7 INTERNET-DRAFT Kurt D. Zeilenga
8 Intended Category: Standard Track OpenLDAP Foundation
9 Expires in six months 17 May 2002
12 Feature Discovery in LDAP
13 <draft-zeilenga-ldap-features-03.txt>
18 This document is an Internet-Draft and is in full conformance with all
19 provisions of Section 10 of RFC2026.
21 This document is intended to be, after appropriate review and
22 revision, submitted to the RFC Editor as an Standard Track document.
23 Distribution of this memo is unlimited. Technical discussion of this
24 document will take place on the IETF LDAP Extension Working Group
25 mailing list <ietf-ldapext@netscape.com>. Please send editorial
26 comments directly to the author <Kurt@OpenLDAP.org>.
28 Internet-Drafts are working documents of the Internet Engineering Task
29 Force (IETF), its areas, and its working groups. Note that other
30 groups may also distribute working documents as Internet-Drafts.
31 Internet-Drafts are draft documents valid for a maximum of six months
32 and may be updated, replaced, or obsoleted by other documents at any
33 time. It is inappropriate to use Internet-Drafts as reference
34 material or to cite them other than as ``work in progress.''
36 The list of current Internet-Drafts can be accessed at
37 <http://www.ietf.org/ietf/1id-abstracts.txt>. The list of
38 Internet-Draft Shadow Directories can be accessed at
39 <http://www.ietf.org/shadow.html>.
41 Copyright 2002, The Internet Society. All Rights Reserved.
43 Please see the Copyright section near the end of this document for
49 The Lightweight Directory Access Protocol (LDAP) is an extensible
50 protocol with numerous elective features. This document introduces a
51 general mechanism for discovery of elective features and extensions
52 which cannot be discovered using existing mechanisms.
58 Zeilenga draft-zeilenga-ldap-features-03 [Page 1]
60 INTERNET-DRAFT LDAP supportedFeatures 17 May 2002
63 1. Background and Intended Use
65 LDAP [RFC2251] is an extensible protocol with numerous elective
66 features. LDAP provides mechanisms for a client to discover supported
67 protocol versions, controls, extended operations, SASL mechanisms, and
68 subschema information. However, these mechanisms are not designed to
69 support general feature discovery.
71 This document describes a simple, general-purpose mechanism which
72 clients may use to discover the set of features supported by a server.
74 Schema definitions are provided using LDAPv3 description formats
75 [RFC2252]. Definitions provided here are formatted (line wrapped) for
78 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
79 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
80 document are to be interpreted as described in BCP 14 [RFC2119].
83 2. Discovery of supported features
85 Each feature whose support may be discovered SHALL be identified by an
86 Object Identifier (OID). A server advertises its support for a given
87 feature by providing the OID associated with the feature as a value of
88 the supportedFeatures attribute held in the root DSE. A client may
89 examine the values of this attribute to determine if a particular
90 feature is supported by the server.
92 The supportedFeatures attribute type is described as follows:
94 ( 1.3.6.1.4.1.4203.1.3.5
95 NAME 'supportedFeatures'
96 DESC 'features supported by the server'
97 EQUALITY objectIdentifierMatch
98 SYNTAX 1.3.6.1.4.1.1466.115.121.1.38
101 Servers MUST be capable of recognizing this attribute type by the name
102 'supportedFeatures'. Servers MAY recognize the attribute type by
106 3. Security Considerations
108 As rogue clients can discover features of a server by other means
109 (such as by trial and error), this feature discovery mechanism is not
110 believed to introduce any new security risk to LDAP.
114 Zeilenga draft-zeilenga-ldap-features-03 [Page 2]
116 INTERNET-DRAFT LDAP supportedFeatures 17 May 2002
119 4. IANA Considerations
121 It is requested that IANA register the LDAP 'supportedFeatures'
122 descriptor used in this document per the following registration
125 Subject: Request for LDAP Descriptor Registration
126 Descriptor (short name): supportedFeatures
127 Object Identifier: 1.3.6.1.4.1.4203.1.3.5
128 Person & email address to contact for further information:
129 Kurt Zeilenga <kurt@OpenLDAP.org>
130 Usage: Attribute Type
131 Specification: RFCXXXX
132 Author/Change Controller: IESG
135 This OID was assigned [ASSIGN] by OpenLDAP Foundation under its IANA
136 assigned private enterprise allocation [PRIVATE] for use in this
142 This document is based upon input from the IETF LDAPext working group.
152 7. Normative References
154 [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate
155 Requirement Levels", BCP 14 (also RFC 2119), March 1997.
157 [RFC2251] M. Wahl, T. Howes, S. Kille, "Lightweight Directory Access
158 Protocol (v3)", RFC 2251, December 1997.
160 [RFC2252] M. Wahl, A. Coulbeck, T. Howes, S. Kille, "Lightweight
161 Directory Access Protocol (v3): Attribute Syntax
162 Definitions", RFC 2252, December 1997.
165 8. Informative References
170 Zeilenga draft-zeilenga-ldap-features-03 [Page 3]
172 INTERNET-DRAFT LDAP supportedFeatures 17 May 2002
177 Copyright 2002, The Internet Society. All Rights Reserved.
179 This document and translations of it may be copied and furnished to
180 others, and derivative works that comment on or otherwise explain it
181 or assist in its implementation may be prepared, copied, published and
182 distributed, in whole or in part, without restriction of any kind,
183 provided that the above copyright notice and this paragraph are
184 included on all such copies and derivative works. However, this
185 document itself may not be modified in any way, such as by removing
186 the copyright notice or references to the Internet Society or other
187 Internet organizations, except as needed for the purpose of
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190 or as required to translate it into languages other than English.
192 The limited permissions granted above are perpetual and will not be
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195 This document and the information contained herein is provided on an
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197 ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED,
198 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
199 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
200 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
226 Zeilenga draft-zeilenga-ldap-features-03 [Page 4]