From a61ec584d60013f7845d0999deb550a2149f4e76 Mon Sep 17 00:00:00 2001 From: Friendika Date: Sat, 30 Jul 2011 00:31:00 -0700 Subject: [PATCH] basic diaspora decryption --- boot.php | 17 ++++++- mod/receive.php | 130 +++++++++++++++++++++++++++++++++++++----------- 2 files changed, 117 insertions(+), 30 deletions(-) diff --git a/boot.php b/boot.php index 68cda3bf2f..5d4f547696 100644 --- a/boot.php +++ b/boot.php @@ -2969,4 +2969,19 @@ function generate_guid() { $found = false; } while ($found == true ); return $guid; -} \ No newline at end of file +} + + +function pkcs5_pad ($text, $blocksize) +{ + $pad = $blocksize - (strlen($text) % $blocksize); + return $text . str_repeat(chr($pad), $pad); +} + +function pkcs5_unpad($text) +{ + $pad = ord($text{strlen($text)-1}); + if ($pad > strlen($text)) return false; + if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) return false; + return substr($text, 0, -1 * $pad); +} diff --git a/mod/receive.php b/mod/receive.php index 6fb68e1545..18f323f422 100644 --- a/mod/receive.php +++ b/mod/receive.php @@ -43,10 +43,68 @@ function receive_post(&$a) { if(! $xml) receive_return(500); - // parse the xml - $dom = simplexml_load_string($xml,'SimpleXMLElement',0,NAMESPACE_SALMON_ME); + $basedom = parse_xml_string($xml); + if($basedom) + logger('parsed dom'); + + $atom = $basedom->children(NAMESPACE_ATOM1); + + logger('atom: ' . count($atom)); + $encrypted_header = json_decode(base64_decode($atom->encrypted_header)); + + print_r($encrypted_header); + + $encrypted_aes_key_bundle = base64_decode($encrypted_header->aes_key); + $ciphertext = base64_decode($encrypted_header->ciphertext); + + logger('encrypted_aes: ' . print_r($encrypted_aes_key_bundle,true)); + logger('ciphertext: ' . print_r($ciphertext,true)); + + $outer_key_bundle = ''; + openssl_private_decrypt($encrypted_aes_key_bundle,$outer_key_bundle,$localprvkey); + + logger('outer_bundle: ' . print_r($outer_key_bundle,true)); + + $j_outer_key_bundle = json_decode($outer_key_bundle); + + $outer_iv = base64_decode($j_outer_key_bundle->iv); + $outer_key = base64_decode($j_outer_key_bundle->key); + + $decrypted = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $outer_key, $ciphertext, MCRYPT_MODE_CBC, $outer_iv); + + $decrypted = pkcs5_unpad($decrypted); + + logger('decrypted: ' . print_r($decrypted,true)); + + /** + * $decrypted now contains something like + * + * + * 8e+G2+ET8l5BPuW0sVTnQw== + * UvSMb4puPeB14STkcDWq+4QE302Edu15oaprAQSkLKU= + * + * Ryan Hughes + * acct:galaxor@diaspora.pirateship.org + * + * + */ + + $idom = parse_xml_string($decrypted,false); + + print_r($idom); + $inner_iv = base64_decode($idom->iv); + $inner_aes_key = base64_decode($idom->aes_key); + + logger('inner_iv: ' . $inner_iv); + + $dom = $basedom->children(NAMESPACE_SALMON_ME); + + if($dom) + logger('have dom'); + + logger('dom: ' . count($dom)); // figure out where in the DOM tree our data is hiding if($dom->provenance->data) @@ -58,12 +116,22 @@ function receive_post(&$a) { if(! $base) { logger('mod-diaspora: unable to locate salmon data in xml '); - receive_return(400); + dt_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); + logger('signature: ' . bin2hex($signature)); + + openssl_public_encrypt('test',$rrr,$ryanpubkey); + logger('rrr: ' . $rrr); + + $pubdecsig = ''; + openssl_public_decrypt($signature,$pubdecsig,$ryanpubkey); + logger('decsig: ' . bin2hex($pubdecsig)); + // unpack the data // strip whitespace so our data element will return to one big base64 blob @@ -76,40 +144,28 @@ function receive_post(&$a) { $encoding = $base->encoding; $alg = $base->alg; - $signed_data = $data . '.' . base64url_encode($type) . '.' . base64url_encode($encoding) . '.' . base64url_encode($alg); + $signed_data = $data . "\n" . '.' . base64url_encode($type) . "\n" . '.' . base64url_encode($encoding) . "\n" . '.' . base64url_encode($alg) . "\n"; + + logger('signed data: ' . $signed_data); // decode the data $data = base64url_decode($data); - // Remove the xml declaration - $data = preg_replace('/\<\?xml[^\?].*\?\>/','',$data); + // Now pull out the inner encrypted blob - // Create a fake feed wrapper so simplepie doesn't choke - $tpl = get_markup_template('fake_feed.tpl'); - - $base = substr($data,strpos($data,''; - logger('mod-diaspora: Processed feed: ' . $feedxml); + $inner_encrypted = base64_decode($data); - // 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(); + $inner_decrypted = + $inner_decrypted = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $inner_aes_key, $inner_encrypted, MCRYPT_MODE_CBC, $inner_iv); + + $inner_decrypted = pkcs5_unpad($inner_decrypted); + + logger('inner_decrypted: ' . $inner_decrypted); - logger('mod-diaspora: Feed parsed.'); - if($feed->get_item_quantity()) { - foreach($feed->get_items() as $item) { - $author = $item->get_author(); - $author_link = unxmlify($author->get_link()); - break; - } - } if(! $author_link) { logger('mod-diaspora: Could not retrieve author URI.'); @@ -117,17 +173,25 @@ function receive_post(&$a) { } // Once we have the author URI, go to the web and try to find their public key + // *** or look it up locally *** - logger('mod-salmon: Fetching key for ' . $author_link ); + logger('mod-diaspora: Fetching key for ' . $author_link ); +// Get diaspora public key (pkcs#1) and convert to pkcs#8 +// $key = get_diaspora_key($author_link); - $key = get_salmon_key($author_link,$keyhash); +// $key = get_salmon_key($author_link,$keyhash); if(! $key) { logger('mod-salmon: Could not retrieve author key.'); receive_return(400); } +// FIXME +// Use non salmon compliant signature + +/* + // Setup RSA stuff to verify the signature set_include_path(get_include_path() . PATH_SEPARATOR . 'library' . PATH_SEPARATOR . 'phpsec'); @@ -155,6 +219,7 @@ function receive_post(&$a) { logger('mod-diaspora: Message did not verify. Discarding.'); receive_return(400); } +*/ logger('mod-diaspora: Message verified.'); @@ -204,7 +269,14 @@ function receive_post(&$a) { $contact_rec = ((count($r)) ? $r[0] : null); - consume_feed($feedxml,$importer,$contact_rec,$hub); + + + +// figure out what kind of diaspora message we have, and process accordingly. + + + + receive_return(200); }