Network Working Group                                        K. Zeilenga
Request for Comments: 3671                           OpenLDAP Foundation
Category: Standards Track                                  December 2003


                        Collective Attributes in
            the Lightweight Directory Access Protocol (LDAP)

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2003).  All Rights Reserved.

Abstract

   X.500 collective attributes allow common characteristics to be shared
   between collections of entries.  This document summarizes the X.500
   information model for collective attributes and describes use of
   collective attributes in LDAP (Lightweight Directory Access
   Protocol).  This document provides schema definitions for collective
   attributes for use in LDAP.

1.  Introduction

   In X.500 [X.500], a collective attribute is "a user attribute whose
   values are the same for each member of an entry collection" [X.501].
   This document details their use in the Lightweight Directory Access
   Protocol (LDAP) [RFC3377].

1.1.  Entry Collections

   A collection of entries is a grouping of object and alias entries
   based upon common properties or shared relationship between the
   corresponding entries which share certain attributes.  An entry
   collection consists of all entries within scope of a collective
   attributes subentry [RFC3672].  An entry can belong to several entry
   collections.







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1.2.  Collective Attributes

   Attributes shared by the entries comprising an entry collection are
   called collective attributes.  Values of collective attributes are
   visible but not updateable to clients accessing entries within the
   collection.  Collective attributes are updated (i.e., modified) via
   their associated collective attributes subentry.

   When an entry belongs to multiple entry collections, the entry's
   values of each collective attribute are combined such that
   independent sources of these values are not manifested to clients.

   Entries can specifically exclude a particular collective attribute by
   listing the attribute as a value of the collectiveExclusions
   attribute.  Like other user attributes, collective attributes are
   subject to a variety of controls including access, administrative,
   and content controls.

1.3.  Conventions

   Schema definitions are provided using LDAPv3 [RFC2251] description
   formats [RFC2252].  Definitions provided here are formatted (line
   wrapped) for readability.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in BCP 14 [RFC2119].

2.  System Schema for Collective Attributes

   The following operational attributes are used to manage Collective
   Attributes.  LDAP servers [RFC3377] MUST act in accordance with the
   X.500 Directory Models [X.501] when providing this service.

2.1.  collectiveAttributeSubentry

   Subentries of this object class are used to administer collective
   attributes and are referred to as collective attribute subentries.

      ( 2.5.17.2 NAME 'collectiveAttributeSubentry' AUXILIARY )

   A collective attribute subentry SHOULD contain at least one
   collective attribute.  The collective attributes contained within a
   collective attribute subentry are available for finding, searching,
   and comparison at every entry within the scope of the subentry.  The
   collective attributes, however, are administered (e.g., modified) via
   the subentry.




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   Implementations of this specification SHOULD support collective
   attribute subentries in both collectiveAttributeSpecificArea
   (2.5.23.5) and collectiveAttributeInnerArea (2.5.23.6) administrative
   areas [RFC3672][X.501].

2.2.  collectiveAttributeSubentries

   The collectiveAttributeSubentries operational attribute identifies
   all collective attribute subentries that affect the entry.

      ( 2.5.18.12 NAME 'collectiveAttributeSubentries'
        EQUALITY distinguishedNameMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
        USAGE directoryOperation NO-USER-MODIFICATION )

2.3.  collectiveExclusions

   The collectiveExclusions operational attribute allows particular
   collective attributes to be excluded from an entry.  It MAY appear in
   any entry and MAY have multiple values.

      ( 2.5.18.7 NAME 'collectiveExclusions'
        EQUALITY objectIdentifierMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.38
        USAGE directoryOperation )

   The descriptor excludeAllCollectiveAttributes is associated with the
   OID 2.5.18.0.  When this descriptor or OID is present as a value of
   the collectiveExclusions attribute, all collective attributes are
   excluded from an entry.

3.  Collective Attribute Types

   A userApplications attribute type can be defined to be COLLECTIVE
   [RFC2252].  This indicates that the same attribute values will appear
   in the entries of an entry collection subject to the use of the
   collectiveExclusions attribute and other administrative controls.
   These administrative controls MAY include DIT Content Rules, if
   implemented.

