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<?php
/**
* Copyright 2011 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License. You may obtain
* a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
defined('_JEXEC') or die('Restricted access');
if (!function_exists('curl_init'))
{
throw new Exception('Facebook needs the CURL PHP extension.');
}
if (!function_exists('json_decode'))
{
throw new Exception('Facebook needs the JSON PHP extension.');
}
/**
* Thrown when an API call returns an exception.
*
* @author Naitik Shah <naitik@facebook.com>
*/
class FacebookApiException extends Exception
{
/**
* The result from the API server that represents the exception information.
*/
protected $result;
/**
* Make a new API Exception with the given result.
*
* @param array $result The result from the API server
*/
public function __construct($result)
{
$this->result = $result;
$code = isset($result['error_code']) ? $result['error_code'] : 0;
if (isset($result['error_description']))
{
// OAuth 2.0 Draft 10 style
$msg = $result['error_description'];
}
else if (isset($result['error']) && is_array($result['error']))
{
// OAuth 2.0 Draft 00 style
$msg = $result['error']['message'];
}
else if (isset($result['error_msg']))
{
// Rest server style
$msg = $result['error_msg'];
}
else
{
$msg = 'Unknown Error. Check getResult()';
}
parent::__construct($msg, $code);
}
/**
* Return the associated result object returned by the API server.
*
* @return array The result from the API server
*/
public function getResult()
{
return $this->result;
}
/**
* Returns the associated type for the error. This will default to
* 'Exception' when a type is not available.
*
* @return string
*/
public function getType()
{
if (isset($this->result['error']))
{
$error = $this->result['error'];
if (is_string($error))
{
// OAuth 2.0 Draft 10 style
return $error;
}
else if (is_array($error))
{
// OAuth 2.0 Draft 00 style
if (isset($error['type']))
{
return $error['type'];
}
}
}
return 'Exception';
}
/**
* To make debugging easier.
*
* @return string The string representation of the error
*/
public function __toString()
{
$str = $this->getType() . ': ';
if ($this->code != 0)
{
$str .= $this->code . ': ';
}
return $str . $this->message;
}
}
/**
* Provides access to the Facebook Platform. This class provides
* a majority of the functionality needed, but the class is abstract
* because it is designed to be sub-classed. The subclass must
* implement the four abstract methods listed at the bottom of
* the file.
*
* @author Naitik Shah <naitik@facebook.com>
*/
abstract class BaseFacebook
{
/**
* Version.
*/
const VERSION = '3.2.1';
/**
* Signed Request Algorithm.
*/
const SIGNED_REQUEST_ALGORITHM = 'HMAC-SHA256';
/**
* Default options for curl.
*/
public static $CURL_OPTS = array(
CURLOPT_CONNECTTIMEOUT => 10,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_TIMEOUT => 60,
CURLOPT_USERAGENT => 'facebook-php-3.2',
);
/**
* List of query parameters that get automatically dropped when rebuilding
* the current URL.
*/
protected static $DROP_QUERY_PARAMS = array(
'code',
'state',
'signed_request',
);
/**
* Maps aliases to Facebook domains.
*/
public static $DOMAIN_MAP = array(
'api' => 'https://api.facebook.com/',
'api_video' => 'https://api-video.facebook.com/',
'api_read' => 'https://api-read.facebook.com/',
'graph' => 'https://graph.facebook.com/',
'graph_video' => 'https://graph-video.facebook.com/',
'www' => 'https://www.facebook.com/',
);
/**
* The Application ID.
*
* @var string
*/
protected $appId;
/**
* The Application App Secret.
*
* @var string
*/
protected $appSecret;
/**
* The ID of the Facebook user, or 0 if the user is logged out.
*
* @var integer
*/
protected $user;
/**
* The data from the signed_request token.
*/
protected $signedRequest;
/**
* A CSRF state variable to assist in the defense against CSRF attacks.
*/
protected $state;
/**
* The OAuth access token received in exchange for a valid authorization
* code. null means the access token has yet to be determined.
*
* @var string
*/
protected $accessToken = null;
/**
* Indicates if the CURL based @ syntax for file uploads is enabled.
*
* @var boolean
*/
protected $fileUploadSupport = false;
/**
* Indicates if we trust HTTP_X_FORWARDED_* headers.
*
* @var boolean
*/
protected $trustForwarded = false;
/**
* Initialize a Facebook Application.
