Supporting Authentication Trailer for OSPFv3
RFC 6506

Internet Engineering Task Force (IETF)                         M. Bhatia
Request for Comments: 6506                                Alcatel-Lucent
Category: Standards Track                                      V. Manral
ISSN: 2070-1721                                          Hewlett Packard
                                                               A. Lindem
                                                                Ericsson
                                                           February 2012

              Supporting Authentication Trailer for OSPFv3

Abstract

   Currently, OSPF for IPv6 (OSPFv3) uses IPsec as the only mechanism
   for authenticating protocol packets.  This behavior is different from
   authentication mechanisms present in other routing protocols (OSPFv2,
   Intermediate System to Intermediate System (IS-IS), RIP, and Routing
   Information Protocol Next Generation (RIPng)).  In some environments,
   it has been found that IPsec is difficult to configure and maintain
   and thus cannot be used.  This document defines an alternative
   mechanism to authenticate OSPFv3 protocol packets so that OSPFv3 does
   not only depend upon IPsec for authentication.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6506.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must

Bhatia, et al.               Standards Track                    [Page 1]
RFC 6506            Authentication Trailer for OSPFv3      February 2012

   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................2
      1.1. Requirements ...............................................3
   2. Proposed Solution ...............................................4
      2.1. AT-Bit in Options Field ....................................4
      2.2. Basic Operation ............................................5
      2.3. IPv6 Source Address Protection .............................5
   3. OSPFv3 Security Association .....................................6
   4. Authentication Procedure ........................................8
      4.1. Authentication Trailer .....................................8
           4.1.1. Sequence Number Wrap ...............................10
      4.2. OSPFv3 Header Checksum ....................................10
      4.3. Cryptographic Authentication Procedure ....................10
      4.4. Cross-Protocol Attack Mitigation ..........................11
      4.5. Cryptographic Aspects .....................................11
      4.6. Message Verification ......................................13
   5. Migration and Backward Compatibility ...........................15
   6. Security Considerations ........................................15
   7. IANA Considerations ............................................16
   8. References .....................................................17
      8.1. Normative References ......................................17
      8.2. Informative References ....................................17
   Appendix A.  Acknowledgments ......................................19

1.  Introduction

   Unlike Open Shortest Path First version 2 (OSPFv2) [RFC2328], OSPF
   for IPv6 (OSPFv3) [RFC5340] does not include the AuType and
   Authentication fields in its headers for authenticating protocol
   packets.  Instead, OSPFv3 relies on the IPsec protocols
   Authentication Header (AH) [RFC4302] and Encapsulating Security
   Payload (ESP) [RFC4303] to provide integrity, authentication, and/or
   confidentiality.

   [RFC4552] describes how IPv6 AH and ESP extension headers can be used
   to provide authentication and/or confidentiality to OSPFv3.