TLS Working Group                                         U. Blumenthal
Internet Draft                                                  P. Goel
Expires: January March 2007                                   Intel Corporation
                                                          July 19,
                                                     September 27, 2006

          Pre-Shared Key Cipher Suite Suites with NULL Encryption for
                      Transport Layer Security

                      draft-ietf-tls-psk-null-00.txt (TLS)

                      draft-ietf-tls-psk-null-01.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 January 19, 27, 2007.

Abstract

   This document specifies authentication-only cipher suites for the
   Pre-Shared Key based [TLS-PSK] Transport Layer Security (TLS) [TLS] protocol to
   support null encryption. These cipher suites are useful for countries
   and places with cryptography-related restrictions.

Internet-Draft   PSK NULL-encryption Cipher Suites for TLS    September
2006

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].

Table of Contents

   1. Introduction...................................................2
   2. Cipher Usage...................................................2
   3. Security Considerations........................................3
   4. IANA Considerations............................................3
   5. Acknowledgments................................................3
   6. References.....................................................3 References.....................................................4
      6.1. Normative References......................................3 References......................................4
   Author's Addresses................................................4
   Intellectual Property Statement...................................4
   Disclaimer of Validity............................................5
   Copyright Statement...............................................5
   Acknowledgment....................................................5

1. Introduction

   The RFC for Pre-Shared Key based TLS [TLS-PSK] specifies cipher
   suites for supporting TLS using pre-shared symmetric keys. However
   all the cipher suites defined in [TLS-PSK] require encryption. There
   is a need for a cipher suite suites that supports support no encryption. This is
   required for implementations to meet import restrictions in some
   countries. Even though no encryption is used, this these cipher suite
   supports suites
   support authentication of the client and server to each other, and
   message integrity. This document augments [TLS-PSK] by adding three
   more cipher suites (PSK, DHE, RSA) with authentication and integrity
   only - no encryption.

2. Cipher Usage

   The new cipher suites proposed here is very similar to cipher suites
   defined in [TLS-PSK], except that they define null encryption.

   The cipher suites defined here uses use the following options for key
   exchange and hash part of the protocol:

Internet-Draft   PSK NULL-encryption Cipher Suites for TLS    September
2006

   CipherSuite                     Key Exchange   Cipher      Hash

   TLS_PSK_WITH_NULL_SHA           PSK            NULL        SHA
   TLS_DHE_PSK_WITH_NULL_SHA       DHE_PSK        NULL        SHA
   TLS_RSA_PSK_WITH_NULL_SHA       RSA_PSK        NULL        SHA

   For the meaning of the terms PSK please refer to section 1 in [TLS-
   PSK]. For the meaning of the terms DHE and RSA please refer to
   section 7.4.2 in [TLS].

3. Security Considerations

   As with all schemes involving shared keys, special care should be
   taken to protect the shared values and to limit their exposure over
   time. As this document augments [TLS-PSK], everything stated in its
   Security Consideration section applies here. In addition, as cipher
   suites defined here do not support confidentiality - care should be
   taken not to send confidential information (such as passwords) over
   TLS-PSK connection with no encryption.

4. IANA Considerations

   This document defines three new cipher suites, whose values are to be
   assigned from the TLS Cipher Suite registry defined in [TLS].

   CipherSuite   TLS_PSK_WITH_NULL_SHA      = { 0x00, 0xTBD1 };
   CipherSuite   TLS_DHE_PSK_WITH_NULL_SHA  = { 0x00, 0xTBD2 };
   CipherSuite   TLS_RSA_PSK_WITH_NULL_SHA  = { 0x00, 0xTBD3 };

5. Acknowledgments

   The cipher suite suites defined in this document is are an augmentation to and
   based on [TLS-PSK].

Internet-Draft   PSK NULL-encryption Cipher Suites for TLS    September
2006

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.

   [TLS]     Dierks, T. and Rescorla, E., "The TLS Protocol Version
             1.1", RFC 4346, April 2006.

   [TLS-PSK] Eronen, P., Tschofenig, H., "Pre-Shared Key CipherSuites
             for Transport Layer Security (TLS)", RFC 4279, December
             2005.

Author's Addresses

   Uri Blumenthal
   Intel Corporation
   1515 State Route 10,
   3PY1-3.536
   PY2-1 10-4
   Parsippany, NJ 07054
   USA

   Email: uri.blumenthal@intel.com Uri.Blumenthal@intel.com

   Purushottam Goel
   Intel Corporation
   2111 N.E. 25 Ave.
   JF3-414
   Hillsboro, OR 97124
   USA

   Email: Purushottam.goel@intel.com Purushottam.Goel@intel.com

Intellectual Property Statement

   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

Internet-Draft   PSK NULL-encryption Cipher Suites for TLS    September
2006

   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.

Disclaimer of Validity

   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.

Copyright Statement

   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.

Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.