[Docs] [txt|pdf] [Tracker] [WG] [Email] [Nits]

Versions: 00 01 02 03 04 RFC 4402

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


               A PRF for the Kerberos V GSS-API Mechanism
                draft-ietf-kitten-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               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
      Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
      Intellectual Property and Copyright Statements . . . . . . . . . 6











































Williams               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               Expires December 30, 2004                [Page 3]

Internet-Draft       A PRF for the Kerberos V Mech             July 2004


2.  Introduction

   The GSS-API PRF [GSS-PRF] function for the Kerberos V mechanism shall
   be the output of a PRF+ function based on 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).

   The PRF+ function is a simple counter-based extension of the
   enctype's prf using an 16-bit network byte order unsigned binary
   counter: PRF+(k, input) = random-to-key( k-truncate( prf(k, 0 ||
   input) || prf(k, 1 || input), ..  prf(k, n || input))).  The maximum
   output length for this PRF+ then is 65536 times the output length of
   the Kerberos V cryptographic framework PRF for the enctype of the
   input key.

   If the desired_output_len input parameter exceeds the maximum output
   of this function then the maximum will be output instead.


































Williams               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 use a key derived from contexts'
   session keys and should preserve the forward security properties of
   the mechanisms' key exchanges.

   See also [GSS-PRF] for generic security considerations of
   GSS_Pseudo_random().

4  Normative

   [GSS-PRF]  Williams, N., "A PRF API extension for the GSS-API".

   [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.


Author's Address

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

   EMail: Nicolas.Williams@sun.com



















Williams               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               Expires December 30, 2004                [Page 6]


Html markup produced by rfcmarkup 1.109, available from https://tools.ietf.org/tools/rfcmarkup/