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diff --git a/contrib/bind9/doc/draft/draft-ietf-dnsext-tsig-sha-06.txt b/contrib/bind9/doc/draft/draft-ietf-dnsext-tsig-sha-06.txt deleted file mode 100644 index 00476ae..0000000 --- a/contrib/bind9/doc/draft/draft-ietf-dnsext-tsig-sha-06.txt +++ /dev/null @@ -1,522 +0,0 @@ - -INTERNET-DRAFT Donald E. Eastlake 3rd -UPDATES RFC 2845 Motorola Laboratories -Expires: July 2006 January 2006 - - HMAC SHA TSIG Algorithm Identifiers - ---- --- ---- --------- ----------- - <draft-ietf-dnsext-tsig-sha-06.txt> - - -Status of This Document - - By submitting this Internet-Draft, each author represents that any - applicable patent or other IPR claims of which he or she is aware - have been or will be disclosed, and any of which he or she becomes - aware will be disclosed, in accordance with Section 6 of BCP 79. - - This draft is intended to be become a Proposed Standard RFC. - Distribution of this document is unlimited. Comments should be sent - to the DNSEXT working group mailing list <namedroppers@ops.ietf.org>. - - 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 - and may be updated, replaced, or obsoleted by other documents at any - time. It is inappropriate to use Internet-Drafts as reference - material or to cite them other than as "work in progress." - - The list of current Internet-Drafts can be accessed at - http://www.ietf.org/1id-abstracts.html - - The list of Internet-Draft Shadow Directories can be accessed at - http://www.ietf.org/shadow.html - - -Abstract - - Use of the Domain Name System TSIG resource record requires - specification of a cryptographic message authentication code. - Currently identifiers have been specified only for the HMAC MD5 - (Message Digest) and GSS (Generic Security Service) TSIG algorithms. - This document standardizes identifiers and implementation - requirements for additional HMAC SHA (Secure Hash Algorithm) TSIG - algorithms and standardizes how to specify and handle the truncation - of HMAC values in TSIG. - - -Copyright Notice - - Copyright (C) The Internet Society (2006). - - - -D. Eastlake 3rd [Page 1] - - -INTERNET-DRAFT HMAC-SHA TSIG Identifiers - - -Table of Contents - - Status of This Document....................................1 - Abstract...................................................1 - Copyright Notice...........................................1 - - Table of Contents..........................................2 - - 1. Introduction............................................3 - - 2. Algorithms and Identifiers..............................4 - - 3. Specifying Truncation...................................5 - 3.1 Truncation Specification...............................5 - - 4. TSIG Truncation Policy and Error Provisions.............6 - - 5. IANA Considerations.....................................7 - 6. Security Considerations.................................7 - 7. Copyright and Disclaimer................................7 - - 8. Normative References....................................8 - 9. Informative References..................................8 - - Author's Address...........................................9 - Additional IPR Provisions..................................9 - Expiration and File Name...................................9 - - - - - - - - - - - - - - - - - - - - - - - - - -D. Eastlake 3rd [Page 2] - - -INTERNET-DRAFT HMAC-SHA TSIG Identifiers - - -1. Introduction - - [RFC 2845] specifies a TSIG Resource Record (RR) that can be used to - authenticate DNS (Domain Name System [STD 13]) queries and responses. - This RR contains a domain name syntax data item which names the - authentication algorithm used. [RFC 2845] defines the HMAC-MD5.SIG- - ALG.REG.INT name for authentication codes using the HMAC [RFC 2104] - algorithm with the MD5 [RFC 1321] hash algorithm. IANA has also - registered "gss-tsig" as an identifier for TSIG authentication where - the cryptographic operations are delegated to the Generic Security - Service (GSS) [RFC 3645]. - - It should be noted that use of TSIG presumes prior agreement, between - the resolver and server involved, as to the algorithm and key to be - used. - - In Section 2, this document