Online Certificate Status Protocol (OCSP) Extensions to IKEv2
RFC 4806
| Document | Type |
RFC - Proposed Standard
(February 2007; No errata)
Was draft-myers-ikev2-ocsp (individual in sec area)
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Replaces | draft-myers-ipsec-ikev2-oscp | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 4806 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Russ Housley | ||
| Send notices to | (None) | ||
Network Working Group M. Myers
Request for Comments: 4806 TraceRoute Security LLC
Category: Standards Track H. Tschofenig
Siemens Networks GmbH & Co KG
February 2007
Online Certificate Status Protocol (OCSP) Extensions to IKEv2
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 IETF Trust (2006).
Abstract
While the Internet Key Exchange Protocol version 2 (IKEv2) supports
public key based authentication, the corresponding use of in-band
Certificate Revocation Lists (CRL) is problematic due to unbounded
CRL size. The size of an Online Certificate Status Protocol (OCSP)
response is however well-bounded and small. This document defines
the "OCSP Content" extension to IKEv2. A CERTREQ payload with "OCSP
Content" identifies zero or more trusted OCSP responders and is a
request for inclusion of an OCSP response in the IKEv2 handshake. A
cooperative recipient of such a request responds with a CERT payload
containing the appropriate OCSP response. This content is
recognizable via the same "OCSP Content" identifier.
When certificates are used with IKEv2, the communicating peers need a
mechanism to determine the revocation status of the peer's
certificate. OCSP is one such mechanism. This document applies when
OCSP is desired and security policy prevents one of the IKEv2 peers
from accessing the relevant OCSP responder directly. Firewalls are
often deployed in a manner that prevents such access by IKEv2 peers
outside of an enterprise network.
Myers & Tschofenig Standards Track [Page 1]
RFC 4806 OCSP Extensions to IKEv2 February 2007
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Extension Definition . . . . . . . . . . . . . . . . . . . . . 4
3.1. OCSP Request . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. OCSP Response . . . . . . . . . . . . . . . . . . . . . . 5
4. Extension Requirements . . . . . . . . . . . . . . . . . . . . 5
4.1. Request for OCSP Support . . . . . . . . . . . . . . . . . 5
4.2. Response to OCSP Support . . . . . . . . . . . . . . . . . 6
5. Examples and Discussion . . . . . . . . . . . . . . . . . . . 6
5.1. Peer to Peer . . . . . . . . . . . . . . . . . . . . . . . 6
5.2. Extended Authentication Protocol (EAP) . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9
9. Normative References . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
Version 2 of the Internet Key Exchange (IKE) protocol [IKEv2]
supports a range of authentication mechanisms, including the use of
public key based authentication. Confirmation of certificate
reliability is essential in order to achieve the security assurances
public key cryptography provides. One fundamental element of such
confirmation is reference to certificate revocation status (see
[RFC3280] for additional detail).
The traditional means of determining certificate revocation status is
through the use of Certificate Revocation Lists (CRLs). IKEv2 allows
CRLs to be exchanged in-band via the CERT payload.
However, CRLs can grow unbounded in size. Many real-world examples
exist to demonstrate the impracticality of including a multi-megabyte
file in an IKE exchange. This constraint is particularly acute in
bandwidth-limited environments (e.g., mobile communications). The
net effect is exclusion of in-band CRLs in favor of out-of-band (OOB)
acquisition of these data, should they even be used at all.
Reliance on OOB methods can be further complicated if access to
revocation data requires use of IPsec (and therefore IKE) to
establish secure and authorized access to the CRLs of an IKE
participant. Such network access deadlock further contributes to a
reduced reliance on the status of certificate revocations in favor of
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