Secure Password Framework for Internet Key Exchange Version 2 (IKEv2)
RFC 6467

Internet Engineering Task Force (IETF)                        T. Kivinen
Request for Comments: 6467                                     AuthenTec
Category: Informational                                    December 2011
ISSN: 2070-1721

 Secure Password Framework for Internet Key Exchange Version 2 (IKEv2)

Abstract

   This document defines a generic way for Internet Key Exchange version
   2 (IKEv2) to use any of the symmetric secure password authentication
   methods.  Multiple methods are already specified in other documents,
   and this document does not add any new one.  This document specifies
   a way to agree on which method is to be used in the current
   connection.  This document also provides a common way to transmit,
   between peers, payloads that are specific to secure password
   authentication methods.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   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).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see 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/rfc6467.

Kivinen                       Informational                     [Page 1]
RFC 6467           Secure Password Framework for IKEv2     December 2011

Copyright Notice

   Copyright (c) 2011 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
   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
   2. Method Negotiation ..............................................4
   3. Generic Secure Password Method Payload ..........................6
   4. IKE_AUTH Exchange ...............................................7
   5. Security Considerations .........................................9
   6. IANA Considerations .............................................9
   7. References .....................................................10
      7.1. Normative References ......................................10
      7.2. Informative References ....................................10

1.  Introduction

   The IPsecME working group was chartered to provide for IKEv2
   ([RFC5996]) a symmetric secure password authentication protocol that
   supports the use of low-entropy shared secrets, and to protect
   against off-line dictionary attacks without requiring the use of
   certificates or the Extensible Authentication Protocol (EAP).  There
   are multiple such methods, and the working group was to pick one.
   Unfortunately, the working group failed to pick one protocol, and
   there are multiple candidates going forward as separate documents.
   As each of those older versions of those documents used a different
   technique to negotiate the use of the method and also used different
   payload formats, it is very hard to try to make an implementation
   where multiple such systems could co-exist.

   Current document versions ([SPSK-AUTH], [PACE], and [PAKE]) use the
   method described in this document.

   This document describes IKEv2 payload formats that can be used for
   multiple secure password methods to negotiate and transmit data so
   each different method can easily co-exist in the same implementation.

Kivinen                       Informational                     [Page 2]
RFC 6467           Secure Password Framework for IKEv2     December 2011

   This document consists of two major parts:

   o  How to negotiate which secure password method negotiation is used.

   o  How to transmit data, between peers, that is specific to secure
      password methods.

   The secure password methods are not usually meant to be used in the
   normal end user (remote access VPN) cases.  In such cases, EAP-based
   authentication works fine, and the asymmetric nature of EAP does not