Network Working Group                                           P. Gietz
Internet-Draft                                  DAASI International GmbH
Expires: September 4, 2003                                     N. Klasen
                                                                  Avinci
                                                           March 3, 2003


                An LDAPv3 Schema for X.509 Certificates
              draft-klasen-ldap-x509certificate-schema-02

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at http://
   www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on May 4, 2003.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document describes an LDAP schema which can be used to implement
   a certificate store for X.509 certificates.  Specifically, a
   structural object class for a X.509 certificate is defined.  Key
   fields of a certificate are stored in LDAP attributes so that
   applications can easily retrieve the certificates needed by using
   basic LDAP search filters.  Multiple certificates for a single entity
   can be stored and retrieved.

Conventions used in this document




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   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 [RFC2119].

   The following syntax specifications use the augmented Backus-Naur
   Form (ABNF) as described in [RFC2234].

   Schema definitions are provided using LDAPv3 description formats
   [RFC2252].  Definitions provided here are formatted (line wrapped)
   for readability.

Table of Contents

   1.      Introduction . . . . . . . . . . . . . . . . . . . . . . .  5
   2.      Comparison with Values Return Filter Control . . . . . . .  5
   3.      Comparision with component matching approach . . . . . . .  6
   4.      The x509certificate object class and its attribute types .  6
   4.1     Attributes for mandatory fields of an X.509 certificate  .  7
   4.1.1   X.509 version  . . . . . . . . . . . . . . . . . . . . . .  7
   4.1.2   Serial number  . . . . . . . . . . . . . . . . . . . . . .  7
   4.1.3   Signature algorithm  . . . . . . . . . . . . . . . . . . .  7
   4.1.4   Issuer . . . . . . . . . . . . . . . . . . . . . . . . . .  8
   4.1.5   Validity . . . . . . . . . . . . . . . . . . . . . . . . .  8
   4.1.6   Subject  . . . . . . . . . . . . . . . . . . . . . . . . .  8
   4.1.7   Subject public key info algorithm  . . . . . . . . . . . .  9
   4.2     Attributes for selected extensions . . . . . . . . . . . .  9
   4.2.1   Authority key identifier extension . . . . . . . . . . . . 10
   4.2.1.1 Authority key identifier . . . . . . . . . . . . . . . . . 10
   4.2.1.2 Authority cert issuer  . . . . . . . . . . . . . . . . . . 10
   4.2.1.3 Authority cert serial number . . . . . . . . . . . . . . . 11
   4.2.2   Subject key identifier extension . . . . . . . . . . . . . 11
   4.2.3   Key usage extension  . . . . . . . . . . . . . . . . . . . 11
   4.2.4   Policy information identifier extension  . . . . . . . . . 12
   4.2.5   Subject alternative name extension . . . . . . . . . . . . 12
   4.2.5.1 Subject RFC822 name  . . . . . . . . . . . . . . . . . . . 12
   4.2.5.2 Subject DNS name . . . . . . . . . . . . . . . . . . . . . 13
   4.2.5.3 Subject directory name . . . . . . . . . . . . . . . . . . 13
   4.2.5.4 Subject Uniform Resource Identifier  . . . . . . . . . . . 13
   4.2.5.5 Subject IP address . . . . . . . . . . . . . . . . . . . . 14
   4.2.5.6 Subject registered ID  . . . . . . . . . . . . . . . . . . 14
   4.2.6   Isssuer alternatvie name extension . . . . . . . . . . . . 14
   4.2.6.1 Issuer RFC 822 name  . . . . . . . . . . . . . . . . . . . 14
   4.2.6.2 Issuer DNS name  . . . . . . . . . . . . . . . . . . . . . 15
   4.2.6.3 Issuer directory name  . . . . . . . . . . . . . . . . . . 15
   4.2.6.4 Issuer Uniform Resource Identifier . . . . . . . . . . . . 15
   4.2.6.5 Issuer IP address  . . . . . . . . . . . . . . . . . . . . 16
   4.2.6.6 Issuer registered ID . . . . . . . . . . . . . . . . . . . 16
   4.2.7   Extended key usage extension . . . . . . . . . . . . . . . 16



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   4.2.8   CRL distribution points extension  . . . . . . . . . . . . 16
   4.3     Additional attributes  . . . . . . . . . . . . . . . . . . 17
   4.3.1   Certificate location . . . . . . . . . . . . . . . . . . . 17
   4.3.2   Certificate holder . . . . . . . . . . . . . . . . . . . . 17
   4.3.3   Email addresses  . . . . . . . . . . . . . . . . . . . . . 17
   4.4     x509certificate object class . . . . . . . . . . . . . . . 18
   4.5     x509certificateHolder object class . . . . . . . . . . . . 19
   5.      DIT Structure and Naming . . . . . . . . . . . . . . . . . 19
   6.      Security Considerations  . . . . . . . . . . . . . . . . . 20
   7.      Acknowledgements . . . . . . . . . . . . . . . . . . . . . 21
           References . . . . . . . . . . . . . . . . . . . . . . . . 21
           Authors' Addresses . . . . . . . . . . . . . . . . . . . . 23
   A.      Sample directory entries . . . . . . . . . . . . . . . . . 23
   B.      Sample searches  . . . . . . . . . . . . . . . . . . . . . 26
   C.      Changes from previous Drafts . . . . . . . . . . . . . . . 26
   C.1     Changes in Draft 01  . . . . . . . . . . . . . . . . . . . 26
           Full Copyright Statement . . . . . . . . . . . . . . . . . 28


































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1. Introduction

   A key component in the wide-spread adoption of a PKI infrastructure
   is the general availabilty of public key and their certificates.
   Today, certificates are often published in an X.500 compliant
   directory service.  These directories are accessed by applications
   using the LDAP v3 [RFC3377] protocol.  An LDAPv3 schema for PKI
   repository objects is specified in [pkix-ldap-schema], where a set of
   object classes, attribute types, syntaxes, and extended matching
   rules are defined.  For storing certificates, the "userCertificate"
   and "cACertificate" attribute types are used.  All certificates of an
   entity are stored as values in these multi-valued attributes.  This
   solution has a serious drawback.  In LDAP, the smallest granularity
   of data access is the attribute.  The directory server will therefore
   always return the full list of certificates of an entry to clients
   dealing with certificates.  If the number of certificates for an
   entity is large this will result in considerable overhead and burden
   to the client.

