1. RFC 5877
Internet Engineering Task Force (IETF)                        R. Housley
Request for Comments: 5877                                Vigil Security
Category: Informational                                         May 2010
ISSN: 2070-1721

  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

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

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RFC 5877          application/pkix-attr-cert Media Type         May 2010

1.  Introduction

   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

      Security considerations:
        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.

      Interoperability considerations:
        The media type will be used with HTTP to fetch attribute
        certificates.  Other uses may emerge in the future.

      Published specification: RFC 5755

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RFC 5877          application/pkix-attr-cert Media Type         May 2010

      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

      Additional information:
        Magic number(s): None
        File extension(s): .ac
        Macintosh File Type Code(s): none

      Person & email address to contact for further information:
        Russ Housley

      Intended usage: COMMON

      Restrictions on usage: none

        Russ Housley <housley@vigilsec.com>

      Intended usage: COMMON

      Change controller:
        The IESG <iesg@ietf.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.  References

4.1.  Normative References

   [RFC5755]   Farrell, S., Housley, R., and S. Turner, "An Internet
               Attribute Certificate Profile for Authorization",
               RFC 5755, January 2010.

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RFC 5877          application/pkix-attr-cert Media Type         May 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,
               December 2005.

   [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
               Rules (DER).

Author's Address

   Russell Housley
   Vigil Security, LLC
   918 Spring Knoll Drive
   Herndon, VA 20170
   EMail: housley@vigilsec.com

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  1. RFC 5877