Server side modifications

Fix bad implementation of PKDBF2 and HMAC
New protocol version (2)

server/functions.php

@@ -24,16 +24,11 @@
   
   Password is salted (3 random characters) and encrypted
 
-  All is encrypted with AES256 and key : sha256(master key)
+  All is encrypted with AES256 and key : PKDBF2(hmac_sha256, master key, url, 1000)
  */
 $MAX_ENTRY_LEN = 512;
 $USERS_PATH = "./users/";
 
-function get_mkey_hash($mkey)
-{
-    return bin2hex(hash("sha256", $mkey, true));
-}
-
 function open_crypto($mkey)
 {
     if (!isset($_SESSION['td']))
@@ -191,6 +186,8 @@ function add_entry($user, $login, $password)
 
     $result = $db->query("INSERT INTO gpass ('login', 'password') VALUES ('" . $login . "', '" . $password . "')");
 
+    $db->close();
+
     echo "OK";
 
     return true;
@@ -208,6 +205,8 @@ function delete_entry($user, $login)
 
     $db->query("DELETE FROM gpass WHERE login='" . $login . "'");
 
+    $db->close();
+
     echo "OK";
 
     return true;

server/ref/index.php

@@ -31,7 +31,7 @@ function load_database()
     return $db;
 }
 
-$PROTOCOL_VERSION = 1;
+$PROTOCOL_VERSION = 2;
 
 $db = load_database();
 

server/ressources/gpass.js

@@ -81,6 +81,14 @@ function url_domain(data) {
    return uri['host'];
 }
 
+// http://stackoverflow.com/questions/3745666/how-to-convert-from-hex-to-ascii-in-javascript
+function hex2a(hex) {
+    var str = '';
+    for (var i = 0; i < hex.length; i += 2)
+	str += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
+    return str;
+}
+
 function a2hex(str) {
     var hex = '';
     for (var i = 0; i < str.length; i++)
@@ -96,7 +104,6 @@ function derive_mkey(user, mkey)
 {
     url = url_domain(document.URL) + "/" + user;
     mkey = a2hex(pkdbf2(mkey, url, 1000, 256/8));
-
     return mkey;
 }
 

server/ressources/hmac.js

@@ -21,15 +21,23 @@ function hmac256(key, message) {
     var ipad = "";
     var opad = "";
 
-    for(i=0; i<key.length; i++)
+    if (key.length > 512/8)
+    {
+	key = digest256(key);
+    }
+
+    for(i=0; i<512/8; i++)
+    {
+	if (i >= key.length)
+	{
+	    ipad += String.fromCharCode(0x36);
+	    opad += String.fromCharCode(0x5c);
+	}
+	else
 	{
 	    ipad += String.fromCharCode(key.charCodeAt(i) ^ 0x36);
 	    opad += String.fromCharCode(key.charCodeAt(i) ^ 0x5c);
 	}
-    while (ipad.length < 512/8)
-    {
-	ipad += String.fromCharCode(0x36);
-	opad += String.fromCharCode(0x5c);
     }
 
     result = digest256(opad + digest256(ipad + message));

server/ressources/jssha256.js

@@ -231,13 +231,24 @@ function sha256_encode_hex() {
 	return output;
 }
 
+/* Get the internal hash as string */
+function sha256_encode() {
+	var output = new String();
+	for(var i=0; i<8; i++) {
+		for(var j=3; j>=0; j--)
+		    output += String.fromCharCode((ihash[i] >>> j*8) & 0xff);
+	}
+	return output;
+}
+
 /* Main function: returns a hex string representing the SHA256 value of the 
    given data */
 function digest256 (data) {
     sha256_init();
     sha256_update(data, data.length);
     sha256_final();
-    return sha256_encode_hex();
+    return sha256_encode();
+    // return sha256_encode_hex();
 }
 
 /* test if the JS-interpreter is working properly */

server/ressources/pkdbf2.js

@@ -17,14 +17,6 @@
   along with gPass.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-// http://stackoverflow.com/questions/3745666/how-to-convert-from-hex-to-ascii-in-javascript
-function hex2a(hex) {
-    var str = '';
-    for (var i = 0; i < hex.length; i += 2)
-        str += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
-    return str;
-}
-
 function pkdbf2 (password, salt, iterations, outlen) {
     var result = "";
     var temp = "";
@@ -34,17 +26,17 @@ function pkdbf2 (password, salt, iterations, outlen) {
 
     for (i=1; result.length < outlen; i++)
     {
-	temp = hex2a(hmac256(salt + 
+	temp = hmac256(password, salt + 
 		       String.fromCharCode((i & 0xff000000) >> 24) +
 		       String.fromCharCode((i & 0x00ff0000) >> 16) +
 		       String.fromCharCode((i & 0x0000ff00) >>  8) +
-			     String.fromCharCode((i & 0x000000ff) >>  0),
-			     password));
+		       String.fromCharCode((i & 0x000000ff) >>  0)
+		       );
 	temp_res = temp;
 
 	for(a=1; a<iterations; a++)
 	{
-	    temp2 = hex2a(hmac256(temp, password));
+	    temp2 = hmac256(password, temp);
 	    temp_res2 = "";
 	    for(b = 0; b<temp_res.length; b++)
 		temp_res2 += String.fromCharCode(temp_res.charCodeAt(b) ^ temp2.charCodeAt(b));