   This document proposes to solve this problem by the use of the
   structural object classes x509userCertificate and x509caCertificate
   for storing certificates.  Each certificate will be stored in a
   separate entry in the directory.  Fields of certificates which are
   needed to identify a certificate and those which are often used in
   searching for an appropriate certificate, are extracted from
   the certificate and stored as attributes of the entry.  Applications
   can thus search for specific certificates with simple LDAP filters.
   This approach could be named a metadata approach, since data
   (attributes) about data (certificate) are stored.  The use of simple
   attributes also makes a large scale widely distributed certificate
   repository service possible by using an indexing service based on The
   Common Indexing Protocol (CIP) [RFC2651].

This document is one of a set following this approach comprising:
i)  the LDAP schema for X.509 public key certificates (this document)
ii)  the LDAP schema for X.509 attribute certificates [ldap-ac-schema]
iii)  the LDAP schema for X.509 CRLs [ldap-crl-schema]

   Two alternative approaches are discussed in the next two sections.

2. Comparison with Values Return Filter Control

   In [matchedval] a control has been defined that allows for only a
   subset of values of a specified attribute to be returned from a
   matching entry, by defining a filter for the returned values.  In
   this section, this approach is compared with the one proposed in this
   document.

   The major benefit of the Values Return Filter Control is that it does
   not require any changes to the DIT.  While it is a simple matter to
   modify the DIT in such a way that all certificate information is
   removed from the entries and placed in the container directly beneath
   the entries according to the definitions of this specification, it is
   less simple to simultaneously modify all of the applications that



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   depend on certificates being stored in the entry.  Thus, it may be
   desirable to duplicate the certificate information, by having it
   appear in the entry, as well as in the container beneath the entry
   for a short period of time, in order to allow for migration of the
   applications to the new LDAP schema.  As in any situation in which
   information is duplicated, great care must be taken in order to
   ensure the integrity of the information.

   There are several advantages in using the x509certificate object
   class.  No special matching rules are needed to retrieve a specific
   certificate.  Any field in the certificate can be used in the search
   filter.  Even information that doesn't appear in the certificate can
   be used in a search filter.  It is easier to remove certificates from
   the DIT, since the entire certificate BER/DER encoding does not have
   to be supplied in the modify operation.  Searches that don't need
   extensible matching rules and Values Return Filter Control will
   perform faster.

   Another advantage of the solution proposed here is that it will not
   be necessary to modify existing server implementations to support
   this schema.  The extended matching rules proposed in [pkix-ldap-
   schema] would require substantial changes in the servers' indexing
   mechanisms.  In contrast, servers implementing the x509certificate
   schema can easily levarage their indexing support for standard LDAPv3
   syntaxes.

   A CIP based indexing system for a wide scale distributed certificate
   repository will only be possible by using the solution proposed here.

3. Comparision with component matching approach

   [componentmatch] defines a new mechanism for matching in complex
   syntaxes, by defining generic matching rules that can match any user
   selected component parts in an attribute value of any arbitrarily
   complex attribute syntax.  We believe that this might be the proper
   way to solve search problems in the longer term, but that it will
   take a long time untill such ASN.1 based mechanisms will be
   implemented in LDAP servers and clients.  Even if this has happened
   the mechanism proposed here, will still be usefull in the frame of
   CIP.  A simple and easy to implement mechanism is needed today and
   this is what this memo wants to provide.

4. The x509certificate object class and its attribute types

   The description of all attributes with relevance to fields of an
   X.509 certificate include a respective reference to [X.509-2000] and
   to [RFC3280].




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4.1 Attributes for mandatory fields of an X.509 certificate

4.1.1 X.509 version

   X.509 Version of the encoded certificate (See X.509(2000) 7,
   RFC3280 4.1.2.1.) or of the CRL.

   ( 1.3.6.1.4.1.10126.1.5.3.1
           NAME 'x509version'
           DESC 'X.509 Version of the certificate, or of the CRL'
           EQUALITY integerMatch
           ORDERING integerOrderingMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
           SINGLE-VALUE )

   Values of this attribute may either be 0, 1, or 2 correspoding to
   X.509 v1, v2 or v3.

4.1.2 Serial number

   The serial number is an integer assigned by the CA to each
   certificate.  It is unique for each certificate issued by a given CA
   (i.e., the issuer name and serial number uniquely identify a
   certificate). See X.509(2000) 7, RFC3280 4.1.2.2

   ( 1.3.6.1.4.1.10126.1.5.3.2
     NAME 'x509serialNumber'
     DESC 'Unique integer for each cerfiticate issued by a
           particular CA'
     EQUALITY integerMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )


4.1.3 Signature algorithm

   OID identifying the algorithm used by the CA in signing the
   certificate (See X.509(2000) 7, RFC3280 4.1.2.3) or the CRL.

   ( 1.3.6.1.4.1.10126.1.5.3.3
     NAME 'x509signatureAlgorithm'
     DESC 'OID of the algorithm used by the CA in signing
           the CRL or the certificate'
     EQUALITY objectIdentifierMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.38
     SINGLE-VALUE )





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4.1.4 Issuer

   String representation of the issuer's distinguished name.
   See X.509(2000) 7, RFC3280 4.1.2.4

   ( 1.3.6.1.4.1.10126.1.5.3.4
     NAME 'x509issuer'
     DESC 'Distinguished name of the entity who has signed and
           issued the certificate or CRL'
     EQUALITY distinguishedNameMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
     SINGLE-VALUE )

   Values of this attribute type must be encoded according to the syntax
   given in [RFC2253].

4.1.5 Validity

   The "validity" attribute in an X.509 certificate (see X.509(2000) 7,
   RFC3280 4.1.2.5) consists of an ASN.1 sequence of two
   timestamps which define the begin and end of the certificate's
   validity period.  This sequence has been split up into two separate
   attributes "x509validityNotBefore" and "x509validityNotAfter".
   The times are represented in string form as defined in [RFC2252].

   ( 1.3.6.1.4.1.10126.1.5.3.5
     NAME 'x509validityNotBefore'
     DESC 'Date on which the certificate validity period begins'
     EQUALITY generalizedTimeMatch
     ORDERING generalizedTimeOrderingMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
     SINGLE-VALUE )


   ( 1.3.6.1.4.1.10126.1.5.3.6
     NAME 'x509validityNotAfter'
     DESC 'Date on which the certificate validity period ends,
           X.509(2000) 7, RFC3280 4.1.2.5'
     EQUALITY generalizedTimeMatch

     ORDERING generalizedTimeOrderingMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
     SINGLE-VALUE )

Note that the field in the certificate may be in UTC or GeneralizedTime format. If in UTC format, the creator of this attribute MUST convert the UTC time into GeneralisedTime format when creating the attribute value.

