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diff --git a/contrib/bind9/doc/rfc/rfc2537.txt b/contrib/bind9/doc/rfc/rfc2537.txt deleted file mode 100644 index cb75cf5..0000000 --- a/contrib/bind9/doc/rfc/rfc2537.txt +++ /dev/null @@ -1,339 +0,0 @@ - - - - - - -Network Working Group D. Eastlake -Request for Comments: 2537 IBM -Category: Standards Track March 1999 - - - RSA/MD5 KEYs and SIGs in the Domain Name System (DNS) - -Status of this Memo - - This document specifies an Internet standards track protocol for the - Internet community, and requests discussion and suggestions for - improvements. Please refer to the current edition of the "Internet - Official Protocol Standards" (STD 1) for the standardization state - and status of this protocol. Distribution of this memo is unlimited. - -Copyright Notice - - Copyright (C) The Internet Society (1999). All Rights Reserved. - -Abstract - - A standard method for storing RSA keys and and RSA/MD5 based - signatures in the Domain Name System is described which utilizes DNS - KEY and SIG resource records. - -Table of Contents - - Abstract...................................................1 - 1. Introduction............................................1 - 2. RSA Public KEY Resource Records.........................2 - 3. RSA/MD5 SIG Resource Records............................2 - 4. Performance Considerations..............................3 - 5. Security Considerations.................................4 - References.................................................4 - Author's Address...........................................5 - Full Copyright Statement...................................6 - -1. Introduction - - The Domain Name System (DNS) is the global hierarchical replicated - distributed database system for Internet addressing, mail proxy, and - other information. The DNS has been extended to include digital - signatures and cryptographic keys as described in [RFC 2535]. Thus - the DNS can now be secured and used for secure key distribution. - - - - - - - -Eastlake Standards Track [Page 1] - -RFC 2537 RSA/MD5 KEYs and SIGs in the DNS March 1999 - - - This document describes how to store RSA keys and and RSA/MD5 based - signatures in the DNS. Familiarity with the RSA algorithm is assumed - [Schneier]. Implementation of the RSA algorithm in DNS is - recommended. - - The key words "MUST", "REQUIRED", "SHOULD", "RECOMMENDED", and "MAY" - in this document are to be interpreted as described in RFC 2119. - -2. RSA Public KEY Resource Records - - RSA public keys are stored in the DNS as KEY RRs using algorithm - number 1 [RFC 2535]. The structure of the algorithm specific portion - of the RDATA part of such RRs is as shown below. - - Field Size - ----- ---- - exponent length 1 or 3 octets (see text) - exponent as specified by length field - modulus remaining space - - For interoperability, the exponent and modulus are each currently - limited to 4096 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 octets are prohibited in the exponent and modulus. - -3. RSA/MD5 SIG Resource Records - - The signature portion of the SIG RR RDATA area, when using the - RSA/MD5 algorithm, is calculated as shown below. The data signed is - determined as specified in [RFC 2535]. See [RFC 2535] for fields in - the SIG RR RDATA which precede the signature itself. - - - hash = MD5 ( data ) - - signature = ( 00 | 01 | FF* | 00 | prefix | hash ) ** e (mod n) - - - - - - - - - - -Eastlake Standards Track [Page 2] - -RFC 2537 RSA/MD5 KEYs and SIGs in the DNS March 1999 - - - where MD5 is the message digest algorithm documented in [RFC 1321], - "|" is concatenation, "e" is the private key exponent of the signer, - and "n" is the 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 [RFC - 2437], that is, - - hex 3020300c06082a864886f70d020505000410 [NETSEC]. - - This prefix is included to make it easier to use RSAREF (or similar - packages such as EuroRef). The FF octet MUST be repeated the maximum - number of times such that the value of the quantity being - exponentiated is the same length in octets as the value of n. - - (The above specifications are identical to the corresponding part of - Public Key Cryptographic Standard #1 [RFC 2437].) - - The size of n, including most and least significant bits (which will - be 1) MUST be not less than 512 bits and not more than 4096 bits. n - and e SHOULD be chosen such that the public exponent is small. - - Leading zero bytes are permitted in the RSA/MD5 algorithm signature. - - A public exponent of 3 minimizes the effort needed to verify a - signature. Use of 3 as the public exponent is 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 [NETSEC], the original plain text - can be easily