GENWiki

Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools


rfc:rfc4325

Network Working Group S. Santesson Request for Comments: 4325 Microsoft Updates: 3280 R. Housley Category: Standards Track Vigil Security

                                                         December 2005
   Internet X.509 Public Key Infrastructure Authority Information
         Access Certificate Revocation List (CRL) Extension

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 Internet Society (2005).

Abstract

 This document updates RFC 3280 by defining the Authority Information
 Access Certificate Revocation List (CRL) extension.  RFC 3280 defines
 the Authority Information Access certificate extension using the same
 syntax.  The CRL extension provides a means of discovering and
 retrieving CRL issuer certificates.

Table of Contents

 1. Introduction ....................................................2
    1.1. Terminology ................................................3
 2. Authority Information Access CRL Extension ......................3
 3. Security Considerations .........................................5
 4. References ......................................................5
    4.1. Normative References .......................................5
    4.2. Informative References .....................................6

Santesson & Housley Standards Track [Page 1] RFC 4325 Authority Information Access CRL Extension December 2005

1. Introduction

 RFC 3280 [PKIX1] specifies the validation of certification paths.
 One aspect involves the determination that a certificate has not been
 revoked, and one revocation checking mechanism is the Certificate
 Revocation List (CRL).  CRL validation is also specified in RFC 3280,
 which involves the constructions of a valid certification path for
 the CRL issuer.  Building a CRL issuer certification path from the
 signer of the CRL to a trust anchor is straightforward when the
 certificate of the CRL issuer is present in the certification path
 associated with the target certificate, but it can be complex in
 other situations.
 There are several legitimate scenarios where the certificate of the
 CRL issuer is not present, or easily discovered, from the target
 certification path.  This can be the case when indirect CRLs are
 used, when the Certification Authority (CA) that issued the target
 certificate changes its certificate signing key, or when the CA
 employs separate keys for certificate signing and CRL signing.
 Methods of finding the certificate of the CRL issuer are currently
 available, such as through an accessible directory location or
 through use of the Subject Information Access extension in
 intermediary CA certificates.
 Directory lookup requires existence and access to a directory that
 has been populated with all of the necessary certificates.  The
 Subject Information Access extension, which supports building the CRL
 issuer certification path top-down (in the direction from the trust
 anchor to the CRL issuer), requires that some certificates in the CRL
 issuer certification path includes an appropriate Subject Information
 Access extension.
 RFC 3280 [PKIX1] provides for bottom-up discovery of certification
 paths through the Authority Information Access extension, where the
 id-ad-caIssuers access method may specify one or more accessLocation
 fields that reference CA certificates associated with the certificate
 containing this extension.
 This document enables the use of the Authority Information Access
 extension in CRLs, enabling a CRL checking application to use the
 access method (id-ad-caIssuers) to locate certificates that may be
 useful in the construction of a valid CRL issuer certification path
 to an appropriate trust anchor.

Santesson & Housley Standards Track [Page 2] RFC 4325 Authority Information Access CRL Extension December 2005

1.1. Terminology

 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].

2. Authority Information Access CRL Extension

 This section defines the use of the Authority Information Access
 extension in a CRL.  The syntax and semantics defined in RFC 3280
 [PKIX1] for the certificate extensions are also used for the CRL
 extension.
 This CRL extension MUST NOT be marked critical.
 This extension MUST be identified by the extension object identifier
 (OID) defined in RFC 3280 (1.3.6.1.5.5.7.1.1), and the
 AuthorityInfoAccessSyntax MUST be used to form the extension value.
 For convenience, the ASN.1 [X.680] definition of the Authority
 Information Access extension is repeated below.
    id-pe-authorityInfoAccess OBJECT IDENTIFIER  ::=  { id-pe 1 }
    AuthorityInfoAccessSyntax  ::=  SEQUENCE SIZE (1..MAX) OF
                             AccessDescription
    AccessDescription  ::=  SEQUENCE {
       accessMethod          OBJECT IDENTIFIER,
       accessLocation        GeneralName  }
    id-ad OBJECT IDENTIFIER  ::=  { id-pkix 48 }
    id-ad-caIssuers OBJECT IDENTIFIER  ::=  { id-ad 2 }
 When present in a CRL, this extension MUST include at least one
 AccessDescription specifying id-ad-caIssuers as the accessMethod.
 Access method types other than id-ad-caIssuers MUST NOT be included.
 At least one instance of AccessDescription SHOULD specify an
 accessLocation that is an HTTP [HTTP/1.1] or Lightweight Directory
 Access Protocol [LDAP] Uniform Resource Identifier [URI].
 Where the information is available via HTTP or FTP, accessLocation
 MUST be a uniformResourceIdentifier and the URI MUST point to a
 certificate containing file.  The certificate file MUST contain
 either a single Distinguished Encoding Rules (DER) [X.690] encoded
 certificate (indicated by the .cer file extension) or a collection of
 certificates (indicated by the .p7c file extension):

Santesson & Housley Standards Track [Page 3] RFC 4325 Authority Information Access CRL Extension December 2005