4.1.6 Subject

   String representation of the subject's distinguished name.




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   ( 1.3.6.1.4.1.10126.1.5.3.7
     NAME 'x509subject'
     DESC 'Distinguished name of the entity associated with this
           public-key, X.509(2000) 7, RFC3280 4.1.2.6'
     EQUALITY distinguishedNameMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
     SINGLE-VALUE )

   Values of this attribute type must be encoded according to the syntax
   given in [RFC2253].

4.1.7 Subject public key info algorithm

   OID of the algorithm of which the certified public key is an instance
   of.

   ( 1.3.6.1.4.1.10126.1.5.3.8
     NAME 'x509subjectPublicKeyInfoAlgorithm'
     DESC 'OID of the algorithm which this public key is an
           instance of, X.509(2000) 7, RFC3280 4.1.2.7'
     EQUALITY objectIdentifierMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.38
     SINGLE-VALUE )


4.2 Attributes for selected extensions

   As this specification intends to only facilitate applications in
   finding certificates, only those extensions have to be defined that
   might be searched for.  Thus extensions described in [RFC3280] like
   the following are not dealt with here:

   o  private key usage period extension

   o  policy mappings extension

   o  subject directory attributes extension

   o  pathLenConstraint of basic constraints extension

   o  name constraints extensions

   o  policy constraints extensions

   o  inhibit any policy extension

   o  freshest CRL extension




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   o  authority information access extension

   o  subject information access extension


4.2.1 Authority key identifier extension

   This attribute identifies the public key to be used to verify the
   signature on this certificate or CRL.  The key may be identified by
   an explicit key identifier in the keyIdentifier component, by
   identification of a certificate for the key (giving certificate
   issuer in the authorityCertIssuer component and certificate serial
   number in the authorityCertSerialNumber component), or by both
   explicit key identifier and identification of a certificate for the
   key.

4.2.1.1 Authority key identifier

   ( 1.3.6.1.4.1.10126.1.5.3.11
     NAME 'x509authorityKeyIdentifier'
     DESC 'keyIdentifier field of the authorityKeyIdentifier
           extension, X.509(2000) 8.2.2.1, RFC3280 4.2.1.1'
     EQUALITY octetStringMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.40
     SINGLE-VALUE )


4.2.1.2 Authority cert issuer

   ( 1.3.6.1.4.1.10126.1.5.3.12
     NAME 'x509authorityCertIssuer'
     DESC 'authorityCertIssuer field of the authorityKeyIdentifier
           extension, X.509(2000) 8.2.2.1, RFC3280 4.2.1.1'
     EQUALITY distinguishedNameMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
     SINGLE-VALUE )

   In this specification, only the "Name" choice,  encoded according to
   [RFC2253], of the "GeneralName" type may be used.












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4.2.1.3 Authority cert serial number

   ( 1.3.6.1.4.1.10126.1.5.3.13
     NAME 'x509authorityCertSerialNumber'
     DESC 'authorityCertSerialNumber field of the
           authorityKeyIdentifier extension, X.509(2000) 8.2.2.1,
           RFC3280 4.2.1.1'
     EQUALITY integerMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
     SINGLE-VALUE )


4.2.2 Subject key identifier extension

   This attribute identifies the public key being certified.  It enables
   distinct keys used by the same subject to be differentiated.

   ( 1.3.6.1.4.1.10126.1.5.3.14
     NAME 'x509subjectKeyIdentifier'
     DESC 'Key identifier which must be unique with respect to all
           key identifiers for the subject, X.509(2000) 8.2.2.2,
           RFC3280 4.2.1.2'
     EQUALITY octetStringMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.40
     SINGLE-VALUE )


4.2.3 Key usage extension

   This attribute defines the purpose (e.g., encipherment, signature,
   certificate signing) of the key contained in the certificate.

   ( 1.3.6.1.4.1.10126.1.5.3.15
     NAME 'x509keyUsage'
     DESC 'Purpose for which the certified public key is used,
           X.509(2000) 8.2.2.3, RFC3280 4.2.1.3'
     EQUALITY caseIgnoreMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )

   Values of this type are encoded according to the following BNF, so
   that each value corresponds to the respective bit in the ASN.1
   "KeyUsage" bitstring:

   x509keyUsage-value ="digitalSignature" / "nonRepudiation" /
     "keyEncipherment" / "dataEncipherment" / "keyAgreement" /
     "keyCertSign" / "cRLSign" / "encipherOnly" / "decipherOnly"





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4.2.4 Policy information identifier extension

   This attribute contains OIDs which indicate the policy under which
   the certificate has been issued and the purposes for which the
   certificate may be used.

   ( 1.3.6.1.4.1.10126.1.5.3.16
     NAME 'x509policyInformationIdentifier'
     DESC 'OID which indicates the policy under which the
           certificate has been issued and the purposes for which
           the certificate may be used, X.509(2000) 8.2.2.6, RFC3280
           4.2.1.5'
     EQUALITY objectIdentifierMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.38
     SINGLE-VALUE )


4.2.5 Subject alternative name extension

   The subject alternative name extension allows additional identities
   to be bound to the subject of the certificate.  Separate attribute
   types are defined for all c hoices of the ASN.1 type "GeneralName"
   except for "otherName", "x400Address" and "ediPartyName".

4.2.5.1 Subject RFC822 name

   ( 1.3.6.1.4.1.10126.1.5.3.17
     NAME 'x509subjectAltNameRfc822Name'
     DESC 'Internet electronic mail address, X.509(2000) 8.3.2.1,
           RFC3280 4.2.1.7'
     EQUALITY caseIgnoreMatch
     SUBSTR caseIgnoreSubstringsMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )

   Values of this attribute must be encoded according to the syntax
   given in [RFC0822].















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4.2.5.2 Subject DNS name

   ( 1.3.6.1.4.1.10126.1.5.3.18
     NAME 'x509subjectDnsName'
     DESC 'Internet domain name, X.509(2000) 8.3.2.1, RFC3280
           4.2.1.7'
     EQUALITY caseIgnoreMatch
     SUBSTR caseIgnoreSubstringsMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )

   Values of this attribute must be encoded as Internet domain names in
   accordance with [RFC1035].

4.2.5.3 Subject directory name

   ( 1.3.6.1.4.1.10126.1.5.3.19
     NAME 'x509subjectDirectoryName'
     DESC 'Distinguished name, X.509(2000) 8.3.2.1, RFC3280
           4.2.1.7'
     EQUALITY distinguishedNameMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 )

   Values of this attribute type must be encoded according to the syntax
   given in [RFC2253].

