[Docs] [txt|pdf|xml|html] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits] [IPR]

Versions: (draft-rescorla-tls-suiteb) 00 01 02 03 04 05 06 07 RFC 5289

Network Working Group                                        E. Rescorla
Internet-Draft                                                RTFM, Inc.
Intended status:  Informational                              May 9, 2008
Expires:  November 10, 2008


TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter
                                  Mode
                   draft-ietf-tls-ecc-new-mac-07.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 November 10, 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 cipher suites for
   TLS 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 November 10, 2008               [Page 1]

Internet-Draft               TLS ECC New MAC                    May 2008


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Conventions Used In This Document . . . . . . . . . . . . . . . 3
   3.  Cipher Suites . . . . . . . . . . . . . . . . . . . . . . . . . 3
     3.1.  HMAC-based Cipher Suites  . . . . . . . . . . . . . . . . . 3
     3.2.  Galois Counter Mode-based Cipher Suites . . . . . . . . . . 4
   4.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 5
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
     7.1.  Normative References  . . . . . . . . . . . . . . . . . . . 5
     7.2.  Informative References  . . . . . . . . . . . . . . . . . . 6
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . . 6
   Intellectual Property and Copyright Statements  . . . . . . . . . . 7




































Rescorla                Expires November 10, 2008               [Page 2]

Internet-Draft               TLS ECC New MAC                    May 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 [SHS]
   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.


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.  Cipher Suites

   This document defines 16 new cipher suites to be added to TLS.  All
   use Elliptic Curve Cryptography for key exchange and digital
   signature, as defined in RFC 4492.

3.1.  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.



Rescorla                Expires November 10, 2008               [Page 3]

Internet-Draft               TLS ECC New MAC                    May 2008


   These SHALL be as follows:

   o  For cipher suites ending with _SHA256, the PRF is the TLS PRF
      [I-D.ietf-tls-rfc4346-bis] with SHA-256 as the hash function.  The
      MAC is HMAC [RFC2104] with SHA-256 as the hash function.
   o  For cipher suites ending with _SHA384, the PRF is the TLS PRF
      [I-D.ietf-tls-rfc4346-bis] with SHA-384 as the hash function.  The
      MAC is HMAC [RFC2104] with SHA-384 as the hash function.

3.2.  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].

   The PRFs SHALL be as follows:

   o  For cipher suites ending with _SHA256, the PRF is the TLS PRF
      [I-D.ietf-tls-rfc4346-bis] with SHA-256 as the hash function.
   o  For cipher suites ending with _SHA384, the PRF is the TLS PRF
      [I-D.ietf-tls-rfc4346-bis] with SHA-384 as the hash function.


4.  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
   addition, as described in [I-D.ietf-tls-rsa-aes-gcm], these cipher
   suites may only be used with TLS 1.2 or greater.


5.  IANA Considerations

   IANA has assigned the following values for these cipher suites:



Rescorla                Expires November 10, 2008               [Page 4]

Internet-Draft               TLS ECC New MAC                    May 2008


       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};


6.  Acknowledgements

   This work was supported by the US Department of Defense.

   David McGrew, Pasi Eronen, and Alfred Hoenes provided reviews of this
   document.


7.  References

7.1.  Normative References

   [RFC2104]  Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
              Hashing for Message Authentication", RFC 2104,
              February 1997.

   [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.

   [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.



Rescorla                Expires November 10, 2008               [Page 5]

Internet-Draft               TLS ECC New MAC                    May 2008


   [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.

   [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.

7.2.  Informative References

   [Wang05]   Wang, X., Yin, Y., and H. Yu, "Finding Collisions in the
              Full SHA-1", CRYPTO 2005, August 2005.


Author's Address

   Eric Rescorla
   RTFM, Inc.
   2064 Edgewood Drive
   Palo Alto  94303
   USA

   Email:  ekr@rtfm.com















Rescorla                Expires November 10, 2008               [Page 6]

Internet-Draft               TLS ECC New MAC                    May 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 November 10, 2008               [Page 7]


Html markup produced by rfcmarkup 1.108, available from http://tools.ietf.org/tools/rfcmarkup/