1. Introduction
Abstract
Each attribute stored in a Lightweight Directory Access Protocol (LDAP) directory, whose values may be transferred in the LDAP protocol, has a defined syntax that constrains the structure and format of its values. The comparison semantics for values of a syntax are not part of the syntax definition but are instead provided through separately defined matching rules. Matching rules specify an argument, an assertion value, which also has a defined syntax. This document defines a base set of syntaxes and matching rules for use in defining attributes for LDAP directories.
1. Introduction
Each attribute stored in a Lightweight Directory Access Protocol (LDAP) directory [RFC4510], whose values may be transferred in the LDAP protocol [RFC4511], has a defined syntax (i.e., data type) that constrains the structure and format of its values. The comparison semantics for values of a syntax are not part of the syntax definition but are instead provided through separately defined matching rules. Matching rules specify an argument, an assertion value, which also has a defined syntax. This document defines a base set of syntaxes and matching rules for use in defining attributes for LDAP directories.
Readers are advised to familiarize themselves with the Directory Information Models [RFC4512] before reading the rest of this document. Section 3 provides definitions for the base set of LDAP syntaxes. Section 4 provides definitions for the base set of matching rules for LDAP.
This document is an integral part of the LDAP technical specification [RFC4510], which obsoletes the previously defined LDAP technical specification, RFC 3377, in its entirety.
Sections 4, 5, and 7 of RFC 2252 are obsoleted by [RFC4512]. The remainder of RFC 2252 is obsoleted by this document. Sections 6 and 8 of RFC 2256 are obsoleted by this document. The remainder of RFC 2256 is obsoleted by [RFC4519] and [RFC4512]. All but Section 2.11 of RFC 3698 is obsoleted by this document.
A number of schema elements that were included in the previous revision of the LDAP technical specification are not included in this revision of LDAP. Public Key Infrastructure schema elements are now specified in [RFC4523]. Unless reintroduced in future technical specifications, the remainder are to be considered Historic.
The changes with respect to RFC 2252 are described in Appendix B of this document.
2. Conventions
In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in BCP 14, RFC 2119 [RFC2119].
Syntax definitions are written according to the <SyntaxDescription> ABNF [RFC4234] rule specified in [RFC4512], and matching rule definitions are written according to the <MatchingRuleDescription> ABNF rule specified in [RFC4512], except that the syntax and matching rule definitions provided in this document are line-wrapped for readability. When such definitions are transferred as attribute values in the LDAP protocol (e.g., as values of the ldapSyntaxes and matchingRules attributes [RFC4512], respectively), then those values would not contain line breaks.