diaspora encrypt+decrypt working !!

1 files changed, 221 insertions, 6 deletions

diff --git a/include/diaspora.php b/include/diaspora.php
index 316105999..6862074c6 100644
--- a/include/diaspora.php
+++ b/include/diaspora.php
@@ -1,6 +1,43 @@
 <?php
 
+require_once('include/certfns.php');
 
+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 . ' ' . $err);
+	killme();
+
+}
+
+
+function get_diaspora_key($uri) {
+	$key = '';
+
+	logger('Fetching diaspora key for: ' . $uri);
+
+	$arr = lrdd($uri);
+
+	if(is_array($arr)) {
+		foreach($arr as $a) {
+			if($a['@attributes']['rel'] === 'diaspora-public-key') {
+				$key = base64_decode($a['@attributes']['href']);
+			}
+		}
+	}
+	else {
+		return '';
+	}
+
+	if($key)
+		return rsatopem($key);
+	return '';
+}
 
 
 function diaspora_base_message($type,$data) {
@@ -26,12 +63,14 @@ function diaspora_msg_build($msg,$user,$contact,$prvkey,$pubkey) {
 	$outer_iv = random_string(32);
 	$b_outer_iv = base64_encode($outer_iv);
 	
-	$handle = 'acct:' . $user['nickname'] . '@' . substr($a->get_baseurl(), strpos('://') + 3);
+	$handle = 'acct:' . $user['nickname'] . '@' . substr($a->get_baseurl(), strpos($a->get_baseurl(),'://') + 3);
 
-	$padded_data = pkcs5_pad($msg);
+	$padded_data = pkcs5_pad($msg,16);
 	$inner_encrypted = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $inner_aes_key, $padded_data, MCRYPT_MODE_CBC, $inner_iv);
 
 	$b64_data = base64_encode($inner_encrypted);
+echo "inner: $b64_data";
+
 	$b64url_data = base64url_encode($b64_data);
 	$b64url_stripped = str_replace(array("\n","\r"," ","\t"),array('','','',''),$b64url_data);
     $lines = str_split($b64url_stripped,60);
@@ -60,10 +99,15 @@ $decrypted_header = <<< EOT
 </decrypted_header>
 EOT;
 
-	$decrypted_header = pkcs5_pad($decrypted_header);
+	$decrypted_header = pkcs5_pad($decrypted_header,16);
+logger("decrypted_header: $decrypted_header");
 	$ciphertext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $outer_aes_key, $decrypted_header, MCRYPT_MODE_CBC, $outer_iv);
 
-	$outer_json = json_encode(array('iv' => $b64_outer_iv,'key' => $b64_outer_aes_key));
+logger( "encrypted_ciphertext: " . base64_encode($ciphertext));
+	logger("encrypt_outer_key: $b_outer_aes_key");
+	logger("ecnrypt_outer_iv: $b_outer_iv");
+
+	$outer_json = json_encode(array('iv' => $b_outer_iv,'key' => $b_outer_aes_key));
 	$encrypted_outer_key_bundle = '';
 	openssl_public_encrypt($outer_json,$encrypted_outer_key_bundle,$pubkey);
 	
@@ -72,7 +116,7 @@ EOT;
 		'ciphertext' => base64_encode($ciphertext)));
 	$encrypted_header = '<encrypted_header>' . base64_encode($encrypted_header_json_object) . '</encrypted_header>';
 
-$magicenv = <<< EOT
+$magic_env = <<< EOT
 <?xml version='1.0' encoding='UTF-8'?>
 <entry xmlns='http://www.w3.org/2005/Atom'>
   $encrypted_header
@@ -87,4 +131,175 @@ EOT;
 
 	return $magic_env;
 
-}
\ No newline at end of file
+}
+
+
+function diaspora_decode($importer,$xml) {
+	$basedom = parse_xml_string($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,$outer_key_bundle,$importer['prvkey']);
+
+	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);
+
+	logger("outer_iv: $outer_iv");
+	logger("outer_key: $outer_key");
+	logger("ciphertext: " . base64_encode($ciphertext));
+
+	$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
+	 *
+	 *  <decrypted_header>
+	 *     <iv>8e+G2+ET8l5BPuW0sVTnQw==</iv>
+	 *     <aes_key>UvSMb4puPeB14STkcDWq+4QE302Edu15oaprAQSkLKU=</aes_key>
+	 *     <author>
+	 *       <name>Ryan Hughes</name>
+	 *       <uri>acct:galaxor@diaspora.pirateship.org</uri>
+	 *     </author>
+	 *  </decrypted_header>
+	 */
+
+	$idom = parse_xml_string($decrypted,false);
+
+	$inner_iv = base64_decode($idom->iv);
+	$inner_aes_key = base64_decode($idom->aes_key);
+logger('idom: ' . print_r($idom,true));
+
+	$author_link = str_replace('acct:','',$idom->author->uri);
+
+	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)
+		$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 ');
+		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));
+
+	// 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);
+	// Add back the 60 char linefeeds
+    $lines = str_split($data,60);
+    $data = implode("\n",$lines);
+
+
+	// 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 = $data  . (($data[-1] != "\n") ? "\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);
+
+	// Now pull out the inner encrypted blob
+
+	$inner_encrypted = base64_decode($data);
+
+	$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);
+
+
+
+	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
+	// *** or look it up locally ***
+
+	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);
+
+	if(! $key) {
+		logger('mod-salmon: Could not retrieve author key.');
+		receive_return(400);
+	}
+
+	$verify = false;
+
+	if (version_compare(PHP_VERSION, '5.3.0', '>=')) {
+    	$verify = openssl_verify($signed_data,$signature,$key,'sha256');
+	}
+	else {
+		// fallback sha256 verify for PHP < 5.3
+		$rawsig = '';
+		$hash = hash('sha256',$signed_data,true);
+		openssl_public_decrypt($signature,$rawsig,$key);
+		$verify = (($rawsig && substr($rawsig,-32) === $hash) ? true : false);
+	}
+
+	if(! $verify) {
+		logger('mod-diaspora: Message did not verify. Discarding.');
+		receive_return(400);
+	}
+
+	logger('mod-diaspora: Message verified.');
+
+	return $inner_decrypted;
+
+}
+
+
+
+