*
* The configuration:
* - appId: the application ID
* - secret: the application secret
* - fileUpload: (optional) boolean indicating if file uploads are enabled
*
* @param array $config The application configuration
*/
public function __construct($config)
{
$this->setAppId($config['appId']);
$this->setAppSecret($config['secret']);
if (isset($config['fileUpload']))
{
$this->setFileUploadSupport($config['fileUpload']);
}
if (isset($config['trustForwarded']) && $config['trustForwarded'])
{
$this->trustForwarded = true;
}
$state = $this->getPersistentData('state');
if (!empty($state))
{
$this->state = $state;
}
}
/**
* Set the Application ID.
*
* @param string $appId The Application ID
*
* @return BaseFacebook
*/
public function setAppId($appId)
{
$this->appId = $appId;
return $this;
}
/**
* Get the Application ID.
*
* @return string the Application ID
*/
public function getAppId()
{
return $this->appId;
}
/**
* Set the App Secret.
*
* @param string $apiSecret The App Secret
*
* @return BaseFacebook
* @deprecated
*/
public function setApiSecret($apiSecret)
{
$this->setAppSecret($apiSecret);
return $this;
}
/**
* Set the App Secret.
*
* @param string $appSecret The App Secret
*
* @return BaseFacebook
*/
public function setAppSecret($appSecret)
{
$this->appSecret = $appSecret;
return $this;
}
/**
* Get the App Secret.
*
* @return string the App Secret
* @deprecated
*/
public function getApiSecret()
{
return $this->getAppSecret();
}
/**
* Get the App Secret.
*
* @return string the App Secret
*/
public function getAppSecret()
{
return $this->appSecret;
}
/**
* Set the file upload support status.
*
* @param boolean $fileUploadSupport The file upload support status.
*
* @return BaseFacebook
*/
public function setFileUploadSupport($fileUploadSupport)
{
$this->fileUploadSupport = $fileUploadSupport;
return $this;
}
/**
* Get the file upload support status.
*
* @return boolean true if and only if the server supports file upload.
*/
public function getFileUploadSupport()
{
return $this->fileUploadSupport;
}
/**
* DEPRECATED! Please use getFileUploadSupport instead.
*
* Get the file upload support status.
*
* @return boolean true if and only if the server supports file upload.
*/
public function useFileUploadSupport()
{
return $this->getFileUploadSupport();
}
/**
* Sets the access token for api calls. Use this if you get
* your access token by other means and just want the SDK
* to use it.
*
* @param string $access_token an access token.
*
* @return BaseFacebook
*/
public function setAccessToken($access_token)
{
$this->accessToken = $access_token;
return $this;
}
/**
* Extend an access token, while removing the short-lived token that might
* have been generated via client-side flow. Thanks to http://bit.ly/b0Pt0H
* for the workaround.
*/
public function setExtendedAccessToken()
{
try
{
// need to circumvent json_decode by calling _oauthRequest
// directly, since response isn't JSON format.
$access_token_response = $this->_oauthRequest(
$this->getUrl('graph', '/oauth/access_token'),
$params = array(
'client_id' => $this->getAppId(),
'client_secret' => $this->getAppSecret(),
'grant_type' => 'fb_exchange_token',
'fb_exchange_token' => $this->getAccessToken(),
)
);
}
catch (FacebookApiException $e)
{
// most likely that user very recently revoked authorization.
// In any event, we don't have an access token, so say so.
return false;
}
if (empty($access_token_response))
{
return false;
}
$response_params = array();
parse_str($access_token_response, $response_params);
if (!isset($response_params['access_token']))
{
return false;
}
$this->destroySession();
$this->setPersistentData(
'access_token', $response_params['access_token']
);
}
/**
* Determines the access token that should be used for API calls.
* The first time this is called, $this->accessToken is set equal
* to either a valid user access token, or it's set to the application
* access token if a valid user access token wasn't available. Subsequent
* calls return whatever the first call returned.
*
* @return string The access token
*/
public function getAccessToken()
{
if ($this->accessToken !== null)
{
// we've done this already and cached it. Just return.
return $this->accessToken;
}
// first establish access token to be the application
// access token, in case we navigate to the /oauth/access_token
// endpoint, where SOME access token is required.
$this->setAccessToken($this->getApplicationAccessToken());
$user_access_token = $this->getUserAccessToken();
if ($user_access_token)
{
$this->setAccessToken($user_access_token);
}
return $this->accessToken;
}
/**
* Determines and returns the user access token, first using
* the signed request if present, and then falling back on
* the authorization code if present. The intent is to
* return a valid user access token, or false if one is determined
* to not be available.
*
* @return string A valid user access token, or false if one
* could not be determined.
*/
protected function getUserAccessToken()
{
// first, consider a signed request if it's supplied.
// if there is a signed request, then it alone determines
// the access token.
