RFC 1823 (rfc1823) - Page 1 of 22

The LDAP Application Program Interface

Network Working Group                                           T. Howes
Request for Comments: 1823                                      M. Smith
Category: Informational                          University of  Michigan
                                                             August 1995


                 The LDAP Application Program Interface

Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

1.  Introduction

   This document defines a C language application program interface to
   the lightweight directory access protocol (LDAP). The LDAP API is
   designed to be powerful, yet simple to use. It defines compatible
   synchronous and asynchronous interfaces to LDAP to suit a wide
   variety of applications.  This document gives a brief overview of the
   LDAP model, then an overview of how the API is used by an application
   program to obtain LDAP information.  The API calls are described in
   detail, followed by an appendix that provides some example code
   demonstrating the use of the API.

2.  Overview of the LDAP Model

   LDAP is the lightweight directory access protocol, described in [2]
   and [7]. It can provide a lightweight frontend to the X.500 directory
   [1], or a stand-alone service. In either mode, LDAP is based on a
   client-server model in which a client makes a TCP connection to an
   LDAP server, over which it sends requests and receives responses.

   The LDAP information model is based on the entry, which contains
   information about some object (e.g., a person).  Entries are composed
   of attributes, which have a type and one or more values. Each
   attribute has a syntax that determines what kinds of values are
   allowed in the attribute (e.g., ASCII characters, a jpeg photograph,
   etc.) and how those values behave during directory operations (e.g.,
   is case significant during comparisons).

   Entries are organized in a tree structure, usually based on
   political, geographical, and organizational boundaries. Each entry is
   uniquely named relative to its sibling entries by its relative
   distinguished name (RDN) consisting of one or more distinguished
   attribute values from the entry.  At most one value from each
   attribute may be used in the RDN.  For example, the entry for the



Howes & Smith                Informational