<?php // Copyright 2004-2009 Facebook. All Rights Reserved. // // +---------------------------------------------------------------------------+ // | Facebook Platform PHP5 client | // +---------------------------------------------------------------------------+ // | Copyright (c) 2007 Facebook, Inc. | // | All rights reserved. | // | | // | Redistribution and use in source and binary forms, with or without | // | modification, are permitted provided that the following conditions | // | are met: | // | | // | 1. Redistributions of source code must retain the above copyright | // | notice, this list of conditions and the following disclaimer. | // | 2. Redistributions in binary form must reproduce the above copyright | // | notice, this list of conditions and the following disclaimer in the | // | documentation and/or other materials provided with the distribution. | // | | // | THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | // | IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | // | OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | // | IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | // | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | // | NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | // | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | // | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | // | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | // | THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | // +---------------------------------------------------------------------------+ // | For help with this library, contact developers-help@facebook.com | // +---------------------------------------------------------------------------+ include_once 'facebookapi_php5_restlib.php'; define('FACEBOOK_API_VALIDATION_ERROR', 1); class Facebook { public $api_client; public $api_key; public $secret; public $generate_session_secret; public $session_expires; public $fb_params; public $user; public $profile_user; public $canvas_user; protected $base_domain; /* * Create a Facebook client like this: * * $fb = new Facebook(API_KEY, SECRET); * * This will automatically pull in any parameters, validate them against the * session signature, and chuck them in the public $fb_params member variable. * * @param api_key your Developer API key * @param secret your Developer API secret * @param generate_session_secret whether to automatically generate a session * if the user doesn't have one, but * there is an auth token present in the url, */ public function __construct($api_key, $secret, $generate_session_secret=false) { $this->api_key = $api_key; $this->secret = $secret; $this->generate_session_secret = $generate_session_secret; $this->api_client = new FacebookRestClient($api_key, $secret, null); $this->validate_fb_params(); // Set the default user id for methods that allow the caller to // pass an explicit uid instead of using a session key. $defaultUser = null; if ($this->user) { $defaultUser = $this->user; } else if ($this->profile_user) { $defaultUser = $this->profile_user; } else if ($this->canvas_user) { $defaultUser = $this->canvas_user; } $this->api_client->set_user($defaultUser); if (isset($this->fb_params['friends'])) { $this->api_client->friends_list = explode(',', $this->fb_params['friends']); } if (isset($this->fb_params['added'])) { $this->api_client->added = $this->fb_params['added']; } if (isset($this->fb_params['canvas_user'])) { $this->api_client->canvas_user = $this->fb_params['canvas_user']; } } /* * Validates that the parameters passed in were sent from Facebook. It does so * by validating that the signature matches one that could only be generated * by using your application's secret key. * * Facebook-provided parameters will come from $_POST, $_GET, or $_COOKIE, * in that order. $_POST and $_GET are always more up-to-date than cookies, * so we prefer those if they are available. * * For nitty-gritty details of when each of these is used, check out * http://wiki.developers.facebook.com/index.php/Verifying_The_Signature * * @param bool resolve_auth_token convert an auth token into a session */ public function validate_fb_params($resolve_auth_token=true) { $this->fb_params = $this->get_valid_fb_params($_POST, 48 * 3600, 'fb_sig'); // note that with preload FQL, it's possible to receive POST params in // addition to GET, so use a different prefix to differentiate them if (!