NETWORK WORKING GROUP                                        N. Williams
Internet-Draft                                                       Sun
Expires: December 30, 2004                                    S. Hartman
                                                                     MIT
                                                               July 2004



               A PRF for the Kerberos V GSS-API Mechanism
                 draft-williams-krb5-gssapi-prf-00.txt


Status of this Memo


   By submitting this Internet-Draft, I certify that any applicable
   patent or other IPR claims of which I am aware have been disclosed,
   and any of which I become aware will be disclosed, in accordance with
   RFC 3668.


   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 December 30, 2004.


Copyright Notice


   Copyright (C) The Internet Society (2004).  All Rights Reserved.


Abstract


   This document defines the Pseudo-Random Function (PRF) for the
   Kerberos V GSS-API mechanism, based on the PRF defined for the
   Kerberos V cryptographic framework, for keying application protocols
   given an established Kerberos V GSS-API security context.








Williams & Hartman     Expires December 30, 2004                [Page 1]
Internet-Draft       A PRF for the Kerberos V Mech             July 2004



Table of Contents


   1. Conventions used in this document  . . . . . . . . . . . . . . . 3
   2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 4
   3. Security Considerations  . . . . . . . . . . . . . . . . . . . . 5
   4. Normative  . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
      Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
      Intellectual Property and Copyright Statements . . . . . . . . . 6












































Williams & Hartman     Expires December 30, 2004                [Page 2]
Internet-Draft       A PRF for the Kerberos V Mech             July 2004



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].















































Williams & Hartman     Expires December 30, 2004                [Page 3]
Internet-Draft       A PRF for the Kerberos V Mech             July 2004



2.  Introduction


   The GSS-API PRF function for the Kerberos V mechanism shall be the
   output of the enctype's PRF function keyed with the negotiated
   session key of the security context (e.g., the acceptor's subkey) and
   key usage X (TBD).














































Williams & Hartman     Expires December 30, 2004                [Page 4]
Internet-Draft       A PRF for the Kerberos V Mech             July 2004



3.  Security Considerations


   Kerberos V enctypes' PRF functions should use a key derived from
   contexts' session keys and should preserve the forward security
   properties of the mechanisms' key exchanges.


   Care should be taken in properly designing a mechanism's PRF
   function.  Cryptographic hash functions which do not provide strong
   collision resistance should not be used, except through HMAC.


4  Normative


   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.


   [RFC2743]  Linn, J., "Generic Security Service Application Program
              Interface Version 2, Update 1", RFC 2743, January 2000.


   [RFC2744]  Wray, J., "Generic Security Service API Version 2 :
              C-bindings", RFC 2744, January 2000.



Authors' Addresses


   Nicolas Williams
   Sun Microsystems
   5300 Riata Trace Ct
   Austin, TX  78727
   US


   EMail: Nicolas.Williams@sun.com



   Sam Hartman
   Massachussets Institute of Technology
   ...
   ..., MA  ...
   US


   EMail: hartmans@mit.edu












Williams & Hartman     Expires December 30, 2004                [Page 5]
Internet-Draft       A PRF for the Kerberos V Mech             July 2004



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
   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 (2004).  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.




Williams & Hartman     Expires December 30, 2004                [Page 6] 