   Collective attribute types are commonly defined as subtypes of non-
   collective attribute types.  By convention, collective attributes are
   named by prefixing the name of their non-collective supertype with
   "c-".  For example, the collective telephone attribute is named
   c-TelephoneNumber after its non-collective supertype telephoneNumber.

   Non-collective attributes types SHALL NOT subtype collective
   attributes.



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   Collective attributes SHALL NOT be SINGLE-VALUED.  Collective
   attribute types SHALL NOT appear in the attribute types of an object
   class definition.

   Operational attributes SHALL NOT be defined to be collective.

   The remainder of section provides a summary of collective attributes
   derived from those defined in [X.520].  The SUPerior attribute types
   are described in [RFC 2256] for use with LDAP.

   Implementations of this specification SHOULD support the following
   collective attributes and MAY support additional collective
   attributes.

3.1.  Collective Locality Name

   The c-l attribute type specifies a locality name for a collection of
   entries.

      ( 2.5.4.7.1 NAME 'c-l'
        SUP l COLLECTIVE )

3.2.  Collective State or Province Name

   The c-st attribute type specifies a state or province name for a
   collection of entries.

      ( 2.5.4.8.1 NAME 'c-st'
        SUP st COLLECTIVE )

3.3.  Collective Street Address

   The c-street attribute type specifies a street address for a
   collection of entries.

      ( 2.5.4.9.1 NAME 'c-street'
        SUP street COLLECTIVE )

3.4.  Collective Organization Name

   The c-o attribute type specifies an organization name for a
   collection of entries.

      ( 2.5.4.10.1 NAME 'c-o'
        SUP o COLLECTIVE )






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3.5.  Collective Organizational Unit Name

   The c-ou attribute type specifies an organizational unit name for a
   collection of entries.

      ( 2.5.4.11.1 NAME 'c-ou'
        SUP ou COLLECTIVE )

3.6.  Collective Postal Address

   The c-PostalAddress attribute type specifies a postal address for a
   collection of entries.

      ( 2.5.4.16.1 NAME 'c-PostalAddress'
        SUP postalAddress COLLECTIVE )

3.7.  Collective Postal Code

   The c-PostalCode attribute type specifies a postal code for a
   collection of entries.

      ( 2.5.4.17.1 NAME 'c-PostalCode'
        SUP postalCode COLLECTIVE )

3.8.  Collective Post Office Box

   The c-PostOfficeBox attribute type specifies a post office box for a
   collection of entries.

      ( 2.5.4.18.1 NAME 'c-PostOfficeBox'
        SUP postOfficeBox COLLECTIVE )

3.9.  Collective Physical Delivery Office Name

   The c-PhysicalDeliveryOfficeName attribute type specifies a physical
   delivery office name for a collection of entries.

      ( 2.5.4.19.1 NAME 'c-PhysicalDeliveryOfficeName'
        SUP physicalDeliveryOfficeName COLLECTIVE )

3.10.  Collective Telephone Number

   The c-TelephoneNumber attribute type specifies a telephone number for
   a collection of entries.

      ( 2.5.4.20.1 NAME 'c-TelephoneNumber'
        SUP telephoneNumber COLLECTIVE )




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3.11.  Collective Telex Number

   The c-TelexNumber attribute type specifies a telex number for a
   collection of entries.

      ( 2.5.4.21.1 NAME 'c-TelexNumber'
        SUP telexNumber COLLECTIVE )

3.13.  Collective Facsimile Telephone Number

   The c-FacsimileTelephoneNumber attribute type specifies a facsimile
   telephone number for a collection of entries.

      ( 2.5.4.23.1 NAME 'c-FacsimileTelephoneNumber'

   SUP facsimileTelephoneNumber COLLECTIVE )

3.14.  Collective International ISDN Number

   The c-InternationalISDNNumber attribute type specifies an
   international ISDN number for a collection of entries.

