Posts tagged ‘Auth’

Setting layout in error pages based on Auth status with CakePHP

CakePHP error pages load within the default layout. This works most of the time, but for some applications, I have a different layout file for logged in users. For example, the navigation changes when a user is logged in. Normally including the proper elements based on the user’s login status would be sufficient, but for a recent project, the entire layout changes based on the user status. Therefore I needed to find a way to be sure the proper layout was loaded when 404 errors appeared.

First thing to do is create an app_error.php file in your /app directory. Your AppError class should extend the ErrorHandler class. Now extend the error404 method. You’ll have a reference to the controller via $this->controller so that you can access the Auth component. So just see if we have a valid logged in user, and if not, set the layout to ‘guest’, or whatever your layout happens to be named.

Be sure to call the parent method, passing in the $params variable to be sure the error is handled properly by the ErrorHandler’s error404 method.

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<?php
class AppError extends ErrorHandler {

    function error404($params) {
            if( !$this->controller->Auth->User() ){
                $this->controller->layout = "guest";
            }
            parent::error404($params);
    }

}

Converting Rail’s RESTful Authentication to PHP

A few months back we were rebuilding an existing site; the mandate was to use PHP for the upcoming release, but the existing site used Ruby on Rail’s RESTful Authentication gem to encrypt user passwords against a unique salt. Each user had both an encrypted password and a salt value that was being updated every time the user successfully logged in. Pretty smart.

Our problem was that we had to re-create the hashing of the user’s password so existing users could log into the site using their old password. With the code below, we are able to hash the user’s entered password in the same way that the Rails app did, allowing authentication to function properly in the new application. Fortunately the existing application used the default hashing method (we didn’t have access to the old site’s source code), so it was just a matter of digging around GIT to understand how the hashing process worked.

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<?php
// $salt variable as retrieved from user's row based on supplied email address
$salt = '36493cef361b8b180863fe3e2685473f676359df';

$password = $_POST['password'];

//NOTE: this assumes a default Restful Auth setup
$password = sha1('--' . $salt . '--' . $password . '--');

//supplied password should now match encrypted database value if entered correctly
?>

Integrating Facebook Connect with CakePHP’s Auth Component

This post is out of date; place check out any of the numerous Cakephp 2+ versions of Facebook Websites implementations out there.

I wanted to be able to leverage all of the advantages of using Cake’s built in Auth component in my latest application; problem was that the application needed to allow for both normal user accounts and Facebook Connect generated user accounts. I struggled for a while to find the most seamless approach, and then it clicked — dynamically set Auth->fields.

First, drop the facebook client libraries in a app/vendors/facebook folder. Then, in your app_controller, import the classes, and set some properties:

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<?php
App::import('Vendor', 'facebook/facebook');

class AppController extends Controller {
    var $components = array('Auth');
    var $uses = array('User');
    var $facebook;
    var $__fbApiKey = 'your_key';
    var $__fbSecret = 'your_secret';
}

Next we’ll overwrite the inherited __construct method to instantiate a Facebook Object:

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  function __construct() {
    parent::__construct();
       
    // Prevent the 'Undefined index: facebook_config' notice from being thrown.
    $GLOBALS['facebook_config']['debug'] = NULL;
       
    // Create a Facebook client API object.
    $this->facebook = new Facebook($this->__fbApiKey, $this->__fbSecret);
  }

In our beforeFilter method, we define the default Auth properties, call a private __checkFBStatus method, and pass any user data to the view:

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function beforeFilter() {
    // Authentication settings
    $this->Auth->fields = array('username' => 'email', 'password' => 'password');
    $this->Auth->logoutRedirect = '/';

    //check to see if user is signed in with facebook
    $this->__checkFBStatus();

    //send all user info to the view
    $this->set('user', $this->Auth->user());
}

Next we’ll define the private method __checkFBStatus that’s called in our beforeFilter method. First we check to make sure $this->Auth->User isn’t already set by a normal user account, and we check to see if there’s a logged in facebook user. The logged in facebook user is available after we use the JavaScript API to log facebook users into the site.

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    private function __checkFBStatus(){
        //check to see if a user is not logged in, but a facebook user_id is set
        if(!$this->Auth->User() &amp;&amp; $this->facebook->get_loggedin_user()):

Next, see if this user has already logged in, and therefore already has an entry in our User table:

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            //see if this facebook id is in the User database; if not, create the user using their fbid hashed as their password
            $user_record =
                $this->User->find('first', array(
                    'conditions' => array('fbid' => $this->facebook->get_loggedin_user()),
                    'fields' => array('User.fbid', 'User.fbpassword', 'User.password'),
                    'contain' => array()
                ));

If no record was found, we create a new record for this user. We are setting 3 variables, fbid, fbpassword, and password. The fbpassword field will hold a randomly generated 20 character string un-hashed so that we can access the value of the field directly from the database. We retrieve this value based on the fbid field, hash it, and that’s our password as the Auth Component expects:

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            //create new user
            if(empty($user_record)):
                $user_record['fbid'] = $this->facebook->get_loggedin_user();
                $user_record['fbpassword'] = $this->__randomString();
                $user_record['password'] = $this->Auth->password($user_record['fbpassword']);
               
                $this->User->create();
                $this->User->save($user_record);
            endif;

We need to then update our Auth Component’s fields property to use fbid as the username.