4.2.5.4 Subject Uniform Resource Identifier

   ( 1.3.6.1.4.1.10126.1.5.3.20
     NAME  'x509subjectUniformResourceIdentifier'
     DESC 'Uniform Resource Identifier for the World-Wide Web,
           X.509(2000) 8.3.2.1, RFC3280 4.2.1.7'
     EQUALITY caseExactMatch
     SUBSTR caseExactSubstringsMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )

   Values of this attribute must be encoded according to the syntax
   given in [RFC2396].














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4.2.5.5 Subject IP address

   ( 1.3.6.1.4.1.10126.1.5.3.21
     NAME 'x509subjectIpAddress'
     DESC 'Internet Protocol address, X.509(2000) 8.3.2.1, RFC3280
           4.2.1.7'
     EQUALITY caseIgnoreMatch
     SUBSTR caseIgnoreSubstringsMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )

   Values of this attribute type must be stored in the syntax given in
   Appendix B of [RFC2373].

4.2.5.6 Subject registered ID

   ( 1.3.6.1.4.1.10126.1.5.3.22
     NAME 'x509subjectRegisteredID'
     DESC 'OID of any registered object, X.509(2000) 8.3.2.1,
           RFC3280 4.2.1.7'
     EQUALITY objectIdentifierMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 )

   registeredID is an identifier of any registered object assigned in
   accordance with ITU-T Rec.  X.660.

4.2.6 Issuer alternative name extension

   The issuer alternative names extension allows additional identities
   to be bound to the issuer of the certificate or CRL.  Separate attribute
   types are defined for all choices of the ASN.1 type "GeneralName"
   except for "otherName", "x400Address" and "ediPartyName".

4.2.6.1 Issuer RFC 822 name

   ( 1.3.6.1.4.1.10126.1.5.3.23
     NAME 'x509issuerRfc822Name'
     DESC 'Internet electronic mail address, X.509(2000) 8.3.2.2,
           RFC3280 4.2.1.8'
     EQUALITY caseIgnoreMatch
     SUBSTR caseIgnoreSubstringsMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )

   Values of this attribute must be encoded according to the syntax
   given in [RFC0822].







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4.2.6.2 Issuer DNS name

   ( 1.3.6.1.4.1.10126.1.5.3.24
     NAME 'x509issuerDnsName'
     DESC 'Internet domain name, X.509(2000) 8.3.2.2, RFC3280
           4.2.1.8'
     EQUALITY caseIgnoreMatch
     SUBSTR caseIgnoreSubstringsMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )

   Values of this attribute must be encoded as Internet domain names in
   accordance with [RFC1035].

4.2.6.3 Issuer directory name

   ( 1.3.6.1.4.1.10126.1.5.3.25
     NAME 'x509issuerDirectoryName'
     DESC 'Distinguished name, X.509(2000) 8.3.2.2, RFC3280
           4.2.1.8'
     EQUALITY distinguishedNameMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 )

   Values of this attribute type must be encoded according to the syntax
   given in [RFC2253].

4.2.6.4 Issuer Uniform Resource Identifier

   ( 1.3.6.1.4.1.10126.1.5.3.26
     NAME  'x509issuerUniformResourceIdentifier'
     DESC 'Uniform Resource Identifier for the World-Wide Web,
           X.509(2000) 8.3.2.2, RFC3280 4.2.1.8'
     EQUALITY caseExactMatch
     SUBSTR caseExactSubstringsMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )

   Values of this attribute must be encoded according to the syntax
   given in [RFC2396].














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4.2.6.5 Issuer IP address

   ( 1.3.6.1.4.1.10126.1.5.3.27
     NAME 'x509issuerIpAddress'
     DESC 'Internet Protocol address, X.509(2000) 8.3.2.2, RFC3280
           4.2.1.8'
     EQUALITY caseIgnoreMatch
     SUBSTR caseIgnoreSubstringsMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )

   Values of this attribute type must be stored in the syntax given in
   Appendix B of [RFC2373].

4.2.6.6 Issuer registered ID

   ( 1.3.6.1.4.1.10126.1.5.3.28
     NAME 'x509issuerRegisteredID'
     DESC 'OID of any registered object, X.509(2000) 8.3.2.2,
           RFC3280 4.2.1.8'
     EQUALITY objectIdentifierMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 )

   registeredID is an identifier of any registered object assigned in
   accordance with ITU-T Rec.  X.660.

4.2.7 Extended key usage extension

   This attribute indicates one or more purposes for which the certified
   public key may be used, in addition to or in place of the basic
   purposes indicated in the "x509keyUsage" attribute.  These purposes
   are identified by their OID.

   ( 1.3.6.1.4.1.10126.1.5.3.30
     NAME 'x509extKeyUsage'
     DESC 'Purposes for which the certified public key may be used
           (identified by OID), X.509(2000) 8.2.2.4, RFC3280
           4.2.1.13'
     EQUALITY objectIdentifierMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 )


4.2.8 CRL distribution points extension

   This attribute identifies how CRL information for this certifacte can
   be obtained.






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   ( 1.3.6.1.4.1.10126.1.5.3.31
     NAME 'x509cRLDistributionPointURI'
     DESC 'DistributionPointName of type URI, X.509(2000) 8.6.2.1,
       RFC3280 4.2.1.14'
     EQUALITY caseExactMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )

   In this specification, only the "uniformResourceIdentifier" choice of
   "distributionPoint.fullName" field is supported.  If this attribute
   exists in an entry, both the "reasons" and "cRLIssuer" fields MUST be
   absent from the certificate, i.e.  the CRL distributed by the
   distribution point contains revocations for all revocation reasons
   and the CRL issuer is identical to the certificate issuer.

   Values of this attribute must be encoded according to the URI syntax
   given in [RFC2396].


4.3 Additional attributes

4.3.1 Certificate location


    This attribute contains a pointer to the directory entry of
    a certificate. Thus it is possible to point to the certificate from
    an, e.g., white pages entry.

   (1.3.6.1.4.1.10126.1.5.4.74
     NAME 'x509certLocation'
     DESC 'Pointer to a x509certificate Entry'
     EQUALITY distinguishedNameMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 )



4.3.2 Certificate holder

   This attribute contains a pointer to the directory entry of the end
   entity to which this certificate was issued.  Thus it is possible to
   link a certificate entry in a certificate repository to, e.g., a
   white pages entry of the subject.