$signed_request = $this->getSignedRequest();
if ($signed_request)
{
// apps.facebook.com hands the access_token in the signed_request
if (array_key_exists('oauth_token', $signed_request))
{
$access_token = $signed_request['oauth_token'];
$this->setPersistentData('access_token', $access_token);
return $access_token;
}
// the JS SDK puts a code in with the redirect_uri of ''
if (array_key_exists('code', $signed_request))
{
$code = $signed_request['code'];
$access_token = $this->getAccessTokenFromCode($code, '');
if ($access_token)
{
$this->setPersistentData('code', $code);
$this->setPersistentData('access_token', $access_token);
return $access_token;
}
}
// signed request states there's no access token, so anything
// stored should be cleared.
$this->clearAllPersistentData();
return false; // respect the signed request's data, even
// if there's an authorization code or something else
}
$code = $this->getCode();
if ($code && $code != $this->getPersistentData('code'))
{
$access_token = $this->getAccessTokenFromCode($code);
if ($access_token)
{
$this->setPersistentData('code', $code);
$this->setPersistentData('access_token', $access_token);
return $access_token;
}
// code was bogus, so everything based on it should be invalidated.
$this->clearAllPersistentData();
return false;
}
// as a fallback, just return whatever is in the persistent
// store, knowing nothing explicit (signed request, authorization
// code, etc.) was present to shadow it (or we saw a code in $_REQUEST,
// but it's the same as what's in the persistent store)
return $this->getPersistentData('access_token');
}
/**
* Retrieve the signed request, either from a request parameter or,
* if not present, from a cookie.
*
* @return string the signed request, if available, or null otherwise.
*/
public function getSignedRequest()
{
if (!$this->signedRequest)
{
if (isset($_REQUEST['signed_request']))
{
$this->signedRequest = $this->parseSignedRequest(
$_REQUEST['signed_request']);
}
else if (isset($_COOKIE[$this->getSignedRequestCookieName()]))
{
$this->signedRequest = $this->parseSignedRequest(
$_COOKIE[$this->getSignedRequestCookieName()]);
}
}
return $this->signedRequest;
}
/**
* Get the UID of the connected user, or 0
* if the Facebook user is not connected.
*
* @return string the UID if available.
*/
public function getUser()
{
if ($this->user !== null)
{
// we've already determined this and cached the value.
return $this->user;
}
return $this->user = $this->getUserFromAvailableData();
}
/**
* Determines the connected user by first examining any signed
* requests, then considering an authorization code, and then
* falling back to any persistent store storing the user.
*
* @return integer The id of the connected Facebook user,
* or 0 if no such user exists.
*/
protected function getUserFromAvailableData()
{
// if a signed request is supplied, then it solely determines
// who the user is.
$signed_request = $this->getSignedRequest();
if ($signed_request)
{
if (array_key_exists('user_id', $signed_request))
{
$user = $signed_request['user_id'];
$this->setPersistentData('user_id', $signed_request['user_id']);
return $user;
}
// if the signed request didn't present a user id, then invalidate
// all entries in any persistent store.
$this->clearAllPersistentData();
return 0;
}
$user = $this->getPersistentData('user_id', $default = 0);
$persisted_access_token = $this->getPersistentData('access_token');
// use access_token to fetch user id if we have a user access_token, or if
// the cached access token has changed.
$access_token = $this->getAccessToken();
if ($access_token &&
$access_token != $this->getApplicationAccessToken() &&
!($user && $persisted_access_token == $access_token)
)
{
$user = $this->getUserFromAccessToken();
if ($user)
{
$this->setPersistentData('user_id', $user);
}
else
{
$this->clearAllPersistentData();
}
}
return $user;
}
/**
* Get a Login URL for use with redirects. By default, full page redirect is
* assumed. If you are using the generated URL with a window.open() call in
* JavaScript, you can pass in display=popup as part of the $params.
*
* The parameters:
* - redirect_uri: the url to go to after a successful login
* - scope: comma separated list of requested extended perms
*
* @param array $params Provide custom parameters
*
* @return string The URL for the login flow
*/
public function getLoginUrl($params = array())
{
$this->establishCSRFTokenState();
$currentUrl = $this->getCurrentUrl();
// if 'scope' is passed as an array, convert to comma separated list
$scopeParams = isset($params['scope']) ? $params['scope'] : null;
if ($scopeParams && is_array($scopeParams))
{
$params['scope'] = implode(',', $scopeParams);
}
return $this->getUrl(
'www',
'dialog/oauth',
array_merge(array(
'client_id' => $this->getAppId(),
'redirect_uri' => $currentUrl, // possibly overwritten
'state' => $this->state),
$params));
}
/**
* Get a Logout URL suitable for use with redirects.
