<?php function post_var($name) { return (x($_POST, $name)) ? notags(trim($_POST[$name])) : ''; } function pubsubhubbub_init(&$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 $r = q("SELECT * FROM `contact` WHERE `uid` = %d AND `blocked` = 0" . " AND `pending` = 0 LIMIT 1", intval($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(); } ?>