It took me a while to get ldap auth working with yii, so I write it down here, maybe it can be of some use. Yii does not have a ldap class by itself, but you can extend it for example with Zend classes. To authenticate users at you page via ldap, change protected/components/UserIdentity.php in the following way: On top of the file add:
 
     
```php 
Yii::import('application.vendors.*'); require_once('Zend/Ldap.php');  
```
Delete or comment out everything in the authenticate() function. Then add
 
     
```php 
$options = array(
'host' => 'your.ldap.host.com',
'username' => 'your_admin_users_username',$this->errorCode=self::ERROR_NONE;
}
return !$this->errorCode;
 
```
For this to work you need Exception.php, Ldap.php and the Ldap folder from the library folder of a Zend installation in the folder protected/vendors/Zend