   ( 1.3.6.1.4.1.10126.1.5.4.75
     NAME 'x509certHolder'
     DESC 'Pointer to the directory entry of the end entity to which this
           certificate was issued'
     EQUALITY distinguishedNameMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 )


4.3.3 Email addresses

   The "mail" (0.9.2342.19200300.100.1.3) attribute from [RFC2798] is
   used to store the subject's email address.  This attribute MUST be
   populated with the values from a subject alternative name extension



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   of type rfc822Name if such an extension is present.  Legacy
   applications conforming to [RFC2312] include an "EmailAddress"
   (1.2.840.113549.1.9.1) attribute in the subject's distinguished name.
   If the subject alternative name extension is absent from the
   certificate, this value MUST be used to populate the "mail"
   attribute.

4.3.4. X.509 User Certificate
   This attribute is used to store the complete certificate. Since it has to be
   single valued the multi valued attribute userCertificate [pkix-ldap-schema]
   cannot be used.

   ( 1.3.6.1.4.1.10126.1.5.4.76
     NAME 'x509userCert'
     DESC 'the complete x.509 user certificate'
     EQUALITY certificateExactMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.8
     SINGLE-VALUE )

4.3.4. X.509 CA Certificate
   This attribute is used to store the complete ca certificate. Since it has
   to be single valued the multi valued attribute caCertificate
   [pkix-ldap-schema] cannot be used.

   ( 1.3.6.1.4.1.10126.1.5.4.77
     NAME 'x509caCert'
     DESC 'the complete x.509 CA certificate'
     EQUALITY certificateExactMatch
     SYNTAX 1.3.6.1.4.1.1466.115.121.1.8
     SINGLE-VALUE )

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4.4 x509PKC object class

   This abstract object class contains the fields of an X.509
   user certificate or CA certificate that are used in searches
   as attributes. It is derived from the abstract objectclass x.509base as
   specified in [ldap-crl-schema] and is base for the two following object
   classes.

   ( 1.3.6.1.4.1.10126.1.5.4.2.3
     NAME 'x509PKC'
     ABSTRACT
     SUP x509base
     MUST ( x509serialNumber $ x509validityNotBefore $
        x509validityNotAfter $ x509subjectPublicKeyInfoAlgorithm )
     MAY  ( mail $ x509authorityKeyIdentifier $
        x509authorityCertIssuer $ x509authorityCertSerialNumber $
        x509subjectKeyIdentifier $ x509keyUsage $
        x509policyInformationIdentifier $
        x509subjectRfc822Name $ x509subjectDnsName $
        x509subjectDirectoryName $ x509subjectURI $
        x509subjectIpAddress $
        x509subjectRegisteredID $
        x509isssuerRfc822Name $ x509isssuerDnsName $
        x509isssuerDirectoryName $ x509isssuerURI $
        x509isssuerIpAddress $
        x509isssuerRegisteredID $
        x509extKeyUsage $
        x509cRLDistributionPoint $ x509certHolder) )

4.4.1. X.509 user Certificate object class

This object class is for storing user certificates.

   ( 1.3.6.1.4.1.10126.1.5.4.2.4
     NAME 'x509userCertificate'
     SUP x509PKC
     MUST x509userCert
     MAY x509subject )

4.4.2. X.509 CA Certificate object class

This object class is for storing CA certificates.

   ( 1.3.6.1.4.1.10126.1.5.4.2.5
     NAME 'x509caCertificate'
     SUP x509PKC
     MUST ( x509caCert $ x509subject ) )


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4.5 x509certificateHolder object class

   This auxiliary object class has an attribute that contains a pointer
   on an entry with x509certicate objectclass.  Thus it is possible to
   link, e.g., an entry of a white pages directory to an entry in a
   certificate store.

   ( 1.3.6.1.4.1.10126.1.5.4.2.2
     NAME 'x509certificateHolder'
     AUXILIARY
     MAY  ( x509certificateLocation ) )


5. DIT Structure and Naming

   If the schema presented in this document is used to store certificate
   information in a directory that contains entries for organizations,
   persons, services, etc., each certificate belonging to an entity
   SHOULD be stored as a direct subordinate to the entity's entry.  In
   this case, these entries MUST be named by a multi-valued RDN formed
   by the certificate issuer and serial number, as this is the only way
   to enforce unique RDN under the siblings.  This is expressed in the
   following name form:

   ---------------------------------------------------------------------


   ( 1.3.6.1.4.1.10126.1.5.5.3
     NAME "x509PKCNameForm"
     OC x509PKC
     MUST ( x509serialNumber $ x509issuer ) )

                         certificate name form

   ---------------------------------------------------------------------

   There are some LDAP implementations that don't support multi-valued RDNs
   These can use following alternative Name Form:

   ( 1.3.6.1.4.1.10126.1.5.5.4
     NAME "x509PKCAltNameForm"
     OC x509PKC
     MUST x509issuerSerial )

The attribute dewscription of x509issuerSerial can be found in [ldap-ac-schema].



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   For public directories of CAs that, besides the data stored in the
   certificates, do not hold any additional data about end entities the
   folloing DIT structure might be preferable.  Entries for certificates
   are stored directly below the issuing CA's entry.  In this case these
   entries SHOULD be named by the certificate serial number.  This is
   expressed in the following name form:


   ---------------------------------------------------------------------



   ( 1.3.6.1.4.1.10126.1.5.5.5
     NAME "x509PKCserialNumberNameForm"
     OC x509PKC
     MUST x509serialNumber )

                    certificate serial number name form

   ---------------------------------------------------------------------

   Care must be taken when encoding DNs that contain an x509issuer
   attribute.  Such a value is a string representation according to
   [RFC2253].  These strings contain RFC2253 special characters and must
   therefore be escaped.  For example, the issuer name in a certificate
   may be:

   x509issuer: OU=VeriSign Trust Network,OU=(c) 1998 VeriSign\2c Inc. -
     For authorized use only,OU=Class 1 Public Primary Certification Au
     thority - G2,O=VeriSign\2c Inc.,C=US

   When used in a DN, this will be appear as:

   dn: x509serialNumber=123456+x509issuer=OU\3dVeriSign Trust Network
    \2cOU\3d(c) 1998 VeriSign\5c\2c Inc. - For authorized use only\2cOU\3d
    Class 1 Public Primary Certification Authority - G2\2cO\3dVeriSig
    n\5c\2c Inc.\2cC\3dUS,cn=Joe Example,...


6. Security Considerations

   Attributes of directory entries are used to provide descriptive
   information about the real-world objects they represent which can be
   people, organizations, or devices.  Most countries have privacy laws
   regarding the publication of information about people.

