Aaron Axelsen

LDAP authentication is configured on a site-wide (as opposed to per-blog) level, so only Network Admin accounts have access to the configuration to LDAP connection information.
Please make sure you have PHP compiled with LDAP support. This will show up as an LDAP section in your phpinfo() if it is correct.
Remember – all the code for the plugin was contributed by volunteers, and you can show your gratitude by giving back to the community!
<h3>How It Works</h3>
When enabled, this plugin can automatically create WordPress user accounts and blogs for LDAP-authenticated users. Assuming user credentials authenticate against the LDAP server, creating local accounts and blogs follows this 
algorithm:
Create a new WPMU User, with LDAP username and a randomly generated password. 
Some user information, such as first and last name, is extracted from the 
 information returned from the LDAP server. 
Actions for user creation and activation are triggered. 
The user’s domain / URL are created depending on plugin configuration (i.e., 
 VHost vs SubDir). 
If the option is set, a blog is created, with path and name based on the LDAP 
 username and the blog is activated with the user being Administrator, and 
 appropriate actions are triggered.
It should be noted that even though a random password is created for a user (for WPMU accounts), it is never displayed to the user. This is intentional so that there is no confusion as to which password should be used; it will always be using LDAP credentials. As a result, though, if ever LDAP is disabled or if the server is unavailable, users created with LDAP authentication will be unable to log in unless their passwords are reset.

WPMU Ldap Authentication

A plugin to override the core WordPress authentication method in order to use a LDAP server for authentication.  Currently only supported on MultiSite …

frankkoenen

This plugin will enable WP authentication and role management from LDAP server. 
Users who log in to your WP site are authenticated by first matching the 
username input against an attribute to local the RDN. Then a bind is performed 
against the RDN. Upon successful bind, authentication is approved. Local WP 
user management is engaged by initializing and maintaining user DB records.
Simply create your users in your LDAP directly. Define access rights or “roles” 
to specific WP sites. When the user logs into the WP site, the local DB user 
entry is created.
Use LDAP to define users in one place for access to one or many WP sites.
User passwords in the local DB are replaced with jumbled text and are unusable. 
All password information is maintained in LDAP.
User information ( Display Name, Nick Name, Nice Name, First Name, Last Name ) 
are maintained in master form in LDAP and stored and updated (synced) to the 
local DB when the user logs in.
<h3>Features</h3>
<ul>
<li>Supports OpenLDAP</li>
<li>Supports TLS</li>
<li>syslog debugging</li>
<li>Centralized roles management.</li>
<li>Password expirary management.</li>
<li>Password reset management in user profile.</li>
<li>Works with WP Multi-Site setup.</li>
</ul>
<h3>Architecture</h3>
Simple LDAP adds an authentication filter to WordPress that authentication requests must pass. 
Consults LDAP for current role configuration.

Plugin Name: ldap_login_password_and_role_manager

Enables LDAP for user authentication, password management and role management.

WPMU Ldap Authentication vs Plugin Name: ldap_login_password_and_role_manager