specifies additional names for TSIG - authentication algorithms based on US NIST SHA (United States, - National Institute of Science and Technology, Secure Hash Algorithm) - algorithms and HMAC and specifies the implementation requirements for - those algorithms. - - In Section 3, this document specifies the effect of inequality - between the normal output size of the specified hash function and the - length of MAC (message authentication code) data given in the TSIG - RR. In particular, it specifies that a shorter length field value - specifies truncation and a longer length field is an error. - - In Section 4, policy restrictions and implications related to - truncation and a new error code to indicate truncation shorter than - permitted by policy are described and specified. - - The use herein of MUST, SHOULD, MAY, MUST NOT, and SHOULD NOT is as - defined in [RFC 2119]. - - - - - - - - - - - - - - - - - - -D. Eastlake 3rd [Page 3] - - -INTERNET-DRAFT HMAC-SHA TSIG Identifiers - - -2. Algorithms and Identifiers - - TSIG Resource Records (RRs) [RFC 2845] are used to authenticate DNS - queries and responses. They are intended to be efficient symmetric - authentication codes based on a shared secret. (Asymmetric signatures - can be provided using the SIG RR [RFC 2931]. In particular, SIG(0) - can be used for transaction signatures.) Used with a strong hash - function, HMAC [RFC 2104] provides a way to calculate such symmetric - authentication codes. The only specified HMAC based TSIG algorithm - identifier has been HMAC-MD5.SIG-ALG.REG.INT based on MD5 [RFC 1321]. - - The use of SHA-1 [FIPS 180-2, RFC 3174], which is a 160 bit hash, as - compared with the 128 bits for MD5, and additional hash algorithms in - the SHA family [FIPS 180-2, RFC 3874, SHA2draft] with 224, 256, 384, - and 512 bits, may be preferred in some cases particularly since - increasingly successful cryptanalytic attacks are being made on the - shorter hashes. - - Use of TSIG between a DNS resolver and server is by mutual agreement. - That agreement can include the support of additional algorithms and - criteria as to which algorithms and truncations are acceptable, - subject to the restriction and guidelines in Section 3 and 4 below. - Key agreement can be by the TKEY mechanism [RFC 2930] or other - mutually agreeable method. - - The current HMAC-MD5.SIG-ALG.REG.INT and gss-tsig identifiers are - included in the table below for convenience. Implementations which - support TSIG MUST also implement HMAC SHA1 and HMAC SHA256 and MAY - implement gss-tsig and the other algorithms listed below. - - Mandatory HMAC-MD5.SIG-ALG.REG.INT - Optional gss-tsig - Mandatory hmac-sha1 - Optional hmac-sha224 - Mandatory hmac-sha256 - Optional hamc-sha384 - Optional hmac-sha512 - - SHA-1 truncated to 96 bits (12 octets) SHOULD be implemented. - - - - - - - - - - - - - -D. Eastlake 3rd [Page 4] - - -INTERNET-DRAFT HMAC-SHA TSIG Identifiers - - -3. Specifying Truncation - - When space is at a premium and the strength of the full length of an - HMAC is not needed, it is reasonable to truncate the HMAC output and - use the truncated value for authentication. HMAC SHA-1 truncated to - 96 bits is an option available in several IETF protocols including - IPSEC and TLS. - - The TSIG RR [RFC 2845] includes a "MAC size" field, which gives the - size of the MAC field in octets. But [RFC 2845] does not specify what - to do if this MAC size differs from the length of the output of HMAC - for a particular hash function. Truncation is indicated by a MAC size - less than the HMAC size as specified below. - - - -3.1 Truncation Specification - - The specification for TSIG handling is changed as follows: - - 1. If "MAC size" field is greater than HMAC output length: - This case MUST NOT be generated and if received MUST cause the - packet to be dropped and RCODE 1 (FORMERR) to be returned. - - 2. If "MAC size" field equals HMAC output length: - Operation is as described in [RFC 2845] with the entire output - HMAC output present. - - 3. "MAC size" field is less than HMAC output length but greater than - that specified in case 4 below: - This is sent when the signer has truncated the HMAC output to - an