Network Working Group                                          R. Braden
Request for Comments: 3097                                           ISI
Updates: 2747                                                   L. Zhang
Category: Standards Track                                           UCLA
                                                              April 2001


                  RSVP Cryptographic Authentication --
                       Updated Message Type Value

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 (2001).  All Rights Reserved.

Abstract

   This memo resolves a duplication in the assignment of RSVP Message
   Types, by changing the Message Types assigned by RFC 2747 to
   Challenge and Integrity Response messages.

1. Introduction

   RFC 2747 ("RSVP Cryptographic Authentication") [RFC2747] assigns RSVP
   Message Type 12 to an Integrity Response message, while RFC 2961
   ("RSVP Refresh Overhead Reduction Extensions") [RFC2961] assigns the
   same value to a Bundle message.  This memo resolves the conflict over
   RSVP Message Type 12 by assigning a different value to the Message
   Type of the Integrity Response Message in RFC 2747.  It is believed
   that the protocol defined by RFC 2961 entered use in the field before
   the RFC's publication and before the conflicting Message Type was
   noticed, and that it may be easier to install new software in
   environments that have deployed the Integrity object than in those
   that have deployed the refresh reduction extension.

   To simplify possible interoperability problems caused by this change,
   we also assign a new value to the Message Type of RFC 2747's
   Challenge message, to which the Integrity Response message is a
   reply.

2. Modification

   Message Types defined in the RSVP Integrity extension [RFC 2747]
   shall be changed as follows:

      o Challenge message has Message Type 25.
      o Integrity Response message has Message Type 25+1.

3. Compatibility

   Two communicating nodes whose Integrity implementations are
   conformant with this modification will interoperate, using Message
   Type 12 for Bundle messages and Message Types 25 and 26 for the
   Integrity handshake.  A non-conformant implementation of the
   Integrity extension will not interoperate with a conformant
   implementation (though two non-conformant implementations can
   interoperate as before).

   There is no possibility of an Integrity handshake succeeding
   accidentally due to this change, since both sides of the handshake
   use the new numbers or the old numbers.  Furthermore, the Integrity
   Response message includes a 32-bit cookie that must match a cookie in
   the Challenge message, else the challenge will fail.  Finally, a
   non-conformant implementation should never receive a Bundle message
   that it interprets as an Integrity Response message, since RFC 2961
   requires that Bundle messages be sent only to a Bundle-capable node.

4. References

   [RFC2747]  Baker, F., Lindell, R. and M. Talwar, "RSVP Cryptographic
              Authentication", RFC 2747, January 2000.

   [RFC2961]  Berger, L., Gan, D., Swallow, G., Pan, P., Tommasi, F.
              and S. Molendini, "RSVP Refresh Overhead Reduction
              Extensions", RFC 2961, April 2001.

Security Considerations

   No new security considerations are introduced beyond RFC 2747 itself
   and the compatibility issues above.

Authors' Addresses

   Bob Braden
   USC Information Sciences Institute
   4676 Admiralty Way
   Marina del Rey, CA 90292

   Phone: (310) 822-1511
   EMail: Braden@ISI.EDU


   Lixia Zhang
   UCLA Computer Science Department
   4531G Boelter Hall
   Los Angeles, CA 90095-1596 USA

   Phone: 310-825-2695
   EMail: lixia@cs.ucla.edu

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   Copyright (C) The Internet Society (2001).  All Rights Reserved.

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Acknowledgement

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