*
* The parameters:
* - next: the url to go to after a successful logout
*
* @param array $params Provide custom parameters
*
* @return string The URL for the logout flow
*/
public function getLogoutUrl($params = array())
{
return $this->getUrl(
'www',
'logout.php',
array_merge(array(
'next' => $this->getCurrentUrl(),
'access_token' => $this->getUserAccessToken(),
), $params)
);
}
/**
* Get a login status URL to fetch the status from Facebook.
*
* The parameters:
* - ok_session: the URL to go to if a session is found
* - no_session: the URL to go to if the user is not connected
* - no_user: the URL to go to if the user is not signed into facebook
*
* @param array $params Provide custom parameters
*
* @return string The URL for the logout flow
*/
public function getLoginStatusUrl($params = array())
{
return $this->getUrl(
'www',
'extern/login_status.php',
array_merge(array(
'api_key' => $this->getAppId(),
'no_session' => $this->getCurrentUrl(),
'no_user' => $this->getCurrentUrl(),
'ok_session' => $this->getCurrentUrl(),
'session_version' => 3,
), $params)
);
}
/**
* Make an API call.
*
* @return mixed The decoded response
*/
public function api( /* polymorphic */)
{
$args = func_get_args();
if (is_array($args[0]))
{
return $this->_restserver($args[0]);
}
else
{
return call_user_func_array(array($this, '_graph'), $args);
}
}
/**
* Constructs and returns the name of the cookie that
* potentially houses the signed request for the app user.
* The cookie is not set by the BaseFacebook class, but
* it may be set by the JavaScript SDK.
*
* @return string the name of the cookie that would house
* the signed request value.
*/
protected function getSignedRequestCookieName()
{
return 'fbsr_' . $this->getAppId();
}
/**
* Constructs and returns the name of the coookie that potentially contain
* metadata. The cookie is not set by the BaseFacebook class, but it may be
* set by the JavaScript SDK.
*
* @return string the name of the cookie that would house metadata.
*/
protected function getMetadataCookieName()
{
return 'fbm_' . $this->getAppId();
}
/**
* Get the authorization code from the query parameters, if it exists,
* and otherwise return false to signal no authorization code was
* discoverable.
*
* @return mixed The authorization code, or false if the authorization
* code could not be determined.
*/
protected function getCode()
{
if (isset($_REQUEST['code']))
{
if ($this->state !== null &&
isset($_REQUEST['state']) &&
$this->state === $_REQUEST['state']
)
{
// CSRF state has done its job, so clear it
$this->state = null;
$this->clearPersistentData('state');
return $_REQUEST['code'];
}
else
{
self::errorLog('CSRF state token does not match one provided.');
return false;
}
}
return false;
}
/**
* Retrieves the UID with the understanding that
* $this->accessToken has already been set and is
* seemingly legitimate. It relies on Facebook's Graph API
* to retrieve user information and then extract
* the user ID.
*
* @return integer Returns the UID of the Facebook user, or 0
* if the Facebook user could not be determined.
*/
protected function getUserFromAccessToken()
{
try
{
$user_info = $this->api('/me');
return $user_info['id'];
}
catch (FacebookApiException $e)
{
return 0;
}
}
/**
* Returns the access token that should be used for logged out
* users when no authorization code is available.
*
* @return string The application access token, useful for gathering
* public information about users and applications.
*/
protected function getApplicationAccessToken()
{
return $this->appId . '|' . $this->appSecret;
}
/**
* Lays down a CSRF state token for this process.
*
* @return void
*/
protected function establishCSRFTokenState()
{
if ($this->state === null)
{
$this->state = md5(uniqid(mt_rand(), true));
$this->setPersistentData('state', $this->state);
}
}
/**
* Retrieves an access token for the given authorization code
* (previously generated from www.facebook.com on behalf of
* a specific user). The authorization code is sent to graph.facebook.com
* and a legitimate access token is generated provided the access token
* and the user for which it was generated all match, and the user is
* either logged in to Facebook or has granted an offline access permission.
*
* @param string $code An authorization code.
*
* @return mixed An access token exchanged for the authorization code, or
* false if an access token could not be generated.
*/
protected function getAccessTokenFromCode($code, $redirect_uri = null)
{
if (empty($code))
{
return false;
}
if ($redirect_uri === null)
{
$redirect_uri = $this->getCurrentUrl();
}
try
{
// need to circumvent json_decode by calling _oauthRequest
// directly, since response isn't JSON format.
