Clearance Attribute and Authority Clearance Constraints Certificate Extension
RFC 5913

Internet Engineering Task Force (IETF)                         S. Turner
Request for Comments: 5913                                          IECA
Category: Standards Track                                    S. Chokhani
ISSN: 2070-1721                                       Cygnacom Solutions
                                                               June 2010

        Clearance Attribute and Authority Clearance Constraints
                         Certificate Extension

Abstract

   This document defines the syntax and semantics for the Clearance
   attribute and the Authority Clearance Constraints extension in X.509
   certificates.  The Clearance attribute is used to indicate the
   clearance held by the subject.  The Clearance attribute may appear in
   the subject directory attributes extension of a public key
   certificate or in the attributes field of an attribute certificate.
   The Authority Clearance Constraints certificate extension values in a
   Trust Anchor (TA), in Certification Authority (CA) public key
   certificates, and in an Attribute Authority (AA) public key
   certificate in a certification path for a given subject constrain the
   effective Clearance of the subject.

Status of This Memo

   This is an Internet Standards Track document.

   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).  Further information on
   Internet Standards is available in 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
   http://www.rfc-editor.org/info/rfc5913.

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

Turner & Chokhani            Standards Track                    [Page 1]
RFC 5913      Clearance and Authority Clearance Constraints    June 2010

   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.

Table of Contents

   1. Introduction ....................................................3
      1.1. Terminology ................................................4
      1.2. ASN.1 Syntax Notation ......................................4
   2. Clearance Attribute .............................................4
   3. Authority Clearance Constraints Certificate Extension ...........5
   4. Processing Clearance and Authority Clearance Constraints
      in a PKC ........................................................6
      4.1. Collecting Constraints .....................................7
           4.1.1. Certification Path Processing .......................7
                  4.1.1.1. Inputs .....................................8
                  4.1.1.2. Initialization .............................8
                  4.1.1.3. Basic Certificate Processing ...............8
                  4.1.1.4. Preparation for Certificate i+1 ............9
                  4.1.1.5. Wrap-up Procedure ..........................9
                           4.1.1.5.1. Wrap Up Clearance ...............9
                  4.1.1.6. Outputs ...................................10
   5. Clearance and Authority Clearance Constraints
      Processing in AC ...............................................10
      5.1. Collecting Constraints ....................................11
           5.1.1. Certification Path Processing ......................11
                  5.1.1.1. Inputs ....................................11
                  5.1.1.2. Initialization ............................11
                  5.1.1.3. Basic PKC Processing ......................12
                  5.1.1.4. Preparation for Certificate i+1 ...........12
                  5.1.1.5. Wrap-up Procedure .........................12
                           5.1.1.5.1. Wrap Up Clearance ..............12
                  5.1.1.6. Outputs ...................................12
   6. Computing the Intersection of permitted-clearances and
      Authority Clearance Constraints Extension ......................12
   7. Computing the Intersection of securityCategories ...............13
   8. Recommended securityCategories .................................15