protected function authenticate($username, $password) {
        $authenticator=$this->config()->authenticator_class;
        
        $member=$authenticator::authenticate(array(
                                                $this->config()->authenticator_username_field=>$username,
                                                'Password'=>$password
                                            ));
        
        return (!empty($member) && $member!==false && $member->exists()==true && Permission::check('KAPOST_API_ACCESS', 'any', $member));
    }