Facebook chat provides two authentication mechanisms for authenticating chat client users. DIGEST-MD5 require chat client users to enter their username and password, while X-FACEBOOK-PLATFORM can be used to provide better user experience by using simple Facebook Platform authentication. In this blog post, I will demonstrate how to use Jaxl library for X-FACEBOOK-PLATFORM authentication.

Echobot using X-FACEBOOK-PLATFORM
Setup Jaxl library on your system and edit packaged sample echobot application with facebook user account details. Alternately you can also specify connecting user details inside jaxl.ini configuration file.

        $jaxl = new JAXL(array(
                'user'=>'fbUsername',
                'pass'=>'', // Not required, we will use user session key instead
                'host'=>'chat.facebook.com',
                'domain'=>'chat.facebook.com'
        ));

Add callback for hook jaxl_get_facebook_key:

JAXLPlugin::add('jaxl_get_facebook_key', array($echobot, 'getFacebookKey'));

Complete getFacebookKey method inside echobot application, which should return back following key information:

function getFacebookKey() {
                        return array(
                                '', // Your application secret key
                                '', // Your application api key
                                '' // Connecting user session key
                        );
                }

Update doAuth method to use X-FACEBOOK-PLATFORM auth mechanism:

                function doAuth($mechanism) {
                        global $jaxl;
                        $jaxl->auth("X-FACEBOOK-PLATFORM");
                }

Finally, run echobot from command line:

root@ubuntu:/usr/share/php/jaxl/app/echobot# jaxl echobot.php
[1942] 2010-08-08 05:35:10 - Socket opened to the jabber host chat.facebook.com:5222 ...
[1942] 2010-08-08 05:35:11 - Performing Auth type: X-FACEBOOK-PLATFORM
[1942] 2010-08-08 05:35:26 - Auth completed...