friendica/mod/pubsubhubbub.php
2018-07-23 11:04:14 -04:00

128 lines
4.2 KiB
PHP

<?php
use Friendica\App;
use Friendica\Core\Config;
use Friendica\Core\System;
use Friendica\Database\DBA;
use Friendica\Model\PushSubscriber;
use Friendica\Util\Network;
function post_var($name) {
return (x($_POST, $name)) ? notags(trim($_POST[$name])) : '';
}
function pubsubhubbub_init(App $a) {
// PuSH subscription must be considered "public" so just block it
// if public access isn't enabled.
if (Config::get('system', 'block_public')) {
System::httpExit(403);
}
// Subscription request from subscriber
// https://pubsubhubbub.googlecode.com/git/pubsubhubbub-core-0.4.html#anchor4
// Example from GNU Social:
// [hub_mode] => subscribe
// [hub_callback] => http://status.local/main/push/callback/1
// [hub_verify] => sync
// [hub_verify_token] => af11...
// [hub_secret] => af11...
// [hub_topic] => http://friendica.local/dfrn_poll/sazius
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
$hub_mode = post_var('hub_mode');
$hub_callback = post_var('hub_callback');
$hub_verify = post_var('hub_verify');
$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') {
$subscribe = 0;
} else {
logger("Invalid hub_mode=$hub_mode, ignoring.");
System::httpExit(404);
}
logger("$hub_mode request from " . $_SERVER['REMOTE_ADDR']);
// get the nick name from the topic, a bit hacky but needed as a fallback
$nick = substr(strrchr($hub_topic, "/"), 1);
// Normally the url should now contain the nick name as last part of the url
if ($a->argc > 1) {
$nick = $a->argv[1];
}
if (!$nick) {
logger('Bad hub_topic=$hub_topic, ignoring.');
System::httpExit(404);
}
// fetch user from database given the nickname
$condition = ['nickname' => $nick, 'account_expired' => false, 'account_removed' => false];
$owner = DBA::selectFirst('user', ['uid', 'hidewall'], $condition);
if (!DBA::isResult($owner)) {
logger('Local account not found: ' . $nick . ' - topic: ' . $hub_topic . ' - callback: ' . $hub_callback);
System::httpExit(404);
}
// abort if user's wall is supposed to be private
if ($owner['hidewall']) {
logger('Local user ' . $nick . 'has chosen to hide wall, ignoring.');
System::httpExit(403);
}
// 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('Self contact for user ' . $owner['uid'] . ' not found.');
System::httpExit(404);
}
// sanity check that topic URLs are the same
$hub_topic2 = str_replace('/feed/', '/dfrn_poll/', $hub_topic);
if (!link_compare($hub_topic, $contact['poll']) && !link_compare($hub_topic2, $contact['poll'])) {
logger('Hub topic ' . $hub_topic . ' != ' . $contact['poll']);
System::httpExit(404);
}
// do subscriber verification according to the PuSH protocol
$hub_challenge = random_string(40);
$params = 'hub.mode=' .
($subscribe == 1 ? 'subscribe' : 'unsubscribe') .
'&hub.topic=' . urlencode($hub_topic) .
'&hub.challenge=' . $hub_challenge .
'&hub.lease_seconds=604800' .
'&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)
$body = Network::fetchUrl($hub_callback . "?" . $params);
$ret = $a->get_curl_code();
// give up if the HTTP return code wasn't a success (2xx)
if ($ret < 200 || $ret > 299) {
logger("Subscriber verification for $hub_topic at $hub_callback returned $ret, ignoring.");
System::httpExit(404);
}
// check that the correct hub_challenge code was echoed back
if (trim($body) !== $hub_challenge) {
logger("Subscriber did not echo back hub.challenge, ignoring.");
logger("\"$hub_challenge\" != \"".trim($body)."\"");
System::httpExit(404);
}
PushSubscriber::renew($owner['uid'], $nick, $subscribe, $hub_callback, $hub_topic, $hub_secret);
System::httpExit(202);
}
killme();
}