunter" Cc: dns-security@TIS.COM Subject: Re: "Null" SIGs, NXT ordering, SIG orig TTL In-Reply-To: <9510101352.AA19385@edisto.watson.ibm.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII I think some of these have already been answered but I'll give it a try also... On Tue, 10 Oct 1995, Edie E. Gunter wrote: > I have a few comments on the draft... > > - Section 3 says: > > Security > aware DNS implementations MUST be designed to handle at least two > simultaneously valid keys of the same type associated with a name. > > Why isn't the ability to handle one enough? Why MUST two valid > keys be supported? Optional support of more than one is fine. > (Why would anyone want more than one KEY of the same type, anyway?) Basicly for key rollover. If a new key is being introduced for a zone, it may take a while for the superzone and various boot files to get update during which time you would want both keys to be used. And if the key is being used in some non-DNS protocol, where DNS is just being used for key distribution, you can have similar problems. > - Section 3.7 refers to type AAAA RR's. What are these? AAAA are the IPv6 equivalent of A. > - Section 4 says: > > The SIG RR unforgably authenticates other RRs of a particular type, > class, and name and binds them to a time interval and the signer's > domain name. > > If this is true, why isn't the SIG on a dynamic update sufficient > to make that name/RR a full-fledged part of the DNS database, > allowing dynamically updated data to be treated just like "static" > data? If this is true, why do we even need the distinction of > static versus dynamic RRs? The essence of the secrity of static RRs, as recommended by DNSsec is that the data, key, and signing are all done off-line so that even corruption of all the servers serving that zone can not lead to spoofing valid RRs to someone who has the zone public key. Any dynamic on-line scheme, including dynamic update, requires the private key on line which means that compromise of that machine breaks your security. > - Section 4.1.3 says: > > Thus > such dynamic RRs are not directly signed by the zone, are not > included in the AXFR SIG, and are not generally protected against > omission from zone transfers. > > I am quite sure this is not what anyone running a secure DNS that > supports secure dynamic updates would want. It seems this section > should cover how to securely include dynamic updates in a zone transfer -- > if not via the method described in 4.1.3 using AXFR SIG, etc. then by > some other method. If something is being updated on-line, you are completely trusting the server to do the right thing. After all, it could tell you that the update was complete but actually ignore it. So if you trust that machine, you can get a trusted zone transfer by using the DNSsec transaction security feature or otherwise having secure communications with it. I'll change the wording to reflect that. > - Section 4.3 says: > > Only a proper SIG RR signed by the zone can authenticate RRs. > > What about entity signed dynamic RRs? I'll fix that. > - Section 4.4 Signature Expiration > > When a SIG expires, the covered RR's are not removed from the database, > but are kept around and the AD bit is used to indicate if the data > is no longer authentic. Is that right? Nope, AD is used only to indicate whether data is (1) Pending or (2) Authentic or Insecure. (Insecure means it has been proven that the data can't authenticated or proved bad becasue it's in or accessed via an non-secure zone or the like.) Data with expired SIG are removed in the TIS implementation, I believe, but would never be returned in any case. > - Section 5.1 says: > > The NXT RRs for a zone should be automatically calculated and added > to the zone by the same recommended off-line process that signs the > zone. > > What about dynamic updates? Can't you get into a situation where > something was added via a dynamic update and the NXT RR computed at > start-up is no longer correct? It seems to me that these NXT RR's > must be computed on the fly to be accurate in the face of dynamic > updates. As answered elsewhere, dynamic updates can't change the name structure as they are authorized by KEYs that have already covered the name for any possible additions. Dynamic updates can, however, change what types exist so I will change the draft to indicate that the NXT type bits only cover zone signed RRs. > - Section 6 says: > > Authenticated means that the data has a valid SIG under a KEY > traceable via a chain of zero