Lightweight Directory Access Protocol (LDAP) Schema Definitions for X.509 Certificates
RFC 4523

Network Working Group                                        K. Zeilenga
Request for Comments: 4523                           OpenLDAP Foundation
Obsoletes: 2252, 2256, 2587                                    June 2006
Category: Standards Track

             Lightweight Directory Access Protocol (LDAP)
               Schema Definitions for X.509 Certificates

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 (2006).

   Abstract

   This document describes schema for representing X.509 certificates,
   X.521 security information, and related elements in directories
   accessible using the Lightweight Directory Access Protocol (LDAP).
   The LDAP definitions for these X.509 and X.521 schema elements
   replace those provided in RFCs 2252 and 2256.

1.  Introduction

   This document provides LDAP [RFC4510] schema definitions [RFC4512]
   for a subset of elements specified in X.509 [X.509] and X.521
   [X.521], including attribute types for certificates, cross
   certificate pairs, and certificate revocation lists; matching rules
   to be used with these attribute types; and related object classes.
   LDAP syntax definitions are also provided for associated assertion
   and attribute values.

   As the semantics of these elements are as defined in X.509 and X.521,
   knowledge of X.509 and X.521 is necessary to make use of the LDAP
   schema definitions provided herein.

   This document, together with [RFC4510], obsoletes RFCs 2252 and 2256
   in their entirety.  The changes (in this document) made since RFC
   2252 and RFC 2256 include:

      -  addition of pkiUser, pkiCA, and deltaCRL classes;

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      -  update of attribute types to include equality matching rules in
         accordance with their X.500 specifications;

      -  addition of certificate, certificate pair, certificate list,
         and algorithm identifier matching rules; and

      -  addition of LDAP syntax for assertion syntaxes for these
         matching rules.

   This document obsoletes RFC 2587.  The X.509 schema descriptions for
   LDAPv2 [RFC1777] are Historic, as is LDAPv2 [RFC3494].

   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 BCP 14 [RFC2119].

   Schema definitions are provided using LDAP description formats
   [RFC4512].  Definitions provided here are formatted (line wrapped)
   for readability.

2.  Syntaxes

   This section describes various syntaxes used in LDAP to transfer
   certificates and related data types.

2.1.  Certificate

      ( 1.3.6.1.4.1.1466.115.121.1.8 DESC 'X.509 Certificate' )

   A value of this syntax is an X.509 Certificate [X.509, clause 7].

   Due to changes made to the definition of a Certificate through time,
   no LDAP-specific encoding is defined for this syntax.  Values of this
   syntax SHOULD be encoded using Distinguished Encoding Rules (DER)
   [X.690] and MUST only be transferred using the ;binary transfer
   option [RFC4522]; that is, by requesting and returning values using
   attribute descriptions such as "userCertificate;binary".

   As values of this syntax contain digitally signed data, values of
   this syntax and the form of each value MUST be preserved as
   presented.

2.2.  CertificateList

      ( 1.3.6.1.4.1.1466.115.121.1.9 DESC 'X.509 Certificate List' )

   A value of this syntax is an X.509 CertificateList [X.509, clause
   7.3].

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   Due to changes made to the definition of a CertificateList through
   time, no LDAP-specific encoding is defined for this syntax.  Values
   of this syntax SHOULD be encoded using DER [X.690] and MUST only be
   transferred using the ;binary transfer option [RFC4522]; that is, by
   requesting and returning values using attribute descriptions such as
   "certificateRevocationList;binary".

   As values of this syntax contain digitally signed data, values of
   this syntax and the form of each value MUST be preserved as
   presented.

2.3.  CertificatePair

      ( 1.3.6.1.4.1.1466.115.121.1.10 DESC 'X.509 Certificate Pair' )

   A value of this syntax is an X.509 CertificatePair [X.509, clause
   11.2.3].

   Due to changes made to the definition of an X.509 CertificatePair
   through time, no LDAP-specific encoding is defined for this syntax.
   Values of this syntax SHOULD be encoded using DER [X.690] and MUST
   only be transferred using the ;binary transfer option [RFC4522]; that
   is, by requesting and returning values using attribute descriptions
   such as "crossCertificatePair;binary".

   As values of this syntax contain digitally signed data, values of
   this syntax and the form of each value MUST be preserved as
   presented.

2.4.  SupportedAlgorithm

      ( 1.3.6.1.4.1.1466.115.121.1.49
           DESC 'X.509 Supported Algorithm' )

   A value of this syntax is an X.509 SupportedAlgorithm [X.509, clause
   11.2.7].

   Due to changes made to the definition of an X.509 SupportedAlgorithm
   through time, no LDAP-specific encoding is defined for this syntax.
   Values of this syntax SHOULD be encoded using DER [X.690] and MUST
   only be transferred using the ;binary transfer option [RFC4522]; that
   is, by requesting and returning values using attribute descriptions
   such as "supportedAlgorithms;binary".

   As values of this syntax contain digitally signed data, values of
   this syntax and the form of the value MUST be preserved as presented.

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2.5.  CertificateExactAssertion

      ( 1.3.6.1.1.15.1 DESC 'X.509 Certificate Exact Assertion' )

   A value of this syntax is an X.509 CertificateExactAssertion [X.509,
   clause 11.3.1].  Values of this syntax MUST be encoded using the
   Generic String Encoding Rules (GSER) [RFC3641].  Appendix A.1
   provides an equivalent Augmented Backus-Naur Form (ABNF) [RFC4234]
   grammar for this syntax.

