8 draft-legg-ldap-acm-admin-02.txt Adacel Technologies
9 Intended Category: Standards Track February 25, 2003
12 Access Control Administration in LDAP
14 Copyright (C) The Internet Society (2003). All Rights Reserved.
19 This document is an Internet-Draft and is in full conformance with
20 all provisions of Section 10 of RFC2026.
22 Internet-Drafts are working documents of the Internet Engineering
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38 Distribution of this document is unlimited. Comments should be sent
39 to the LDUP working group mailing list <ietf-ldup@imc.org> or to the
42 This Internet-Draft expires on 25 August 2003.
47 This document adapts the X.500 directory administrative model, as it
48 pertains to access control administration, for use by the Lightweight
49 Directory Access Protocol. The administrative model partitions the
50 Directory Information Tree for various aspects of directory data
51 administration, e.g. subschema, access control and collective
52 attributes. This document provides the particular definitions that
53 support access control administration, but does not define a
54 particular access control scheme.
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65 1. Abstract ...................................................... 1
66 2. Table of Contents ............................................. 2
67 3. Introduction .................................................. 2
68 4. Conventions ................................................... 2
69 5. Access Control Administrative Areas ........................... 3
70 6. Access Control Scheme Indication .............................. 3
71 7. Access Control Information .................................... 4
72 8. Access Control Subentries ..................................... 4
73 9. Applicable Access Control Information ......................... 5
74 10. Security Considerations ...................................... 6
75 11. Acknowledgements ............................................. 6
76 12. IANA Considerations .......................................... 6
77 13. Normative References ......................................... 7
78 14. Informative References ....................................... 7
79 15. Copyright Notice ............................................. 7
80 16. Author's Address ............................................. 8
85 This document adapts the X.500 directory administrative model [X501],
86 as it pertains to access control administration, for use by the
87 Lightweight Directory Access Protocol (LDAP) [RFC3377].
89 The administrative model [ADMIN] partitions the Directory Information
90 Tree (DIT) for various aspects of directory data administration, e.g.
91 subschema, access control and collective attributes. The parts of
92 the administrative model that apply to every aspect of directory data
93 administration are described in [ADMIN]. This document describes the
94 administrative framework for access control.
96 An access control scheme describes the means by which access to
97 directory information, and potentially to access rights themselves,
98 may be controlled. This document describes the framework for
99 employing access control schemes but does not define a particular
100 access control scheme. Two access control schemes known as Basic
101 Access Control and Simplified Access Control are defined by [BAC].
102 Other access control schemes may be defined by other documents.
104 This document is derived from, and duplicates substantial portions
105 of, Sections 4 and 8 of [X501].
109 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
110 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
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119 document are to be interpreted as described in RFC 2119 [RFC2119].
121 Schema definitions are provided using LDAP description formats
122 [RFC2252]. Note that the LDAP descriptions have been rendered with
123 additional white-space and line breaks for the sake of readability.
126 5. Access Control Administrative Areas
128 The specific administrative area [ADMIN] for access control is termed
129 an Access Control Specific Area (ACSA). The root of the ACSA is
130 termed an Access Control Specific Point (ACSP) and is represented in
131 the DIT by an administrative entry [ADMIN] which includes
132 accessControlSpecificArea as a value of its administrativeRole
133 operational attribute [SUBENTRY].
135 An ACSA MAY be partitioned into subtrees termed inner administrative
136 areas [ADMIN]. Each such inner area is termed an Access Control
137 Inner Area (ACIA). The root of the ACIA is termed an Access Control
138 Inner Point (ACIP) and is represented in the DIT by an administrative
139 entry which includes accessControlInnerArea as a value of its
140 administrativeRole operational attribute.
142 An administrative entry can never be both an ACSP and an ACIP. The
143 corresponding values can therefore never be present simultaneously in
144 the administrativeRole attribute.
146 Each entry necessarily falls within one and only one ACSA. Each such
147 entry may also fall within one or more ACIAs nested inside the ACSA
148 containing the entry.