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            //change the Auth fields
            $this->Auth->fields = array('username' => 'fbid', 'password' => 'password');

            //log in the user with facebook credentials
            $this->Auth->login($user_record);
           
        endif;
    }

Here’s the complete app_controller.php:

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<?php
App::import('Vendor', 'facebook/facebook');

class AppController extends Controller {
    var $components = array('Auth');
    var $uses = array('User');
  var $facebook;
  var $__fbApiKey = 'your_key';
  var $__fbSecret = 'your_secret';
   
  function __construct() {
    parent::__construct();
       
    // Prevent the 'Undefined index: facebook_config' notice from being thrown.
    $GLOBALS['facebook_config']['debug'] = NULL;
       
    // Create a Facebook client API object.
    $this->facebook = new Facebook($this->__fbApiKey, $this->__fbSecret);
  }

    function beforeFilter() {
    // Authentication settings
    $this->Auth->fields = array('username' => 'email', 'password' => 'password');
    $this->Auth->logoutRedirect = '/';

        //check to see if user is signed in with facebook
        $this->__checkFBStatus();

        //send all user info to the view
        $this->set('user', $this->Auth->user());
  }

    private function __checkFBStatus(){
        //check to see if a user is not logged in, but a facebook user_id is set
        if(!$this->Auth->User() &amp;&amp; $this->facebook->get_loggedin_user()):

            //see if this facebook id is in the User database; if not, create the user using their fbid hashed as their password
            $user_record =
                $this->User->find('first', array(
                    'conditions' => array('fbid' => $this->facebook->get_loggedin_user()),
                    'fields' => array('User.fbid', 'User.fbpassword', 'User.password'),
                    'contain' => array()
                ));

            //create new user
            if(empty($user_record)):
                $user_record['fbid'] = $this->facebook->get_loggedin_user();
                $user_record['fbpassword'] = $this->__randomString();
                $user_record['password'] = $this->Auth->password($user_record['fbpassword']);
               
                $this->User->create();
                $this->User->save($user_record);
            endif;

            //change the Auth fields
            $this->Auth->fields = array('username' => 'fbid', 'password' => 'password');

            //log in the user with facebook credentials
            $this->Auth->login($user_record);
           
        endif;
    }

    private function __randomString($minlength = 20, $maxlength = 20, $useupper = true, $usespecial = false, $usenumbers = true){
        $charset = "abcdefghijklmnopqrstuvwxyz";
        if ($useupper) $charset .= "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        if ($usenumbers) $charset .= "0123456789";
        if ($usespecial) $charset .= "~@#$%^*()_+-={}|][";
        if ($minlength > $maxlength) $length = mt_rand ($maxlength, $minlength);
        else $length = mt_rand ($minlength, $maxlength);
        $key = '';
        for ($i=0; $i<$length; $i++){
            $key .= $charset[(mt_rand(0,(strlen($charset)-1)))];
        }
        return $key;
    }

}
?>

Next we need to make a few changes to our default.ctp layout; first add the facebook namespace:

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<html xmlns="http://www.w3.org/1999/xhtml" xmlns:fb="http://www.facebook.com/2008/fbml">

Add these 2 javascript snippets (be sure your xd_receiver.htm file is accessible in your webroot):

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<script type="text/javascript" src="http://static.ak.connect.facebook.com/js/api_lib/v0.4/FeatureLoader.js.php"></script>
<script type="text/javascript">FB.init("your_api_key","/xd_receiver.htm");</script>

Last step, place your login and logout buttons in your default view. Few things to point out here; onlogin=”window.location.reload();” will cause the page to reload after a successful Facebook Connect login. This is how we are able to access $this->facebook->get_loggedin_user() in our app_controller to force the manual Auth login. If the user is a facebook user (determined with $user['User']['fbid'] > 0), add an onclick event that calls the FB.Connect.logout() function with a redirect URL as the parameter. This will log the User out of the Auth Component after it logs the user out of Facebook.

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<?php
            if(!empty($user)):
                if($user['User']['fbid'] > 0):
                    echo $html->link('logout', '#', array('onclick' => 'FB.Connect.logout(function() { document.location = \'http://your_server/users/logout/\'; }); return false;'));
                else:
                    echo $html->link('logout', array('controller' => 'users', 'action' => 'logout'));
                endif;
            else:
                echo '<fb:login-button onlogin="window.location.reload();"></fb:login-button>';
            endif;
?>

One last thing to consider, for security reasons… In your login method, be sure only users with fbid = 0 can login via the normal auth fields (username / password). Just an extra precaution considering you have an unhashed password in your database for those facebook users.

Hope that helps someone else out. Let me know if you run into any problems, I slapped this post up quickly and hopefully didn’t make many mistakes. And per Matt’s spot-on recommendation (via pseudocoder.com), I’m working on rolling this into a plugin… Will post when it’s complete.