      ( 2.5.4.25.1 NAME 'c-InternationalISDNNumber'
        SUP internationalISDNNumber COLLECTIVE )

4.  Security Considerations

   Collective attributes, like other attributes, are subject to access
   control restrictions and other administrative policy.  Generally
   speaking, collective attributes accessed via an entry in a collection
   are governed by rules restricting access to attributes of that entry.
   And collective attributes access via a subentry are governed by rules
   restricting access to attributes of that subentry.  However, as LDAP
   does not have a standard access model, the particulars of each
   server's access control system may differ.

   General LDAP security considerations [RFC3377] also apply.














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5.  IANA Considerations

   The IANA has registered the LDAP descriptors [RFC3383] defined in
   this technical specification.  The following registration template is
   suggested:

      Subject: Request for LDAP Descriptor Registration
      Descriptor see comments
      Object Identifier: see comment
      Person & email address to contact for further information:
           Kurt Zeilenga <kurt@OpenLDAP.org>
      Usage: see comment
      Specification: RFC3671
      Author/Change Controller: IESG
      Comments:

         NAME                           Type OID
         ------------------------       ---- -----------------
         c-FacsimileTelephoneNumber     A    2.5.4.23.1
         c-InternationalISDNNumber      A    2.5.4.25.1
         c-PhysicalDeliveryOffice       A    2.5.4.19.1
         c-PostOfficeBox                A    2.5.4.18.1
         c-PostalAddress                A    2.5.4.16.1
         c-PostalCode                   A    2.5.4.17.1
         c-TelephoneNumber              A    2.5.4.20.1
         c-TelexNumber                  A    2.5.4.21.1
         c-l                            A    2.5.4.7.1
         c-o                            A    2.5.4.10.1
         c-ou                           A    2.5.4.11.1
         c-st                           A    2.5.4.8.1
         c-street                       A    2.5.4.9.1
         collectiveAttributeSubentries  A    2.5.18.12
         collectiveAttributeSubentry    O    2.5.17.2
         collectiveExclusions           A    2.5.18.7

      where Type A is Attribute and Type O is ObjectClass.

   The Object Identifiers used in this document were assigned by the
   ISO/IEC Joint Technical Committee 1 - Subcommittee 6 to identify
   elements of X.500 schema [X.520].  This document make no OID
   assignments, it only provides LDAP schema descriptions with existing
   elements of X.500 schema.









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6.  Intellectual Property Statement

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights.  Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in BCP-11.  Copies of
   claims of rights made available for publication and any assurances of
   licenses to be made available, or the result of an attempt made to
   obtain a general license or permission for the use of such
   proprietary rights by implementors or users of this specification can
   be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard.  Please address the information to the IETF Executive
   Director.

7.  Acknowledgments

   This document is based upon the ITU Recommendations for the Directory
   [X.501][X.520].

8.  References

8.1.  Normative References

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

   [RFC2251]  Wahl, M., Howes, T. and S. Kille, "Lightweight Directory
              Access Protocol (v3)", RFC 2251, December 1997.

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

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

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




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   [RFC3383]  Zeilenga, K., "Internet Assigned Numbers Authority (IANA)
              Considerations for the Lightweight Directory Access
              Protocol (LDAP)", BCP 64, RFC 3383, September 2002.

   [RFC3672]  Zeilenga, K. and S. Legg, "Subentries in Lightweight
              Directory Access Protocol (LDAP)", RFC 3672, December
              2003.

   [X.501]    "The Directory: Models", ITU-T Recommendation X.501, 1993.

8.2.  Informative References

   [X.500]    "The Directory: Overview of Concepts, Models", ITU-T
              Recommendation X.500, 1993.

   [X.520]    "The Directory: Selected Attribute Types", ITU-T
              Recommendation X.520, 1993.

9.  Author's Address

   Kurt D. Zeilenga
   OpenLDAP Foundation

   EMail: Kurt@OpenLDAP.org



























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10.  Full Copyright Statement

   Copyright (C) The Internet Society (2003).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assignees.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

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



















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