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author | Simon Josefsson <simon@josefsson.org> | 2008-04-29 23:59:56 +0200 |
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committer | Simon Josefsson <simon@josefsson.org> | 2008-04-29 23:59:56 +0200 |
commit | 1d5cf5a4f19ab9bd70ef5fece695540b6be5d2c4 (patch) | |
tree | 0b89c4fdb5cc4da895bf684ff7a4f08ee304639d | |
parent | 241ec54003376a8b942bb2776d6a5d4dae03ca7a (diff) | |
download | gnutls-1d5cf5a4f19ab9bd70ef5fece695540b6be5d2c4.tar.gz |
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diff --git a/doc/protocol/draft-ietf-tls-ecc-new-mac-06.txt b/doc/protocol/draft-ietf-tls-ecc-new-mac-06.txt new file mode 100644 index 0000000000..2ac8fcaee7 --- /dev/null +++ b/doc/protocol/draft-ietf-tls-ecc-new-mac-06.txt @@ -0,0 +1,392 @@ + + + +Network Working Group E. Rescorla +Internet-Draft RTFM, Inc. +Intended status: Informational April 29, 2008 +Expires: October 31, 2008 + + +TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter + Mode + draft-ietf-tls-ecc-new-mac-06.txt + +Status of this Memo + + 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. + + 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/ietf/1id-abstracts.txt. + + The list of Internet-Draft Shadow Directories can be accessed at + http://www.ietf.org/shadow.html. + + This Internet-Draft will expire on October 31, 2008. + +Copyright Notice + + Copyright (C) The IETF Trust (2008). + +Abstract + + RFC 4492 describes elliptic curve cipher suites for Transport Layer + Security (TLS). However, all those cipher suites use SHA-1 as their + MAC algorithm. This document describes sixteen new CipherSuites for + TLS/DTLS which specify stronger digest algorithms. Eight use HMAC + with SHA-256 or SHA-384 and eight use AES in Galois Counter Mode + (GCM). + + + + +Rescorla Expires October 31, 2008 [Page 1] + +Internet-Draft TLS ECC New MAC April 2008 + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 1.1. Conventions Used In This Document . . . . . . . . . . . . . 3 + 2. Cipher Suites . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 2.1. HMAC-based Cipher Suites . . . . . . . . . . . . . . . . . 3 + 2.2. Galois Counter Mode-based Cipher Suites . . . . . . . . . . 4 + 3. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 + 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 + 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 + 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 + 6.1. Normative References . . . . . . . . . . . . . . . . . . . 5 + 6.2. Informative References . . . . . . . . . . . . . . . . . . 6 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 6 + Intellectual Property and Copyright Statements . . . . . . . . . . 7 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Rescorla Expires October 31, 2008 [Page 2] + +Internet-Draft TLS ECC New MAC April 2008 + + +1. Introduction + + RFC 4492 [RFC4492] describes Elliptic Curve Cryptography (ECC) cipher + suites for Transport Layer Security (TLS). However, all of the RFC + 4492 suites use HMAC-SHA1 as their MAC algorithm. Due to recent + analytic work on SHA-1 [Wang05], the IETF is gradually moving away + from SHA-1 and towards stronger hash algorithms. This document + specifies TLS ECC cipher suites which use SHA-256 and SHA-384 rather + than SHA-1. + + TLS 1.2 [I-D.ietf-tls-rfc4346-bis], adds support for authenticated + encryption with additional data (AEAD) cipher modes [RFC5116]. This + document also specifies a set of ECC cipher suites using one such + mode, Galois Counter Mode (GCM) [GCM]. Another document + [I-D.ietf-tls-rsa-aes-gcm], provides support for GCM with other key + establishment methods. + +1.1. Conventions Used In This Document + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in [RFC2119]. + + +2. Cipher Suites + + This document defines 8 new cipher suites to be added to TLS. All + use Elliptic Curve Cryptography for key exchange and digital + signature, as defined in RFC 4492. + +2.1. HMAC-based Cipher Suites + + The first eight cipher suites use AES [AES] in CBC [CBC] mode with an + HMAC-based MAC: + + CipherSuite TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 = {0xXX,XX}; + + These eight cipher suites are the same as the corresponding cipher + suites in RFC 4492 (with names ending in "_SHA" in place of "_SHA256" + or "_SHA384"), except for the hash and PRF algorithms, which use SHA- + 256 and SHA-384 [SHS] as follows. + + + +Rescorla Expires October 31, 2008 [Page 3] + +Internet-Draft TLS ECC New MAC April 2008 + + + Cipher Suite MAC PRF + ------------ --- --- + TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 HMAC-SHA-256 P_SHA256 + TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 HMAC-SHA-384 P_SHA384 + TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 HMAC-SHA-256 P_SHA256 + TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 HMAC-SHA-384 P_SHA384 + TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 