Network Working Group                                           P. Gietz
Internet-Draft                                  DAASI International GmbH
Expires: December 29, 2003                                     N. Klasen
                                                                  Avinci
                                                           June 30, 2003


                An LDAPv3 Schema for X.509 Certificates
              draft-klasen-ldap-x509certificate-schema-03

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.

   Comments and suggestions on this document are encouraged.  They
   should be sent to the PKIX working group discussion list <ietf-
   pkix@imc.org> or directly to the authors.

   This Internet-Draft will expire on December 29, 2003.

Copyright Notice

   Copyright (C) The Internet Society (2003).  All Rights Reserved.
   Please see the full copyright statement near the end of this document
   for more information

Abstract

   This document describes an LDAP schema which can be used to implement
   a certificate store for X.509 certificates.  Specifically, two
   structural object classes for X.509 user and CA certificates are
   defined.  Key fields of a certificate are stored in LDAP attributes



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   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

   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.



































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Table of Contents

   1.      Introduction . . . . . . . . . . . . . . . . . . . . . . .  6
   2.      Comparison with Values Return Filter Control . . . . . . .  7
   3.      Comparison with component matching approach  . . . . . . .  8
   4.      The x509certificate object classes and their attribute
           types  . . . . . . . . . . . . . . . . . . . . . . . . . .  8
   4.1     Attributes for mandatory fields of an X.509 certificate  .  8
   4.1.1   X.509 version  . . . . . . . . . . . . . . . . . . . . . .  8
   4.1.2   Serial number  . . . . . . . . . . . . . . . . . . . . . .  8
   4.1.3   Signature algorithm  . . . . . . . . . . . . . . . . . . .  9
   4.1.4   Issuer . . . . . . . . . . . . . . . . . . . . . . . . . .  9
   4.1.5   Validity . . . . . . . . . . . . . . . . . . . . . . . . .  9
   4.1.6   Subject  . . . . . . . . . . . . . . . . . . . . . . . . . 10
   4.1.7   Subject public key info algorithm  . . . . . . . . . . . . 10
   4.2     Attributes for selected extensions . . . . . . . . . . . . 11
   4.2.1   Authority key identifier extension . . . . . . . . . . . . 11
   4.2.1.1 Authority key identifier . . . . . . . . . . . . . . . . . 12
   4.2.1.2 Authority cert issuer  . . . . . . . . . . . . . . . . . . 12
   4.2.1.3 Authority cert serial number . . . . . . . . . . . . . . . 12
   4.2.2   Subject key identifier extension . . . . . . . . . . . . . 12
   4.2.3   Key usage extension  . . . . . . . . . . . . . . . . . . . 13
   4.2.4   Policy information identifier extension  . . . . . . . . . 13
   4.2.5   Subject alternative name extension . . . . . . . . . . . . 13
   4.2.5.1 Subject RFC822 name  . . . . . . . . . . . . . . . . . . . 14
   4.2.5.2 Subject DNS name . . . . . . . . . . . . . . . . . . . . . 14
   4.2.5.3 Subject directory name . . . . . . . . . . . . . . . . . . 14
   4.2.5.4 Subject Uniform Resource Identifier  . . . . . . . . . . . 15
   4.2.5.5 Subject IP address . . . . . . . . . . . . . . . . . . . . 15
   4.2.5.6 Subject registered ID  . . . . . . . . . . . . . . . . . . 15
   4.2.6   Issuer alternative name extension  . . . . . . . . . . . . 15
   4.2.6.1 Issuer RFC 822 name  . . . . . . . . . . . . . . . . . . . 16
   4.2.6.2 Issuer DNS name  . . . . . . . . . . . . . . . . . . . . . 16
   4.2.6.3 Issuer directory name  . . . . . . . . . . . . . . . . . . 16
   4.2.6.4 Issuer Uniform Resource Identifier . . . . . . . . . . . . 17
   4.2.6.5 Issuer IP address  . . . . . . . . . . . . . . . . . . . . 17
   4.2.6.6 Issuer registered ID . . . . . . . . . . . . . . . . . . . 17
   4.2.7   Basic constraints extension  . . . . . . . . . . . . . . . 17
   4.2.8   Extended key usage extension . . . . . . . . . . . . . . . 18
   4.2.9   CRL distribution points extension  . . . . . . . . . . . . 18
   4.3     Additional attributes  . . . . . . . . . . . . . . . . . . 19
   4.3.1   Certificate location . . . . . . . . . . . . . . . . . . . 19
   4.3.2   Certificate holder . . . . . . . . . . . . . . . . . . . . 19
   4.3.3   X.509 user certificate . . . . . . . . . . . . . . . . . . 19
   4.3.4   X.509 CA certificate . . . . . . . . . . . . . . . . . . . 19
   4.4     X.509 PKC object class . . . . . . . . . . . . . . . . . . 20
   4.5     X.509 user certificate object class  . . . . . . . . . . . 20
   4.6     X.509 CA certificate object class  . . . . . . . . . . . . 21