2.6.  CertificateAssertion

      ( 1.3.6.1.1.15.2 DESC 'X.509 Certificate Assertion' )

   A value of this syntax is an X.509 CertificateAssertion [X.509,
   clause 11.3.2].  Values of this syntax MUST be encoded using GSER
   [RFC3641].  Appendix A.2 provides an equivalent ABNF [RFC4234]
   grammar for this syntax.

2.7.  CertificatePairExactAssertion

      ( 1.3.6.1.1.15.3
           DESC 'X.509 Certificate Pair Exact Assertion' )

   A value of this syntax is an X.509 CertificatePairExactAssertion
   [X.509, clause 11.3.3].  Values of this syntax MUST be encoded using
   GSER [RFC3641].  Appendix A.3 provides an equivalent ABNF [RFC4234]
   grammar for this syntax.

2.8.  CertificatePairAssertion

      ( 1.3.6.1.1.15.4 DESC 'X.509 Certificate Pair Assertion' )

   A value of this syntax is an X.509 CertificatePairAssertion [X.509,
   clause 11.3.4].  Values of this syntax MUST be encoded using GSER
   [RFC3641].  Appendix A.4 provides an equivalent ABNF [RFC4234]
   grammar for this syntax.

2.9.  CertificateListExactAssertion

      ( 1.3.6.1.1.15.5
           DESC 'X.509 Certificate List Exact Assertion' )

   A value of this syntax is an X.509 CertificateListExactAssertion
   [X.509, clause 11.3.5].  Values of this syntax MUST be encoded using
   GSER [RFC3641].  Appendix A.5 provides an equivalent ABNF grammar for
   this syntax.

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2.10.  CertificateListAssertion

      ( 1.3.6.1.1.15.6 DESC 'X.509 Certificate List Assertion' )

   A value of this syntax is an X.509 CertificateListAssertion [X.509,
   clause 11.3.6].  Values of this syntax MUST be encoded using GSER
   [RFC3641].  Appendix A.6 provides an equivalent ABNF [RFC4234]
   grammar for this syntax.

2.11.  AlgorithmIdentifier

      ( 1.3.6.1.1.15.7 DESC 'X.509 Algorithm Identifier' )

   A value of this syntax is an X.509 AlgorithmIdentifier [X.509, Clause
   7].  Values of this syntax MUST be encoded using GSER [RFC3641].

   Appendix A.7 provides an equivalent ABNF [RFC4234] grammar for this
   syntax.

3.  Matching Rules

   This section introduces a set of certificate and related matching
   rules for use in LDAP.  These rules are intended to act in accordance
   with their X.500 counterparts.

3.1.  certificateExactMatch

   The certificateExactMatch matching rule compares the presented
   certificate exact assertion value with an attribute value of the
   certificate syntax as described in clause 11.3.1 of [X.509].

      ( 2.5.13.34 NAME 'certificateExactMatch'
           DESC 'X.509 Certificate Exact Match'
           SYNTAX 1.3.6.1.1.15.1 )

3.2.  certificateMatch

   The certificateMatch matching rule compares the presented certificate
   assertion value with an attribute value of the certificate syntax as
   described in clause 11.3.2 of [X.509].

      ( 2.5.13.35 NAME 'certificateMatch'
           DESC 'X.509 Certificate Match'
           SYNTAX 1.3.6.1.1.15.2 )

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3.3.  certificatePairExactMatch

   The certificatePairExactMatch matching rule compares the presented
   certificate pair exact assertion value with an attribute value of the
   certificate pair syntax as described in clause 11.3.3 of [X.509].

      ( 2.5.13.36 NAME 'certificatePairExactMatch'
           DESC 'X.509 Certificate Pair Exact Match'
           SYNTAX 1.3.6.1.1.15.3 )

3.4.  certificatePairMatch

   The certificatePairMatch matching rule compares the presented
   certificate pair assertion value with an attribute value of the
   certificate pair syntax as described in clause 11.3.4 of [X.509].

      ( 2.5.13.37 NAME 'certificatePairMatch'
           DESC 'X.509 Certificate Pair Match'
           SYNTAX 1.3.6.1.1.15.4 )

3.5.  certificateListExactMatch

   The certificateListExactMatch matching rule compares the presented
   certificate list exact assertion value with an attribute value of the
   certificate pair syntax as described in clause 11.3.5 of [X.509].

      ( 2.5.13.38 NAME 'certificateListExactMatch'
           DESC 'X.509 Certificate List Exact Match'
           SYNTAX 1.3.6.1.1.15.5 )

3.6.  certificateListMatch

   The certificateListMatch matching rule compares the presented
   certificate list assertion value with an attribute value of the
   certificate pair syntax as described in clause 11.3.6 of [X.509].

      ( 2.5.13.39 NAME 'certificateListMatch'
           DESC 'X.509 Certificate List Match'
           SYNTAX 1.3.6.1.1.15.6 )

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3.7.  algorithmIdentifierMatch

   The algorithmIdentifierMatch mating rule compares a presented
   algorithm identifier with an attribute value of the supported
   algorithm as described in clause 11.3.7 of [X.509].

      ( 2.5.13.40 NAME 'algorithmIdentifier'
           DESC 'X.509 Algorithm Identifier Match'
           SYNTAX 1.3.6.1.1.15.7 )

4.  Attribute Types

   This section details a set of certificate and related attribute types
   for use in LDAP.

