Merge pull request #290 from DSheirer/289-shoutcast-2-credentials-enc…

…ryption-error

289 Shoutcast 2 Login Error

src/audio/broadcast/shoutcast/v2/ultravox/AuthenticateBroadcast.java

@@ -72,31 +72,48 @@ public void setCredentials(String encryptionKey, int streamID, String userID, St
     }
 
     /**
-     * Encrypts the value using the XTEA block cipher algorithm and returns the encrypted value as a 16 hex value
+     * Encrypts the value using the XTEA block cipher algorithm.  The byte array is sliced into 8-byte chunks and each
+     * chunk is encrypted into a 16 hexadecimal character string.  All encrypted chunks are concatenated and returned
+     * as a single string.  If the value byte array is not an even multiple of 8 characters, it will be padded with
+     * zero valued bytes to make it an even multiple of eight.
      *
      * @param xtea instance of the XTEA algorithm with a loaded encryption key
      * @param value to encode
-     * @return encrypted password as 64-bit, 16 character hexadecimal value
+     * @return value encrypted into one or more multiples of 16 hexadecimal characters
      */
-    private static String encrypt(XTEA xtea, String value)
+    private static String encrypt(XTEA xtea, byte[] value)
     {
-        byte[] valueBytes = value.getBytes();
-
-        if(valueBytes.length % 8 != 0 || valueBytes.length == 0)
+        if(value.length % 8 != 0 || value.length == 0)
         {
-            int newLength = ((valueBytes.length / 8) + 1) * 8;
-            valueBytes = Arrays.copyOf(valueBytes, newLength);
+            int newLength = ((value.length / 8) + 1) * 8;
+            value = Arrays.copyOf(value, newLength);
         }
 
-        byte[] encrypted = xtea.encrypt(valueBytes);
-
         StringBuilder sb = new StringBuilder();
 
-        for(byte b: encrypted)
+        for(int x = 0; x < value.length; x += 8)
         {
-            sb.append(String.format("%02x", b));
+            byte[] plaintext = Arrays.copyOfRange(value, x, x + 8);
+            byte[] encrypted = xtea.encrypt(plaintext);
+
+            for(byte b: encrypted)
+            {
+                sb.append(String.format("%02x", b));
+            }
         }
 
         return sb.toString();
     }
+
+    /**
+     * Encrypts the value using the XTEA block cipher algorithm and returns the encrypted value as a 16 hex value
+     *
+     * @param xtea instance of the XTEA algorithm with a loaded encryption key
+     * @param value to encode
+     * @return encrypted password as 64-bit, 16 character hexadecimal value
+     */
+    private static String encrypt(XTEA xtea, String value)
+    {
+        return encrypt(xtea, value.getBytes());
+    }
 }