friendica/mod/salmon.php

193 lines
5.1 KiB
PHP

<?php
/**
* @file mod/salmon.php
*/
use Friendica\App;
use Friendica\Core\Logger;
use Friendica\Core\PConfig;
use Friendica\Core\Protocol;
use Friendica\Core\System;
use Friendica\Database\DBA;
use Friendica\Model\Contact;
use Friendica\Protocol\OStatus;
use Friendica\Protocol\Salmon;
use Friendica\Util\Crypto;
use Friendica\Util\Strings;
function salmon_post(App $a, $xml = '') {
if (empty($xml)) {
$xml = file_get_contents('php://input');
}
Logger::log('new salmon ' . $xml, Logger::DATA);
$nick = (($a->argc > 1) ? Strings::escapeTags(trim($a->argv[1])) : '');
$r = q("SELECT * FROM `user` WHERE `nickname` = '%s' AND `account_expired` = 0 AND `account_removed` = 0 LIMIT 1",
DBA::escape($nick)
);
if (! DBA::isResult($r)) {
System::httpExit(500);
}
$importer = $r[0];
// parse the xml
$dom = simplexml_load_string($xml,'SimpleXMLElement',0,NAMESPACE_SALMON_ME);
$base = null;
// figure out where in the DOM tree our data is hiding
if (!empty($dom->provenance->data))
$base = $dom->provenance;
elseif (!empty($dom->env->data))
$base = $dom->env;
elseif (!empty($dom->data))
$base = $dom;
if (empty($base)) {
Logger::log('unable to locate salmon data in xml ');
System::httpExit(400);
}
// Stash the signature away for now. We have to find their key or it won't be good for anything.
$signature = Strings::base64UrlDecode($base->sig);
// unpack the data
// strip whitespace so our data element will return to one big base64 blob
$data = str_replace([" ","\t","\r","\n"],["","","",""],$base->data);
// stash away some other stuff for later
$type = $base->data[0]->attributes()->type[0];
$keyhash = $base->sig[0]->attributes()->keyhash[0];
$encoding = $base->encoding;
$alg = $base->alg;
// Salmon magic signatures have evolved and there is no way of knowing ahead of time which
// flavour we have. We'll try and verify it regardless.
$stnet_signed_data = $data;
$signed_data = $data . '.' . Strings::base64UrlEncode($type) . '.' . Strings::base64UrlEncode($encoding) . '.' . Strings::base64UrlEncode($alg);
$compliant_format = str_replace('=', '', $signed_data);
// decode the data
$data = Strings::base64UrlDecode($data);
$author = OStatus::salmonAuthor($data, $importer);
$author_link = $author["author-link"];
if(! $author_link) {
Logger::log('Could not retrieve author URI.');
System::httpExit(400);
}
// Once we have the author URI, go to the web and try to find their public key
Logger::log('Fetching key for ' . $author_link);
$key = Salmon::getKey($author_link, $keyhash);
if(! $key) {
Logger::log('Could not retrieve author key.');
System::httpExit(400);
}
$key_info = explode('.',$key);
$m = Strings::base64UrlDecode($key_info[1]);
$e = Strings::base64UrlDecode($key_info[2]);
Logger::log('key details: ' . print_r($key_info,true), Logger::DEBUG);
$pubkey = Crypto::meToPem($m, $e);
// We should have everything we need now. Let's see if it verifies.
// Try GNU Social format
$verify = Crypto::rsaVerify($signed_data, $signature, $pubkey);
$mode = 1;
if (! $verify) {
Logger::log('message did not verify using protocol. Trying compliant format.');
$verify = Crypto::rsaVerify($compliant_format, $signature, $pubkey);
$mode = 2;
}
if (! $verify) {
Logger::log('message did not verify using padding. Trying old statusnet format.');
$verify = Crypto::rsaVerify($stnet_signed_data, $signature, $pubkey);
$mode = 3;
}
if (! $verify) {
Logger::log('Message did not verify. Discarding.');
System::httpExit(400);
}
Logger::log('Message verified with mode '.$mode);
/*
*
* If we reached this point, the message is good. Now let's figure out if the author is allowed to send us stuff.
*
*/
$r = q("SELECT * FROM `contact` WHERE `network` IN ('%s', '%s')
AND (`nurl` = '%s' OR `alias` = '%s' OR `alias` = '%s')
AND `uid` = %d LIMIT 1",
DBA::escape(Protocol::OSTATUS),
DBA::escape(Protocol::DFRN),
DBA::escape(Strings::normaliseLink($author_link)),
DBA::escape($author_link),
DBA::escape(Strings::normaliseLink($author_link)),
intval($importer['uid'])
);
if (!DBA::isResult($r)) {
Logger::log('Author ' . $author_link . ' unknown to user ' . $importer['uid'] . '.');
if (PConfig::get($importer['uid'], 'system', 'ostatus_autofriend')) {
$result = Contact::createFromProbe($importer['uid'], $author_link);
if ($result['success']) {
$r = q("SELECT * FROM `contact` WHERE `network` = '%s' AND ( `url` = '%s' OR `alias` = '%s')
AND `uid` = %d LIMIT 1",
DBA::escape(Protocol::OSTATUS),
DBA::escape($author_link),
DBA::escape($author_link),
intval($importer['uid'])
);
}
}
}
// Have we ignored the person?
// If so we can not accept this post.
//if((DBA::isResult($r)) && (($r[0]['readonly']) || ($r[0]['rel'] == Contact::FOLLOWER) || ($r[0]['blocked']))) {
if (DBA::isResult($r) && $r[0]['blocked']) {
Logger::log('Ignoring this author.');
System::httpExit(202);
// NOTREACHED
}
// Placeholder for hub discovery.
$hub = '';
$contact_rec = ((DBA::isResult($r)) ? $r[0] : []);
OStatus::import($data, $importer, $contact_rec, $hub);
System::httpExit(200);
}