$access_token_response =
$this->_oauthRequest(
$this->getUrl('graph', '/oauth/access_token'),
$params = array('client_id' => $this->getAppId(),
'client_secret' => $this->getAppSecret(),
'redirect_uri' => $redirect_uri,
'code' => $code));
}
catch (FacebookApiException $e)
{
// most likely that user very recently revoked authorization.
// In any event, we don't have an access token, so say so.
return false;
}
if (empty($access_token_response))
{
return false;
}
$response_params = array();
parse_str($access_token_response, $response_params);
if (!isset($response_params['access_token']))
{
return false;
}
return $response_params['access_token'];
}
/**
* Invoke the old restserver.php endpoint.
*
* @param array $params Method call object
*
* @return mixed The decoded response object
* @throws FacebookApiException
*/
protected function _restserver($params)
{
// generic application level parameters
$params['api_key'] = $this->getAppId();
$params['format'] = 'json-strings';
$result = json_decode($this->_oauthRequest(
$this->getApiUrl($params['method']),
$params
), true);
// results are returned, errors are thrown
if (is_array($result) && isset($result['error_code']))
{
$this->throwAPIException($result);
// @codeCoverageIgnoreStart
}
// @codeCoverageIgnoreEnd
$method = strtolower($params['method']);
if ($method === 'auth.expiresession' ||
$method === 'auth.revokeauthorization'
)
{
$this->destroySession();
}
return $result;
}
/**
* Return true if this is video post.
*
* @param string $path The path
* @param string $method The http method (default 'GET')
*
* @return boolean true if this is video post
*/
protected function isVideoPost($path, $method = 'GET')
{
if ($method == 'POST' && preg_match("/^(\/)(.+)(\/)(videos)$/", $path))
{
return true;
}
return false;
}
/**
* Invoke the Graph API.
*
* @param string $path The path (required)
* @param string $method The http method (default 'GET')
* @param array $params The query/post data
*
* @return mixed The decoded response object
* @throws FacebookApiException
*/
protected function _graph($path, $method = 'GET', $params = array())
{
if (is_array($method) && empty($params))
{
$params = $method;
$method = 'GET';
}
$params['method'] = $method; // method override as we always do a POST
if ($this->isVideoPost($path, $method))
{
$domainKey = 'graph_video';
}
else
{
$domainKey = 'graph';
}
$result = json_decode($this->_oauthRequest(
$this->getUrl($domainKey, $path),
$params
), true);
// results are returned, errors are thrown
if (is_array($result) && isset($result['error']))
{
$this->throwAPIException($result);
// @codeCoverageIgnoreStart
}
// @codeCoverageIgnoreEnd
return $result;
}
/**
* Make a OAuth Request.
*
* @param string $url The path (required)
* @param array $params The query/post data
*
* @return string The decoded response object
* @throws FacebookApiException
*/
protected function _oauthRequest($url, $params)
{
if (!isset($params['access_token']))
{
$params['access_token'] = $this->getAccessToken();
}
// json_encode all params values that are not strings
foreach ($params as $key => $value)
{
if (!is_string($value))
{
$params[$key] = json_encode($value);
}
}
return $this->makeRequest($url, $params);
}
/**
* Makes an HTTP request. This method can be overridden by subclasses if
* developers want to do fancier things or use something other than curl to
* make the request.
*
* @param string $url The URL to make the request to
* @param array $params The parameters to use for the POST body
* @param CurlHandler $ch Initialized curl handle
*
* @return string The response text
*/
protected function makeRequest($url, $params, $ch = null)
{
if (!$ch)
{
$ch = curl_init();
}
$opts = self::$CURL_OPTS;
if ($this->getFileUploadSupport())
{
$opts[CURLOPT_POSTFIELDS] = $params;
}
else
{
$opts[CURLOPT_POSTFIELDS] = http_build_query($params, null, '&');
}
$opts[CURLOPT_URL] = $url;
// disable the 'Expect: 100-continue' behaviour. This causes CURL to wait
// for 2 seconds if the server does not support this header.
if (isset($opts[CURLOPT_HTTPHEADER]))
{
$existing_headers = $opts[CURLOPT_HTTPHEADER];
$existing_headers[] = 'Expect:';
$opts[CURLOPT_HTTPHEADER] = $existing_headers;
}
else
{
$opts[CURLOPT_HTTPHEADER] = array('Expect:');
}
curl_setopt_array($ch, $opts);
$result = curl_exec($ch);
if (curl_errno($ch) == 60)
{ // CURLE_SSL_CACERT
self::errorLog('Invalid or no certificate authority found, ' .