   Without additional mechanisms such as Operation Signatures [RFC2649]
   which allow a client to verify the origin and integrity of the data
   contained in the attributes defined in this document, a client MUST
   NOT treat this data as authentic.  Clients MUST only use - after
   proper validation - the data which they obtained directly from the
   certificate.  Directory administrators MAY deploy ACLs which limit
   access to the attributes defined in this document to search filters.

   Transfer of cleartext passwords is strongly discouraged where the
   underlying transport service cannot guarantee confidentiality and may
   result in disclosure of the password to unauthorized parties.


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   In order to protect the directory and its contents, strong
   authentication MUST have been used to identify the Client when an
   update operation is requested.

7. Acknowledgements

   This document borrows from a number of IETF documents, including
   [certinfo-schema].

   The authors wish to thank Michael StrĂ·der and David Chadwick for
   their significant contributions to this document.

   This work is part of the DFN Project "Ausbau und Weiterbetrieb eines
   Directory Kompetenzzentrums" funded by the German Ministry of
   Research (BMBF).

   This document has been written in XML according to the DTD specified
   in RFC2629.  xml2rfc has been used to generate an RFC2033 compliant
   plain text form.  The XML source and a HTML version are available on
   request.

References

   [RFC0822]           Crocker, D., "Standard for the format of ARPA
                       Internet text messages", STD 11, RFC 822, August
                       1982.

   [RFC1035]           Mockapetris, P., "Domain names - implementation
                       and specification", STD 13, RFC 1035, November
                       1987.

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

   [RFC2234]           Crocker, D. and P. Overell, "Augmented BNF for
                       Syntax Specifications: ABNF", RFC 2234, November
                       1997.

   [RFC2252]           Wahl, M., Coulbeck, A., Howes, T. and S. Kille,
                       "Lightweight Directory Access Protocol (v3):
                       Attribute Syntax Definitions", RFC 2252, December
                       1997.

   [RFC2253]           Wahl, M., Kille, S. and T. Howes, "Lightweight
                       Directory Access Protocol (v3): UTF-8 String
                       Representation of Distinguished Names", RFC 2253,
                       December 1997.

   [RFC2256]           Wahl, M., "A Summary of the X.500(96) User Schema
                       for use with LDAPv3", RFC 2256, December 1997.

   [RFC2312]           Dusse, S., Hoffman, P., Ramsdell, B. and J.
                       Weinstein, "S/MIME Version 2 Certificate
                       Handling", RFC 2312, March 1998.


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   [RFC2373]           Hinden, R. and S. Deering, "IP Version 6
                       Addressing Architecture", RFC 2373, July 1998.

   [RFC2396]           Berners-Lee, T., Fielding, R. and L. Masinter,
                       "Uniform Resource Identifiers (URI): Generic
                       Syntax", RFC 2396, August 1998.

   [RFC2649]           Greenblatt, B. and P. Richard, "An LDAP Control
                       and Schema for Holding Operation Signatures", RFC
                       2649, August 1999.

   [RFC2651]           Allen, J. and M. Mealling, "The Architecture of
                       the Common Indexing Protocol (CIP)", RFC 2651,
                       August 1999.

   [RFC2798]           Smith, M., "Definition of the inetOrgPerson LDAP
                       Object Class", RFC 2798, April 2000.

   [RFC3280]           Housley, R., Polk, T., Ford, W. and D. Solo,
                       "Internet X.509 Public Key Infrastructure
                       Certificate and CRL Profile", RFC 3280, April
                       2002.

   [RFC3377]           Hodges, J. and RL. Morgan, "Lightweight Directory
                       Access Protocol (v3):  Technical Specification",
                       RFC 3377, September 2002.

   [X.509-2000]        ITU, "Information  Technology - Open Systems
                       Interconnection - The  Directory: Public-key and
                       attribute certificate frameworks", ITU-T
                       Recommendation   X.509, March 2000.

   [certinfo-schema]   Greenblatt, B., "LDAP Object Class for Holding
                       Certificate Information", Internet Draft (work in
                       progress), Februar 2000, <http://
                       www.watersprings.org/pub/id/draft-greenblatt-
                       ldap-certinfo-schema-02.txt>.

   [componentmatch]    Legg, S., "LDAP & X.500 Component Matching
                       Rules", Internet Draft (work in progress),
                       October 2002, <draft-legg-ldapext-component-
                       matching-09.txt>.

   [matchedval]        Chadwick, D. and S. Mullan, "Returning Matched
                       Values with LDAPv3", Internet Draft (work in
                       progress), June 2002, <draft-ietf-ldapext-
                       matchedval-06.txt>.

   [pkix-ldap-schema]  Chadwick, D. and S. Legg, "Internet X.509 Public
                       Key Infrastructure - LDAP Schema and Syntaxes for
                       PKIs", Internet Draft (work in progress), June
                       2002, <draft-ietf-pkix-ldap-pki-schema-00.txt>.


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   [ldap-ac-schema]    Chadwick, D. W. and M. V. Sahalayev, "Internet X.509
                       Public Key Infrastructure - LDAP Schema for X.509
                       Attribute Certificates, Internet Draft (work in
                       progress), February 2003, <draft-ietf-pkix-ldap-ac-
                       schema-00.txt>.

   [ldap-crl-schema]   Chadwick, D. W. and M. V. Sahalayev, "Internet X.509
                       Public Key Infrastructure - LDAP Schema for X.509
                       CRLs, Internet Draft (work in progress), February 2003,
                       <draft-ietf-pkix-ldap-crl-schema-00.txt>.


Authors' Addresses

   Peter Gietz
   DAASI International GmbH
   Wilhelmstr. 106
   Tuebingen  72074
   DE

   Phone: +49 7071 29 70336
   EMail: peter.gietz@daasi.de
   URI:   http://www.daasi.de/


   Norbert Klasen
   Avinci
   Halskestr. 38
   Ratingen  40880
   DE

   EMail: norbert.klasen@daasi.de

Appendix A. Sample directory entries

   A sample x509certificate directory entry for an intermediate CA
   certificate in LDIF format:

   dn: x509serialNumber=4903272,EMAILADDRESS=certify@pca.dfn.de,CN=DFN T
    oplevel Certification Authority,OU=DFN-PCA,OU=DFN-CERT GmbH,O=Deutsc
    hes Forschungsnetz,C=DE
   objectclass: x509certificate
   x509version: 2
   x509serialNumber: 4903272
   x509issuer: EMAILADDRESS=certify@pca.dfn.de,CN=DFN Toplevel Certifica
    tion Authority,OU=DFN-PCA,OU=DFN-CERT GmbH,O=Deutsches Forschungsnet
    z,C=DE
   x509validityNotBefore: 20020110170112Z
   x509validityNotAfter: 20060110170112Z
   x509subject: EMAILADDRESS=ca@daasi.de,OU=DAASI CA,O=DAASI Internation
    al GmbH,C=DE
   x509subjectPublicKeyInfoAlgorithm: 1.2.840.113549.1.1.1
   x509basicConstraintsCa: TRUE
   x509keyUsage: keyCertSign
   x509keyUsage: cRLSign
   x509subjectKeyIdentifier:: 5nrZFpVK4RKfIglqQ4N4JXBS4Bk=


