Authenticate user using CAS.

You have to set it up correctly in conf/bootstrap_plugins.php using the following keys in $PLUGINS["AUTH_DRIVER"]["OPTIONS"] array:

      CAS_SERVER: hostname of the CAS server (example: login.example.com)
      CAS_URI: URI where CAS server is installed on (example: /cas)
      CAS_PORT: port where CAS server is listening on waiting for connections
      USERS_FILEPATH: Inherited from auth.serial. File where user data is stored

So, if your CAS server is at https://login.example.com:8443/cas and you want to store user data at AJXP_DATA_PATH/plugins/auth.serial/users.ser, your AUTH_DRIVER section at conf/bootstrap_plugins.php will look like this:

      "AUTH_DRIVER" => array(
        "NAME"    => "cas",
        "OPTIONS" => array(
          "CAS_SERVER" => "login.example.com",
          "CAS_URI" => "/cas",
          "CAS_PORT" => "8443",
          "USERS_FILEPATH" => "AJXP_DATA_PATH/plugins/auth.serial/users.ser"
        )
      )