INTERNET-DRAFT
draft-ietf-ldup-subentry-08.txt
Ed Reed
Reed-Matthews, Inc.
April 6, 2001
LDAP Subentry Schema
1 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 expires on October 6, 2001.
2 Abstract / Description
This document describes an administrative model for LDAP,
and an object class called ldapSubEntry and a control
ldapSubentriesControl (to control the visibility of entries
of type ldapSubEntry) that are to be used by directory
servers claiming support for the administrative model
defined here.
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 sections below reiterate these
definitions and include some additional ones.
Reed [Page 1]
Expires October 6, 2001
INTERNET-DRAFT 6 April 2001
LDAP Subentry Schema
3 Table of Contents
1 Status of this Memo 1
2 Abstract / Description 1
3 Table of Contents 2
4 Administrative Areas in the Directory 2
4.1 X.501 Administrative Model Overview 2
4.2 An LDAP Administrative Model 3
5 Object Class Definitions 4
5.1 ldapSubEntry Class 4
5.1.1 Naming and Structure constraints 4
5.1.2 Scope Rules 5
6 Visibility Control 6
6.1 ldapSubentriesControl 6
6.1.1 Other LDAP operations 6
6.1.2 Correspondence to [X511] 6
7 Security Considerations 7
8 References 7
9 Copyright Notice 8
10 Acknowledgements 8
11 Author's Address 9
4 Administrative Areas in the Directory
4.1 X.501 Administrative Model Overview
[X501] contains the definitive description of
Administrative Areas and their role in the management and
administration of directories. The LDAP administrative
model defined here is intended to be a compatible, proper
subset of the [X501] model. The description here draws
heavily on the descriptions and concepts laid out in
[X501].
An administrative area is a sub-tree of the directory
information tree, rooted at an administrative point (the
root-most entry in the sub-tree), where administrative
entries (perhaps including subentries, operational
attributes, or both) are located. Autonomous
administrative areas are distinct partitions of the
directory information tree whose entries are all
administered by a single administrative authority. Each
entry in the directory information tree is administered by
exactly one autonomous administrative authority.
Reed [Page 2]
Expires October 6, 2001
INTERNET-DRAFT 6 April 2001
LDAP Subentry Schema
There may be many aspects of administration defined by the
directory and other applications for specific purposes,
such as subschema administration areas, access control
administration areas, collective-attribute administration
areas, context default administrative areas, and service
administrative areas. Within an autonomous administrative
area, specific administrative areas for these (and other)
different aspects may overlap one another.
Specific administrative areas may be sub-partitioned by the
applications or services which define them to facilitate
delegation of authority or for other purposes. That means
that a single entry in the directory may be part of many
different specific administrative areas, but only be part
of one specific administrative area (or sub-area) of each
aspect of administration.
The [X501] subentry specification optionally uses a
SubtreeSpecification to indicate a subset of entries in a
sub-tree with which the subentry is concerned. When the
SubtreeSpecification is empty the scope of the [X501]
subentry is implicitly defined by the context in which it
occurs.
4.2 An LDAP Administrative Model
The administrative model for LDAP defined here is a
simplified version of the one described in [X501], in that
the scope defined for the ldapSubentry object class is
limited.
The LDAP Subentry definition below specifically does not
include a SubtreeSpecification, so its scope is explicitly
the complete set of entries in the specific administrative
area (or sub-area) in which it occurs. All administrative
areas are considered to be specific administrative areas
within an autonomous administrative area.
If a specific administration area is not partitioned, then
its extent (or scope) is said to be that of the autonomous
administrative area in which it is defined.
Applications and services which define specific
administrative areas must specify whether the areas may be
partitioned or not. By default, the scope of LDAP
Subentries is limited to the sub-area of the partitioned
specific administrative area in which they are present.
Reed [Page 3]
Expires October 6, 2001
INTERNET-DRAFT 6 April 2001
LDAP Subentry Schema
5 Object Class Definition
5.1 ldapSubEntry Class
( 2.16.840.1.113719.2.142.6.1.1 NAME 'ldapSubEntry'
DESC 'LDAP Subentry class, version 1'
SUP top STRUCTURAL
MAY ( cn ) )
The class ldapSubEntry is intended to be used as a super-
class when defining other structural classes to be used as
LDAP Subentries, and as the structural class to which
Auxiliary classes may be added for application specific
subentry information. Where possible, the use of Auxiliary
classes to extend LDAP Subentries is strongly preferred.
The presence of ldapSubEntry in the list of super-classes
of an entry in the directory makes that entry an LDAP
Subentry. Object classes derived from ldapSubEntry are
themselves considered ldapSubEntry classes, for the purpose
of this discussion.
5.1.1Naming and Structure constraints
LDAP Subentries MAY be named by their commonName attribute
[RFC2251]. Other naming attributes are also permitted.
For compatibility with [X501], the commonName attribute is
optional ([X501] requires EITHER cn OR a
SubTreeSpecification), but note that in the absence of any
other naming attribute, a cn is required to name the LDAP
Subentry.
LDAP Subentries MAY be containers, unlike their [X501]
counterparts. This is a departure from [X501], but is
considered an important extension to increase the ability
to more easily construct richer (i.e., more complex) policy
representations in the directory using LDAP Subentries.
Using LDAP Subentry containers to hold entries that are not
themselves LDAP Subentries is prohibited, as that would
significantly affect compatibility with [X501] services.