or more SIG and KEY RRs to a KEY > configured at the resolver via its boot file. > > So, if the KEY RR for a name was in the statically read master > file for the zone, then RR's added dynamically and signed with > the private part of that KEY are considered authenticated? Yes. > - Section 6.1 says: > > Security aware servers never return Bad data. > > Is this true, given that zone transfers may omit dynamically added > RR's and given that NXT RR's are calculated offline? Perhaps I > don't understand the definition of Bad data here. "Bad" data is data for which their should be authenticating SIGs but for which all the SIGs have been checked and they all either fail or have expired. (If they have not all been checked yet, the data is Pending.) > - Section 6.3 says: > > A resolver should keep track of the number of successive secure zones > traversed from a starting point to any secure zone it can reach. <...> > Should a query encounter > different data for the same query with different distance values, > that with a larger value should be ignored. > > I don't see exactly how this is supposed to work. Are you suggesting > that after sending out a query, the client waits around for multiple > query responses and then picks the one with the lower distance value? > In practice, wouldn't a client just take the first response with > a non-empty answer section and use that? Sure. The comment applies to the case of conflicting data in the cache. > - Section 7.2 says: > > Periodically an application can be > run to re-sign the RRs in a zone by adding NXT and SIG RRs. > > It seems to get dynamic updates to work within the DNSSEC framework, > this period would have to be such that everything is re-signed > after each dynamic update. The update becomes part of the "static" > data and all the "static" data is then resigned. No, this can't be right. If you wanted to keep the zone owner private key on line and have everything zone signed, you would have to at least re-sign the SOA, AXFR, and maybe a changed NXT (due to type bit map) or two after each dynamic update but you won't have to re-sign everything. > - Section 7.5 says: > > It is recommended that signature lifetime be a small multiple of the > TTL but not less than a reasonable re-signing interval. > > In an environment where DHCP is used to hand out IP address leases > and DNS is updated dynamically to reflect the lease information, > the lifetime of the data will usually be that of the lease duration. > In the case of mobile clients, this lease duration may be just 5 - 10 > minutes. That said, what is your idea of a reasonable re-signing interval? This was meant to apply to the off line zone signing procedure. I'll add some words to the effect that shorter times are fine if you *want* the data to expire sooner (in which case the TTL should be shorter also). > - Also, it was mentioned to me in private email that: > > if you want a completely dynamic zone, you can just have > the zone key sign an entity key with wildcard authority over the > entire zone and then use the entity key for everything in the zone > > I don't see anything like this discussed in the draft -- > particularly with respect to zone transfers and handling > NXT records. (And if there really is this other way to do security > in DNS servers that support dynamic updates, I'd really > like to understand how it would work!) It's not an "other way", it's just a way, completely within the framework contemplated in the DNSsec draft, to move almost everything from the fixed master file to the dynamic master file... If you have a wildcard entity key covering the whole zone, there are only two NXT records ever (one with an owner name of the zone name and one with an owner name of the zone wide wildcard name). If you want update keys with more limited scope, they could be signed by either the zone key or this zone wide update key. > Edie Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa19080; 22 Nov 95 12:03 EST Received: from callandor.cybercash.com(204.178.186.70) by relay.tis.com via smap (g3.0.1) id xma001021; Wed, 22 Nov 95 11:26:52 -0500 Received: by callandor.cybercash.com; id LAA19918; Wed, 22 Nov 1995 11:51:13 -0500 Received: from cybercash.com(204.254.34.52) by callandor.cybercash.com via smap (g3.0.3) id xma019914; Wed, 22 Nov 95 11:50:48 -0500 Received: by cybercash.com.cybercash.com (4.1/SMI-4.1) id AA09678; Wed, 22 Nov 95 11:48:22 EST Date: Wed, 22 Nov 1995 11:48:21 -0500 (EST) From: "Donald E. Eastlake 3rd" To: "Edie E. Gunter" Cc: dnssec@fireball.lz.att.com, dns-security@TIS.COM MMDF-Warning: Unable to confirm address in preceding line at neptune.TIS.COM Subject: Re: A Simple Question In-Reply-To: <9511101845.AA18042@edisto.watson.ibm.