Network Working Group D. Cooper
Internet-Draft NIST
Updates: 3281 (if approved) September 29, 2006
Expires: March 2007
Authority Information Access Attribute Certificate Extension
draft-cooper-pkix-aiaac-00.txt
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Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
This document updates RFC 3281 by specifying the use of the id-ad-
caIssuers access method of the Authority Information Access extension
in an attribute certificate (AC). The Authority Information Access
extension is defined in RFC 3280 and RFC 3281 specifies the use of
the id-ad-ocsp access method of the Authority Information Access
extension in attribute certificates. When present in an attribute
certificate, the id-ad-caIssuers access method provides a means of
discovering and retrieving the public key certificate of the
attribute certificate's issuer.
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Table of Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . 2
1.1 Terminology . . . . . . . . . . . . . . . . . . . . . . 2
2 Authority Information Access AC Extension . . . . . . . . 3
3 References . . . . . . . . . . . . . . . . . . . . . . . 4
3.1 Normative References . . . . . . . . . . . . . . . . . 4
3.2 Informative References . . . . . . . . . . . . . . . . 5
4 Intellectual Property Rights . . . . . . . . . . . . . . 5
5 Security Considerations . . . . . . . . . . . . . . . . . 6
6 IANA Considerations . . . . . . . . . . . . . . . . . . . 6
7 Authors' Addresses . . . . . . . . . . . . . . . . . . . 6
Full Copyright Statement . . . . . . . . . . . . . . . . . . 6
1 Introduction
[RFC 3281] specifies the validation of attribute certificates. As
part of the validation process, the verifier must ensure that the
attribute certificate (AC) signature is cryptographically correct and
must verify the AC issuer's entire public key certificate (PKC)
certification path in accordance with [RFC 3280].
Methods of finding the PKC of the AC issuer are currently available,
such as through an accessible directory location. Directory lookup
requires existence and access to a directory that has been populated
with all of the necessary certificates.
[RFC 3280] provides for discovery of certificates needed to construct
a certification path 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 id-ad-caIssuers access method of
the Authority Information Access extension in ACs, enabling an AC
checking application to use the access method (id-ad-caIssuers) to
locate certificates that may be used to verify the signature on the
attribute certificate.
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].
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2 Authority Information Access AC Extension
This section defines the use of the id-ad-caIssuers access method of
the Authority Information Access extension in an attribute
certificate. The syntax and semantics defined in [RFC 3280] for the
certificate extension are also used for the AC extension.
This 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 }
id-ad-ocsp OBJECT IDENTIFIER ::= { id-ad 1 }
When the id-ad-caIssuers access method is used in an AC, at least one
instance of AccessDescription SHOULD specify an accessLocation that
is an HTTP [RFC 1738] or Lightweight Directory Access Protocol (LDAP)
[RFC 4516] 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):
.cer A single DER encoded certificate as specified in
[RFC 2585].
.p7c A BER or DER "certs-only" CMS message as specified
in [RFC 2797].
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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 [RFC 2585] for a single DER encoded certificate
and application/pkcs7-mime [RFC 2797] for "certs-only" CMS messages.
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 the AC issuer is not a CA, as required by [RFC
3281], the desired certificate is stored in the userCertificate
attribute as specified in [RFC 4523]. When the AC issuer is also a
CA, the desired certificate may be stored in the cACertificate and/or
crossCertificatePair 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
distinguishedName and attribute(s) and SHOULD specify a host name
(e.g., ldap://ldap.example.com/cn=example%20AA,dc=example,dc=com?
userCertificate;binary). Omitting the host name (e.g.,
ldap:///cn=example%20AA,dc=example,dc=com?userCertificate;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.
3 References
3.1 Normative References
[RFC 1738] Berners-Lee, T., L. Masinter and M. McCahill, "Uniform
Resource Locators (URL)", RFC 1738, December 1994.
[RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC 2585] Housley, R. and P. Hoffman, "Internet X.509 Public Key
Infrastructure Operational Protocols: FTP and HTTP", RFC
2585, May 1999.
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[RFC 2797] Myers, M., X. Liu, J. Schaad and J. Weinstein,
"Certificate Management Messages over CMS", RFC 2797,
April 2000.
[RFC 3280] Housley, R., W. Polk, W. Ford and D. Solo, "Internet
X.509 Public Key Infrastructure Certificate and
Certificate Revocation List (CRL) Profile", RFC 3280,
April 2002.
[RFC 3281] Farrell, S. and R. Housley, "An Internet Attribute
Certificate Profile for Authorization", RFC 3281, April
2002.
[RFC 4516] Smith, M. and T. Howes, "Lightweight Directory Access
Protocol (LDAP): Uniform Resource Locator", RFC 4516,
June 2006.
[RFC 4523] Zeilenga, K., "Lightweight Directory Access Protocol
(LDAP) Schema Definitions for X.509 Certificates", June
2006.
3.2 Informative References
[X.680] ITU-T Recommendation X.680 (2002) | ISO/IEC 8824-1:2002,
Information technology - Abstract Syntax Notation One
(ASN.1): Specification of basic notation.
[X.690] ITU-T Recommendation X.690 (2002) | ISO/IEC 8825-1:2002,
Information technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER), Canonical
Encoding Rules (CER) and Distinguished Encoding Rules
(DER).
4 Intellectual Property Rights
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
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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.
5 Security Considerations
Implementers should be aware of risks involved if the Authority
Information Access extensions of corrupted attribute certificates
contain links to malicious code. Implementers should always take the
steps of validating the retrieved data to ensure that the data is
properly formed.
6 IANA Considerations
Extensions in certificates are identified using object identifiers.
The objects are defined in an arc delegated by IANA to the PKIX
Working Group. No further action by IANA is necessary for this
document or any anticipated updates.
7 Authors' Addresses
David Cooper
National Institute of Standards and Technology
100 Bureau Drive, Mail Stop 8930
Gaithersburg, MD 20899-8930
USA
EMail: david.cooper@nist.gov
Full Copyright Statement
Copyright (C) The Internet Society (2006). This document is subject
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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.
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