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   4.7     X.509 certificate holder object class  . . . . . . . . . . 21
   5.      DIT structure and naming . . . . . . . . . . . . . . . . . 21
   6.      Security Considerations  . . . . . . . . . . . . . . . . . 23
   7.      Open issues  . . . . . . . . . . . . . . . . . . . . . . . 23
   8.      Acknowledgments  . . . . . . . . . . . . . . . . . . . . . 24
   9.      References . . . . . . . . . . . . . . . . . . . . . . . . 24
           Normative references . . . . . . . . . . . . . . . . . . . 24
           Non-normative references . . . . . . . . . . . . . . . . . 26
           Authors' Addresses . . . . . . . . . . . . . . . . . . . . 27
   A.      Sample directory entries . . . . . . . . . . . . . . . . . 27
   B.      Sample searches  . . . . . . . . . . . . . . . . . . . . . 29
   C.      Changes from previous Drafts . . . . . . . . . . . . . . . 30
   C.1     Changes in Draft 01  . . . . . . . . . . . . . . . . . . . 30
   C.2     Changes in Draft 02  . . . . . . . . . . . . . . . . . . . 30
   C.3     Changes in Draft 03  . . . . . . . . . . . . . . . . . . . 31
           Full Copyright Statement . . . . . . . . . . . . . . . . . 32



































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1. Introduction

   A key component in the wide-spread adoption of a PKI infrastructure
   is the general availability of public keys 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.

   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 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 and consistency of the
   information.

   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.  Each attribute type uses existing LDAP
   syntax, so that no new matching rules need to be defined.
   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



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   indexing service based on The Common Indexing Protocol (CIP)
   [RFC2651], which defines a protocol between index servers for
   exchanging indexobjects in order to facilitate query routing.  The
   Tagged Index Object format as specified in [RFC2654] was specified to
   carry directory server information, by collecting the single
   attributetypes and values.

   This document is one of a set following this approach comprising:

   1.  the LDAP schema for X.509 public key certificates (this document)

   2.  the LDAP schema for X.509 attribute certificates [ldap-ac-schema]

   3.  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.

   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 leverage their indexing support for standard LDAPv3
   syntaxes.

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



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   here due to its dependency on attribute values.

3. Comparison 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 until 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 useful 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 classes and their attribute types

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

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
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
           SINGLE-VALUE )

   Values of this attribute may either be 0, 1, 2 or 3 corresponding to
   X.509 v1, v2, v3, or v4.

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







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   ( 1.3.6.1.4.1.10126.1.5.3.2
        NAME 'x509serialNumber'
        DESC 'Unique integer for each certificate 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 )


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'
        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].





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   ( 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'
        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 (see
   X.509(2000) 7, RFC3280 4.1.2.6).

   ( 1.3.6.1.4.1.10126.1.5.3.7
        NAME 'x509subject'
        DESC 'Distinguished name of the entity associated with this
              public-key'
        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 identifying the algorithm associated with the certified public
   key (see X.509(2000) 7, RFC3280 4.1.2.7).









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   ( 1.3.6.1.4.1.10126.1.5.3.8
        NAME 'x509subjectPublicKeyInfoAlgorithm'
        DESC 'OID identifying the algorithm associated with the certified
              public key'
        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  basic constraints extension

   o  name constraints extensions

   o  policy constraints extensions

   o  inhibit any policy extension

   o  freshest CRL extension

   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 (see X.509(2000) 8.2.2.1,
   RFC3280 4.2.1.1).  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.