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Fri, 10 Nov 1995, Edie E. Gunter wrote: > > So I'm a security aware resolver and I query for, say, Type A records > > on name A.B.C.D. I get back an A record and a SIG record: > > > > A.B.C.D IN A [some ttl] 135.24.40.12 > > A.B.C.D IN SIG [some ttl] [Type A SIG RDATA] > > > > How do I figure out which public KEY I'm supposed to use to > > authenticate the A record? > > The RR's for A.B.C.D can be signed by the entity A.B.C.D > and/or the zone. So, if you don't have the public key for > A.B.C.D and/or the zone, you'll have to query the > server for those KEY RR's also (perhaps using transaction SIGs if > you're really paranoid.) > > Now, there can be multiple keys per name. (i.e. A.B.C.D may > have multiple KEY RRs for the same algorithm type.) The best > explanation I've heard for handling this is to just > try them all and see if any work... That should almost never be necessary. It's the primary reason for the 16 bit "key footprint" field in the SIG RR. Unless you have a log of zone and/or entity keys, the probability should be very low that two have the same footprint. > All KEY RR's are signed by the zone. (Well, in principle, you could have an entity key for B.C.D sign an entity key for A.B.C.D but I don't know if that feature will be used in practice.) > W.X.Y.Z can't generate a SIG for A.B.C.D unless it knows > either the private key for A.B.C.D or the private key for > the zone (and you're allowing dynamic updates.) W.X.Y.Z should > never know another name's private key. Once the private key is > exposed, you're no longer secure. > > Edie Donald ===================================================================== Donald E. Eastlake 3rd +1 508-287-4877(tel) dee@cybercash.com 318 Acton Street +1 508-371-7148(fax) dee@world.std.com Carlisle, MA 01741 USA +1 703-620-4200(main office, Reston, VA)   Received: from relay.tis.com by neptune.TIS.COM id aa09106; 27 Nov 95 10:12 EST Received: from mailhost1.primenet.com(198.68.32.51) by relay.tis.com via smap (g3.0.1) id xma012739; Mon, 27 Nov 95 09:50:00 -0500 Received: from usr2.primenet.com (root@usr2.primenet.com [198.68.32.12]) by mailhost1.primenet.com (8.7.1/8.7.1) with ESMTP id IAA08739 for ; Mon, 27 Nov 1995 08:14:23 -0700 (MST) Received: from ip141.flg.primenet.com (ip141.flg.primenet.com [198.68.40.141]) by usr2.primenet.com (8.7.1/8.7.1) with SMTP id IAA14634 for ; Mon, 27 Nov 1995 08:14:22 -0700 (MST) Date: Mon, 27 Nov 1995 08:14:22 -0700 (MST) Message-Id: <199511271514.IAA14634@usr2.primenet.com> X-Sender: srm@mailhost.primenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: dns-security@TIS.COM From: "Scott R. 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Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII ------------------------------------- E-mail: bprice@bsan.com General Manager, Internet Services BellSouth Date: 11/27/95 Time: 15:58:49 This message was sent by Chameleon -------------------------------------   Received: from relay.tis.com by neptune.TIS.COM id aa23092; 30 Nov 95 13:29 EST Received: from sol.tis.com(192.33.112.100) by relay.tis.com via smap (g3.0.1) id xma004373; Thu, 30 Nov 95 13:05:59 -0500 Received: from antares.tis.com by tis.com (4.1/SUN-5.64) id AA12393; Thu, 30 Nov 95 13:29:00 EST Message-Id: <9511301829.AA12393@tis.com> Reply-To: James M Galvin To: dns-security@TIS.COM Subject: Agenda for Dallas IETF Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Id: <12059.817756170.1@tis.com> Date: Thu, 30 Nov 1995 13:29:31 -0500 From: James M Galvin Sorry for the late posting. In case you haven't noticed, the meeting is scheduled for Tuesday during the 9am meeting slot. I've got three items for the agenda: o specification status - DNS security - Autonomous system numbers o implementation status o dynamic update - charter update - technical issues With respect to the latter item, many of you already know that those working on dynamic update have asked that we accept as a work item to address security issues. Our security area director has, in fact, told me as Chair that we will do this. As a strictly procedural issue, we need to update our charter to reflect this new work item. I expect we will spend most of our time on dynamic update issues unless, of course, no one is prepared to discuss them. See you in Dallas, Jim