Expires in six months 11 February 2005

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 replaces those provided in RFC 2252 and RFC 2256. 1. Background and Intended Use This document provides LDAP [Roadmap] schema definitions [Models] 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 [Roadmap], obsoletes RFC 2252 and RFC 2256 in their entirety. The changes (in this document) made since RFC 2252 and RFC 2256 include: addition of pkiUser, pkiCA, and deltaCRL classes; updated of attribute types to include equality matching rules in accordance with their X.500 specifications; addition of certificate, certificate pair, certificate list, and algorithm identifer 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 [Models]. Definitions provided here are formatted (line wrapped) for readability. Zeilenga draft-zeilenga-ldap-x509-01 [Page 2] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 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 made 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 [Binary]. 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 the 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]. Due to changes made to the definition of a CertificateList made 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 [Binary]. 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 the 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]. Zeilenga draft-zeilenga-ldap-x509-01 [Page 3] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 Due to changes made to the definition of an X.509 CertificatePair made 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 [Binary]. 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 the value, MUST be preserved as presented. 2.4 SupportedAlgorithm ( 1.3.6.1.4.1.1466.115.121.1.49 DESC ’X.508 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 made 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 [Binary]. 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. 2.5. CertificateExactAssertion ( IANA-ASSIGNED-OID.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 GSER [RFC3641]. Appendix A.1 provides an equivalent ABNF [RFC2242] grammar for this syntax. 2.6. CertificateAssertion ( IANA-ASSIGNED-OID.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 [RFC2242] grammar for this syntax. Zeilenga draft-zeilenga-ldap-x509-01 [Page 4] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 2.7. CertificatePairExactAssertion ( IANA-ASSIGNED-OID.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 [RFC2242] grammar for this syntax. 2.8. CertificatePairAssertion ( IANA-ASSIGNED-OID.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 [RFC2242] grammar for this syntax. 2.9. CertificateListExactAssertion ( IANA-ASSIGNED-OID.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. 2.10. CertificateListAssertion ( IANA-ASSIGNED-OID.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 [RFC2242] grammar for this syntax. 2.11 AlgorithmIdentifier ( IANA-ASSIGNED-OID.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]. Zeilenga draft-zeilenga-ldap-x509-01 [Page 5] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 Appendix A.7 provides an equivalent ABNF [RFC2242] 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 IANA-ASSIGNED-OID.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 IANA-ASSIGNED-OID.2 ) 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 IANA-ASSIGNED-OID.3 ) 3.4. certificatePairMatch The certificatePairMatch matching rule compares the presented certificate pair assertion value with an attribute value of the Zeilenga draft-zeilenga-ldap-x509-01 [Page 6] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 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 IANA-ASSIGNED-OID.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 IANA-ASSIGNED-OID.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 IANA-ASSIGNED-OID.6 ) 3.7. algorithmIdentifierMatch The algorithmIdentifierMatch mating rule compares a presented algorithm identifier with an attribute value of 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 IANA-ASSIGNED-OID.7 ) 4. Attribute Types This section details a set of certificate and related attribute types for use in LDAP. 4.1. userCertificate Zeilenga draft-zeilenga-ldap-x509-01 [Page 7] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 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". 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]. Zeilenga draft-zeilenga-ldap-x509-01 [Page 8] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 ( 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". 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 Zeilenga draft-zeilenga-ldap-x509-01 [Page 9] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 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 ) 5.2. pkiCA This object class is used to augment entries for objects which 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 which 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 ) ) Zeilenga draft-zeilenga-ldap-x509-01 [Page 10] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 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 ) 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 which 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 ) Zeilenga draft-zeilenga-ldap-x509-01 [Page 11] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 5.8. certificationAuthority-V2 This object class is used to augment entries for objects which 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 [Roadmap] apply as well. While elements of certificate information are commonly signed, these signatures only protect the integrity of the signed information. In absence of a 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 transit. Hence, it is generally recommended implementations make use of authentication and data integrity services in LDAP [AuthMeth][Protocol]. 7. IANA Considerations 7.1. Object Identifier Registration It is requested that IANA register upon Standards Action an LDAP Object Identifier for use in this technical specification. Subject: Request for LDAP OID Registration Person & email address to contact for further information: Kurt Zeilenga Specification: RFC XXXX Author/Change Controller: IESG Comments: Identifies the LDAP X.509 Certificate schema elements introduced in this document. 7.2. Registration of the descriptor Zeilenga draft-zeilenga-ldap-x509-01 [Page 12] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 It is requested that IANA update upon Standards Action the LDAP Descriptor registry 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 Usage: see table Specification: RFC XXXX Author/Change Controller: IESG algorithmIdentifierMatch R 2.5.13.40 authorityRevocationList A 2.5.4.38 * cACertificate A 2.5.4.37 * cRLDistributionPoint O 2.5.6.19 * certificateExactMatch R 2.5.13.34 certificateListExactMatch R 2.5.13.38 certificateListMatch R 2.5.13.39 certificateMatch R 2.5.13.35 certificatePairExactMatch R 2.5.13.36 certificatePairMatch R 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 * 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. Acknowledgments This document is based upon X.509, a product of the ITU-T. A number of LDAP schema definitions were based on those found RFC 2252 and RFC 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/or Steven Legg to refine LDAP X.509 schema. Zeilenga draft-zeilenga-ldap-x509-01 [Page 13] INTERNET-DRAFT LDAP X.509 Schema 11 February 2005 9. Author’s AddressKurt D. ZeilengaOpenLDAP FoundationEmail: [email protected] 10. References[[Note to the RFC Editor: please replace the citation tags used inreferencing Internet-Drafts with tags of the form RFCnnnn wherepossible.]] 10.1. Normative References[RFC2119] Bradner, S., "