INTERNET-DRAFT Editor: Kurt D. Zeilenga
Intended Category: Standard Track OpenLDAP Foundation
Expires: 15 April 2002 15 October 2001
Subentries in LDAP
<draft-zeilenga-ldap-subentry-00.txt>
Status of this Memo
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.
This document is intended to be, after appropriate review and
revision, submitted to the RFC Editor as a Informational document.
Distribution of this memo is unlimited. Technical discussion of this
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Copyright 2001, The Internet Society. All Rights Reserved.
Please see the Copyright section near the end of this document for
more information.
Abstract
Subentries are special entries used to hold information associated
with a subtree or subtree refinement [X.501]. This document adapts
X.500 subentries mechanisms for use with LDAP [LDAPTS].
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Conventions
Schema definitions are provided using LDAPv3 description formats
[RFC2252].
The key words ``MUST'', ``MUST NOT'', ``REQUIRED'', ``SHALL'', ``SHALL
NOT'', ``SHOULD'', ``SHOULD NOT'', ``RECOMMENDED'', and ``MAY'' in
this document are to be interpreted as described in RFC 2119
[RFC2119].
1. Overview
From X.501 [X.501]:
A subentry is a special kind of entry immediately subordinate to
an administrative point. It contains attributes that pertain to a
subtree (or subtree refinement) associated with its administrative
point. The subentries and their administrative point are part of
the same naming context.
A single subentry may serve all or several aspects of
administrative authority. Alternatively, a specific aspect of
administrative authority may be handled through one or more of its
own subentries.
LDAP subentries SHALL behave in accordance with X.501 unless noted
otherwise in this specification.
In absence of the subentries control (detailed in Section 4),
subentries SHALL NOT be considered in one-level and subtree scope
search operations (unlike X.501). For all other operations, including
base scope search operations, subentries SHALL be considered.
2. Subentry Schema
2.1. Subtree Specification Syntax
This syntax is described in X.501, Section 11.3. The ASN.1 data type
definition is provided here for completeness.
SubtreeSpecification ::= SEQUENCE {
base [0] LocalName DEFAULT { },
COMPONENTS OF ChopSpecification,
specificationFilter [4] Refinement OPTIONAL }
ChopSpecification ::= SEQUENCE {
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specificExclusions [1] SET OF CHOICE {
chopBefore [0] LocalName,
chopAfter [1] LocalName } OPTIONAL,
minimum [2] BaseDistance DEFAULT 0,
maximum [3] BaseDistance OPTIONAL}
BaseDistance ::= INTEGER (0 .. MAX)
Refinement ::= CHOICE {
item [0] OBJECT-CLASS.&id,
and [1] SET OF Refinement,
or [2] SET OF Refinement,
not [3] Refinement }
The LDAP syntax specification is:
( OID-TBD DESC 'SubtreeSpecification' )
Values of this syntax are be encoded as strings using the rules
described in Section 8 of [COMPONENT].
2.2 Administrative Role Attribute Type
The Administrative Model defined in X.501, clause 10 requires that
administrative entries contain an administrativeRole attribute to
indicate that the associated administrative area is concerned with one
or more administrative roles.
The administrativeRole operational attribute is specified as follows:
( id-oa-administrativeRole
NAME 'administrativeRole'
EQUALITY objectIdentifierMatch
USAGE directoryOperation
SYNTAX OID
)
The values of this attribute defined in X.501 are:
OID NAME
-------- -------------------------------
2.5.23.1 autonomousArea
2.5.23.2 accessControlSpecificArea
2.5.23.3 accessControlInnerArea
2.5.23.4 subschemaAdminSpecificArea
2.5.23.5 collectiveAttributeSpecificArea
2.5.23.6 collectiveAttributeInnerArea
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Other values may be defined by in other specifications. Names
associated with each administrative role are Object Identifier
Descriptors [LDAPIANA].
The administrativeRole operational attribute is also used to regulate
the subentries permitted to be subordinate to an administrative entry.
A subentry not of a class permitted by the administrativeRole
attribute cannot be subordinate to the administrative entry.
2.3. Subtree Specification Attribute Type
The subtreeSpecification operational attribute is defined as follows:
( id-oa-subtreeSpecification
NAME 'subtreeSpecification'
SINGLE-VALUE
USAGE directoryOperation
SYNTAX subtreeSpecification
)
This attribute is present in all subentries. See X.501, clause 10.
2.4. Subentry Object Class
The subentry object class is a structural object class.
( id-sc-subentry
NAME 'subentry'
SUP top STRUCTURAL
MUST ( cn $ subtreeSpecification ) )
3. Subentries Control
The subentries control may be sent with a searchRequest to control the
visibility of subentries which are within scope. Non-visible entries
or subentries are not returned in response to the request.
The subentries control is an LDAPv3 Control whose controlType is
OID.TDB, criticality is True or False (hence absent), and controlValue
is absent or contains a zero-length octet string. An absent
controlValue indicates that normal entries are visible and subentries
are not. An empty controlValue indicates that subentries are visible
and normal entries are not. A non-empty controlValue SHALL be treated
as a protocol error.
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In absence of this control, subentries are not visible to one-level
and subtree scope search requests but are visible to base scope search
requests.
This control is not appropriate for non-search operations.
4. Security Considerations
Subentries often hold administrative information or other sensitive
information and should be protected from unauthorized access and
disclosure as described in [RFC2829][RFC2830].
5. Acknowledgment
This document is based on engineering done by LDUP and LDAPext Working
Groups including the "LDAP Subentry Schema" by Ed Reeds. This
document also borrows from a number of ITU documents including X.501.
6. Author's Address
Kurt D. Zeilenga
OpenLDAP Foundation
<Kurt@OpenLDAP.org>
References
[X.501] "The Directory -- Models," ITU-T Rec. X.501(1993).
[RFC2219] S. Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[RFC2251] M. Wahl, T. Howes, S. Kille, "Lightweight Directory Access
Protocol (v3)", RFC 2251, December 1997.
[RFC2252] M. Wahl, A. Coulbeck, T. Howes, S. Kille, "Lightweight
Directory Access Protocol (v3): Attribute Syntax
Definitions", RFC 2252, December 1997.
[RFC2829] M. Wahl, H. Alvestrand, J. Hodges, R. Morgan,
"Authentication Methods for LDAP", RFC 2829, May 2000
[RFC2830] J. Hodges, R. Morgan, M. Wahl, "Lightweight Directory Access
Protocol (v3): Extension for Transport Layer Security", RFC
2830, May 2000.
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[LDAPTS] J. Hodges, R.L. Morgan, "Lightweight Directory Access
Protocol (v3): Technical Specification", draft-ietf-ldapbis-
ldapv3-ts-00.txt, a work in progress.
Full Copyright
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