Alex Deacon
INTERNET-DRAFT                                             VeriSign, Inc
Expires February 2004                                        August 2003

                 AIA Access Method for XKMS Services
                  <draft-deacon-xkms-aia-00.txt>

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   Internet-Drafts are working documents of the Internet Engineering
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   Copyright (C) The Internet Society (2002). All Rights Reserved.

Abstract

   Authority Information Access extension that is used to indicate how
   to access CA information and services for the issuer of the
   certificate in which this extension appears.  This document defines
   an access method identifier that indicates the location of XKMS
   [XKMS] services.

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 RFC-2119
   [RFC2119].

1. XKMS Access Method

   In order to convey to relying parties the location of an XKMS
   service, CA's SHOULD use the following AuthorityInfoAccess
   accessMethod OID:

   id-ad-xkms     OBJECT IDENTIFIER ::= { id-ad 8 }

   When using the id-ad-xkms accessMethod, the associated
   accessLocation value MUST be a URI.
   
   This specification does not mandate which XKMS services should be
   made available by the XKMS service provider.

2. Example ASN.1

   The following example shows an AuthorityKeyIdentifier extension
   that contains the id-ad-xkms accessMethod OID and a URI pointing to
   an XKMS service running at http://xkms.example.com/

         SEQUENCE {
           OBJECT IDENTIFIER
             authorityInfoAccess (1 3 6 1 5 5 7 1 1)
           OCTET STRING, encapsulates {
               SEQUENCE {
                 SEQUENCE {
                   OBJECT IDENTIFIER 1 3 6 1 5 5 7 48 8)
                   [6] 'http://xkms.example.com/'
                   }
                 }
               }
         }

3. Security Considerations

3.1 Trusing the XKMS Responder

   The signature on the response from the XKMS service may not have any
   trust relationship to the signature on the certificate that contains
   the AIA extension.  As such, relying parties MUST establish the 
   trustworthiness of the XKMS service before acting upon any of the 
   information contained in the response.  

4. IANA Considerations

   Certificate extensions and attribute certificate extensions are
   identified by object identifiers (OIDs).  The OID for the extension
   defined in this document was assigned from an arc delegated by the
   IANA to the PKIX Working Group.  No further action by the IANA is
   necessary for this document or any anticipated updates

5. References

5.1 Normative References

   [RFC3280]    R. Housley, W. Polk, W. Ford, and D. Solo, "Internet
                X.509 Public Key Infrastructure: Certificate and
                Certificate Revocation List (CRL) Profile", RFC 3280,
                April 2002.

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

   [URI]        T. Berners-Lee, R. Fielding, L. Masinter, "Uniform 
                Resource Identifiers (URI): Generic Syntax", RFC 2396,
                August 1998.

   [RFC2026]    Bradner, S., "The Internet Standards Process -- Revision
                3", BCP 9, RFC 2026, October 1996.

5.2 Informative References

   [XKMS]      XML Key Management Specification (XKMS) v2.0.
               W3C Working Draft.  P. Halam-Baker, Editor. 
               http://www.w3.org/TR/xkms2/.  April 2003.	



Author's Addresses

   Alex Deacon
   VeriSign, Inc.
   487 East Middlefield Road
   Mountain View, CA USA
   Email: alex@verisign.com