For using ActiveDirectory authentication with autodeployment, I used a copy of auth.php and modified it, see attachment.
I used a 1 in the define variables, so it might be possible with some changes to authenticate against more DCs.
Changes to config.php
define ('LDAP_AUTH_1_SERVER', 'ad.company.com');
define ('LDAP_AUTH_1_VERSION', '3');
define ('LDAP_AUTH_1_USER', 'CN=Serviceaccount,OU=User,DC=company,DC=com');
define ('LDAP_AUTH_1_PASSWORD', 'password');
define ('LDAP_AUTH_1_SEARCH', 'OU=Users,DC=company,DC=com');
define ('LDAP_AUTH_1_USERNAME', 'sAMAccountName');
//require_once (dirname(__FILE__).'/inc/auth.php');
require_once (dirname(__FILE__).'/inc/auth_ldap.php');
auth LDAP Plugin