LDAP Subentries MAY be contained by, and will usually be
located in the directory information tree immediately
subordinate to their administrative points. LDAP
Subentries MAY also be contained by other LDAP Subentries
(the way organizational units may be contained by other
Reed [Page 4]
Expires October 6, 2001
INTERNET-DRAFT 6 April 2001
LDAP Subentry Schema
organizational units). Deep nesting of LDAP Subentries are
discouraged, but not prohibited. Developers are warned
that deep nesting of LDAP Subentries may not be supported
by all (or indeed, by any) LDAP server implementations.
For compatibility with [X501], a sub-tree made up of a
collection of LDAP Subentries may be mapped onto a single
(possibly very complex) [X501] subentry, and vice versa.
5.1.2Scope Rules
The default scope of an LDAP Subentry is limited to the
specific administrative area (or sub-area) in which it is
defined. Specifically, the subtree of the directory
namespace based at the administrative point most
immediately superior to the LDAP Subentry, down to but not
including any subordinate administrative points or areas of
the same aspect or type. Policy defined in an LDAP
Subentry is not inheritable, unless such inheritance is
explicitly defined by an application-specific policy.
If an LDAP Subentry is subordinate to another LDAP
Subentry, it takes the same default scope as the parent
LDAP Subentry.
Applications MAY define alternative scope semantics for
classes they define which are derived from the ldapSubEntry
class. This means that an application can derive a new
class from the ldapSubEntry class and add an attribute,
like SubTreeSpecification [X501] to define a new scope rule
for that application to use.
Applications MUST NOT define alternative scope rules for
auxiliary classes used to decorate entries of the
ldapSubEntry class. This restriction is required to avoid
having conflicting or contradictory scope definitions
applied by different applications to the same LDAP
Subentry.
Reed [Page 5]
Expires October 6, 2001
INTERNET-DRAFT 6 April 2001
LDAP Subentry Schema
6 Visibility Control
6.1 ldapSubentriesControl
This control is included in the searchRequest message as
part of the controls field of the LDAPMessage, as defined
in Section 4.1.12 of [RFC2251].
The controlType is set to "1.3.6.1.4.1.7628.5.101.1". The
criticality MAY be set to either TRUE or FALSE. The
controlValue is absent.
There is no corresponding response control defined.
LDAP servers that support this control MUST treat LDAP
Subentries as "operational objects" in much the same way
that "operational attributes" are not returned in search
results and [X511] read operations when only user
attributes are requested.
Entries which are not LDAP Subentries may be referenced in
the base object of search operations where the
ldapSubentriesControl is present in the request.
In the absence of the LDAP Subentries visibility control,
subentries are not visible to search operations UNLESS the
target/base of the operation is a subentry.
In presence of the subentry visibility control, ONLY
subentries are visible.
6.1.1Other LDAP operations
The ldapSubentriesControl is not defined for any LDAP
operation other than Search. However, an LDAPv3 Extension
MAY define a use of this control with that extension as
long as such use is consistent with this specification.
6.1.2Correspondence to [X511]
In presence of the visibility control, the semantics of the
LDAPSubentriesControl are in accordance with the indication
of the [X511] common argument serviceControls options
subentries being set.
Reed [Page 6]
Expires October 6, 2001
INTERNET-DRAFT 6 April 2001
LDAP Subentry Schema
In [X511] a ServiceControl option is used to govern the
visibility of [X501] subentries. The subentry
ServiceControl option is a specific bit of a bitstring
that, when set in the common arguments of an [X511] Search
or List operation, indicates that the operation is to
access ONLY the subentries found in the context of the list
or search. In fact, normal entries are explicitly NOT
returned in the result of a list or search operation when
the [X511] subentries ServiceControl is set.
Entries which are not subentries may be used in the base
object of list and search operations where the subentries
control is set.
The [X511] subentries ServiceControl has no meaning for
operations other than Search and List (i.e., it is not
defined for Read, Modify, Delete, etc.).
7 Security Considerations
LDAP Subentries will frequently be used to hold data which
reflects either the actual or intended behavior of the
directory service. As such, permission to read such
entries MAY need to be restricted to authorized users.
More importantly, if a directory service treats the
information in an LDAP Subentry as the authoritative source
of policy to be used to control the behavior of the
directory, then permission to create, modify, or delete
such entries MUST be carefully restricted to authorized
administrators.
8 References
[RFC2119] S. Bradner, "Key words for use in RFCs to
Indicate Requirement Levels", RFC 2119, March 1997
[RFC2251] S. Kille, M. Wahl, and T. Howes, "Lightweight
Directory Access Protocol (v3)", RFC 2251, December 1997
[X501] ITU-T Rec. X.501, "The Directory: Models", 1993 and
subsequent versions
[X501] ITU-T Rec. X.511, "The Directory: Abstract Service
Definition", 1993 and subsequent versions
Reed [Page 7]
Expires October 6, 2001
INTERNET-DRAFT 6 April 2001
LDAP Subentry Schema
9 Copyright Notice
Copyright (C) The Internet Society (2000). 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 assigns.
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."
10 Acknowledgements
The utility of subEntry object class was originally
suggested as a means to store Replica and Replication
Agreement information with a the lucid explanation by Mark
Wahl, (then of Innosoft), of how they could be used and
extended.
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
Reed [Page 8]
Expires October 6, 2001
INTERNET-DRAFT 6 April 2001
LDAP Subentry Schema
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
implementers 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.
11 Author's Address
Edwards E. Reed
Reed-Matthews, Inc.
1064 E 140 North
Lindon, UT 84042
USA
E-mail: eer@oncalldba.com
LDUP Mailing List: ietf-ldup@imc.org
LDAPEXT Mailing List: ietf-ldapext@netscape.com
Reed [Page 9]
Expires October 6, 2001