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4.2.1.1 Authority key identifier

   ( 1.3.6.1.4.1.10126.1.5.3.11
        NAME 'x509authorityKeyIdentifier'
        DESC 'Key Identifier field of the Authority Key Identifier
              extension'
        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 'Authority Cert Issuer field of the Authority Key Identifier
              extension'
        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.

4.2.1.3 Authority cert serial number

   ( 1.3.6.1.4.1.10126.1.5.3.13
        NAME 'x509authorityCertSerialNumber'
        DESC 'Authority Cert Serial Number field of the
              Authority Key Identifier extension'
        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 (see
   X.509(2000) 8.2.2.2, RFC3280 4.2.1.2).  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'
        EQUALITY octetStringMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.40
        SINGLE-VALUE )



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4.2.3 Key usage extension

   This attribute defines the purpose (e.g., encipherment, signature,
   certificate signing) of the key contained in the certificate (see
   X.509(2000) 8.2.2.3, RFC3280 4.2.1.3).

   ( 1.3.6.1.4.1.10126.1.5.3.15
        NAME 'x509keyUsage'
        DESC 'Purpose for which the certified public key is used'
        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"


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 (see X.509(2000) 8.2.2.6, RFC3280 4.2.1.5).

   ( 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'
        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 (see X.509(2000)
   8.3.2.1, RFC3280 4.2.1.7).  Separate attribute types are defined for
   all choices of the ASN.1 type "GeneralName" except for "otherName",
   "x400Address" and "ediPartyName".







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4.2.5.1 Subject RFC822 name

   ( 1.3.6.1.4.1.10126.1.5.3.17
        NAME 'x509subjectRfc822Name'
        DESC 'Internet electronic mail address of the entity
              associated with this public-key'
        EQUALITY caseIgnoreIA5Match
        SUBSTR caseIgnoreIA5SubstringsMatch
        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].

4.2.5.2 Subject DNS name

   ( 1.3.6.1.4.1.10126.1.5.3.18
        NAME 'x509subjectDnsName'
        DESC 'Internet domain name of the entity
              associated with this public-key'
        EQUALITY caseIgnoreIA5Match
        SUBSTR caseIgnoreIA5SubstringsMatch
        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 of the entity
              associated with this public-key'
        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].














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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
                 of the entity associated with this public-key'
        EQUALITY caseExactIA5Match
        SUBSTR caseExactIA5SubstringsMatch
        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].

4.2.5.5 Subject IP address

   ( 1.3.6.1.4.1.10126.1.5.3.21
        NAME 'x509subjectIpAddress'
        DESC 'Internet Protocol address of the entity
              associated with this public-key'
        EQUALITY caseIgnoreIA5Match
        SUBSTR caseIgnoreIA5SubstringsMatch
        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 identifying the entity
              associated with this public-key'
        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 subject of the certificate or CRL (see X.509(2000)
   8.3.2.2, RFC3280 4.2.1.8).  Separate attribute types are defined for
   all choices of the ASN.1 type "GeneralName" except for "otherName",
   "x400Address" and "ediPartyName".






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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 of the entity who has
              signed and issued the certificate'
        EQUALITY caseIgnoreIA5Match
        SUBSTR caseIgnoreIA5SubstringsMatch
        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].

4.2.6.2 Issuer DNS name

   ( 1.3.6.1.4.1.10126.1.5.3.24
        NAME 'x509issuerDnsName'
        DESC 'Internet domain name of the entity who has
              signed and issued the certificate'
        EQUALITY caseIgnoreIA5Match
        SUBSTR caseIgnoreIA5SubstringsMatch
        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 of the entity who has
              signed and issued the certificate'
        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].














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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
                 of the entity who has signed and issued the certificate'
        EQUALITY caseExactIA5Match
        SUBSTR caseExactIA5SubstringsMatch
        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].

4.2.6.5 Issuer IP address

   ( 1.3.6.1.4.1.10126.1.5.3.27
        NAME 'x509issuerIpAddress'
        DESC 'Internet Protocol address of the entity who has
              signed and issued the certificate'
        EQUALITY caseIgnoreIA5Match
        SUBSTR caseIgnoreIA5SubstringsMatch
        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 identifying the entity who has
              signed and issued the certificate'
        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 Basic constraints extension

   This attribute indicates whether the subject of the certificate is a
   CA (see X.509(2000) 8.4.2.1, RFC3280 4.2.1.10).  If the value of this
   attribute is "TRUE", the certificate MUST be stored in the
   "cacertificate" attribute.