4.1.  userCertificate

   The userCertificate attribute holds the X.509 certificates issued to
   the user by one or more certificate authorities, as discussed in
   clause 11.2.1 of [X.509].

      ( 2.5.4.36 NAME 'userCertificate'
           DESC 'X.509 user certificate'
           EQUALITY certificateExactMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.8 )

   As required by this attribute type's syntax, values of this attribute
   are requested and transferred using the attribute description
   "userCertificate;binary".

4.2.  cACertificate

   The cACertificate attribute holds the X.509 certificates issued to
   the certificate authority (CA), as discussed in clause 11.2.2 of
   [X.509].

      ( 2.5.4.37 NAME 'cACertificate'
           DESC 'X.509 CA certificate'
           EQUALITY certificateExactMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.8 )

   As required by this attribute type's syntax, values of this attribute
   are requested and transferred using the attribute description
   "cACertificate;binary".

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4.3.  crossCertificatePair

   The crossCertificatePair attribute holds an X.509 certificate pair,
   as discussed in clause 11.2.3 of [X.509].

      ( 2.5.4.40 NAME 'crossCertificatePair'
           DESC 'X.509 cross certificate pair'
           EQUALITY certificatePairExactMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.10 )

   As required by this attribute type's syntax, values of this attribute
   are requested and transferred using the attribute description
   "crossCertificatePair;binary".

4.4.  certificateRevocationList

   The certificateRevocationList attribute holds certificate lists, as
   discussed in 11.2.4 of [X.509].

      ( 2.5.4.39 NAME 'certificateRevocationList'
           DESC 'X.509 certificate revocation list'
           EQUALITY certificateListExactMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.9 )

   As required by this attribute type's syntax, values of this attribute
   are requested and transferred using the attribute description
   "certificateRevocationList;binary".

4.5.  authorityRevocationList

   The authorityRevocationList attribute holds certificate lists, as
   discussed in 11.2.5 of [X.509].

      ( 2.5.4.38 NAME 'authorityRevocationList'
           DESC 'X.509 authority revocation list'
           EQUALITY certificateListExactMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.9 )

   As required by this attribute type's syntax, values of this attribute
   are requested and transferred using the attribute description
   "authorityRevocationList;binary".

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4.6.  deltaRevocationList

   The deltaRevocationList attribute holds certificate lists, as
   discussed in 11.2.6 of [X.509].

      ( 2.5.4.53 NAME 'deltaRevocationList'
           DESC 'X.509 delta revocation list'
           EQUALITY certificateListExactMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.9 )

   As required by this attribute type's syntax, values of this attribute
   MUST be requested and transferred using the attribute description
   "deltaRevocationList;binary".

4.7.  supportedAlgorithms

   The supportedAlgorithms attribute holds supported algorithms, as
   discussed in 11.2.7 of [X.509].

      ( 2.5.4.52 NAME 'supportedAlgorithms'
           DESC 'X.509 supported algorithms'
           EQUALITY algorithmIdentifierMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.49 )

   As required by this attribute type's syntax, values of this attribute
   MUST be requested and transferred using the attribute description
   "supportedAlgorithms;binary".

5.  Object Classes

   This section details a set of certificate-related object classes for
   use in LDAP.

5.1.  pkiUser

   This object class is used in augment entries for objects that may be
   subject to certificates, as defined in clause 11.1.1 of [X.509].

      ( 2.5.6.21 NAME 'pkiUser'
           DESC 'X.509 PKI User'
           SUP top AUXILIARY
           MAY userCertificate )

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5.2.  pkiCA

   This object class is used to augment entries for objects that act as
   certificate authorities, as defined in clause 11.1.2 of [X.509]

      ( 2.5.6.22 NAME 'pkiCA'
           DESC 'X.509 PKI Certificate Authority'
           SUP top AUXILIARY
           MAY ( cACertificate $ certificateRevocationList $
                authorityRevocationList $ crossCertificatePair ) )

5.3.  cRLDistributionPoint

   This class is used to represent objects that act as CRL distribution
   points, as discussed in clause 11.1.3 of [X.509].

      ( 2.5.6.19 NAME 'cRLDistributionPoint'
           DESC 'X.509 CRL distribution point'
           SUP top STRUCTURAL
           MUST cn
           MAY ( certificateRevocationList $
                authorityRevocationList $ deltaRevocationList ) )

5.4.  deltaCRL

   The deltaCRL object class is used to augment entries to hold delta
   revocation lists, as discussed in clause 11.1.4 of [X.509].

      ( 2.5.6.23 NAME 'deltaCRL'
           DESC 'X.509 delta CRL'
           SUP top AUXILIARY
           MAY deltaRevocationList )

5.5.  strongAuthenticationUser

   This object class is used to augment entries for objects
   participating in certificate-based authentication, as defined in
   clause 6.15 of [X.521].  This object class is deprecated in favor of
   pkiUser.

      ( 2.5.6.15 NAME 'strongAuthenticationUser'
           DESC 'X.521 strong authentication user'
           SUP top AUXILIARY
           MUST userCertificate )

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5.6.  userSecurityInformation

   This object class is used to augment entries with needed additional
   associated security information, as defined in clause 6.16 of
   [X.521].