'using bundled information');
curl_setopt($ch, CURLOPT_CAINFO,
dirname(__FILE__) . '/fb_ca_chain_bundle.crt');
$result = curl_exec($ch);
}
// With dual stacked DNS responses, it's possible for a server to
// have IPv6 enabled but not have IPv6 connectivity. If this is
// the case, curl will try IPv4 first and if that fails, then it will
// fall back to IPv6 and the error EHOSTUNREACH is returned by the
// operating system.
if ($result === false && empty($opts[CURLOPT_IPRESOLVE]))
{
$matches = array();
$regex = '/Failed to connect to ([^:].*): Network is unreachable/';
if (preg_match($regex, curl_error($ch), $matches))
{
if (strlen(@inet_pton($matches[1])) === 16)
{
self::errorLog('Invalid IPv6 configuration on server, ' .
'Please disable or get native IPv6 on your server.');
self::$CURL_OPTS[CURLOPT_IPRESOLVE] = CURL_IPRESOLVE_V4;
curl_setopt($ch, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
$result = curl_exec($ch);
}
}
}
if ($result === false)
{
$e = new FacebookApiException(array(
'error_code' => curl_errno($ch),
'error' => array(
'message' => curl_error($ch),
'type' => 'CurlException',
),
));
curl_close($ch);
throw $e;
}
curl_close($ch);
return $result;
}
/**
* Parses a signed_request and validates the signature.
*
* @param string $signed_request A signed token
*
* @return array The payload inside it or null if the sig is wrong
*/
protected function parseSignedRequest($signed_request)
{
list($encoded_sig, $payload) = explode('.', $signed_request, 2);
// decode the data
$sig = self::base64UrlDecode($encoded_sig);
$data = json_decode(self::base64UrlDecode($payload), true);
if (strtoupper($data['algorithm']) !== self::SIGNED_REQUEST_ALGORITHM)
{
self::errorLog(
'Unknown algorithm. Expected ' . self::SIGNED_REQUEST_ALGORITHM);
return null;
}
// check sig
$expected_sig = hash_hmac('sha256', $payload,
$this->getAppSecret(), $raw = true);
if ($sig !== $expected_sig)
{
self::errorLog('Bad Signed JSON signature!');
return null;
}
return $data;
}
/**
* Makes a signed_request blob using the given data.
*
* @param array The data array.
*
* @return string The signed request.
*/
protected function makeSignedRequest($data)
{
if (!is_array($data))
{
throw new InvalidArgumentException(
'makeSignedRequest expects an array. Got: ' . print_r($data, true));
}
$data['algorithm'] = self::SIGNED_REQUEST_ALGORITHM;
$data['issued_at'] = time();
$json = json_encode($data);
$b64 = self::base64UrlEncode($json);
$raw_sig = hash_hmac('sha256', $b64, $this->getAppSecret(), $raw = true);
$sig = self::base64UrlEncode($raw_sig);
return $sig . '.' . $b64;
}
/**
* Build the URL for api given parameters.
*
* @param $method String the method name.
*
* @return string The URL for the given parameters
*/
protected function getApiUrl($method)
{
static $READ_ONLY_CALLS =
array('admin.getallocation' => 1,
'admin.getappproperties' => 1,
'admin.getbannedusers' => 1,
'admin.getlivestreamvialink' => 1,
'admin.getmetrics' => 1,
'admin.getrestrictioninfo' => 1,
'application.getpublicinfo' => 1,
'auth.getapppublickey' => 1,
'auth.getsession' => 1,
'auth.getsignedpublicsessiondata' => 1,
'comments.get' => 1,
'connect.getunconnectedfriendscount' => 1,
'dashboard.getactivity' => 1,
'dashboard.getcount' => 1,
'dashboard.getglobalnews' => 1,
'dashboard.getnews' => 1,
'dashboard.multigetcount' => 1,
'dashboard.multigetnews' => 1,
'data.getcookies' => 1,
'events.get' => 1,
'events.getmembers' => 1,
'fbml.getcustomtags' => 1,
'feed.getappfriendstories' => 1,
'feed.getregisteredtemplatebundlebyid' => 1,
'feed.getregisteredtemplatebundles' => 1,
'fql.multiquery' => 1,
'fql.query' => 1,
'friends.arefriends' => 1,
'friends.get' => 1,
'friends.getappusers' => 1,
'friends.getlists' => 1,
'friends.getmutualfriends' => 1,
'gifts.get' => 1,
'groups.get' => 1,
'groups.getmembers' => 1,
'intl.gettranslations' => 1,
'links.get' => 1,
'notes.get' => 1,
'notifications.get' => 1,
'pages.getinfo' => 1,
'pages.isadmin' => 1,
'pages.isappadded' => 1,
'pages.isfan' => 1,
'permissions.checkavailableapiaccess' => 1,
'permissions.checkgrantedapiaccess' => 1,
'photos.get' => 1,
'photos.getalbums' => 1,
'photos.gettags' => 1,
'profile.getinfo' => 1,
'profile.getinfooptions' => 1,
'stream.get' => 1,
'stream.getcomments' => 1,
'stream.getfilters' => 1,
'users.getinfo' => 1,
'users.getloggedinuser' => 1,
'users.getstandardinfo' => 1,
'users.hasapppermission' => 1,
'users.isappuser' => 1,
'users.isverified' => 1,
'video.getuploadlimits' => 1);
$name = 'api';
if (isset($READ_ONLY_CALLS[strtolower($method)]))
{
$name = 'api_read';
}
else if (strtolower($method) == 'video.upload')
{
$name = 'api_video';
}
return self::getUrl($name, 'restserver.php');
}
/**
* Build the URL for given domain alias, path and parameters.
