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diff --git a/contrib/bind9/doc/rfc/rfc2536.txt b/contrib/bind9/doc/rfc/rfc2536.txt deleted file mode 100644 index 88be242..0000000 --- a/contrib/bind9/doc/rfc/rfc2536.txt +++ /dev/null @@ -1,339 +0,0 @@ - - - - - - -Network Working Group D. EastLake -Request for Comments: 2536 IBM -Category: Standards Track March 1999 - - - DSA 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 US Government Digital Signature - Algorithm keys and 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. DSA KEY Resource Records................................2 - 3. DSA SIG Resource Records................................3 - 4. Performance Considerations..............................3 - 5. Security Considerations.................................4 - 6. IANA Considerations.....................................4 - References.................................................5 - 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 can be used for secure key - distribution. - - - - - -Eastlake Standards Track [Page 1] - -RFC 2536 DSA in the DNS March 1999 - - - This document describes how to store US Government Digital Signature - Algorithm (DSA) keys and signatures in the DNS. Familiarity with the - US Digital Signature Algorithm is assumed [Schneier]. Implementation - of DSA is mandatory for DNS security. - -2. DSA KEY Resource Records - - DSA public keys are stored in the DNS as KEY RRs using algorithm - number 3 [RFC 2535]. The structure of the algorithm specific portion - of the RDATA part of this RR is as shown below. These fields, from Q - through Y are the "public key" part of the DSA KEY RR. - - The period of key validity is not in the KEY RR but is indicated by - the SIG RR(s) which signs and authenticates the KEY RR(s) at that - domain name. - - Field Size - ----- ---- - T 1 octet - Q 20 octets - P 64 + T*8 octets - G 64 + T*8 octets - Y 64 + T*8 octets - - As described in [FIPS 186] and [Schneier]: T is a key size parameter - chosen such that 0 <= T <= 8. (The meaning for algorithm 3 if the T - octet is greater than 8 is reserved and the remainder of the RDATA - portion may have a different format in that case.) Q is a prime - number selected at key generation time such that 2**159 < Q < 2**160 - so Q is always 20 octets long and, as with all other fields, is - stored in "big-endian" network order. P, G, and Y are calculated as - directed by the FIPS 186 key generation algorithm [Schneier]. P is - in the range 2**(511+64T) < P < 2**(512+64T) and so is 64 + 8*T - octets long. G and Y are quantities modulus P and so can be up to - the same length as P and are allocated fixed size fields with the - same number of octets as P. - - During the key generation process, a random number X must be - generated such that 1 <= X <= Q-1. X is the private key and is used - in the final step of public key generation where Y is computed as - - Y = G**X mod P - - - - - - - - - -Eastlake Standards Track [Page 2] - -RFC 2536 DSA in the DNS March 1999 - - -3. DSA SIG Resource Records - - The signature portion of the SIG RR RDATA area, when using the US - Digital Signature Algorithm, is shown below with fields in the order - they occur. See [RFC 2535] for fields in the SIG RR RDATA which - precede the signature itself. - - Field Size - ----- ---- - T 1 octet - R 20 octets - S 20 octets - - The data signed is determined as specified in [RFC 2535]. Then the - following steps are taken, as specified in [FIPS 186], where Q, P, G, - and Y are as specified in the public key [Schneier]: - - hash = SHA-1 ( data ) - - Generate a random K such that 0 < K < Q. - - R = ( G**K mod P ) mod Q - - S = ( K**(-1) * (hash + X*R) ) mod Q - - Since Q is 160 bits long, R and S can not be larger than 20 octets, - which is the space allocated. - - T is copied from the public key. It is not logically necessary in - the SIG but is present so that values of T > 8 can more conveniently - be used as an escape for extended versions of DSA or other algorithms - as later specified. - -4. Performance Considerations - - General signature generation speeds are roughly the same for RSA [RFC - 2537] and DSA. 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 than - RSA 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 - transfers more efficient, it is still advisable at this time to make - reasonable efforts to minimize the size of KEY RR sets stored within - - - -Eastlake Standards Track [Page 3] - -RFC 2536 DSA in the DNS March 1999 - - - 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. - - The key size limitation of a maximum of 1024 bits ( T = 8 ) in the - current DSA standard may limit the security of DSA. For particularly - critical applications, implementors are encouraged to consider the - range of available algorithms and key sizes. - - DSA assumes the ability to frequently generate high quality random - numbers. See [RFC 1750] for guidance. DSA is designed so that if - manipulated rather than random numbers are used, very high bandwidth - covert channels are possible. See [Schneier] and more recent - research. The leakage of an entire DSA private key in only two DSA - signatures has been demonstrated. DSA provides security only if - trusted implementations, including trusted random number generation, - are used. - -6. IANA Considerations - - Allocation of meaning to values of the T parameter that are not - defined herein requires an IETF standards actions. It is intended - that values unallocated herein be used to cover future extensions of - the DSS standard. - - - - - - - - - - - - - - - - -Eastlake Standards Track [Page 4] - -RFC 2536 DSA in the DNS March 1999 - - -References - - [FIPS 186] U.S. Federal Information Processing Standard: Digital - Signature Standard. - - [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 1750] Eastlake, D., Crocker, S. and J. Schiller, "Randomness - Recommendations for Security", RFC 1750, December 1994. - - [RFC 2535] Eastlake, D., "Domain Name System Security Extensions", - RFC 2535, March 1999. - - [RFC 2537] Eastlake, D., "RSA/MD5 KEYs and SIGs in the Domain Name - System (DNS)", RFC 2537, March 1999. - - [Schneier] Schneier, B., "Applied Cryptography Second Edition: - protocols, algorithms, and source code in C", 1996. - -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 2536 DSA 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] - |