      ( 2.5.6.18 NAME 'userSecurityInformation'
           DESC 'X.521 user security information'
           SUP top AUXILIARY
           MAY ( supportedAlgorithms ) )

5.7.  certificationAuthority

   This object class is used to augment entries for objects that act as
   certificate authorities, as defined in clause 6.17 of [X.521].  This
   object class is deprecated in favor of pkiCA.

      ( 2.5.6.16 NAME 'certificationAuthority'
           DESC 'X.509 certificate authority'
           SUP top AUXILIARY
           MUST ( authorityRevocationList $
                certificateRevocationList $ cACertificate )
           MAY crossCertificatePair )

5.8.  certificationAuthority-V2

   This object class is used to augment entries for objects that act as
   certificate authorities, as defined in clause 6.18 of [X.521].  This
   object class is deprecated in favor of pkiCA.

      ( 2.5.6.16.2 NAME 'certificationAuthority-V2'
           DESC 'X.509 certificate authority, version 2'
           SUP certificationAuthority AUXILIARY
           MAY deltaRevocationList )

6.  Security Considerations

   General certificate considerations [RFC3280] apply to LDAP-aware
   certificate applications.  General LDAP security considerations
   [RFC4510] apply as well.

   While elements of certificate information are commonly signed, these
   signatures only protect the integrity of the signed information.  In
   the absence of data integrity protections in LDAP (or lower layer,
   e.g., IPsec), a server is not assured that client certificate request
   (or other request) was unaltered in transit.  Likewise, a client
   cannot be assured that the results of the query were unaltered in

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   transit.  Hence, it is generally recommended that implementations
   make use of authentication and data integrity services in LDAP
   [RFC4513][RFC4511].

7.  IANA Considerations

7.1.  Object Identifier Registration

   The IANA has registered an LDAP Object Identifier [RFC4520] for use
   in this technical specification.

      Subject: Request for LDAP OID Registration
      Person & email address to contact for further information:
          Kurt Zeilenga <kurt@OpenLDAP.org>
      Specification: RFC 4523
      Author/Change Controller: IESG
      Comments:
          Identifies the LDAP X.509 Certificate schema elements
           introduced in this document.

7.2.  Descriptor Registration

   The IANA has updated the LDAP
   Descriptor registry [RFC44520] as indicated below.

      Subject: Request for LDAP Descriptor Registration
      Descriptor (short name): see table
      Object Identifier: see table
      Person & email address to contact for further information:
          Kurt Zeilenga <kurt@OpenLDAP.org>
      Usage: see table
      Specification: RFC 4523
      Author/Change Controller: IESG

      algorithmIdentifierMatch     M 2.5.13.40
      authorityRevocationList      A 2.5.4.38 *
      cACertificate                A 2.5.4.37 *
      cRLDistributionPoint         O 2.5.6.19 *
      certificateExactMatch        M 2.5.13.34
      certificateListExactMatch    M 2.5.13.38
      certificateListMatch         M 2.5.13.39
      certificateMatch             M 2.5.13.35
      certificatePairExactMatch    M 2.5.13.36
      certificatePairMatch         M 2.5.13.37
      certificateRevocationList    A 2.5.4.39 *
      certificationAuthority       O 2.5.6.16 *
      certificationAuthority-V2    O 2.5.6.16.2 *
      crossCertificatePair         A 2.5.4.40 *

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      deltaCRL                     O 2.5.6.23 *
      deltaRevocationList          A 2.5.4.53 *
      pkiCA                        O 2.5.6.22 *
      pkiUser                      O 2.5.6.21 *
      strongAuthenticationUser     O 2.5.6.15 *
      supportedAlgorithms          A 2.5.4.52 *
      userCertificate              A 2.5.4.36 *
      userSecurityInformation      O 2.5.6.18 *

      * Updates previous registration

8.  Acknowledgements

   This document is based on X.509, a product of the ITU-T.  A number of
   LDAP schema definitions were based on those found in RFCs 2252 and
   2256, both products of the IETF ASID WG.  The ABNF productions in
   Appendix A were provided by Steven Legg.  Additional material was
   borrowed from prior works by David Chadwick and Steven Legg to refine
   the LDAP X.509 schema.

9.  References

9.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3641]  Legg, S., "Generic String Encoding Rules (GSER) for ASN.1
              Types", RFC 3641, October 2003.

   [RFC4510]  Zeilenga, K., Ed., "Lightweight Directory Access Protocol
              (LDAP): Technical Specification Road Map", RFC 4510, June
              2006.

   [RFC4512]  Zeilenga, K., "Lightweight Directory Access Protocol
              (LDAP): Directory Information Models", RFC 4512, June
              2006.

   [RFC4522]  Legg, S., "Lightweight Directory Access Protocol (LDAP):
              The Binary Encoding Option", RFC 4522, June 2006.

   [X.509]    International Telecommunication Union - Telecommunication
              Standardization Sector, "The Directory: Authentication
              Framework", X.509(2000).

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   [X.521]    International Telecommunication Union - Telecommunication
              Standardization Sector, "The Directory: Selected Object
              Classes", X.521(2000).

   [X.690]    International Telecommunication Union - Telecommunication
              Standardization Sector, "Specification of ASN.1 encoding
              rules: Basic Encoding Rules (BER), Canonical Encoding
              Rules (CER), and Distinguished Encoding Rules (DER)",
              X.690(2002) (also ISO/IEC 8825-1:2002).

9.2.  Informative References

   [RFC1777]  Yeong, W., Howes, T., and S. Kille, "Lightweight Directory
              Access Protocol", RFC 1777, March 1995.

