...
In the config file is a section named authentication. You can verify users logging into Open-AudIT Enterprise using their Open-AudIT Community credentials if you set auth_method_1 to openaudit in this section. You can have up to three methods of authentication. openaudit then htaccess are the defaults. These should mostly be left as their defaults unless a specific requirement is to be met. To enable MS Active Directory and/or OpenLDAP, see the bottom of this page.
To change these using the GUI in Open-AudIT navigate to menu -> Admin -> Configuration -> Authentication
...