mod/pubsubhubbub.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2022, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 use Friendica\App;
  23 use Friendica\Core\Logger;
  24 use Friendica\Database\DBA;
  25 use Friendica\DI;
  26 use Friendica\Model\PushSubscriber;
  27 use Friendica\Util\Strings;
  28
  29 function pubsubhubbub_init(App $a) {
  30         // PuSH subscription must be considered "public" so just block it
  31         // if public access isn't enabled.
  32         if (DI::config()->get('system', 'block_public')) {
  33                 throw new \Friendica\Network\HTTPException\ForbiddenException();
  34         }
  35
  36         // Subscription request from subscriber
  37         // https://pubsubhubbub.googlecode.com/git/pubsubhubbub-core-0.4.html#anchor4
  38         // Example from GNU Social:
  39         // [hub_mode] => subscribe
  40         // [hub_callback] => http://status.local/main/push/callback/1
  41         // [hub_verify] => sync
  42         // [hub_verify_token] => af11...
  43         // [hub_secret] => af11...
  44         // [hub_topic] => http://friendica.local/dfrn_poll/sazius
  45
  46         if (DI::args()->getMethod() === App\Router::POST) {
  47                 $hub_mode         = $_POST['hub_mode']         ?? '';
  48                 $hub_callback     = $_POST['hub_callback']     ?? '';
  49                 $hub_verify_token = $_POST['hub_verify_token'] ?? '';
  50                 $hub_secret       = $_POST['hub_secret']       ?? '';
  51                 $hub_topic        = $_POST['hub_topic']        ?? '';
  52
  53                 // check for valid hub_mode
  54                 if ($hub_mode === 'subscribe') {
  55                         $subscribe = 1;
  56                 } elseif ($hub_mode === 'unsubscribe') {
  57                         $subscribe = 0;
  58                 } else {
  59                         Logger::notice("Invalid hub_mode=$hub_mode, ignoring.");
  60                         throw new \Friendica\Network\HTTPException\NotFoundException();
  61                 }
  62
  63                 Logger::info("$hub_mode request from " . $_SERVER['REMOTE_ADDR']);
  64
  65                 if (DI::args()->getArgc() > 1) {
  66                         // Normally the url should now contain the nick name as last part of the url
  67                         $nick = DI::args()->getArgv()[1];
  68                 } else {
  69                         // Get the nick name from the topic as a fallback
  70                         $nick = $hub_topic;
  71                 }
  72                 // Extract nick name and strip any .atom extension
  73                 $nick = basename($nick, '.atom');
  74
  75                 if (!$nick) {
  76                         Logger::notice('Bad hub_topic=$hub_topic, ignoring.');
  77                         throw new \Friendica\Network\HTTPException\NotFoundException();
  78                 }
  79
  80                 // fetch user from database given the nickname
  81                 $condition = ['nickname' => $nick, 'account_expired' => false, 'account_removed' => false];
  82                 $owner = DBA::selectFirst('user', ['uid', 'nickname'], $condition);
  83                 if (!DBA::isResult($owner)) {
  84                         Logger::notice('Local account not found: ' . $nick . ' - topic: ' . $hub_topic . ' - callback: ' . $hub_callback);
  85                         throw new \Friendica\Network\HTTPException\NotFoundException();
  86                 }
  87
  88                 // get corresponding row from contact table
  89                 $condition = ['uid' => $owner['uid'], 'blocked' => false,
  90                         'pending' => false, 'self' => true];
  91                 $contact = DBA::selectFirst('contact', ['poll'], $condition);
  92                 if (!DBA::isResult($contact)) {
  93                         Logger::notice('Self contact for user ' . $owner['uid'] . ' not found.');
  94                         throw new \Friendica\Network\HTTPException\NotFoundException();
  95                 }
  96
  97                 // sanity check that topic URLs are the same
  98                 $hub_topic2 = str_replace('/feed/', '/dfrn_poll/', $hub_topic);
  99                 $self = DI::baseUrl() . '/api/statuses/user_timeline/' . $owner['nickname'] . '.atom';
 100
 101                 if (!Strings::compareLink($hub_topic, $contact['poll']) && !Strings::compareLink($hub_topic2, $contact['poll']) && !Strings::compareLink($hub_topic, $self)) {
 102                         Logger::notice('Hub topic ' . $hub_topic . ' != ' . $contact['poll']);
 103                         throw new \Friendica\Network\HTTPException\NotFoundException();
 104                 }
 105
 106                 // do subscriber verification according to the PuSH protocol
 107                 $hub_challenge = Strings::getRandomHex(40);
 108
 109                 $params = http_build_query([
 110                         'hub.mode' => $subscribe == 1 ? 'subscribe' : 'unsubscribe',
 111                         'hub.topic' => $hub_topic,
 112                         'hub.challenge' => $hub_challenge,
 113                         'hub.verify_token' => $hub_verify_token,
 114
 115                         // lease time is hard coded to one week (in seconds)
 116                         // we don't actually enforce the lease time because GNU
 117                         // Social/StatusNet doesn't honour it (yet)
 118                         'hub.lease_seconds' => 604800,
 119                 ]);
 120
 121                 $hub_callback = rtrim($hub_callback, ' ?&#');
 122                 $separator = parse_url($hub_callback, PHP_URL_QUERY) === null ? '?' : '&';
 123
 124                 $fetchResult = DI::httpClient()->fetchFull($hub_callback . $separator . $params);
 125                 $body = $fetchResult->getBody();
 126                 $ret = $fetchResult->getReturnCode();
 127
 128                 // give up if the HTTP return code wasn't a success (2xx)
 129                 if ($ret < 200 || $ret > 299) {
 130                         Logger::notice("Subscriber verification for $hub_topic at $hub_callback returned $ret, ignoring.");
 131                         throw new \Friendica\Network\HTTPException\NotFoundException();
 132                 }
 133
 134                 // check that the correct hub_challenge code was echoed back
 135                 if (trim($body) !== $hub_challenge) {
 136                         Logger::notice("Subscriber did not echo back hub.challenge, ignoring.");
 137                         Logger::notice("\"$hub_challenge\" != \"".trim($body)."\"");
 138                         throw new \Friendica\Network\HTTPException\NotFoundException();
 139                 }
 140
 141                 PushSubscriber::renew($owner['uid'], $nick, $subscribe, $hub_callback, $hub_topic, $hub_secret);
 142
 143                 throw new \Friendica\Network\HTTPException\AcceptedException();
 144         }
 145         exit();
 146 }