   [RFC2156]  Kille, S., "MIXER (Mime Internet X.400 Enhanced Relay):
              Mapping between X.400 and RFC 822/MIME", RFC 2156, January
              1998.

   [RFC3280]  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.

   [RFC3494]  Zeilenga, K., "Lightweight Directory Access Protocol
              version 2 (LDAPv2) to Historic Status", RFC 3494, March
              2003.

   [RFC3642]  Legg, S., "Common Elements of Generic String Encoding
              Rules (GSER) Encodings", RFC 3642, October 2003.

   [RFC4234]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", RFC 4234, October 2005.

   [RFC4511]  Sermersheim, J., Ed., "Lightweight Directory Access
              Protocol (LDAP): The Protocol", RFC 4511, June 2006.

   [RFC4513]  Harrison, R. Ed., "Lightweight Directory Access Protocol
              (LDAP): Authentication Methods and Security Mechanisms",
              RFC 4513, June 2006.

   [RFC4520]  Zeilenga, K., "Internet Assigned Numbers Authority (IANA)
              Considerations for the Lightweight Directory Access
              Protocol (LDAP)", BCP 64, RFC 4520, June 2006.

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Appendix A.

   This appendix is informative.

   This appendix provides ABNF [RFC4234] grammars for GSER-based
   [RFC3641] LDAP-specific encodings specified in this document.  These
   grammars where produced using, and relying on, Common Elements for
   GSER Encodings [RFC3642].

A.1.  CertificateExactAssertion

   CertificateExactAssertion = "{" sp cea-serialNumber ","
        sp cea-issuer sp "}"

   cea-serialNumber = id-serialNumber msp CertificateSerialNumber
   cea-issuer = id-issuer msp Name

   id-serialNumber =
        %x73.65.72.69.61.6C.4E.75.6D.62.65.72 ; 'serialNumber'
   id-issuer = %x69.73.73.75.65.72 ; 'issuer'

   Name = id-rdnSequence ":" RDNSequence
   id-rdnSequence = %x72.64.6E.53.65.71.75.65.6E.63.65 ; 'rdnSequence'

   CertificateSerialNumber = INTEGER

A.2.  CertificateAssertion

CertificateAssertion = "{" [ sp ca-serialNumber ]
     [ sep sp ca-issuer ]
     [ sep sp ca-subjectKeyIdentifier ]
     [ sep sp ca-authorityKeyIdentifier ]
     [ sep sp ca-certificateValid ]
     [ sep sp ca-privateKeyValid ]
     [ sep sp ca-subjectPublicKeyAlgID ]
     [ sep sp ca-keyUsage ]
     [ sep sp ca-subjectAltName ]
     [ sep sp ca-policy ]
     [ sep sp ca-pathToName ]
     [ sep sp ca-subject ]
     [ sep sp ca-nameConstraints ] sp "}"

ca-serialNumber = id-serialNumber msp CertificateSerialNumber
ca-issuer = id-issuer msp Name
ca-subjectKeyIdentifier = id-subjectKeyIdentifier msp
     SubjectKeyIdentifier
ca-authorityKeyIdentifier = id-authorityKeyIdentifier msp
     AuthorityKeyIdentifier

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ca-certificateValid = id-certificateValid msp Time
ca-privateKeyValid = id-privateKeyValid msp GeneralizedTime
ca-subjectPublicKeyAlgID = id-subjectPublicKeyAlgID msp
     OBJECT-IDENTIFIER
ca-keyUsage = id-keyUsage msp KeyUsage
ca-subjectAltName = id-subjectAltName msp AltNameType
ca-policy = id-policy msp CertPolicySet
ca-pathToName = id-pathToName msp Name
ca-subject = id-subject msp Name
ca-nameConstraints = id-nameConstraints msp NameConstraintsSyntax

id-subjectKeyIdentifier =
     %x73.75.62.6A.65.63.74.4B.65.79.49.64.65.6E.74.69.66.69.65.72
     ; 'subjectKeyIdentifier'
id-authorityKeyIdentifier =
     %x61.75.74.68.6F.72.69.74.79.4B.65.79.49.64.65.6E.74.69.66.69.65.72
     ; 'authorityKeyIdentifier'
id-certificateValid = %x63.65.72.74.69.66.69.63.61.74.65.56.61.6C.69.64
     ; 'certificateValid'
id-privateKeyValid = %x70.72.69.76.61.74.65.4B.65.79.56.61.6C.69.64
     ; 'privateKeyValid'
id-subjectPublicKeyAlgID  =
     %x73.75.62.6A.65.63.74.50.75.62.6C.69.63.4B.65.79.41.6C.67.49.44
     ; 'subjectPublicKeyAlgID'
id-keyUsage = %x6B.65.79.55.73.61.67.65 ; 'keyUsage'
id-subjectAltName = %x73.75.62.6A.65.63.74.41.6C.74.4E.61.6D.65
     ; 'subjectAltName'
id-policy = %x70.6F.6C.69.63.79 ; 'policy'
id-pathToName = %x70.61.74.68.54.6F.4E.61.6D.65 ; 'pathToName'
id-subject = %x73.75.62.6A.65.63.74 ; 'subject'
id-nameConstraints = %x6E.61.6D.65.43.6F.6E.73.74.72.61.69.6E.74.73
     ; 'nameConstraints'