recovered. This weakness is not significant for DNS - security because we seek only authentication, not confidentiality. - -4. Performance Considerations - - General signature generation speeds are roughly the same for RSA and - DSA [RFC 2536]. With sufficient pre-computation, signature - generation with DSA is faster than RSA. Key generation is also - faster for DSA. However, signature verification is an order of - magnitude slower with DSA when the RSA public exponent is chosen to - be small as is recommended for KEY RRs used in domain name system - (DNS) data authentication. - - Current DNS implementations are optimized for small transfers, - typically less than 512 bytes including overhead. While larger - transfers will perform correctly and work is underway to make larger - - - - - - - -Eastlake Standards Track [Page 3] - -RFC 2537 RSA/MD5 KEYs and SIGs in the DNS March 1999 - - - transfers more efficient, it is still advisable at this time to make - reasonable efforts to minimize the size of KEY RR sets stored within - the DNS consistent with adequate security. Keep in mind that in a - secure zone, at least one authenticating SIG RR will also be - returned. - -5. Security Considerations - - Many of the general security consideration in [RFC 2535] apply. Keys - retrieved from the DNS should not be trusted unless (1) they have - been securely obtained from a secure resolver or independently - verified by the user and (2) this secure resolver and secure - obtainment or independent verification conform to security policies - acceptable to the user. As with all cryptographic algorithms, - evaluating the necessary strength of the key is essential and - dependent on local policy. - - For interoperability, the RSA key size is limited to 4096 bits. For - particularly critical applications, implementors are encouraged to - consider the range of available algorithms and key sizes. - -References - - [NETSEC] Kaufman, C., Perlman, R. and M. Speciner, "Network - Security: PRIVATE Communications in a PUBLIC World", - Series in Computer Networking and Distributed - Communications, 1995. - - [RFC 2437] Kaliski, B. and J. Staddon, "PKCS #1: RSA Cryptography - Specifications Version 2.0", RFC 2437, October 1998. - - [RFC 1034] Mockapetris, P., "Domain Names - Concepts and - Facilities", STD 13, RFC 1034, November 1987. - - [RFC 1035] Mockapetris, P., "Domain Names - Implementation and - Specification", STD 13, RFC 1035, November 1987. - - [RFC 1321] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321 - April 1992. - - [RFC 2535] Eastlake, D., "Domain Name System Security Extensions", - RFC 2535, March 1999. - - [RFC 2536] EastLake, D., "DSA KEYs and SIGs in the Domain Name - System (DNS)", RFC 2536, March 1999. - - - - - - -Eastlake Standards Track [Page 4] - -RFC 2537 RSA/MD5 KEYs and SIGs in the DNS March 1999 - - - [Schneier] Bruce Schneier, "Applied Cryptography Second Edition: - protocols, algorithms, and source code in C", 1996, John - Wiley and Sons, ISBN 0-471-11709-9. - -Author's Address - - Donald E. Eastlake 3rd - IBM - 65 Shindegan Hill Road, RR #1 - Carmel, NY 10512 - - Phone: +1-914-276-2668(h) - +1-914-784-7913(w) - Fax: +1-914-784-3833(w) - EMail: dee3@us.ibm.com - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Eastlake Standards Track [Page 5] - -RFC 2537 RSA/MD5 KEYs and SIGs in the DNS March 1999 - - -Full Copyright Statement - - Copyright (C) The Internet Society (1999). All Rights Reserved. - - This document and translations of it may be copied and furnished to - others, and derivative works that comment on or otherwise explain it - or assist in its implementation may be prepared, copied, published - and distributed, in whole or in part, without restriction of any - kind, provided that the above copyright notice and this paragraph are - included on all such copies and derivative works. However, this - document itself may not be modified in any way, such as by removing - the copyright notice or references to the Internet Society or other - Internet organizations, except as needed for the purpose of - developing Internet standards in which case the procedures for - copyrights defined in the Internet Standards process must be - followed, or as required to translate it into languages other than - English. - - The limited permissions granted above are perpetual and will not be - revoked by the Internet Society or its successors or assigns. - - This document and the information contained herein is provided on an - "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING - TASK FORCE DISCLAIMS 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. - - - - - - - - - - - - - - - - - - - - - - - - -Eastlake Standards Track [Page 6] - |
