--- /dev/null
+<?php
+/**
+ * @copyright Copyright (C) 2010-2022, the Friendica project
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Module\OStatus;
+
+use Friendica\App;
+use Friendica\Core\Config\Capability\IManageConfigValues;
+use Friendica\Core\L10n;
+use Friendica\Database\Database;
+use Friendica\Model\PushSubscriber;
+use Friendica\Module\Response;
+use Friendica\Network\HTTPClient\Capability\ICanSendHttpRequests;
+use Friendica\Network\HTTPException;
+use Friendica\Util\Profiler;
+use Friendica\Util\Strings;
+use Psr\Log\LoggerInterface;
+
+/**
+ * An open, simple, web-scale and decentralized pubsub protocol.
+ *
+ * Part of the OStatus stack.
+ *
+ * See https://pubsubhubbub.github.io/PubSubHubbub/pubsubhubbub-core-0.4.html
+ *
+ * @version 0.4
+ */
+class PubSubHubBub extends \Friendica\BaseModule
+{
+ /** @var IManageConfigValues */
+ private $config;
+ /** @var Database */
+ private $database;
+ /** @var ICanSendHttpRequests */
+ private $httpClient;
+ /** @var App\Request */
+ private $request;
+
+ public function __construct(App\Request $request, ICanSendHttpRequests $httpClient, Database $database, IManageConfigValues $config, L10n $l10n, App\BaseURL $baseUrl, App\Arguments $args, LoggerInterface $logger, Profiler $profiler, Response $response, array $server, array $parameters = [])
+ {
+ parent::__construct($l10n, $baseUrl, $args, $logger, $profiler, $response, $server, $parameters);
+
+ $this->config = $config;
+ $this->database = $database;
+ $this->httpClient = $httpClient;
+ $this->request = $request;
+ }
+
+ protected function post(array $request = [])
+ {
+ // PuSH subscription must be considered "public" so just block it
+ // if public access isn't enabled.
+ if ($this->config->get('system', 'block_public')) {
+ throw new HTTPException\ForbiddenException();
+ }
+
+ // Subscription request from subscriber
+ // https://pubsubhubbub.github.io/PubSubHubbub/pubsubhubbub-core-0.4.html#rfc.section.5.1
+ // Example from GNU Social:
+ // [hub_mode] => subscribe
+ // [hub_callback] => http://status.local/main/push/callback/1
+ // [hub_verify] => sync
+ // [hub_verify_token] => af11...
+ // [hub_secret] => af11...
+ // [hub_topic] => http://friendica.local/dfrn_poll/sazius
+
+ $hub_mode = $request['hub_mode'] ?? '';
+ $hub_callback = $request['hub_callback'] ?? '';
+ $hub_verify_token = $request['hub_verify_token'] ?? '';
+ $hub_secret = $request['hub_secret'] ?? '';
+ $hub_topic = $request['hub_topic'] ?? '';
+
+ // check for valid hub_mode
+ if ($hub_mode === 'subscribe') {
+ $subscribe = 1;
+ } elseif ($hub_mode === 'unsubscribe') {
+ $subscribe = 0;
+ } else {
+ $this->logger->notice('Invalid hub_mod - ignored.', ['mode' => $hub_mode]);
+ throw new HTTPException\NotFoundException();
+ }
+
+ $this->logger->info('hub_mode request details.', ['from' => $this->request->getRemoteAddress(), 'mode' => $hub_mode]);
+
+ $nickname = $this->parameters['nickname'] ?? $hub_topic;
+
+ // Extract nickname and strip any .atom extension
+ $nickname = basename($nickname, '.atom');
+ if (!$nickname) {
+ $this->logger->notice('Empty nick, ignoring.');
+ throw new HTTPException\NotFoundException();
+ }
+
+ // fetch user from database given the nickname
+ $condition = ['nickname' => $nickname, 'account_expired' => false, 'account_removed' => false];
+ $owner = $this->database->selectFirst('user', ['uid', 'nickname'], $condition);
+ if (!$owner) {
+ $this->logger->notice('Local account not found', ['nickname' => $nickname, 'topic' => $hub_topic, 'callback' => $hub_callback]);
+ throw new HTTPException\NotFoundException();
+ }
+
+ // get corresponding row from contact table
+ $condition = ['uid' => $owner['uid'], 'blocked' => false, 'pending' => false, 'self' => true];
+ $contact = $this->database->selectFirst('contact', ['poll'], $condition);
+ if (!$contact) {
+ $this->logger->notice('Self contact for user not found.', ['uid' => $owner['uid']]);
+ throw new HTTPException\NotFoundException();
+ }
+
+ // sanity check that topic URLs are the same
+ $hub_topic2 = str_replace('/feed/', '/dfrn_poll/', $hub_topic);
+ $self = $this->baseUrl . '/api/statuses/user_timeline/' . $owner['nickname'] . '.atom';
+
+ if (!Strings::compareLink($hub_topic, $contact['poll']) && !Strings::compareLink($hub_topic2, $contact['poll']) && !Strings::compareLink($hub_topic, $self)) {
+ $this->logger->notice('Hub topic invalid', ['hub_topic' => $hub_topic, 'poll' => $contact['poll']]);
+ throw new HTTPException\NotFoundException();
+ }
+
+ // do subscriber verification according to the PuSH protocol
+ $hub_challenge = Strings::getRandomHex(40);
+
+ $params = http_build_query([
+ 'hub.mode' => $subscribe == 1 ? 'subscribe' : 'unsubscribe',
+ 'hub.topic' => $hub_topic,
+ 'hub.challenge' => $hub_challenge,
+ 'hub.verify_token' => $hub_verify_token,
+
+ // lease time is hard coded to one week (in seconds)
+ // we don't actually enforce the lease time because GNU
+ // Social/StatusNet doesn't honour it (yet)
+ 'hub.lease_seconds' => 604800,
+ ]);
+
+ $hub_callback = rtrim($hub_callback, ' ?&#');
+ $separator = parse_url($hub_callback, PHP_URL_QUERY) === null ? '?' : '&';
+
+ $fetchResult = $this->httpClient->fetchFull($hub_callback . $separator . $params);
+ $body = $fetchResult->getBody();
+ $returnCode = $fetchResult->getReturnCode();
+
+ // give up if the HTTP return code wasn't a success (2xx)
+ if ($returnCode < 200 || $returnCode > 299) {
+ $this->logger->notice('Subscriber verification ignored', ['hub_topic' => $hub_topic, 'callback' => $hub_callback, 'returnCode' => $returnCode]);
+ throw new HTTPException\NotFoundException();
+ }
+
+ // check that the correct hub_challenge code was echoed back
+ if (trim($body) !== $hub_challenge) {
+ $this->logger->notice('Subscriber did not echo back hub.challenge, ignoring.', ['hub_challenge' => $hub_challenge, 'body' => trim($body)]);
+ throw new HTTPException\NotFoundException();
+ }
+
+ PushSubscriber::renew($owner['uid'], $nickname, $subscribe, $hub_callback, $hub_topic, $hub_secret);
+
+ throw new HTTPException\AcceptedException();
+ }
+}