diff options
| -rw-r--r-- | mod/receive.php | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/mod/receive.php b/mod/receive.php new file mode 100644 index 000000000..6e36109b3 --- /dev/null +++ b/mod/receive.php @@ -0,0 +1,215 @@ +<?php + +/** + * Diaspora endpoint + */ + + + +require_once('include/salmon.php'); +require_once('library/simplepie/simplepie.inc'); + +function receive_return($val) { + + if($val >= 400) + $err = 'Error'; + if($val >= 200 && $val < 300) + $err = 'OK'; + + logger('mod-diaspora returns ' . $val); + header($_SERVER["SERVER_PROTOCOL"] . ' ' . $val . ' ' . $err); + killme(); + +} + +function receive_post(&$a) { + + if($a->argc != 3 || $a->argv[1] !== 'users') + receive_return(500); + + $guid = $a->argv[2]; + + $r = q("SELECT * FROM `user` WHERE `guid` = '%s' LIMIT 1", + dbesc($guid) + ); + if(! count($r)) + salmon_return(500); + + $importer = $r[0]; + + $xml = $_POST['xml']; + + logger('mod-diaspora: new salmon ' . $xml, LOGGER_DATA); + + if(! $xml) + receive_return(500); + + // parse the xml + + $dom = simplexml_load_string($xml,'SimpleXMLElement',0,NAMESPACE_SALMON_ME); + + // figure out where in the DOM tree our data is hiding + + if($dom->provenance->data) + $base = $dom->provenance; + elseif($dom->env->data) + $base = $dom->env; + elseif($dom->data) + $base = $dom; + + if(! $base) { + logger('mod-diaspora: unable to locate salmon data in xml '); + receive_return(400); + } + + // Stash the signature away for now. We have to find their key or it won't be good for anything. + $signature = base64url_decode($base->sig); + + // unpack the data + + // strip whitespace so our data element will return to one big base64 blob + $data = str_replace(array(" ","\t","\r","\n"),array("","","",""),$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; + + $signed_data = $data . '.' . base64url_encode($type) . '.' . base64url_encode($encoding) . '.' . base64url_encode($alg); + + // decode the data + $data = base64url_decode($data); + + // Remove the xml declaration + $data = preg_replace('/\<\?xml[^\?].*\?\>/','',$data); + + // Create a fake feed wrapper so simplepie doesn't choke + + $tpl = get_markup_template('fake_feed.tpl'); + + $base = substr($data,strpos($data,'<entry')); + + $feedxml = $tpl . $base . '</feed>'; + + logger('mod-diaspora: Processed feed: ' . $feedxml); + + // Now parse it like a normal atom feed to scrape out the author URI + + $feed = new SimplePie(); + $feed->set_raw_data($feedxml); + $feed->enable_order_by_date(false); + $feed->init(); + + logger('mod-diaspora: Feed parsed.'); + + if($feed->get_item_quantity()) { + foreach($feed->get_items() as $item) { + $author = $item->get_author(); + $author_link = unxmlify($author->get_link()); + break; + } + } + + if(! $author_link) { + logger('mod-diaspora: Could not retrieve author URI.'); + receive_return(400); + } + + // Once we have the author URI, go to the web and try to find their public key + + logger('mod-salmon: Fetching key for ' . $author_link ); + + + $key = get_salmon_key($author_link,$keyhash); + + if(! $key) { + logger('mod-salmon: Could not retrieve author key.'); + receive_return(400); + } + + // Setup RSA stuff to verify the signature + + set_include_path(get_include_path() . PATH_SEPARATOR . 'library' . PATH_SEPARATOR . 'phpsec'); + + require_once('library/phpsec/Crypt/RSA.php'); + + $key_info = explode('.',$key); + + $m = base64url_decode($key_info[1]); + $e = base64url_decode($key_info[2]); + + logger('mod-salmon: key details: ' . print_r($key_info,true)); + + $rsa = new CRYPT_RSA(); + $rsa->signatureMode = CRYPT_RSA_SIGNATURE_PKCS1; + $rsa->setHash('sha256'); + + $rsa->modulus = new Math_BigInteger($m, 256); + $rsa->k = strlen($rsa->modulus->toBytes()); + $rsa->exponent = new Math_BigInteger($e, 256); + + $verify = $rsa->verify($signed_data,$signature); + + if(! $verify) { + logger('mod-diaspora: Message did not verify. Discarding.'); + receive_return(400); + } + + logger('mod-diaspora: Message verified.'); + + /* decrypt the sucker */ + /* + // TODO + */ + + /* + * + * If we reached this point, the message is good. Now let's figure out if the author is allowed to send us stuff. + * + */ + + $r = q("SELECT * FROM `contact` WHERE `network` = 'dspr' AND ( `url` = '%s' OR `alias` = '%s') + AND `uid` = %d LIMIT 1", + dbesc($author_link), + dbesc($author_link), + intval($importer['uid']) + ); + if(! count($r)) { + logger('mod-diaspora: Author unknown to us.'); + } + + // is this a follower? Or have we ignored the person? + // If so we can not accept this post. + + if((count($r)) && (($r[0]['readonly']) || ($r[0]['rel'] == REL_VIP) || ($r[0]['blocked']))) { + logger('mod-diaspora: Ignoring this author.'); + receive_return(202); + // NOTREACHED + } + + require_once('include/items.php'); + + // Placeholder for hub discovery. We shouldn't find any hubs + // since we supplied the fake feed header - and it doesn't have any. + + $hub = ''; + + /** + * + * anti-spam measure: consume_feed will accept a follow activity from + * this person (and nothing else) if there is no existing contact record. + * + */ + + $contact_rec = ((count($r)) ? $r[0] : null); + + consume_feed($feedxml,$importer,$contact_rec,$hub); + + receive_return(200); +} + + + + |