SubjectKeyIdentifier = KeyIdentifier

KeyIdentifier = OCTET-STRING

AuthorityKeyIdentifier = "{" [ sp aki-keyIdentifier ]
     [ sep sp aki-authorityCertIssuer ]
     [ sep sp aki-authorityCertSerialNumber ] sp "}"

aki-keyIdentifier = id-keyIdentifier msp KeyIdentifier
aki-authorityCertIssuer = id-authorityCertIssuer msp GeneralNames

GeneralNames = "{" sp GeneralName *( "," sp GeneralName ) sp "}"
GeneralName  = gn-otherName
     / gn-rfc822Name
     / gn-dNSName

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RFC 4523                   LDAP X.509 Schema                   June 2006

     / gn-x400Address
     / gn-directoryName
     / gn-ediPartyName
     / gn-uniformResourceIdentifier
     / gn-iPAddress
     / gn-registeredID

gn-otherName = id-otherName ":" OtherName
gn-rfc822Name = id-rfc822Name ":" IA5String
gn-dNSName = id-dNSName ":" IA5String
gn-x400Address = id-x400Address ":" ORAddress
gn-directoryName = id-directoryName ":" Name
gn-ediPartyName = id-ediPartyName ":" EDIPartyName
gn-iPAddress = id-iPAddress ":" OCTET-STRING
gn-registeredID = gn-id-registeredID ":" OBJECT-IDENTIFIER

gn-uniformResourceIdentifier = id-uniformResourceIdentifier
     ":" IA5String

id-otherName = %x6F.74.68.65.72.4E.61.6D.65 ; 'otherName'
gn-id-registeredID = %x72.65.67.69.73.74.65.72.65.64.49.44
     ; 'registeredID'

OtherName = "{" sp on-type-id "," sp on-value sp "}"
on-type-id = id-type-id msp OBJECT-IDENTIFIER
on-value = id-value msp Value
     ;; <Value> as defined in Section 3 of [RFC3641]

id-type-id = %x74.79.70.65.2D.69.64 ; 'type-id'
id-value = %x76.61.6C.75.65 ; 'value'

ORAddress = dquote *SafeIA5Character dquote
SafeIA5Character = %x01-21 / %x23-7F / ; ASCII minus dquote
     dquote dquote ; escaped double quote
dquote = %x22 ; '"' (double quote)

;; Note: The <ORAddress> rule encodes the x400Address component
;; of a GeneralName as a character string between double quotes.
;; The character string is first derived according to Section 4.1
;; of [RFC2156], and then any embedded double quotes are escaped
;; by being repeated. This resulting string is output between
;; double quotes.

EDIPartyName = "{" [ sp nameAssigner "," ] sp partyName sp "}"
nameAssigner = id-nameAssigner msp DirectoryString
partyName = id-partyName msp DirectoryString
id-nameAssigner = %x6E.61.6D.65.41.73.73.69.67.6E.65.72
     ; 'nameAssigner'

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id-partyName    = %x70.61.72.74.79.4E.61.6D.65 ; 'partyName'

aki-authorityCertSerialNumber = id-authorityCertSerialNumber
     msp CertificateSerialNumber

id-keyIdentifier = %x6B.65.79.49.64.65.6E.74.69.66.69.65.72
     ; 'keyIdentifier'
id-authorityCertIssuer =
     %x61.75.74.68.6F.72.69.74.79.43.65.72.74.49.73.73.75.65.72
     ; 'authorityCertIssuer'

id-authorityCertSerialNumber = %x61.75.74.68.6F.72.69.74.79.43
     %x65.72.74.53.65.72.69.61.6C.4E.75.6D.62.65.72
     ; 'authorityCertSerialNumber'

Time = time-utcTime / time-generalizedTime
time-utcTime = id-utcTime ":" UTCTime
time-generalizedTime = id-generalizedTime ":" GeneralizedTime
id-utcTime = %x75.74.63.54.69.6D.65 ; 'utcTime'
id-generalizedTime = %x67.65.6E.65.72.61.6C.69.7A.65.64.54.69.6D.65
     ; 'generalizedTime'

KeyUsage = BIT-STRING / key-usage-bit-list
key-usage-bit-list = "{" [ sp key-usage *( "," sp key-usage ) ] sp "}"

;; Note: The <key-usage-bit-list> rule encodes the one bits in
;; a KeyUsage value as a comma separated list of identifiers.

key-usage = id-digitalSignature
     / id-nonRepudiation
     / id-keyEncipherment
     / id-dataEncipherment
     / id-keyAgreement
     / id-keyCertSign
     / id-cRLSign
     / id-encipherOnly
     / id-decipherOnly

id-digitalSignature = %x64.69.67.69.74.61.6C.53.69.67.6E.61.74
     %x75.72.65 ; 'digitalSignature'
id-nonRepudiation   = %x6E.6F.6E.52.65.70.75.64.69.61.74.69.6F.6E
     ; 'nonRepudiation'
id-keyEncipherment  = %x6B.65.79.45.6E.63.69.70.68.65.72.6D.65.6E.74
     ; 'keyEncipherment'
id-dataEncipherment = %x64.61.74.61.45.6E.63.69.70.68.65.72.6D.65.6E
     %x74 ; "dataEncipherment'
id-keyAgreement     = %x6B.65.79.41.67.72.65.65.6D.65.6E.74
     ; 'keyAgreement'