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   x509cLRdistributionPointURI: http://www.dfn-pca.de/certification/x509
    /g1/data/crls/root-ca-crl.crx
   x509cLRdistributionPointURI: http://www.dfn-pca.de/certification/x509
    /g1/data/crls/root-ca-crl.crl
   x509policyInformationIdentifier: 1.3.6.1.4.1.11418.300.1.1
   mail: ca@daasi.de
   objectClass: pkiCa
   caCertificate:: MIIHTTCCBjWgAwIBAgIDStFoMA0GCSqGSIb3DQEBBQUAMI
    GsMQswCQYDVQQGEwJERTEhMB8GA1UEChMYRGV1dHNjaGVzIEZvcnNjaHVuZ3NuZXR6MR
    YwFAYD VQQLEw1ERk4tQ0VSVCBHbWJIMRAwDgYDVQQLEwdERk4tUENBMS0wKwYDVQQDE
    yRERk4gVG9 wbGV2ZWwgQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkxITAfBgkqhkiG9w0B
    CQEWEmNlcnRpZnlAcGNhLmRmbi5kZTAeFw0wMjAxMTAxNzAxMTJaFw0wNjAxMTAxNzAx
    MTJaMF8xCzAJBgNVBAYTAkRFMSEwHwYDVQQKExhEQUFTSSBJbnRlcm5hdGlvbmFsIEdt
    YkgxETAPBgNVBAsTCERB QVNJIENBMRowGAYJKoZIhvcNAQkBFgtjYUBkYWFzaS5kZTC
    CASIwDQYJKoZIhvcNAQEBBQA DggEPADCCAQoCggEBAKmQBp+Gr28/qlEWjnJoiH3Awm
    hNEYMRWgXMXMMjM3S4mSmXZ8FZfTSPhi5O1zx5nyHecfl01fAO79Kpc6XkOTOl4iKBwu
    7+DM6my9Iizp2puhOQ6iuuchAIyJQPR0lfWAvvW+4n7Nf13Js5qFHvXBDqvgt6fud1l8
    XZ4nPWBSbs6OnB4EUDlRLx5fdCX2sEPQINKeu0INMtjHI6eGbspmahup0ArPA9RYZVjV
    q6ZHkh4205/JAhji9KtFifKCztXNTRMba7AHd2uS6GbF9+chGLPWGNZKtMhad1SvU7Zl
    w/ySHkFbBFZMu6x3kAVgwW8gKQa5qSFnMw/WTKATJRPekCAwEAAaOCA8IwggO+MA8GA1
    UdEwEB/wQFMAMBAf8wCwYDVR0PBAQDAgEGMB0GA1UdDgQWBBTmetkWlUrhEp8iCWpDg3
    glcFLgGTCB2wYDVR0jBIHTMIHQgBQGC/q1+Eh4oyCxCz7PoNDE0X990KGBsqSBrzCBrD
    ELMAkGA1UEBhMCREUxITAfBgNVBAoTGERldXRzY2hlcyBGb3JzY2h1bmdzbmV0ejEWMB
    QGA1UECxMNREZOLUNFUlQgR21iSDEQMA4GA1UECxMHREZOLVBDQTEtMCsGA1UEAxMkRE
    ZOIFRvcGxldmVsIENlcnRpZmljYXRpb24gQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFh
    JjZXJ0aWZ5QHBjYS5kZm4uZGWCAxXP/TCBpQYDVR0fBIGdMIGaMEugSaBHhkVodHRwOi
    8vd3d3LmRmbi1wY2EuZGUvY2VydGlmaWNhdGlvbi94NTA5L2cxL2RhdGEvY3Jscy9yb2
    90LWNhLWNybC5jcngwS6BJoEeGRWh0dHA6Ly93d3cuZGZuLXBjYS5kZS9jZXJ0aWZpY2
    F0aW9uL3g1MDkvZzEvZGF0YS9jcmxzL3Jvb3QtY2EtY3JsLmNybDARBglghkgBhvhCAQ
    EEBAMCAQYwSwYJYIZIAYb4QgEIBD4WPGh0dHA6Ly93d3cuZGZuLXBjYS5kZS9jZXJ0aW
    ZpY2F0aW9uL3BvbGljaWVzL3g1MDlwb2xpY3kuaHRtbDCB+QYJYIZIAYb4QgENBIHrFo
    HoVGhpcyBjZXJ0aWZpY2F0ZSB3YXMgaXNzdWVkIGJ5IHRoZSBERk4tUENBLCB0aGUgVG
    9wCkxldmVsIENlcnRpZmljYXRpb24gQXV0aG9yaXR5IG9mIHRoZSBHZXJtYW4gUmVzZW
    FyY2gKTmV0d29yayAoRGV1dHNjaGVzIEZvcnNjaHVuZ3NuZXR6LCBERk4pLgpUaGUga2
    V5IG93bmVyJ3MgaWRlbnRpdHkgd2FzIGF1dGhlbnRpY2F0ZWQgaW4KYWNjb3JkYW5jZS
    B3aXRoIHRoZSBERk4tUENBIHg1MDkgUG9saWN5LjA3BglghkgBhvhCAQMEKhYoaHR0cH
    M6Ly93d3cuZGZuLXBjYS5kZS9jZ2kvY2hlY2stcmV2LmNnaTBkBgNVHSAEXTBbMFkGCy
    sGAQQB2RqCLAEBMEowSAYIKwYBBQUHAgEWPGh0dHA6Ly93d3cuZGZuLXBjYS5kZS9jZX
    J0aWZpY2F0aW9uL3BvbGljaWVzL3g1MDlwb2xpY3kuaHRtbDANBgkqhkiG9w0BAQUFAA
    OCAQEAU9GmwCW6LwsyHfC241afldqj/GULv8mfSkUEpK2OtYU1JAYFzmQx69iweOKHbg
    XZKZA2Wox+9AydIe98MJCSCOFKYjkzgXU4fEZbEgnZBo+/1+W2BoB6gFAWy77KVHgimA
    7AqCcfbObeyCmyfLg1ro8/KpE01OjNr0S+EfZ3gX9sezjVkCy12HBNQknz/hT2af25UU
    hyFTcvUY4xvlKAQpla29qyO28sfO93Qhkum6SU2XPlsKU+3lyqF33Xy84Y2z8ScVlsMu
    VWbUGtmVshnpT5K91n42pu/f0rLtkZDssEDbcLnQDLWEz1aUDkLC++4CeFJxC/Dd/SOr
    E0yR0hNQ=