    .cer   A single DER encoded certificate as specified in
           RFC 2585 [PKIX-CERT].
    .p7c   A "certs-only" CMS message as specified in RFC 2797 [CMC].
   Conforming applications that support HTTP or FTP for accessing
   certificates MUST be able to accept .cer files and SHOULD be able
   to accept .p7c files.
   HTTP server implementations accessed via the URI SHOULD use the
   appropriate MIME content-type for the certificate containing file.
   Specifically, the HTTP server SHOULD use the content-type
   application/pkix-cert [PKIX-CERT] for a single DER encoded
   certificate and application/pkcs7-mime [CMC] for CMS certs-only
   (PKCS#7).  Consuming clients may use the MIME type and file
   extension as a hint to the file content, but should not depend
   solely on the presence of the correct MIME type or file extension
   in the server response.
   When the accessLocation is a directoryName, the information is to
   be obtained by the application from whatever directory server is
   locally configured.  When one CA public key is used to validate
   signatures on certificates and CRLs, the desired CA certificate is
   stored in the crossCertificatePair and/or cACertificate attributes
   as specified in [RFC2587].  When different public keys are used to
   validate signatures on certificates and CRLs, the desired
   certificate is stored in the userCertificate attribute as specified
   in [RFC2587].  Thus, implementations that support the directoryName
   form of accessLocation MUST be prepared to find the needed
   certificate in any of these three attributes.  The protocol that an
   application uses to access the directory (e.g., DAP or LDAP) is a
   local matter.
   Where the information is available via LDAP, the accessLocation
   SHOULD be a uniformResourceIdentifier.  The URI MUST specify a
   distingishedName and attribute(s) and MAY specify a host name
   (e.g., ldap://ldap.example.com/cn=example%20CA,dc=example,dc=com?
   cACertificate;binary,crossCertificatePair;binary).  Omitting the
   host name (e.g.,
   ldap:///cn=example%20CA,dc=example,dc=com?cACertificate;binary) has
   the effect of specifying the use of whatever LDAP server is locally
   configured.  The URI MUST list appropriate attribute descriptions
   for one or more attributes holding certificates or cross-
   certificate pairs.

Santesson & Housley Standards Track [Page 4] RFC 4325 Authority Information Access CRL Extension December 2005

3. Security Considerations

   Implementers should take into account the possible existence of
   multiple unrelated CAs and CRL issuers with the same name.
   Implementers should be aware of risks involved if the Authority
   Information Access extensions of corrupted CRLs contain links to
   malicious code.  Implementers should always take the steps of
   validating the retrieved data to ensure that the data is properly
   formed.

4. References

4.1. Normative References

 [RFC2119]   Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC2587]   Boeyen, S., Howes, T., and P. Richard, "Internet X.509
             Public Key Infrastructure: LDAPv2 Schema", RFC 2587, June
             1999.
 [PKIX1]     Housley, R., Polk, W., Ford, W., and D. Solo, "Internet
             X.509 Public Key Infrastructure Certificate and
             Certificate Revocation List (CRL) Profile", RFC 3280,
             April 2002.
 [HTTP/1.1]  Fielding,  R., Gettys, J., Mogul, J., Frystyk, H.,
             Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
             Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
 [URI]       Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
             Resource Identifier (URI): Generic Syntax", STD 66, RFC
             3986, January 2005.
 [LDAP]      Wahl, M., Howes, T., and S. Kille, "Lightweight Directory
             Access Protocol (v3)", RFC 2251, December 1997.
 [PKIX-CERT] Housley, R. and P. Hoffman, "Internet X.509 Public Key
             Infrastructure Operational Protocols: FTP and HTTP", RFC
             2585, May 1999.
 [CMC]       Myers, M., Liu, X., Schaad, J., and J. Weinstein,
             "Certificate Management Messages over CMS", RFC 2797,
             April 2000.

Santesson & Housley Standards Track [Page 5] RFC 4325 Authority Information Access CRL Extension December 2005

4.2. Informative References

 [X.680]     ITU-T Recommendation X.680 (2002) | ISO/IEC 8824-1:2002),
             Information Technology - Abstract Syntax Notation One,
             2002.
 [X.690]     ITU-T Recommendation X.690 Information Technology - ASN.1
             encoding rules: Specification of Basic Encoding Rules
             (BER), Canonical Encoding Rules (CER) and Distinguished
             Encoding Rules (DER), 1997.

Authors' Addresses

 Stefan Santesson
 Microsoft
 Tuborg Boulevard 12
 2900 Hellerup
 Denmark
 EMail: stefans@microsoft.com
 Russell Housley
 Vigil Security, LLC
 918 Spring Knoll Drive
 Herndon, VA 20170
 USA
 EMail: housley@vigilsec.com

Santesson & Housley Standards Track [Page 6] RFC 4325 Authority Information Access CRL Extension December 2005

Full Copyright Statement

 Copyright (C) The Internet Society (2005).
 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.
 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.

Intellectual Property

 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.

Acknowledgement

 Funding for the RFC Editor function is currently provided by the
 Internet Society.

Santesson & Housley Standards Track [Page 7]

/data/webs/external/dokuwiki/data/pages/rfc/rfc4325.txt · Last modified: 2005/12/14 22:58 by 127.0.0.1

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki