friendica_2021-01/mod/pubsubhubbub.php
Andrej Stieben db949bb802 Updated modules to allow for partial overrides without errors
Only define functions if they have not been defined before, e.g. in themes. This makes it possible to override parts of a module and still use the other functions.
2016-02-05 21:52:39 +01:00

166 lines
5 KiB
PHP

<?php
if(! function_exists('post_var')) {
function post_var($name) {
return (x($_POST, $name)) ? notags(trim($_POST[$name])) : '';
}
}
if(! function_exists('pubsubhubbub_init')) {
function pubsubhubbub_init(&$a) {
// PuSH subscription must be considered "public" so just block it
// if public access isn't enabled.
if (get_config('system', 'block_public')) {
http_status_exit(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') {
$subscribe = 1;
} else if ($hub_mode === 'unsubscribe') {
$subscribe = 0;
} else {
logger("pubsubhubbub: invalid hub_mode=$hub_mode, ignoring.");
http_status_exit(404);
}
logger("pubsubhubbub: $hub_mode request from " .
$_SERVER['REMOTE_ADDR']);
// get the nick name from the topic, a bit hacky but needed
$nick = substr(strrchr($hub_topic, "/"), 1);
if (!$nick) {
logger('pubsubhubbub: bad hub_topic=$hub_topic, ignoring.');
http_status_exit(404);
}
// fetch user from database given the nickname
$r = q("SELECT * FROM `user` WHERE `nickname` = '%s'" .
" AND `account_expired` = 0 AND `account_removed` = 0 LIMIT 1",
dbesc($nick));
if(!count($r)) {
logger('pubsubhubbub: local account not found: ' . $nick);
http_status_exit(404);
}
$owner = $r[0];
// abort if user's wall is supposed to be private
if ($r[0]['hidewall']) {
logger('pubsubhubbub: local user ' . $nick .
'has chosen to hide wall, ignoring.');
http_status_exit(403);
}
// get corresponding row from contact table
$r = q("SELECT * FROM `contact` WHERE `uid` = %d AND NOT `blocked`".
" AND NOT `pending` AND `self` LIMIT 1",
intval($owner['uid']));
if(!count($r)) {
logger('pubsubhubbub: contact not found.');
http_status_exit(404);
}
$contact = $r[0];
// sanity check that topic URLs are the same
if(!link_compare($hub_topic, $contact['poll'])) {
logger('pubsubhubbub: hub topic ' . $hub_topic . ' != ' .
$contact['poll']);
http_status_exit(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)
$body = fetch_url($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("pubsubhubbub: subscriber verification at $hub_callback ".
"returned $ret, ignoring.");
http_status_exit(404);
}
// check that the correct hub_challenge code was echoed back
if (trim($body) !== $hub_challenge) {
logger("pubsubhubbub: subscriber did not echo back ".
"hub.challenge, ignoring.");
logger("\"$hub_challenge\" != \"".trim($body)."\"");
http_status_exit(404);
}
// fetch the old subscription if it exists
$r = q("SELECT * FROM `push_subscriber` WHERE `callback_url` = '%s'",
dbesc($hub_callback));
// delete old subscription if it exists
q("DELETE FROM `push_subscriber` WHERE `callback_url` = '%s'",
dbesc($hub_callback));
if ($subscribe) {
$last_update = datetime_convert('UTC','UTC','now','Y-m-d H:i:s');
$push_flag = 0;
// if we are just updating an old subscription, keep the
// old values for push and last_update
if (count($r)) {
$last_update = $r[0]['last_update'];
$push_flag = $r[0]['push'];
}
// subscribe means adding the row to the table
q("INSERT INTO `push_subscriber` (`uid`, `callback_url`, " .
"`topic`, `nickname`, `push`, `last_update`, `secret`) values " .
"(%d, '%s', '%s', '%s', %d, '%s', '%s')",
intval($owner['uid']),
dbesc($hub_callback),
dbesc($hub_topic),
dbesc($nick),
intval($push_flag),
dbesc($last_update),
dbesc($hub_secret));
logger("pubsubhubbub: successfully subscribed [$hub_callback].");
} else {
logger("pubsubhubbub: successfully unsubscribed [$hub_callback].");
// we do nothing here, since the row was already deleted
}
http_status_exit(202);
}
killme();
}
}
?>