   A sample x509certificate directory entry for an end identity
   certificate in LDIF format:

   dn: x509serialNumber=1581631808272310054353257112721713,EMAILADDRESS=
    certificate@trustcenter.de,OU=TC TrustCenter Class 1 CA,O=TC TrustCe
    nter for Security in Data Networks GmbH,L=Hamburg,ST=Hamburg,C=DE
   objectclass: x509certificate
   x509version: 2


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   x509serialNumber: 1581631808272310054353257112721713
   x509issuer: EMAILADDRESS=certificate@trustcenter.de,OU=TC TrustCente
    r Class 1 CA,O=TC TrustCenter for Security in Data Networks GmbH,L=
    Hamburg, ST=Hamburg,C=DE
   x509validityNotBefore: 20011030180757Z
   x509validityNotAfter: 20021030180757Z
   x509subject: EMAILADDRESS=norbert.klasen@daasi.de,CN=Norbert Klasen,C
    =DE
   x509subjectPublicKeyInfoAlgorithm: 1.2.840.113549.1.1.1
   mail: norbert.klasen@daasi.de
   objectClass: pkiUser
   userCertificate:: MIIDOTCCAqKgAwIBAgIOTfsAAAACxOstmlOu2TEwDQYJ
    KoZIhvcNAQEEBQAwgbwxCzAJBgNVBAYTAkRFMRAwDgYDVQQIEwdIYW1idXJnMRAwDgYD
    VQQHEwdIYW1idXJnMTowOAYDVQQKEzFUQyBUcnVzdENlbnRlciBmb3IgU2VjdXJpdHkg
    aW4gRGF0YSBOZXR3b3JrcyBHbWJIMSIwIAYDVQQLExlUQyBUcnVzdENlbnRlciBDbGFz
    cyAxIENBMSkwJwYJKoZIhvcNAQkBFhpjZXJ0aWZpY2F0ZUB0cnVzdGNlbnRlci5kZTAe
    Fw0wMTEwMzAxODA3NTdaFw0wMjEwMzAxODA3NTdaME4xCzAJBgNVBAYTAkRFMRcwFQYD
    VQQDEw5Ob3JiZXJ0IEtsYXNlbjEmMCQGCSqGSIb3DQEJARYXbm9yYmVydC5rbGFzZW5A
    ZGFhc2kuZGUwgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBAL8+XK98p4YjD7Wq7Apm
    hAN/j2tfVsFCS0ufy12vGpEtG4ny1tbbBORCJI8vIlDr2/vVTESl6UjzceloVUCib5V8
    55mKUVmLL9Ay4qQLFd4wAoRSPAu9DkfbR+ygjzaYq+MUKMwaB61sG6911xk/e2/IIq8/
    IHKrRoYQGmHkaaJpAgMBAAGjgaowgacwMwYJYIZIAYb4QgEIBCYWJGh0dHA6Ly93d3cu
    dHJ1c3RjZW50ZXIuZGUvZ3VpZGVsaW5lczARBglghkgBhvhCAQEEBAMCBaAwXQYJYIZI
    AYb4QgEDBFAWTmh0dHBzOi8vd3d3LnRydXN0Y2VudGVyLmRlL2NnaS1iaW4vY2hlY2st
    cmV2LmNnaS80REZCMDAwMDAwMDJDNEVCMkQ5QTUzQUVEOTMxPzANBgkqhkiG9w0BAQQF
    AAOBgQCrAzuZzLztupeqcHa8OUOcnRuTacMpBEeICbZMKv6mN9rMYkAxFKerj/yXbdCE
    8/3X3L00eGj+a8A7PumATiJSfmvYqa4EMZwHC2FFqPxYyAj+xVuSlL5AC4HGHu4SOCp/
    UJu1xysoD16chOOLpj7+ZWZWLHIjA3zeXwUGl4kFvw==


Appendix B. Sample searches

   This section details how clients should access the certstore.  The
   searches are presented in LDAP URL format.

   Retrieve all certificates for an end entity from a certstore using
   the first DIT structure:

   ldap:///CN=Norbert%20Klasen,O=DAASI%20International%20GmbH,C=de?
     userCertificate?one?(objectClass=x509certificate)

   Find a certificate in a trustcenter's certstore suitable for sending
   an encrypted S/MIME message to "norbert.klasen@daasi.de"

   ldap:///O=TC%20TrustCenter%20for%20Security%20in%20Data%20Networks
     %20GmbH,L=Hamburg,ST=Hamburg,C=de?userCertificate?sub?
     (&(objectClass=x509certificate)(mail=norbert.klasen@daasi.de)
      (|(x509keyUsage=keyEncipherment)(x509keyUsage=keyAgreement)
        (x509extendedKeyUsage=1.3.6.1.5.5.7.3.4)))

   Find a CA certificate by its "subjectKeyIdentifier" obtained from the
   "keyIdentifier" field of the "autorityKeyIdentifier" extension in an
   end entity certificate:



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   ldap:///?caCertificate?sub?
     (&(objectClass=x509certificate)(x509subjectKeyIdentifier=%5CE6
      %5C7A%5CD9%5C16%5C95%5C4A%5CE1%5C12%5C9F%5C22%5C09%5C6A%5C43%
      5C83%5C78%5C25%5C70%5C52%5CE0%5C19))


Appendix C. Changes from previous Drafts

C.1 Changes in Draft 01

   o  Included new Attributes x509authorityKeyIdentifier,
      x509authorityCertissuer, x509authorityCertSerialNumber,
      x509certificateLocation, x509certificateHolder, and new
      objectclass x509certificateHolder

   o  Fixed bug in definition of objectclass x509certificate

   o  Changed references from RFC 2459 to RFC 3280 and included some
      respective language in 3.2.

   o  Changed references from RFC 2251 to RFC 3377 and deleted all
      references to LDAPv2.

   o  Deleted ";binary" in examples

   o  Included new section: Comparision with component matching approach

   o  Some changes in wording and section titles, and elimination of
      typos

   o  Changed order of authors, and one author's address


C.1 Changes in Draft 01

   o  abstract object class x509PKC

   o  aligned to [ldap-ac-schema] and [ldap-crl-schema]



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