$this->fb_params) { $fb_params = $this->get_valid_fb_params($_GET, 48 * 3600, 'fb_sig'); $fb_post_params = $this->get_valid_fb_params($_POST, 48 * 3600, 'fb_post_sig'); $this->fb_params = array_merge($fb_params, $fb_post_params); } // Okay, something came in via POST or GET if ($this->fb_params) { $user = isset($this->fb_params['user']) ? $this->fb_params['user'] : null; $this->profile_user = isset($this->fb_params['profile_user']) ? $this->fb_params['profile_user'] : null; $this->canvas_user = isset($this->fb_params['canvas_user']) ? $this->fb_params['canvas_user'] : null; $this->base_domain = isset($this->fb_params['base_domain']) ? $this->fb_params['base_domain'] : null; if (isset($this->fb_params['session_key'])) { $session_key = $this->fb_params['session_key']; } else if (isset($this->fb_params['profile_session_key'])) { $session_key = $this->fb_params['profile_session_key']; } else { $session_key = null; } $expires = isset($this->fb_params['expires']) ? $this->fb_params['expires'] : null; $this->set_user($user, $session_key, $expires); } // if no Facebook parameters were found in the GET or POST variables, // then fall back to cookies, which may have cached user information // Cookies are also used to receive session data via the Javascript API else if ($cookies = $this->get_valid_fb_params($_COOKIE, null, $this->api_key)) { $base_domain_cookie = 'base_domain_' . $this->api_key; if (isset($_COOKIE[$base_domain_cookie])) { $this->base_domain = $_COOKIE[$base_domain_cookie]; } // use $api_key . '_' as a prefix for the cookies in case there are // multiple facebook clients on the same domain. $expires = isset($cookies['expires']) ? $cookies['expires'] : null; $this->set_user($cookies['user'], $cookies['session_key'], $expires); } // finally, if we received no parameters, but the 'auth_token' GET var // is present, then we are in the middle of auth handshake, // so go ahead and create the session else if ($resolve_auth_token && isset($_GET['auth_token']) && $session = $this->do_get_session($_GET['auth_token'])) { if ($this->generate_session_secret && !empty($session['secret'])) { $session_secret = $session['secret']; } if (isset($session['base_domain'])) { $this->base_domain = $session['base_domain']; } $this->set_user($session['uid'], $session['session_key'], $session['expires'], isset($session_secret) ? $session_secret : null); } return !empty($this->fb_params); } // Store a temporary session secret for the current session // for use with the JS client library public function promote_session() { try { $session_secret = $this->api_client->auth_promoteSession(); if (!$this->in_fb_canvas()) { $this->set_cookies($this->user, $this->api_client->session_key, $this->session_expires, $session_secret); } return $session_secret; } catch (FacebookRestClientException $e) { // API_EC_PARAM means we don't have a logged in user, otherwise who // knows what it means, so just throw it. if ($e->getCode() != FacebookAPIErrorCodes::API_EC_PARAM) { throw $e; } } } public function do_get_session($auth_token) { try { return $this->api_client->auth_getSession($auth_token, $this->generate_session_secret); } catch (FacebookRestClientException $e) { // API_EC_PARAM means we don't have a logged in user, otherwise who // knows what it means, so just throw it. if ($e->getCode() != FacebookAPIErrorCodes::API_EC_PARAM) { throw $e; } } } // Invalidate the session currently being used, and clear any state associated // with it. Note that the user will still remain logged into Facebook. public function expire_session() { if ($this->api_client->auth_expireSession()) { $this->clear_cookie_state(); return true; } else { return false; } } /** Logs the user out of all temporary application sessions as well as their * Facebook session. Note this will only work if the user has a valid current * session with the application. * * @param string $next URL to redirect to upon logging out * */ public function logout($next) { $logout_url = $this->get_logout_url($next); // Clear any stored state $this->clear_cookie_state(); $this->redirect($logout_url); } /** * Clears any persistent state stored about the user, including * cookies and information related to the current session in the * client. * */ public function clear_cookie_state() { if (!$this->in_fb_canvas() && isset($_COOKIE[$this->api_key . '_user'])) { $cookies = array('user', 'session_key', 'expires', 'ss'); foreach ($cookies as $name) { setcookie($this->api_key . '_' . $name, false, time() - 3600); unset($_COOKIE[$this->api_key . '_' . $name]); } setcookie($this->api_key, false, time() - 3600); unset($_COOKIE[$this->api_key]); } // now, clear the rest of the stored state $this->user = 0; $this->api_client->session_key = 0; } public function redirect($url) { if ($this->in_fb_canvas()) { echo '<fb:redirect url="' . $url . '"/>'; } else if (preg_match('/^https?:\/\/([^\/]*\.)?facebook\.com(:\d+)?