Internet Engineering Task Force (IETF) R. Housley
Request for Comments: 5877 Vigil Security
Category: Informational May 2010
The application/pkix-attr-cert Media Type for Attribute Certificates
This document specifies a MIME media type used to carry a single
attribute certificate as defined in RFC 5755.
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
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RFC 2585 [RFC2585] defines the MIME media types for public key
certificates and certificate revocation lists (CRLs). This document
specifies a MIME media type for use with attribute certificates as
defined in RFC 5755 [RFC5755].
Attribute certificates are ASN.1 encoded [X.680]. RFC 5755 [RFC5755]
tells which portions of the attribute certificate must use the
distinguished encoding rules (DER) [X.690] and which portions are
permitted to use the basic encoding rules (BER) [X.690]. Since DER
is a proper subset of BER, BER decoding all parts of a properly
constructed attribute certificate will be successful.
2. IANA Considerations
This document registers with IANA the "application/pkix-attr-cert"
Internet Media Type for use with an attribute certificate as defined
in [RFC5755]. This registration follows the procedures defined in
BCP 13 [RFC4288].
Type name: application
Subtype name: pkix-attr-cert
Required parameters: None
Optional parameters: None
Encoding considerations: binary
An attribute certificate provides authorization information. An
attribute certificate is most often used in conjunction with a
public key certificate [RFC5280], and the two certificates
should use the same encoding of the distinguished name as
described in the Security Considerations of this document.
The media type will be used with HTTP to fetch attribute
certificates. Other uses may emerge in the future.
Published specification: RFC 5755
Applications that use this media type:
The media type is used with a MIME-compliant transport to
transfer an attribute certificate. Attribute certificates
convey authorization information, and they are most often used
in conjunction with public key certificates as defined in
Magic number(s): None
File extension(s): .ac
Macintosh File Type Code(s): none
Person & email address to contact for further information:
Intended usage: COMMON
Restrictions on usage: none
Russ Housley <email@example.com>
Intended usage: COMMON
The IESG <firstname.lastname@example.org>
3. Security Considerations
Attribute certificate issuers must encode the holder entity name in
exactly the same way as the public key certificate distinguished
name. If they are encoded differently, implementations may fail to
recognize that the attribute certificate and public key certificate
belong to the same entity.
4.1. Normative References
[RFC5755] Farrell, S., Housley, R., and S. Turner, "An Internet
Attribute Certificate Profile for Authorization",
RFC 5755, January 2010.
4.2. Informative References
[RFC2585] Housley, R. and P. Hoffman, "Internet X.509 Public Key
Infrastructure Operational Protocols: FTP and HTTP",
RFC 2585, May 1999.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", BCP 13, RFC 4288,
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation
List (CRL) Profile", RFC 5280, May 2008.
[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
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