allowable length, as described in RFC 2104, taking initial - octets and discarding trailing octets. TSIG truncation can only be - to an integral number of octets. On receipt of a packet with - truncation thus indicated, the locally calculated MAC is similarly - truncated and only the truncated values compared for - authentication. The request MAC used when calculating the TSIG MAC - for a reply is the truncated request MAC. - - 4. "MAC size" field is less than the larger of 10 (octets) and half - the length of the hash function in use: - With the exception of certain TSIG error messages described in - RFC 2845 section 3.2 where it is permitted that the MAC size be - zero, this case MUST NOT be generated and if received MUST cause - the packet to be dropped and RCODE 1 (FORMERR) to be returned. The - size limit for this case can also, for the hash functions - mentioned in this document, be stated as less than half the hash - function length for hash functions other than MD5 and less than 10 - octets for MD5. - - - -D. Eastlake 3rd [Page 5] - - -INTERNET-DRAFT HMAC-SHA TSIG Identifiers - - -4. TSIG Truncation Policy and Error Provisions - - Use of TSIG is by mutual agreement between a resolver and server. - Implicit in such "agreement" are criterion as to acceptable keys and - algorithms and, with the extensions in this document, truncations. - Note that it is common for implementations to bind the TSIG secret - key or keys that may be in place at a resolver and server to - particular algorithms. Thus such implementations only permit the use - of an algorithm if there is an associated key in place. Receipt of an - unknown, unimplemented, or disabled algorithm typically results in a - BADKEY error. - - Local policies MAY require the rejection of TSIGs even though they - use an algorithm for which implementation is mandatory. - - When a local policy permits acceptance of a TSIG with a particular - algorithm and a particular non-zero amount of truncation it SHOULD - also permit the use of that algorithm with lesser truncation (a - longer MAC) up to the full HMAC output. - - Regardless of a lower acceptable truncated MAC length specified by - local policy, a reply SHOULD be sent with a MAC at least as long as - that in the corresponding request unless the request specified a MAC - length longer than the HMAC output. - - Implementations permitting multiple acceptable algorithms and/or - truncations SHOULD permit this list to be ordered by presumed - strength and SHOULD allow different truncations for the same - algorithm to be treated as separate entities in this list. When so - implemented, policies SHOULD accept a presumed stronger algorithm and - truncation than the minimum strength required by the policy. - - If a TSIG is received with truncation which is permitted under - Section 3 above but the MAC is too short for the local policy in - force, an RCODE of TBA [22 suggested](BADTRUNC) MUST be returned. - - - - - - - - - - - - - - - - - -D. Eastlake 3rd [Page 6] - - -INTERNET-DRAFT HMAC-SHA TSIG Identifiers - - -5. IANA Considerations - - This document, on approval for publication as a standards track RFC, - (1) registers the new TSIG algorithm identifiers listed in Section 2 - with IANA and (2) allocates the BADTRUNC RCODE TBA [22 suggested] in - Section 4. [RFC 2845] - - - -6. Security Considerations - - For all of the message authentication code algorithms listed herein, - those producing longer values are believed to be stronger; however, - while there have been some arguments that mild truncation can - strengthen a MAC by reducing the information available to an - attacker, excessive truncation clearly weakens authentication by - reducing the number of bits an attacker has to try to break the - authentication by brute force [RFC 2104]. - - Significant progress has been made recently in cryptanalysis of hash - function of the type used herein, all of which ultimately derive from - the design of MD4. While the results so far should not effect HMAC, - the stronger SHA-1 and SHA-256 algorithms are being made mandatory - due to caution. - - See the Security Considerations section of [RFC 2845]. See also the - Security Considerations section of [RFC 2104] from which the limits - on truncation in this RFC were taken. - - - -7. Copyright and Disclaimer - - Copyright (C) The Internet Society (2006). - - This document is subject to the rights, licenses and restrictions - contained in BCP 78, and except as set forth therein, the authors - retain all their rights. - - - This document and the information contained herein are provided on an - "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS - OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET - ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, - INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE - INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED - WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. - - - - - -D. Eastlake 3rd [Page 7] - - -INTERNET-DRAFT HMAC-SHA TSIG Identifiers - - -8. Normative References - - [FIPS 180-2] - "Secure Hash Standard", (SHA-1/224/256/384/512) US - Federal Information Processing Standard, with Change Notice 1, - February 2004. - - [RFC 1321] - Rivest, R., "The MD5 Message-Digest Algorithm ", RFC - 1321, April 1992. - - [RFC 2104] - Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- - Hashing for Message Authentication", RFC 2104, February 1997. - - [RFC 2119] - Bradner, S., "Key words for use in RFCs to Indicate - Requirement Levels", BCP 14, RFC 2119, March 1997. - - [RFC 2845] - Vixie, P., Gudmundsson, O., Eastlake 3rd, D., and B. - Wellington, "Secret Key Transaction Authentication for DNS (TSIG)", - RFC 2845, May 2000. - - [RFC 3174] - Eastlake 3rd, D. and P. Jones, "US Secure Hash Algorithm - 1 (SHA1)", RFC 3174, September 2001. - - [RFC 3874] - R. Housely, "A 224-bit One-way Hash Function: SHA-224", - September 2004, - - [SHA2draft] - Eastlake, D., T. Hansen, "US Secure Hash Algorithms - (SHA)", draft-eastlake-sha2-*.txt, work in progress. - - [STD 13] - Mockapetris, P., "Domain names - concepts and facilities", STD - 13, RFC 1034, November 1987. - - Mockapetris, P., "Domain names - implementation and - specification", STD 13, RFC 1035, November 1987. - - - -9. Informative References. - - [RFC 2930] - Eastlake 3rd, D., "Secret Key Establishment for DNS - (TKEY RR)", RFC 2930, September 2000. - - [RFC 2931] - Eastlake 3rd, D., "DNS Request and Transaction - Signatures ( SIG(0)s )", RFC 2931, September 2000. - - [RFC 3645] - Kwan, S., Garg, P., Gilroy, J., Esibov, L., Westhead, - J., and R. Hall, "Generic Security Service Algorithm for Secret Key - Transaction Authentication for DNS (GSS-TSIG)", RFC 3645, October - 2003. - - - -D. Eastlake 3rd [Page 8] - - -INTERNET-DRAFT HMAC-SHA TSIG Identifiers - - -Author's Address - - Donald E. Eastlake 3rd - Motorola Laboratories - 155 Beaver Street - Milford, MA 01757 USA - - Telephone: +1-508-786-7554 (w) - - EMail: Donald.Eastlake@motorola.com - - - -Additional IPR Provisions - - The IETF takes no position regarding the validity or scope of any - Intellectual Property Rights or other rights that might be claimed - to pertain to the implementation or use of the technology - described in this document or the extent to which any license - under such rights might or might not be available; nor does it - represent that it has made any independent effort to identify any - such rights. Information on the procedures with respect to - rights in RFC documents can be found in BCP 78 and BCP 79. - - Copies of IPR disclosures made to the IETF Secretariat and any - assurances of licenses to be made available, or the result of an - attempt made to obtain a general license or permission for the use - of such proprietary rights by implementers or users of this - specification can be obtained from the IETF on-line IPR repository - at http://www.ietf.org/ipr. - - The IETF invites any interested party to bring to its attention - any copyrights, patents or patent applications, or other - proprietary rights that may cover technology that may be required - to implement this standard. Please address the information to the - IETF at ietf-ipr@ietf.org. - - - -Expiration and File Name - - This draft expires in July 2006. - - Its file name is draft-ietf-dnsext-tsig-sha-06.txt - - - - - - - - -D. Eastlake 3rd [Page 9] - |
