<?php
/**
* Zend Framework (http://framework.zend.com/)
*
* @link http://github.com/zendframework/zf2 for the canonical source repository
* @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
namespace Zend\Feed\PubSubHubbub\Subscriber;
use Zend\Feed\PubSubHubbub;
use Zend\Feed\PubSubHubbub\Exception;
use Zend\Feed\Uri;
class Callback extends PubSubHubbub\AbstractCallback
{
/**
* Contains the content of any feeds sent as updates to the Callback URL
*
* @var string
*/
protected $feedUpdate = null;
/**
* Holds a manually set subscription key (i.e. identifies a unique
* subscription) which is typical when it is not passed in the query string
* but is part of the Callback URL path, requiring manual retrieval e.g.
* using a route and the \Zend\Mvc\Router\RouteMatch::getParam() method.
*
* @var string
*/
protected $subscriptionKey = null;
/**
* After verification, this is set to the verified subscription's data.
*
* @var array
*/
protected $currentSubscriptionData = null;
/**
* Set a subscription key to use for the current callback request manually.
* Required if usePathParameter is enabled for the Subscriber.
*
* @param string $key
* @return \Zend\Feed\PubSubHubbub\Subscriber\Callback
*/
public function setSubscriptionKey($key)
{
$this->subscriptionKey = $key;
return $this;
}
/**
* Handle any callback from a Hub Server responding to a subscription or
* unsubscription request. This should be the Hub Server confirming the
* the request prior to taking action on it.
*
* @param array $httpGetData GET data if available and not in $_GET
* @param bool $sendResponseNow Whether to send response now or when asked
* @return void
*/
public function handle(array $httpGetData = null, $sendResponseNow = false)
{
if ($httpGetData === null) {
$httpGetData = $_GET;
}
/**
* Handle any feed updates (sorry for the mess :P)
*
* This DOES NOT attempt to process a feed update. Feed updates
* SHOULD be validated/processed by an asynchronous process so as
* to avoid holding up responses to the Hub.
*/
$contentType = $this->_getHeader('Content-Type');
if (strtolower($_SERVER['REQUEST_METHOD']) == 'post'
&& $this->_hasValidVerifyToken(null, false)
&& (stripos($contentType, 'application/atom+xml') === 0
|| stripos($contentType, 'application/rss+xml') === 0
|| stripos($contentType, 'application/xml') === 0
|| stripos($contentType, 'text/xml') === 0
|| stripos($contentType, 'application/rdf+xml') === 0)
) {
$this->setFeedUpdate($this->_getRawBody());
$this->getHttpResponse()->setHeader('X-Hub-On-Behalf-Of', $this->getSubscriberCount());
/**
* Handle any (un)subscribe confirmation requests
*/
} elseif ($this->isValidHubVerification($httpGetData)) {
$this->getHttpResponse()->setContent($httpGetData['hub_challenge']);
switch (strtolower($httpGetData['hub_mode'])) {
case 'subscribe':
$data = $this->currentSubscriptionData;
$data['subscription_state'] = PubSubHubbub\PubSubHubbub::SUBSCRIPTION_VERIFIED;
if (isset($httpGetData['hub_lease_seconds'])) {
$data['lease_seconds'] = $httpGetData['hub_lease_seconds'];
}
$this->getStorage()->setSubscription($data);
break;
case 'unsubscribe':
$verifyTokenKey = $this->_detectVerifyTokenKey($httpGetData);
$this->getStorage()->deleteSubscription($verifyTokenKey);
break;
default:
throw new Exception\RuntimeException(sprintf(
'Invalid hub_mode ("%s") provided',
$httpGetData['hub_mode']
));
}
/**
* Hey, C'mon! We tried everything else!
*/
} else {
$this->getHttpResponse()->setStatusCode(404);
}
if ($sendResponseNow) {
$this->sendResponse();
}
}
/**
* Checks validity of the request simply by making a quick pass and
* confirming the presence of all REQUIRED parameters.
*
* @param array $httpGetData
* @return bool
*/
public function isValidHubVerification(array $httpGetData)
{
/**
* As per the specification, the hub.verify_token is OPTIONAL. This
* implementation of Pubsubhubbub considers it REQUIRED and will
* always send a hub.verify_token parameter to be echoed back
* by the Hub Server. Therefore, its absence is considered invalid.