/i', $url)) { // make sure facebook.com url's load in the full frame so that we don't // get a frame within a frame. echo "<script type=\"text/javascript\">\ntop.location.href = \"$url\";\n</script>"; } else { header('Location: ' . $url); } exit; } public function in_frame() { return isset($this->fb_params['in_canvas']) || isset($this->fb_params['in_iframe']); } public function in_fb_canvas() { return isset($this->fb_params['in_canvas']); } public function get_loggedin_user() { return $this->user; } public function get_canvas_user() { return $this->canvas_user; } public function get_profile_user() { return $this->profile_user; } public static function current_url() { return 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']; } // require_add and require_install have been removed. // see http://developer.facebook.com/news.php?blog=1&story=116 for more details public function require_login() { if ($user = $this->get_loggedin_user()) { return $user; } $this->redirect($this->get_login_url(self::current_url(), $this->in_frame())); } public function require_frame() { if (!$this->in_frame()) { $this->redirect($this->get_login_url(self::current_url(), true)); } } public static function get_facebook_url($subdomain='www') { return 'http://' . $subdomain . '.facebook.com'; } public function get_install_url($next=null) { // this was renamed, keeping for compatibility's sake return $this->get_add_url($next); } public function get_add_url($next=null) { $page = self::get_facebook_url().'/add.php'; $params = array('api_key' => $this->api_key); if ($next) { $params['next'] = $next; } return $page . '?' . http_build_query($params); } public function get_login_url($next, $canvas) { $page = self::get_facebook_url().'/login.php'; $params = array('api_key' => $this->api_key, 'v' => '1.0'); if ($next) { $params['next'] = $next; } if ($canvas) { $params['canvas'] = '1'; } return $page . '?' . http_build_query($params); } public function get_logout_url($next) { $page = self::get_facebook_url().'/logout.php'; $params = array('app_key' => $this->api_key, 'session_key' => $this->api_client->session_key); if ($next) { $params['connect_next'] = 1; $params['next'] = $next; } return $page . '?' . http_build_query($params); } public function set_user($user, $session_key, $expires=null, $session_secret=null) { if (!$this->in_fb_canvas() && (!isset($_COOKIE[$this->api_key . '_user']) || $_COOKIE[$this->api_key . '_user'] != $user)) { $this->set_cookies($user, $session_key, $expires, $session_secret); } $this->user = $user; $this->api_client->session_key = $session_key; $this->session_expires = $expires; } public function set_cookies($user, $session_key, $expires=null, $session_secret=null) { $cookies = array(); $cookies['user'] = $user; $cookies['session_key'] = $session_key; if ($expires != null) { $cookies['expires'] = $expires; } if ($session_secret != null) { $cookies['ss'] = $session_secret; } foreach ($cookies as $name => $val) { setcookie($this->api_key . '_' . $name, $val, (int)$expires, '', $this->base_domain); $_COOKIE[$this->api_key . '_' . $name] = $val; } $sig = self::generate_sig($cookies, $this->secret); setcookie($this->api_key, $sig, (int)$expires, '', $this->base_domain); $_COOKIE[$this->api_key] = $sig; if ($this->base_domain != null) { $base_domain_cookie = 'base_domain_' . $this->api_key; setcookie($base_domain_cookie, $this->base_domain, (int)$expires, '', $this->base_domain); $_COOKIE[$base_domain_cookie] = $this->base_domain; } } /** * Tries to undo the badness of magic quotes as best we can * @param string $val Should come directly from $_GET, $_POST, etc. * @return string val without added slashes */ public static function no_magic_quotes($val) { if (get_magic_quotes_gpc()) { return stripslashes($val); } else { return $val; } } /* * Get the signed parameters that were sent from Facebook. Validates the set * of parameters against the included signature. * * Since Facebook sends data to your callback URL via unsecured means, the * signature is the only way to make sure that the data actually came from * Facebook. So if an app receives a request at the callback URL, it should * always verify the signature that comes with against your own secret key. * Otherwise, it's possible for someone to spoof a request by * pretending to be someone else, i.e.: * www.your-callback-url.com/?fb_user=10101 * * This is done automatically by verify_fb_params. * * @param assoc $params a full array of external parameters. * presumed $_GET, $_POST, or $_COOKIE * @param int $timeout number of seconds that the args are good for. * Specifically good for forcing cookies to expire. * @param string $namespace prefix string for the set of parameters we want * to verify. i.e., fb_sig or fb_post_sig * * @return assoc the subset of parameters containing the given prefix, * and also matching the signature associated with them. * OR an empty array if the params do not validate */ public