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   ( 1.3.6.1.4.1.10126.1.5.3.29
        NAME 'x509basicConstraintsCa'
        DESC 'Identifies whether the subject of the certificate is a
              CA'
        EQUALITY booleanMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
        SINGLE-VALUE )


4.2.8 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 (see X.509(2000)
   8.2.2.4, RFC3280 4.2.1.13).  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 an OID'
        EQUALITY objectIdentifierMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 )


4.2.9 CRL distribution points extension

   This attribute identifies how the full CRL information for this
   certifacte can be obtained (see X.509(2000) 8.6.2.1, RFC3280
   4.2.1.14).

   ( 1.3.6.1.4.1.10126.1.5.3.32
        NAME 'x509fullCRLDistributionPointURI'
        DESC 'URI type of DistributionPointName for the full CRL'
        EQUALITY caseExactIA5Match
        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].





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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 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 'Complete x.509 user certificate'
         SUP userCertificate
         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.



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   ( 1.3.6.1.4.1.10126.1.5.4.77
         NAME 'x509caCert'
         DESC 'Complete x.509 CA certificate'
         SUP caCertificate
         SINGLE-VALUE )


4.4 X.509 PKC 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
   and in name forms.  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'
           SUP x509base
        ABSTRACT
        MUST ( x509serialNumber $ x509validityNotBefore $
              x509validityNotAfter $ x509subjectPublicKeyInfoAlgorithm )
        MAY  ( x509authorityKeyIdentifier $
           x509authorityCertIssuer $ x509authorityCertSerialNumber $
           x509subjectKeyIdentifier $ x509keyUsage $
           x509policyInformationIdentifier $
           x509subjectRfc822Name $ x509subjectDnsName $
           x509subjectDirectoryName $ x509subjectUniformResourceIdentifier $
           x509subjectIpAddress $
           x509subjectRegisteredID $
           x509issuerRfc822Name $ x509issuerDnsName $
           x509issuerDirectoryName $ x509issuerUniformResourceIdentifier $
           x509issuerIpAddress $
           x509issuerRegisteredID $
           x509extKeyUsage $
           x509FullcRLDistributionPointURI $ x509certHolder $
              x509issuerSerial $ x509basicConstraintsCa ) )

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

4.5 X.509 user certificate object class

   This object class is for storing user certificates.








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

   The attribute type x509subject is specified here as a MAY attribute.
   Nevertheless if this attribute is not used at least one of the
   following attributes MUST be filled in: x509subjectRfc822Name,
   x509subjectDnsName, x509subjectDirectoryName,
   x509subjectUniformResourceIdentifier, x509subjectIpAddress, or
   x509subjectRegisteredID.

4.6 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
         STRUCTURAL
         MUST ( x509caCert $ x509subject ) )


4.7 X.509 certificate holder object class

   This auxiliary object class has an attribute that contains a pointer
   to 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  ( x509certLocation ) )


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 two name forms:



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   ( 1.3.6.1.4.1.10126.1.5.5.6
        NAME "x509userCertificateNameform"
        OC x509userCeriticate
        MUST ( x509serialNumber $ x509issuer ) )


   ( 1.3.6.1.4.1.10126.1.5.5.7
        NAME "x509caCertificateNameform"
        OC x509caCertificate
        MUST ( x509serialNumber $ x509issuer ) )

   There are some LDAP implementations that don't support multi-valued
   RDNs.  These can use following alternative two name forms:

   ( 1.3.6.1.4.1.10126.1.5.5.8
         NAME "x509userCertificateAltNameForm"
         OC x509userCertificate
         MUST x509issuerSerial )


   ( 1.3.6.1.4.1.10126.1.5.5.9
         NAME "x509PcaCertificateAltNameForm"
         OC x509caCertificate
         MUST x509issuerSerial )

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

   For public directories of CAs that, besides the data stored in the
   certificates, do not hold any additional data about end entities the
   following 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 two name forms:

   ( 1.3.6.1.4.1.10126.1.5.5.10
        NAME "x509userCertificateSerialNumberNameForm"
        OC x509userCertificate
        MUST x509serialNumber )


   ( 1.3.6.1.4.1.10126.1.5.5.11
        NAME "x509caCertificateSerialNumberNameForm"
        OC x509caCertificate
        MUST x509serialNumber )

   Care must be taken when encoding DNs that contain an x509issuer
   attribute.  Such a value is a string representation according to



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   [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.