*/
if (strtolower($_SERVER['REQUEST_METHOD']) !== 'get') {
return false;
}
$required = array(
'hub_mode',
'hub_topic',
'hub_challenge',
'hub_verify_token',
);
foreach ($required as $key) {
if (!array_key_exists($key, $httpGetData)) {
return false;
}
}
if ($httpGetData['hub_mode'] !== 'subscribe'
&& $httpGetData['hub_mode'] !== 'unsubscribe'
) {
return false;
}
if ($httpGetData['hub_mode'] == 'subscribe'
&& !array_key_exists('hub_lease_seconds', $httpGetData)
) {
return false;
}
if (!Uri::factory($httpGetData['hub_topic'])->isValid()) {
return false;
}
/**
* Attempt to retrieve any Verification Token Key attached to Callback
* URL's path by our Subscriber implementation
*/
if (!$this->_hasValidVerifyToken($httpGetData)) {
return false;
}
return true;
}
/**
* Sets a newly received feed (Atom/RSS) sent by a Hub as an update to a
* Topic we've subscribed to.
*
* @param string $feed
* @return \Zend\Feed\PubSubHubbub\Subscriber\Callback
*/
public function setFeedUpdate($feed)
{
$this->feedUpdate = $feed;
return $this;
}
/**
* Check if any newly received feed (Atom/RSS) update was received
*
* @return bool
*/
public function hasFeedUpdate()
{
if ($this->feedUpdate === null) {
return false;
}
return true;
}
/**
* Gets a newly received feed (Atom/RSS) sent by a Hub as an update to a
* Topic we've subscribed to.
*
* @return string
*/
public function getFeedUpdate()
{
return $this->feedUpdate;
}
/**
* Check for a valid verify_token. By default attempts to compare values
* with that sent from Hub, otherwise merely ascertains its existence.
*
* @param array $httpGetData
* @param bool $checkValue
* @return bool
*/
protected function _hasValidVerifyToken(array $httpGetData = null, $checkValue = true)
{
$verifyTokenKey = $this->_detectVerifyTokenKey($httpGetData);
if (empty($verifyTokenKey)) {
return false;
}
$verifyTokenExists = $this->getStorage()->hasSubscription($verifyTokenKey);
if (!$verifyTokenExists) {
return false;
}
if ($checkValue) {
$data = $this->getStorage()->getSubscription($verifyTokenKey);
$verifyToken = $data['verify_token'];
if ($verifyToken !== hash('sha256', $httpGetData['hub_verify_token'])) {
return false;
}
$this->currentSubscriptionData = $data;
return true;
}
return true;
}
/**
* Attempt to detect the verification token key. This would be passed in
* the Callback URL (which we are handling with this class!) as a URI
* path part (the last part by convention).
*
* @param null|array $httpGetData
* @return false|string
*/
protected function _detectVerifyTokenKey(array $httpGetData = null)
{
/**
* Available when sub keys encoding in Callback URL path
*/
if (isset($this->subscriptionKey)) {
return $this->subscriptionKey;
}
/**
* Available only if allowed by PuSH 0.2 Hubs
*/
if (is_array($httpGetData)
&& isset($httpGetData['xhub_subscription'])
) {
return $httpGetData['xhub_subscription'];
}
/**
* Available (possibly) if corrupted in transit and not part of $_GET
*/
$params = $this->_parseQueryString();
if (isset($params['xhub.subscription'])) {
return rawurldecode($params['xhub.subscription']);
}
return false;
}
/**
* Build an array of Query String parameters.
* This bypasses $_GET which munges parameter names and cannot accept
* multiple parameters with the same key.
*
* @return array|void
*/
protected function _parseQueryString()
{
$params = array();
$queryString = '';
if (isset($_SERVER['QUERY_STRING'])) {
$queryString = $_SERVER['QUERY_STRING'];
}
if (empty($queryString)) {
return array();
}
$parts = explode('&', $queryString);
foreach ($parts as $kvpair) {
$pair = explode('=', $kvpair);
$key = rawurldecode($pair[0]);
$value = rawurldecode($pair[1]);
if (isset($params[$key])) {
if (is_array($params[$key])) {
$params[$key][] = $value;
} else {
$params[$key] = array($params[$key], $value);
}
} else {
$params[$key] = $value;
}
}
return $params;
}
}