150 An ACSP or ACIP has zero, one or more subentries that contain Access
151 Control Information (ACI).
154 6. Access Control Scheme Indication
156 The access control scheme (e.g. Basic Access Control [BAC]) in force
157 in an ACSA is indicated by the accessControlScheme operational
158 attribute contained in the administrative entry for the relevant
161 The LDAP description [RFC2252] for the accessControlScheme
162 operational attribute is:
164 ( 2.5.24.1 NAME 'accessControlScheme'
165 EQUALITY objectIdentifierMatch
166 SYNTAX 1.3.6.1.4.1.1466.115.121.1.38
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175 SINGLE-VALUE USAGE directoryOperation )
177 An access control scheme conforming to the access control framework
178 described in this document MUST define a distinct OBJECT IDENTIFIER
179 value to identify it through the accessControlScheme attribute.
180 Object Identifier Descriptors for access control scheme identifiers
181 may be registered with IANA [RFC3383].
183 Only administrative entries for ACSPs are permitted to contain an
184 accessControlScheme attribute. If the accessControlScheme attribute
185 is absent from a given ACSP, the access control scheme in force in
186 the corresponding ACSA, and its effect on operations, results and
187 errors, is implementation defined.
189 Any entry or subentry in an ACSA is permitted to contain ACI if and
190 only if such ACI is permitted by, and consistent with, the access
191 control scheme identified by the value of the accessControlScheme
192 attribute of the ACSP.
195 7. Access Control Information
197 There are three categories of Access Control Information (ACI):
198 entry, subentry and prescriptive.
200 Entry ACI applies to only the entry or subentry in which it appears,
201 and the contents thereof. Subject to the access control scheme, any
202 entry or subentry MAY hold entry ACI.
204 Subentry ACI applies to only the subentries of the administrative
205 entry in which it appears. Subject to the access control scheme, any
206 administrative entry, for any aspect of administration, MAY hold
209 Prescriptive ACI applies to all the entries within a subtree or
210 subtree refinement of an administrative area (either an ACSA or an
211 ACIA), as defined by the subtreeSpecification attribute of the
212 subentry in which it appears. Prescriptive ACI is only permitted in
213 subentries of an ACSP or ACIP. Prescriptive ACI in the subentries of
214 a particular administrative point never applies to the same or any
215 other subentry of that administrative point, but does apply to the
216 subentries of subordinate administrative points, where those
217 subentries are within the subtree or subtree refinement.
220 8. Access Control Subentries
222 Each subentry which contains prescriptive ACI MUST have
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231 accessControlSubentry as a value of its objectClass attribute. Such
232 a subentry is called an access control subentry.
234 The LDAP description [RFC2252] for the accessControlSubentry
235 auxiliary object class is:
237 ( 2.5.17.1 NAME 'accessControlSubentry' AUXILIARY )
239 A subentry of this object class MUST contain at least one
240 prescriptive ACI attribute of a type consistent with the value of the
241 accessControlScheme attribute of the corresponding ACSP.
243 The subtree or subtree refinement for an access control subentry is
244 termed a Directory Access Control Domain (DACD). A DACD can contain
245 zero entries, and can encompass entries that have not yet been added
246 to the DIT, but does not extend beyond the scope of the ACSA or ACIA
247 with which it is associated.
249 Since a subtreeSpecification may define a subtree refinement, DACDs
250 within a given ACSA may arbitrarily overlap.
253 9. Applicable Access Control Information
255 Although particular items of ACI may specify attributes or values as
256 the protected items, ACI is logically associated with entries.
258 The ACI that is considered in access control decisions regarding an
261 (1) Entry ACI from that particular entry.
263 (2) Prescriptive ACI from access control subentries whose DACDs
264 contain the entry. Each of these access control subentries is
265 necessarily either a subordinate of the ACSP for the ACSA
266 containing the entry, or a subordinate of the ACIP for an ACIA
267 that contains the entry.
269 The ACI that is considered in access control decisions regarding a
272 (1) Entry ACI from that particular subentry.
274 (2) Prescriptive ACI from access control subentries whose DACDs
275 contain the subentry, excluding those belonging to the same
276 administrative point as the subentry for which the decision is
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287 (3) Subentry ACI from the administrative point associated with the
291 10. Security Considerations
293 This document defines a framework for employing an access control
294 scheme, i.e. the means by which access to directory information and
295 potentially to access rights themselves may be controlled, but does
296 not itself define any particular access control scheme. The degree
297 of protection provided, and any security risks, are determined by the
298 provisions of the access control schemes (defined elsewhere) making
299 use of this framework.