HMAC-SHA-256 P_SHA256 + TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 HMAC-SHA-384 P_SHA384 + TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 HMAC-SHA-256 P_SHA256 + TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 HMAC-SHA-384 P_SHA384 + +2.2. Galois Counter Mode-based Cipher Suites + + The second eight cipher suites use the same asymmetric algorithms as + those in the previous section but use the new authenticated + encryption modes defined in TLS 1.2 with AES in Galois Counter Mode + (GCM) [GCM]: + + CipherSuite TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 = {0xXX,XX}; + + These cipher suites use authenticated encryption with additional data + algorithms AEAD_AES_128_GCM and AEAD_AES_256_GCM described in + [RFC5116]. GCM is used as described in [I-D.ietf-tls-rsa-aes-gcm]. + + + Cipher Suite PRF + ------------ --- + TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 P_SHA256 + TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 P_SHA384 + TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 P_SHA256 + TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 P_SHA384 + TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 P_SHA256 + TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 P_SHA384 + TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 P_SHA256 + TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 P_SHA384 + + +3. Security Considerations + + The security considerations in RFC 4346, RFC 4492, and + [I-D.ietf-tls-rsa-aes-gcm] apply to this document as well. In + + + +Rescorla Expires October 31, 2008 [Page 4] + +Internet-Draft TLS ECC New MAC April 2008 + + + addition, as described in [I-D.ietf-tls-rsa-aes-gcm], these cipher + suites may only be used with TLS 1.2 or greater. + + +4. IANA Considerations + + IANA has assigned the following values for these cipher suites: + + CipherSuite TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 = {0xXX,XX}; + CipherSuite TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 = {0xXX,XX}; + CipherSuite TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 = {0xXX,XX}; + + +5. Acknowledgements + + This work was supported by the US Department of Defense. + + David McGrew contributed substantual sections of the GCM nonce text + as well as providing a review of this document. + + +6. References + +6.1. Normative References + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC4492] Blake-Wilson, S., Bolyard, N., Gupta, V., Hawk, C., and B. + Moeller, "Elliptic Curve Cryptography (ECC) Cipher Suites + for Transport Layer Security (TLS)", RFC 4492, May 2006. + + [RFC5116] McGrew, D., "An Interface and Algorithms for Authenticated + Encryption", RFC 5116, January 2008. + + + + +Rescorla Expires October 31, 2008 [Page 5] + +Internet-Draft TLS ECC New MAC April 2008 + + + [I-D.ietf-tls-rfc4346-bis] + Dierks, T. and E. Rescorla, "The Transport Layer Security + (TLS) Protocol Version 1.2", draft-ietf-tls-rfc4346-bis-10 + (work in progress), March 2008. + + [AES] National Institute of Standards and Technology, + "Specification for the Advanced Encryption Standard + (AES)", FIPS 197, November 2001. + + [SHS] National Institute of Standards and Technology, "Secure + Hash Standard", FIPS 180-2, August 2002. + + [CBC] National Institute of Standards and Technology, + "Recommendation for Block Cipher Modes of Operation - + Methods and Techniques", SP 800-38A, December 2001. + + [GCM] National Institute of Standards and Technology, + "Recommendation for Block Cipher Modes of Operation: + Galois;/Counter Mode (GCM) for Confidentiality and + Authentication", SP 800-38D, November 2007. + +6.2. Informative References + + [Wang05] Wang, X., Yin, Y., and H. Yu, "Finding Collisions in the + Full SHA-1", CRYPTO 2005, August 2005. + + [I-D.ietf-tls-rsa-aes-gcm] + Salowey, J., Choudhury, A., and D. McGrew, "AES-GCM Cipher + Suites for TLS", draft-ietf-tls-rsa-aes-gcm-03 (work in + progress), April 2008. + + +Author's Address + + Eric Rescorla + RTFM, Inc. + 2064 Edgewood Drive + Palo Alto 94303 + USA + + Email: ekr@rtfm.com + + + + + + + + + + +Rescorla Expires October 31, 2008 [Page 6] + +Internet-Draft TLS ECC New MAC April 2008 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2008). + + 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, THE IETF TRUST 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. + + +Intellectual Property + + 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. + + +Acknowledgment + + Funding for the RFC Editor function is provided by the IETF + Administrative Support Activity (IASA). + + + + + +Rescorla Expires October 31, 2008 [Page 7] + diff --git a/doc/protocol/draft-rescorla-tls-extended-random-00.txt b/doc/protocol/draft-rescorla-tls-extended-random-00.txt new file mode 100644 index 0000000000..5b33f74178 --- /dev/null +++ b/doc/protocol/draft-rescorla-tls-extended-random-00.txt @@ -0,0 +1,448 @@ + + + +Network Working Group E. Rescorla +Internet-Draft