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RFC 4523                   LDAP X.509 Schema                   June 2006

id-keyCertSign      = %x6B.65.79.43.65.72.74.53.69.67.6E
     ; 'keyCertSign'
id-cRLSign          = %x63.52.4C.53.69.67.6E ; "cRLSign"
id-encipherOnly     = %x65.6E.63.69.70.68.65.72.4F.6E.6C.79
     ; 'encipherOnly'
id-decipherOnly     = %x64.65.63.69.70.68.65.72.4F.6E.6C.79
     ; 'decipherOnly'

AltNameType = ant-builtinNameForm / ant-otherNameForm

ant-builtinNameForm = id-builtinNameForm ":" BuiltinNameForm
ant-otherNameForm = id-otherNameForm ":" OBJECT-IDENTIFIER

id-builtinNameForm = %x62.75.69.6C.74.69.6E.4E.61.6D.65.46.6F.72.6D
     ; 'builtinNameForm'
id-otherNameForm   = %x6F.74.68.65.72.4E.61.6D.65.46.6F.72.6D
     ; 'otherNameForm'

BuiltinNameForm  = id-rfc822Name
     / id-dNSName
     / id-x400Address
     / id-directoryName
     / id-ediPartyName
     / id-uniformResourceIdentifier
     / id-iPAddress
     / id-registeredId

id-rfc822Name = %x72.66.63.38.32.32.4E.61.6D.65 ; 'rfc822Name'
id-dNSName = %x64.4E.53.4E.61.6D.65 ; 'dNSName'
id-x400Address  = %x78.34.30.30.41.64.64.72.65.73.73 ; 'x400Address'
id-directoryName = %x64.69.72.65.63.74.6F.72.79.4E.61.6D.65
     ; 'directoryName'
id-ediPartyName  = %x65.64.69.50.61.72.74.79.4E.61.6D.65
     ; 'ediPartyName'
id-iPAddress = %x69.50.41.64.64.72.65.73.73 ; 'iPAddress'
id-registeredId = %x72.65.67.69.73.74.65.72.65.64.49.64
     ; 'registeredId'

id-uniformResourceIdentifier = %x75.6E.69.66.6F.72.6D.52.65.73.6F.75
     %x72.63.65.49.64.65.6E.74.69.66.69.65.72
     ; 'uniformResourceIdentifier'

CertPolicySet = "{" sp CertPolicyId *( "," sp CertPolicyId ) sp "}"
CertPolicyId = OBJECT-IDENTIFIER

NameConstraintsSyntax = "{" [ sp ncs-permittedSubtrees ]
     [ sep sp ncs-excludedSubtrees ] sp "}"

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RFC 4523                   LDAP X.509 Schema                   June 2006

ncs-permittedSubtrees = id-permittedSubtrees msp GeneralSubtrees
ncs-excludedSubtrees = id-excludedSubtrees  msp GeneralSubtrees

id-permittedSubtrees =
     %x70.65.72.6D.69.74.74.65.64.53.75.62.74.72.65.65.73
     ; 'permittedSubtrees'
id-excludedSubtrees =
     %x65.78.63.6C.75.64.65.64.53.75.62.74.72.65.65.73
     ; 'excludedSubtrees'

GeneralSubtrees = "{" sp GeneralSubtree
     *( "," sp GeneralSubtree ) sp "}"
GeneralSubtree  = "{" sp gs-base
     [ "," sp gs-minimum ]
     [ "," sp gs-maximum ] sp "}"

gs-base = id-base msp GeneralName
gs-minimum = id-minimum msp BaseDistance
gs-maximum = id-maximum msp BaseDistance

id-base = %x62.61.73.65 ; 'base'
id-minimum = %x6D.69.6E.69.6D.75.6D ; 'minimum'
id-maximum = %x6D.61.78.69.6D.75.6D ; 'maximum'

BaseDistance = INTEGER-0-MAX

A.3.  CertificatePairExactAssertion

  CertificatePairExactAssertion = "{" [ sp cpea-issuedTo ]
       [sep sp cpea-issuedBy ] sp "}"
  ;; At least one of <cpea-issuedTo> or <cpea-issuedBy> MUST be present.

  cpea-issuedTo = id-issuedToThisCAAssertion msp
       CertificateExactAssertion
  cpea-issuedBy = id-issuedByThisCAAssertion msp
       CertificateExactAssertion

  id-issuedToThisCAAssertion = %x69.73.73.75.65.64.54.6F.54.68.69.73
       %x43.41.41.73.73.65.72.74.69.6F.6E ; 'issuedToThisCAAssertion'
  id-issuedByThisCAAssertion = %x69.73.73.75.65.64.42.79.54.68.69.73
       %x43.41.41.73.73.65.72.74.69.6F.6E ; 'issuedByThisCAAssertion'

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A.4.  CertificatePairAssertion

   CertificatePairAssertion = "{" [ sp cpa-issuedTo ]
        [sep sp cpa-issuedBy ] sp "}"
   ;; At least one of <cpa-issuedTo> and <cpa-issuedBy> MUST be present.

   cpa-issuedTo = id-issuedToThisCAAssertion msp CertificateAssertion
   cpa-issuedBy = id-issuedByThisCAAssertion msp CertificateAssertion

