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 …

Paul Ryan

jojaba

the_elusive

Eduardo Larequi

Anil Natha

pkarjala

Authorizer restricts access to a WordPress site to specific users, typically students enrolled in a university course. It maintains a list of approved users that you can edit to determine who has access. It also replaces the default WordPress login/authorization system with one relying on an external server, such as Google, CAS, LDAP, or an OAuth2 provider. Finally, Authorizer lets you limit invalid login attempts to prevent bots from compromising your users’ accounts.
View or contribute to the plugin source on GitHub: <a href="https://github.com/uhm-coe/authorizer" rel="nofollow ugc">https://github.com/uhm-coe/authorizer</a>
Authorizer requires the following:
<ul>
<li>CAS server (2.x, 3.x, 4.x, 5.x, 6.x, or 7.x) or LDAP server (plugin needs the URL)</li>
<li>PHP extensions: php-ldap, php-curl, php-dom</li>
</ul>
Authorizer provides the following options:
<ul>
<li>Authentication: WordPress accounts; Google accounts; CAS accounts; LDAP accounts; OAuth2 accounts</li>
<li>Login Access: All authenticated users (all local and all external can log in); Only specific users (all local and approved external users can log in)</li>
<li>View Access: Everyone (open access); Only logged in users</li>
<li>Limit Login Attempts: Progressively increase the amount of time required between invalid login attempts.</li>
<li>Shortcode: Use the <code>[authorizer_login_form]</code> shortcode to embed a wp_login_form() outside of wp-login.php.</li>
</ul>

Authorizer

Integrates nicely with Google hosted domain/s. Couldn't be happier with how it works!

Integrates well with Google Logins

I've experimented this plugin on a multisite and everything works pretty well.

Works great even on a multisite setup

Authorizer limits login attempts, restricts access to specific users, and authenticates against external sources (OAuth2, Google, LDAP, or CAS).

WPMU Ldap Authentication vs Authorizer