Feature Discovery in Lightweight Directory Access Protocol (LDAP) (RFC3674)
Original Publication Date: 2003-Dec-01
Included in the Prior Art Database: 2003-Dec-17
Internet Society Requests For Comment (RFCs)
The Lightweight Directory Access Protocol (LDAP) is an extensible protocol with numerous elective features. This document introduces a general mechanism for discovery of elective features and extensions which cannot be discovered using existing mechanisms.
Network Working Group K. Zeilenga
Request for Comments: 3674 OpenLDAP Foundation
Category: Standards Track December 2003
Feature Discovery in 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 (C) The Internet Society (2003). All Rights Reserved.
The Lightweight Directory Access Protocol (LDAP) is an extensible
protocol with numerous elective features. This document introduces a
general mechanism for discovery of elective features and extensions
which cannot be discovered using existing mechanisms.
1. Background and Intended Use
The Lightweight Directory Access Protocol (LDAP) [RFC3377] is an
extensible protocol with numerous elective features. LDAP provides
mechanisms for a client to discover supported protocol versions,
controls, extended operations, Simple Authentication and Security
Layer (SASL) mechanisms, and subschema information. However, these
mechanisms are not designed to support general feature discovery.
This document describes a simple, general-purpose mechanism which
clients may use to discover the set of elective features supported by
a server. For example, this mechanism could be used by a client to
discover whether or not the server supports requests for all
operational attributes, e.g., "+" [RFC3673]. As another example,
this mechanism could be used to discover absolute true, e.g., "(&)"
and false, e.g., "(|)", search filters [T-F] support.
This document extends the LDAP Protocol Mechanism registry [RFC3383]
to support registration of values of the supportedFeatures attribute.
This registry is managed by the Internet Assigned Numbers Authority
Zeilenga Standards Track [Page 1]
RFC 3674 Feature Discovery in LDAP December 2003
Schema definitions are provided using LDAP description formats
[RFC2252]. Definitions provided here are formatted (line wrapped)
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. Discovery of supported features
Each elective feature whose support may be discovered SHALL be
identified by an Object Identifier (OID). A server advertises its
support for a given feature by providing the OID associated with the
feature as a value of the 'supportedFeatures' attribute held in the
root DSE. A client may examine the values of this attribute to
determine if a particular feature is supported by the server. A
client MUST ignore values it doesn't recognize as they refer to
elective features it doesn't implement.
Features associated with Standard Track protocol m...