A.5.  CertificateListExactAssertion

   CertificateListExactAssertion = "{" sp clea-issuer ","
        sp clea-thisUpdate
        [ "," sp clea-distributionPoint ] sp "}"

   clea-issuer = id-issuer msp Name
   clea-thisUpdate = id-thisUpdate msp Time
   clea-distributionPoint = id-distributionPoint msp
        DistributionPointName

   id-thisUpdate = %x74.68.69.73.55.70.64.61.74.65 ; 'thisUpdate'
   id-distributionPoint =
        %x64.69.73.74.72.69.62.75.74.69.6F.6E.50.6F.69.6E.74
        ; 'distributionPoint'

   DistributionPointName = dpn-fullName / dpn-nameRelativeToCRLIssuer

   dpn-fullName = id-fullName ":" GeneralNames
   dpn-nameRelativeToCRLIssuer = id-nameRelativeToCRLIssuer ":"
        RelativeDistinguishedName

   id-fullName = %x66.75.6C.6C.4E.61.6D.65 ; 'fullName'
   id-nameRelativeToCRLIssuer = %x6E.61.6D.65.52.65.6C.61.74.69.76.65
        %x54.6F.43.52.4C.49.73.73.75.65.72 ; 'nameRelativeToCRLIssuer'

A.6.  CertificateListAssertion

   CertificateListAssertion = "{" [ sp cla-issuer ]
        [ sep sp cla-minCRLNumber ]
        [ sep sp cla-maxCRLNumber ]
        [ sep sp cla-reasonFlags ]
        [ sep sp cla-dateAndTime ]
        [ sep sp cla-distributionPoint ]
        [ sep sp cla-authorityKeyIdentifier ] sp "}"

   cla-issuer = id-issuer msp Name
   cla-minCRLNumber = id-minCRLNumber msp CRLNumber
   cla-maxCRLNumber = id-maxCRLNumber msp CRLNumber

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RFC 4523                   LDAP X.509 Schema                   June 2006

   cla-reasonFlags = id-reasonFlags msp ReasonFlags
   cla-dateAndTime = id-dateAndTime msp Time

   cla-distributionPoint = id-distributionPoint msp
        DistributionPointName

   cla-authorityKeyIdentifier = id-authorityKeyIdentifier msp
        AuthorityKeyIdentifier

   id-minCRLNumber = %x6D.69.6E.43.52.4C.4E.75.6D.62.65.72
        ; 'minCRLNumber'
   id-maxCRLNumber = %x6D.61.78.43.52.4C.4E.75.6D.62.65.72
        ; 'maxCRLNumber'
   id-reasonFlags = %x72.65.61.73.6F.6E.46.6C.61.67.73 ; 'reasonFlags'
   id-dateAndTime = %x64.61.74.65.41.6E.64.54.69.6D.65 ; 'dateAndTime'

   CRLNumber = INTEGER-0-MAX

   ReasonFlags = BIT-STRING
        / "{" [ sp reason-flag *( "," sp reason-flag ) ] sp "}"

   reason-flag = id-unused
        / id-keyCompromise
        / id-cACompromise
        / id-affiliationChanged
        / id-superseded
        / id-cessationOfOperation
        / id-certificateHold
        / id-privilegeWithdrawn
        / id-aACompromise

   id-unused = %x75.6E.75.73.65.64 ; 'unused'
   id-keyCompromise = %x6B.65.79.43.6F.6D.70.72.6F.6D.69.73.65
        ; 'keyCompromise'
   id-cACompromise = %x63.41.43.6F.6D.70.72.6F.6D.69.73.65
        ; 'cACompromise'
   id-affiliationChanged =
        %x61.66.66.69.6C.69.61.74.69.6F.6E.43.68.61.6E.67.65.64
        ; 'affiliationChanged'
   id-superseded = %x73.75.70.65.72.73.65.64.65.64 ; 'superseded'
   id-cessationOfOperation =
        %x63.65.73.73.61.74.69.6F.6E.4F.66.4F.70.65.72.61.74.69.6F.6E
        ; 'cessationOfOperation'
   id-certificateHold = %x63.65.72.74.69.66.69.63.61.74.65.48.6F.6C.64
        ; 'certificateHold'
   id-privilegeWithdrawn =
        %x70.72.69.76.69.6C.65.67.65.57.69.74.68.64.72.61.77.6E
        ; 'privilegeWithdrawn'

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RFC 4523                   LDAP X.509 Schema                   June 2006

   id-aACompromise = %x61.41.43.6F.6D.70.72.6F.6D.69.73.65
        ; 'aACompromise'

A.7.  AlgorithmIdentifier

   AlgorithmIdentifier = "{" sp ai-algorithm
        [ "," sp ai-parameters ] sp "}"

   ai-algorithm = id-algorithm msp OBJECT-IDENTIFIER
   ai-parameters = id-parameters msp Value
   id-algorithm = %x61.6C.67.6F.72.69.74.68.6D ; 'algorithm'
   id-parameters = %x70.61.72.61.6D.65.74.65.72.73 ; 'parameters'

Author's Address

   Kurt D. Zeilenga
   OpenLDAP Foundation

   EMail: Kurt@OpenLDAP.org

Zeilenga                    Standards Track                    [Page 23]
RFC 4523                   LDAP X.509 Schema                   June 2006

Full Copyright Statement

   Copyright (C) The Internet Society (2006).

   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.

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   this document or the extent to which any license under such rights
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   on the procedures with respect to rights in RFC documents can be
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   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
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   this standard.  Please address the information to the IETF at
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Acknowledgement

   Funding for the RFC Editor function is provided by the IETF
   Administrative Support Activity (IASA).

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