$self->authen->config(
    DRIVER => [ 'DBI',
      DBH         => $self->dbh,
      TABLE       => 'user_info',
      CONSTRAINTS => {
        'user_info.username'     => '__CREDENTIAL_1__',
        'MD5:user_info.password' => '__CREDENTIAL_2__'
      },
    ],

    STORE                => 'Session',
    LOGOUT_RUNMODE       => 'logout',
    LOGIN_RUNMODE        => 'login',
    POST_LOGIN_RUNMODE   => 'okay',
    RENDER_LOGIN         => \&my_login_form,
  );