301 Security considerations that apply to directory administration in
302 general [ADMIN] also apply to access control administration.
307 This document is derived from, and duplicates substantial portions
308 of, Sections 4 and 8 of [X501].
311 12. IANA Considerations
313 The Internet Assigned Numbers Authority (IANA) is requested to update
314 the LDAP descriptors registry as indicated by the following
317 Subject: Request for LDAP Descriptor Registration
318 Descriptor (short name): accessControlScheme
319 Object Identifier: 2.5.24.1
320 Person & email address to contact for further information:
321 Steven Legg <steven.legg@adacel.com.au>
322 Usage: attribute type
323 Specification: RFC XXXX
324 Author/Change Controller: IESG
326 Subject: Request for LDAP Descriptor Registration
327 Descriptor (short name): accessControlSubentry
328 Object Identifier: 2.5.17.1
329 Person & email address to contact for further information:
330 Steven Legg <steven.legg@adacel.com.au>
332 Specification: RFC XXXX
333 Author/Change Controller: IESG
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343 13. Normative References
345 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
346 Requirement Levels", BCP 14, RFC 2119, March 1997.
348 [RFC2252] Wahl, M., Coulbeck, A., Howes, T. and S. Kille,
349 "Lightweight Directory Access Protocol (v3): Attribute
350 Syntax Definitions", RFC 2252, December 1997.
352 [RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access
353 Protocol (v3): Technical Specification", RFC 3377,
356 [RFC3383] Zeilenga, K., "Internet Assigned Numbers Authority (IANA
357 Considerations for the Lightweight Directory Access
358 Protocol (LDAP)", BCP 64, RFC 3383, September 2002.
360 [ADMIN] Legg, S., "Directory Administrative Model in LDAP",
361 draft-legg-ldap-admin-xx.txt, a work in progress, February
364 [SUBENTRY] Zeilenga, K. and S. Legg, "Subentries in LDAP",
365 draft-zeilenga-ldap-subentry-xx.txt, a work in progress,
369 14. Informative References
371 [BAC] Legg, S., "Basic and Simplified Access Control in LDAP",
372 draft-legg-ldap-acm-bac-xx.txt, a work in progress,
375 [COLLECT] Zeilenga, K., "Collective Attributes in LDAP",
376 draft-zeilenga-ldap-collective-xx.txt, a work in progress,
379 [X501] ITU-T Recommendation X.501 (02/2001), Information
380 technology - Open Systems Interconnection - The Directory:
386 Copyright (C) The Internet Society (2003). All Rights Reserved.
388 This document and translations of it may be copied and furnished to
389 others, and derivative works that comment on or otherwise explain it
390 or assist in its implementation may be prepared, copied, published
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399 and distributed, in whole or in part, without restriction of any
400 kind, provided that the above copyright notice and this paragraph are
401 included on all such copies and derivative works. However, this
402 document itself may not be modified in any way, such as by removing
403 the copyright notice or references to the Internet Society or other
404 Internet organizations, except as needed for the purpose of
405 developing Internet standards in which case the procedures for
406 copyrights defined in the Internet Standards process must be
407 followed, or as required to translate it into languages other than
410 The limited permissions granted above are perpetual and will not be
411 revoked by the Internet Society or its successors or assigns.
413 This document and the information contained herein is provided on an
414 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
415 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
416 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
417 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
418 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
424 Adacel Technologies Ltd.
426 Brighton, Victoria 3186
429 Phone: +61 3 8530 7710
431 EMail: steven.legg@adacel.com.au
434 Appendix A - Changes From Previous Drafts
436 A.1 Changes in Draft 01
438 Section 4 has been extracted to become a separate Internet draft,
439 draft-legg-ldap-admin-00.txt. The subsections of Section 5 have
440 become the new Sections 4 to 8. Editorial changes have been made to
441 accommodate this split. No technical changes have been introduced.
443 A.2 Changes in Draft 02
445 RFC 3377 replaces RFC 2251 as the reference for LDAP.
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455 An IANA Considerations section has been added.
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