function get_valid_fb_params($params, $timeout=null, $namespace='fb_sig') { $prefix = $namespace . '_'; $prefix_len = strlen($prefix); $fb_params = array(); if (empty($params)) { return array(); } foreach ($params as $name => $val) { // pull out only those parameters that match the prefix // note that the signature itself ($params[$namespace]) is not in the list if (strpos($name, $prefix) === 0) { $fb_params[substr($name, $prefix_len)] = self::no_magic_quotes($val); } } // validate that the request hasn't expired. this is most likely // for params that come from $_COOKIE if ($timeout && (!isset($fb_params['time']) || time() - $fb_params['time'] > $timeout)) { return array(); } // validate that the params match the signature $signature = isset($params[$namespace]) ? $params[$namespace] : null; if (!$signature || (!$this->verify_signature($fb_params, $signature))) { return array(); } return $fb_params; } /** * Validates the account that a user was trying to set up an * independent account through Facebook Connect. * * @param user The user attempting to set up an independent account. * @param hash The hash passed to the reclamation URL used. * @return bool True if the user is the one that selected the * reclamation link. */ public function verify_account_reclamation($user, $hash) { return $hash == md5($user . $this->secret); } /** * Validates that a given set of parameters match their signature. * Parameters all match a given input prefix, such as "fb_sig". * * @param $fb_params an array of all Facebook-sent parameters, * not including the signature itself * @param $expected_sig the expected result to check against */ public function verify_signature($fb_params, $expected_sig) { return self::generate_sig($fb_params, $this->secret) == $expected_sig; } /** * Validate the given signed public session data structure with * public key of the app that * the session proof belongs to. * * @param $signed_data the session info that is passed by another app * @param string $public_key Optional public key of the app. If this * is not passed, function will make an API call to get it. * return true if the session proof passed verification. */ public function verify_signed_public_session_data($signed_data, $public_key = null) { // If public key is not already provided, we need to get it through API if (!$public_key) { $public_key = $this->api_client->auth_getAppPublicKey( $signed_data['api_key']); } // Create data to verify $data_to_serialize = $signed_data; unset($data_to_serialize['sig']); $serialized_data = implode('_', $data_to_serialize); // Decode signature $signature = base64_decode($signed_data['sig']); $result = openssl_verify($serialized_data, $signature, $public_key, OPENSSL_ALGO_SHA1); return $result == 1; } /* * Generate a signature using the application secret key. * * The only two entities that know your secret key are you and Facebook, * according to the Terms of Service. Since nobody else can generate * the signature, you can rely on it to verify that the information * came from Facebook. * * @param $params_array an array of all Facebook-sent parameters, * NOT INCLUDING the signature itself * @param $secret your app's secret key * * @return a hash to be checked against the signature provided by Facebook */ public static function generate_sig($params_array, $secret) { $str = ''; ksort($params_array); // Note: make sure that the signature parameter is not already included in // $params_array. foreach ($params_array as $k=>$v) { $str .= "$k=$v"; } $str .= $secret; return md5($str); } public function encode_validationError($summary, $message) { return json_encode( array('errorCode' => FACEBOOK_API_VALIDATION_ERROR, 'errorTitle' => $summary, 'errorMessage' => $message)); } public function encode_multiFeedStory($feed, $next) { return json_encode( array('method' => 'multiFeedStory', 'content' => array('next' => $next, 'feed' => $feed))); } public function encode_feedStory($feed, $next) { return json_encode( array('method' => 'feedStory', 'content' => array('next' => $next, 'feed' => $feed))); } public function create_templatizedFeedStory($title_template, $title_data=array(), $body_template='', $body_data = array(), $body_general=null, $image_1=null, $image_1_link=null, $image_2=null, $image_2_link=null, $image_3=null, $image_3_link=null, $image_4=null, $image_4_link=null) { return array('title_template'=> $title_template, 'title_data' => $title_data, 'body_template'=> $body_template, 'body_data' => $body_data, 'body_general' => $body_general, 'image_1' => $image_1, 'image_1_link' => $image_1_link, 'image_2' => $image_2, 'image_2_link' => $image_2_link, 'image_3' => $image_3, 'image_3_link' => $image_3_link, 'image_4' => $image_4, 'image_4_link' => $image_4_link); } }