def _xor_bytes(aggregating_bytearray, updating_bytes):
 for i in xrange(len(aggregating_bytearray)):
  aggregating_bytearray[i] ^= ord(updating_bytes[i])
 return aggregating_bytearray

def _xor_bytes ( aggregating_bytearray , updating_bytes ) : for i in xrange ( len ( aggregating_bytearray ) ) : aggregating_bytearray [ i ] ^= ord ( updating_bytes [ i ] ) return aggregating_bytearray
aggregate bytes into a bytearray using xor .