Simple Zend Framework admin controller secured by basic HTTP authentication

AdminController.php

<?php

/**
 * Admin area.
 */
class AdminController extends Zend_Controller_Action {
    
    public function preDispatch() {
        
        if (
            !isset($_SERVER['PHP_AUTH_USER']) 
            || !isset($_SERVER['PHP_AUTH_PW']) 
            || 'admin' != $_SERVER['PHP_AUTH_USER'] 
            || 'admin' != $_SERVER['PHP_AUTH_PW']
        ) {
            $this->getResponse()->setHeader('WWW-Authenticate', 'Basic realm="Authentication required"');
            $this->getResponse()->setHttpResponseCode(401);
            if ('not-auth' !== $this->getRequest()->getActionName()) {
                $this->_forward('not-auth');
            }
        }
    }
    
    public function indexAction() { }
    
    public function notAuthAction() { }
    
}