RTFM, Inc. +Intended status: Informational M. Salter +Expires: October 31, 2008 National Security Agency + April 29, 2008 + + + Extended Random Values for TLS + draft-rescorla-tls-extended-random-00.txt + +Status of this Memo + + 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. + + 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/ietf/1id-abstracts.txt. + + The list of Internet-Draft Shadow Directories can be accessed at + http://www.ietf.org/shadow.html. + + This Internet-Draft will expire on October 31, 2008. + +Copyright Notice + + Copyright (C) The IETF Trust (2008). + +Abstract + + This document describes an extension for using larger client and + server Random values with Transport Layer Security (TLS) and Datagram + TLS (DTLS). + + + + + + + +Rescorla & Salter Expires October 31, 2008 [Page 1] + +Internet-Draft Extended TLS Random April 2008 + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 2. Conventions Used In This Document . . . . . . . . . . . . . . . 3 + 3. The ExtendedRandom Extension . . . . . . . . . . . . . . . . . 3 + 3.1. Negotiating the ExtendedRandom Extension . . . . . . . . . 4 + 3.2. PRF Modifications . . . . . . . . . . . . . . . . . . . . . 4 + 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 + 4.1. Threats to TLS . . . . . . . . . . . . . . . . . . . . . . 5 + 4.2. Scope of Randomness . . . . . . . . . . . . . . . . . . . . 5 + 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 + 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6 + 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 + 7.1. Normative References . . . . . . . . . . . . . . . . . . . 6 + 7.2. Informative References . . . . . . . . . . . . . . . . . . 6 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 + Intellectual Property and Copyright Statements . . . . . . . . . . 8 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Rescorla & Salter Expires October 31, 2008 [Page 2] + +Internet-Draft Extended TLS Random April 2008 + + +1. Introduction + + TLS [I-D.ietf-tls-rfc4346-bis] and DTLS [RFC4347] use a 32-byte + "Random" value consisting of a 32-bit time value time and 28 randomly + generated bytes: + + struct { + uint32 gmt_unix_time; + opaque random_bytes[28]; + } Random; + + The client and server each contribute a Random value which is then + mixed with secret keying material to produce the final per- + association keying material. + + The United States Department of Defense has requested a TLS mode + which allows the use of longer public randomness values for use with + high security level cipher suites like those specified in Suite B + [I-D.rescorla-tls-suiteb]. The rationale for this as stated by DoD + is that the public randomness for each side should be at least twice + as long as the security level for cryptographic parity, which makes + the 224 bits of randomness provided by the current TLS random values + insufficient. + + This document specifies an extension which allows for additional + randomness to be exchanged in the Hello messages. + + +2. Conventions Used In This Document + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in [RFC2119]. + + +3. The ExtendedRandom Extension + + This document defines a new TLS extension called "extended_random". + + The "extended_random" extension carried in a new TLS extension called + "ExtendedRandom". + + struct { + opaque extended_random_value<0..2^16-1>; + } ExtendedRandom; + + The extended_random_value MUST be a randomly generated byte string. + A cryptographically secure PRNG [RFC4086] SHOULD be used. + + + +Rescorla & Salter Expires October 31, 2008 [Page 3] + +Internet-Draft Extended TLS Random April 2008 + + +3.1. Negotiating the ExtendedRandom Extension + + The client requests support for the extended randomness feature by + sending an "extended_random" extension in its ClientHello. The + "extension_data" field contains an ExtendedRandom value. + + When a server which does not recognize the "extended_random" + extension receives one, it will ignore it as required. A server + which recognizes the extension MAY choose to ignore it, in which case + it SHOULD continue with the exchange as if it had not received the + extension. + + If the server wishes to use the extended randomness feature, it MUST + send its own "extended_random" extension with an + extended_random_value equal in length to the client's + extended_random_value. Clients SHOULD check the length of the + server's extended_random_value and generate a fatal + "illegal_parameter" error if it is present but does does not match + the length that was transmitted in the ClientHello. + + Because TLS does not permit servers to request extensions which the + client did not offer, the client may not offer the "extended_random" + extension even if the server requires it. In this case, the server + should generate a fatal "handshake_failure" alert. + + Because there is no way to mark extensions as critical, the server + may ignore the "extended_random" extension even though the client + requires it. If a client requires the extended randomness input + feature but the server does not negotiate it, the client SHOULD + generate a fatal "handshake_failure" alert. + +3.2. PRF Modifications + + When the extended randomness feature is in use, the extended random + values MUST be mixed into the PRF along with the client and server + random values during the PMS->MS conversion. Thus, the PRF becomes: + + master_secret = PRF(pre_master_secret, "master secret", + ClientHello.random + + ClientHello.extended_random_value + + ServerHello.random + + ServerHello.extended_random_value)[0..47]; + + Because new extensions may not be introduced in resumed handshakes, + mixing in the extended inputs during the MS->keying material + conversion would simply involve mixing in the same material twice. + Therefore, the extended random inputs are only used when the PMS is + converted into the MS. + + + +Rescorla & Salter Expires October 31, 2008 [Page 4] + +Internet-Draft Extended TLS Random April 2008 + + +4. Security Considerations + +4.1. Threats to TLS + + When this extension is in use it increases the amount of data that an + attacker can inject into the PRF. This potentially would allow an + attacker who had partially compromised the PRF greater scope for + influencing the output. Hash-based PRFs like the one in TLS are + designed to be fairly indifferent to the input size (the input is + already greater than the block size of most hash functions), however + there is currently no proof that a larger input space would not make + attacks easier. + + Another concern is that bad implementations might generate low + entropy extented random values. TLS is designed to function + correctly even when fed low-entropy random values because they are + primarily used to generate distinct keying material for each + connection. + +4.2. Scope of Randomness + + TLS specifies that when a session is resumed the extensions from the + original connection are used: + + If, on the other hand, the older session is resumed, then the + server MUST ignore the extensions and send a server hello + containing none of the extension types. In this case, the + functionality of these extensions negotiated during the original + session initiation is applied to the resumed session. + + This motivates why the the extended randomness does not get mixed + into the PRF when generating the keying material from the master + secret. Because the same values would be used for every connection + in a session, they would not provide any differentiation in the + keying material between the connections. + + +5. IANA Considerations + + This document defines an extension to TLS, in accordance with + [I-D.ietf-tls-rfc4366-bis]: + + enum { extended_random (??) } ExtensionType; + + [[ NOTE: These values need to be assigned by IANA ]] + + + + + + +Rescorla & Salter Expires October 31, 2008 [Page 5] + +Internet-Draft Extended TLS Random April 2008 + + +6. Acknowledgements + + This work was supported by the US Department of Defense. + + +7. References + +7.1. Normative References + + [I-D.ietf-tls-rfc4346-bis] + Dierks, T. and E. Rescorla, "The Transport Layer Security + (TLS) Protocol Version 1.2", draft-ietf-tls-rfc4346-bis-10 + (work in progress), March 2008. + + [RFC4086] Eastlake, D., Schiller, J., and S. Crocker, "Randomness + Requirements for Security", BCP 106, RFC 4086, June 2005. + +7.2. Informative References + + [I-D.ietf-tls-rfc4366-bis] + 3rd, D., "Transport Layer Security (TLS) Extensions: + Extension Definitions", draft-ietf-tls-rfc4366-bis-02 + (work in progress), February 2008. + + [I-D.rescorla-tls-suiteb] + Salter, M. and E. Rescorla, "Suite B Cipher Suites for + TLS", draft-rescorla-tls-suiteb-02 (work in progress), + April 2008. + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC4347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer + Security", RFC 4347, April 2006. + + +Authors' Addresses + + Eric Rescorla + RTFM, Inc. + 2064 Edgewood Drive + Palo Alto, CA 94303 + USA + + Email: ekr@rtfm.com + + + + + + +Rescorla & Salter Expires October 31, 2008 [Page 6] + +Internet-Draft Extended TLS Random April 2008 + + + Margaret Salter + National Security Agency + 9800 Savage Rd. + Fort Meade 20755-6709 + USA + + Email: msalter@restarea.ncsc.mil + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Rescorla & Salter Expires October 31, 2008 [Page 7] + +Internet-Draft Extended TLS Random April 2008 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2008). + + 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, THE IETF TRUST 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. + + +Intellectual Property + + 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. + + +Acknowledgment + + Funding for the RFC Editor function is provided by the IETF + Administrative Support Activity (IASA). + + + + + +Rescorla & Salter Expires October 31, 2008 [Page 8] + |