*
* @param $name string The name of the domain
* @param $path string Optional path (without a leading slash)
* @param $params array Optional query parameters
*
* @return string The URL for the given parameters
*/
protected function getUrl($name, $path = '', $params = array())
{
$url = self::$DOMAIN_MAP[$name];
if ($path)
{
if ($path[0] === '/')
{
$path = substr($path, 1);
}
$url .= $path;
}
if ($params)
{
$url .= '?' . http_build_query($params, null, '&');
}
return $url;
}
protected function getHttpHost()
{
if ($this->trustForwarded && isset($_SERVER['HTTP_X_FORWARDED_HOST']))
{
return $_SERVER['HTTP_X_FORWARDED_HOST'];
}
return $_SERVER['HTTP_HOST'];
}
protected function getHttpProtocol()
{
if ($this->trustForwarded && isset($_SERVER['HTTP_X_FORWARDED_PROTO']))
{
if ($_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https')
{
return 'https';
}
return 'http';
}
if (isset($_SERVER['HTTPS']) &&
($_SERVER['HTTPS'] === 'on' || $_SERVER['HTTPS'] == 1)
)
{
return 'https';
}
return 'http';
}
/**
* Get the base domain used for the cookie.
*/
protected function getBaseDomain()
{
// The base domain is stored in the metadata cookie if not we fallback
// to the current hostname
$metadata = $this->getMetadataCookie();
if (array_key_exists('base_domain', $metadata) &&
!empty($metadata['base_domain'])
)
{
return trim($metadata['base_domain'], '.');
}
return $this->getHttpHost();
}
/**
*
* /**
* Returns the Current URL, stripping it of known FB parameters that should
* not persist.
*
* @return string The current URL
*/
protected function getCurrentUrl()
{
$protocol = $this->getHttpProtocol() . '://';
$host = $this->getHttpHost();
$currentUrl = $protocol . $host . $_SERVER['REQUEST_URI'];
$parts = parse_url($currentUrl);
$query = '';
if (!empty($parts['query']))
{
// drop known fb params
$params = explode('&', $parts['query']);
$retained_params = array();
foreach ($params as $param)
{
if ($this->shouldRetainParam($param))
{
$retained_params[] = $param;
}
}
if (!empty($retained_params))
{
$query = '?' . implode($retained_params, '&');
}
}
// use port if non default
$port =
isset($parts['port']) &&
(($protocol === 'http://' && $parts['port'] !== 80) ||
($protocol === 'https://' && $parts['port'] !== 443))
? ':' . $parts['port'] : '';
// rebuild
return $protocol . $parts['host'] . $port . $parts['path'] . $query;
}
/**
* Returns true if and only if the key or key/value pair should
* be retained as part of the query string. This amounts to
* a brute-force search of the very small list of Facebook-specific
* params that should be stripped out.
*
* @param string $param A key or key/value pair within a URL's query (e.g.
* 'foo=a', 'foo=', or 'foo'.
*
* @return boolean
*/
protected function shouldRetainParam($param)
{
foreach (self::$DROP_QUERY_PARAMS as $drop_query_param)
{
if (strpos($param, $drop_query_param . '=') === 0)
{
return false;
}
}
return true;
}
/**
* Analyzes the supplied result to see if it was thrown
* because the access token is no longer valid. If that is
* the case, then we destroy the session.
*
* @param $result array A record storing the error message returned
* by a failed API call.
