OrbitaNET

This plug-in extends Simple LDAP Authentication plug-in <a href="https://wordpress.org/extend/plugins/simple-ldap-authentication" rel="ugc">Simple LDAP Authentication</a>. 
Plug-in works as followed:
Entered credentials are checked by all hash types available on LDAP-server (ssha, smd5, crypt/standart-des, crypt/enhanced, crypt/md5, crypt/blowfish, sha, clear, md5) by specified login.
If password is correct:
If user already exist in WordPress database
<ul>
<li>Password, name, surname, e-mail are changed to those existing on LDAP-server.</li>
</ul>
If no such user is in WordPress database:
If automatic user transfer is disabled by plug-in settings:
<ul>
<li>Existing user data is updated</li>
</ul>
If automatic user transfer is enabled by plug-in settings:
<ul>
<li>
Existing user data is updated
</li>
<li>
New user is created with profile received from LDAP-server.
</li>
</ul>
If the password was incorrect:
<ul>
<li>Wrong password error is shown.</li>
</ul>
Features
<ol>
<li>Update user data</li>
<li>Updates user password</li>
<li>Checks password hash using crypt/standart-des, crypt/enhanced, crypt/md5, crypt/blowfish, ssha, smd5, sha, md5</li>
</ol>

LDAP Authentication 2

Paul Ryan

jojaba

the_elusive

Anil Natha

pkarjala

Eduardo Larequi

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).

LDAP Authentication 2 vs Authorizer