friendica/mod/pubsubhubbub.php

152 lines
5.6 KiB
PHP

<?php
/**
* @copyright Copyright (C) 2020, Friendica
*
* @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/>.
*
*/
use Friendica\App;
use Friendica\Core\Logger;
use Friendica\Database\DBA;
use Friendica\DI;
use Friendica\Model\PushSubscriber;
use Friendica\Network\HTTPRequest;
use Friendica\Util\Strings;
function post_var($name) {
return !empty($_POST[$name]) ? Strings::escapeTags(trim($_POST[$name])) : '';
}
function pubsubhubbub_init(App $a) {
// PuSH subscription must be considered "public" so just block it
// if public access isn't enabled.
if (DI::config()->get('system', 'block_public')) {
throw new \Friendica\Network\HTTPException\ForbiddenException();
}
// Subscription request from subscriber
// https://pubsubhubbub.googlecode.com/git/pubsubhubbub-core-0.4.html#anchor4
// Example from GNU Social:
// [hub_mode] => subscribe
// [hub_callback] => http://status.local/main/push/callback/1
// [hub_verify] => sync
// [hub_verify_token] => af11...
// [hub_secret] => af11...
// [hub_topic] => http://friendica.local/dfrn_poll/sazius
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
$hub_mode = post_var('hub_mode');
$hub_callback = post_var('hub_callback');
$hub_verify_token = post_var('hub_verify_token');
$hub_secret = post_var('hub_secret');
$hub_topic = post_var('hub_topic');
// check for valid hub_mode
if ($hub_mode === 'subscribe') {
$subscribe = 1;
} elseif ($hub_mode === 'unsubscribe') {
$subscribe = 0;
} else {
Logger::log("Invalid hub_mode=$hub_mode, ignoring.");
throw new \Friendica\Network\HTTPException\NotFoundException();
}
Logger::log("$hub_mode request from " . $_SERVER['REMOTE_ADDR']);
if ($a->argc > 1) {
// Normally the url should now contain the nick name as last part of the url
$nick = $a->argv[1];
} else {
// Get the nick name from the topic as a fallback
$nick = $hub_topic;
}
// Extract nick name and strip any .atom extension
$nick = basename($nick, '.atom');
if (!$nick) {
Logger::log('Bad hub_topic=$hub_topic, ignoring.');
throw new \Friendica\Network\HTTPException\NotFoundException();
}
// fetch user from database given the nickname
$condition = ['nickname' => $nick, 'account_expired' => false, 'account_removed' => false];
$owner = DBA::selectFirst('user', ['uid', 'nickname'], $condition);
if (!DBA::isResult($owner)) {
Logger::log('Local account not found: ' . $nick . ' - topic: ' . $hub_topic . ' - callback: ' . $hub_callback);
throw new \Friendica\Network\HTTPException\NotFoundException();
}
// get corresponding row from contact table
$condition = ['uid' => $owner['uid'], 'blocked' => false,
'pending' => false, 'self' => true];
$contact = DBA::selectFirst('contact', ['poll'], $condition);
if (!DBA::isResult($contact)) {
Logger::log('Self contact for user ' . $owner['uid'] . ' not found.');
throw new \Friendica\Network\HTTPException\NotFoundException();
}
// sanity check that topic URLs are the same
$hub_topic2 = str_replace('/feed/', '/dfrn_poll/', $hub_topic);
$self = DI::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)) {
Logger::log('Hub topic ' . $hub_topic . ' != ' . $contact['poll']);
throw new \Friendica\Network\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 ? '?' : '&';
$fetchResult = HTTPRequest::fetchUrlFull($hub_callback . $separator . $params);
$body = $fetchResult->getBody();
$ret = $fetchResult->getReturnCode();
// give up if the HTTP return code wasn't a success (2xx)
if ($ret < 200 || $ret > 299) {
Logger::log("Subscriber verification for $hub_topic at $hub_callback returned $ret, ignoring.");
throw new \Friendica\Network\HTTPException\NotFoundException();
}
// check that the correct hub_challenge code was echoed back
if (trim($body) !== $hub_challenge) {
Logger::log("Subscriber did not echo back hub.challenge, ignoring.");
Logger::log("\"$hub_challenge\" != \"".trim($body)."\"");
throw new \Friendica\Network\HTTPException\NotFoundException();
}
PushSubscriber::renew($owner['uid'], $nick, $subscribe, $hub_callback, $hub_topic, $hub_secret);
throw new \Friendica\Network\HTTPException\AcceptedException();
}
exit();
}