*/
protected function throwAPIException($result)
{
$e = new FacebookApiException($result);
switch ($e->getType())
{
// OAuth 2.0 Draft 00 style
case 'OAuthException':
// OAuth 2.0 Draft 10 style
case 'invalid_token':
// REST server errors are just Exceptions
case 'Exception':
$message = $e->getMessage();
if ((strpos($message, 'Error validating access token') !== false) ||
(strpos($message, 'Invalid OAuth access token') !== false) ||
(strpos($message, 'An active access token must be used') !== false)
)
{
$this->destroySession();
}
break;
}
throw $e;
}
/**
* Prints to the error log if you aren't in command line mode.
*
* @param string $msg Log message
*/
protected static function errorLog($msg)
{
// disable error log if we are running in a CLI environment
// @codeCoverageIgnoreStart
if (php_sapi_name() != 'cli')
{
error_log($msg);
}
// uncomment this if you want to see the errors on the page
// print 'error_log: '.$msg."\n";
// @codeCoverageIgnoreEnd
}
/**
* Base64 encoding that doesn't need to be urlencode()ed.
* Exactly the same as base64_encode except it uses
* - instead of +
* _ instead of /
* No padded =
*
* @param string $input base64UrlEncoded string
*
* @return string
*/
protected static function base64UrlDecode($input)
{
return base64_decode(strtr($input, '-_', '+/'));
}
/**
* Base64 encoding that doesn't need to be urlencode()ed.
* Exactly the same as base64_encode except it uses
* - instead of +
* _ instead of /
*
* @param string $input string
*
* @return string base64Url encoded string
*/
protected static function base64UrlEncode($input)
{
$str = strtr(base64_encode($input), '+/', '-_');
$str = str_replace('=', '', $str);
return $str;
}
/**
* Destroy the current session
*/
public function destroySession()
{
$this->accessToken = null;
$this->signedRequest = null;
$this->user = null;
$this->clearAllPersistentData();
// Javascript sets a cookie that will be used in getSignedRequest that we
// need to clear if we can
$cookie_name = $this->getSignedRequestCookieName();
if (array_key_exists($cookie_name, $_COOKIE))
{
unset($_COOKIE[$cookie_name]);
if (!headers_sent())
{
$base_domain = $this->getBaseDomain();
setcookie($cookie_name, '', 1, '/', '.' . $base_domain);
}
else
{
// @codeCoverageIgnoreStart
self::errorLog(
'There exists a cookie that we wanted to clear that we couldn\'t ' .
'clear because headers was already sent. Make sure to do the first ' .
'API call before outputing anything.'
);
// @codeCoverageIgnoreEnd
}
}
}
/**
* Parses the metadata cookie that our Javascript API set
*
* @return an array mapping key to value
*/
protected function getMetadataCookie()
{
$cookie_name = $this->getMetadataCookieName();
if (!array_key_exists($cookie_name, $_COOKIE))
{
return array();
}
// The cookie value can be wrapped in "-characters so remove them
$cookie_value = trim($_COOKIE[$cookie_name], '"');
if (empty($cookie_value))
{
return array();
}
$parts = explode('&', $cookie_value);
$metadata = array();
foreach ($parts as $part)
{
$pair = explode('=', $part, 2);
if (!empty($pair[0]))
{
$metadata[urldecode($pair[0])] =
(count($pair) > 1) ? urldecode($pair[1]) : '';
}
}
return $metadata;
}
protected static function isAllowedDomain($big, $small)
{
if ($big === $small)
{
return true;
}
return self::endsWith($big, '.' . $small);
}
protected static function endsWith($big, $small)
{
$len = strlen($small);
if ($len === 0)
{
return true;
}
return substr($big, -$len) === $small;
}
/**
* Each of the following four methods should be overridden in
* a concrete subclass, as they are in the provided Facebook class.
* The Facebook class uses PHP sessions to provide a primitive
* persistent store, but another subclass--one that you implement--
* might use a database, memcache, or an in-memory cache.
*
* @see Facebook
*/
/**
* Stores the given ($key, $value) pair, so that future calls to
* getPersistentData($key) return $value. This call may be in another request.
*
* @param string $key
* @param array $value
*
* @return void
*/
abstract protected function setPersistentData($key, $value);
/**
* Get the data for $key, persisted by BaseFacebook::setPersistentData()
*
* @param string $key The key of the data to retrieve
* @param boolean $default The default value to return if $key is not found
*
* @return mixed
*/
abstract protected function getPersistentData($key, $default = false);
/**
* Clear the data with $key from the persistent storage
*
* @param string $key
*
* @return void
*/
abstract protected function clearPersistentData($key);
/**
* Clear all data from the persistent storage
*
* @return void
*/
abstract protected function clearAllPersistentData();
}