   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. Open issues

   There are still a number of todos with respect to this draft.
   Following work items will be dealt with in the next version of this
   draft:

   o  Section on IANA considerations

   o  Specification of an auxiliary object class with additional



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      attributes for storing a Qualified certificates as defined in
      RFC3039

   o  Specification of an auxiliary object class with attributes
      standardized elsewhere (e.g.  RFC 2798) for additional certificate
      search possibilities, e.g.  for the attribute mail.

   o  complete alignment with [ldap-ac-schema] and [ldap-crl-schema]


8. Acknowledgments

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

   The authors wish to thank David Chadwick, Russ Housley, Mikhail
   Sahalayev, Michael Stroeder, and Kurt Zeilenga for their
   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.

9. References

Normative 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.




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   [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.

   [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.

   [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.

   [ldap-ac-schema]    Chadwick, D. and M. Sahalayev, "Internet X.509
                       Public Key Infrastructure -  LDAP Schema for
                       X.509 Attribute Certificates", Internet Draft
                       (work in progress), June 2003, <draft-ietf-pkix-
                       ldap-ac-schema-01.txt>.

   [ldap-crl-schema]   Chadwick, D. and M. Sahalayev, "Internet X.509
                       Public Key Infrastructure -  LDAP Schema for
                       X.509 CRLs", Internet Draft (work in progress),
                       June 2003, <draft-ietf-pkix-ldap-crl-schema-
                       01.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-



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                       00.txt>.

Non-normative references

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

   [RFC2654]          Hedberg, R., Greenblatt, B., Moats, R. and M.
                      Wahl, "A Tagged Index Object for use in the Common
                      Indexing Protocol", RFC 2654, August 1999.

   [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
                      (expired), 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>.












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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@avinci.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: x509caCertificate
   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=
   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



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   x509policyInformationIdentifier: 1.3.6.1.4.1.11418.300.1.1
   x509caCert:: 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:









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   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: x509userCertificate
   x509version: 2
   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
   x509userCert:: 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?
        x509userCert?one?(objectClass=x509userCertificate)

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





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   ldap:///O=TC%20TrustCenter%20for%20Security%20in%20Data%20Networks
        %20GmbH,L=Hamburg,ST=Hamburg,C=de?x509userCert?sub?
        ((&(objectClass=x509userCertificate)
          (x509subjectRfc822Name=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:

   ldap:///?caCertificate?sub?
        (&(objectClass=x509caCertificate)(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.2 Changes in Draft 02

   o  abstract object class x509PKC




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


C.3 Changes in Draft 03

   o  Changed Matching Rules from caseIgnoreMatch to caseIgnoreIA5Match
      etc.

   o  moved the references to RFC 3280 from the DESC part of the
      attribute definition to the text

   o  added some additional text about CIP in Introduction

   o  reworded text in Section 4.1.7

   o  changed x509userCert and x509caCert to be inherited from
      userCertificate and caCertificate respectively

   o  added clarification about x509subject and subject alternative
      names in section Section 4.5

   o  added attribute type x509issuerSerial to x509PKC object class

   o  added attribute type x509basicConstraintsCa to x509PKC object
      class

   o  renamed attributetype x509cRLDistributionPointURI to
      x509FullcRLDistributionPointURI

   o  devided references in normative and non normative

   o  deleted attributetype mail from x509PKC objectclass

   o  created separate Name Forms for x509userCertificate and
      x509caCertificate object classes.

   o  changed attributetype x509SerialNumber to MULTI-VALUE

   o  adjusted examples to new schema

   o  Fixed more typos










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Full Copyright Statement

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   or assist in its implementation may be prepared, copied, published
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   The limited permissions granted above are perpetual and will not be
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   This document and the information contained herein is provided on an
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   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
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Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.



















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