CakePHP 1.2: How do I lock a given controller from access from anyone but admins?

if (isset($this->params[Configure::read('Routing.admin')])) { //User is trying to access a page using the admin route
    if ($this->Session->check('someSessionVariable')) { //Check user has some session variable set.
    	// User is accessing an admin page and has permission, do something, or in most cases do nothing.
     } else { //No sessions set for user, redirect to login page.
    	$this->redirect('/yourLoginPage'); //Redirect
    }
}