code: def hash_to_exponent(self, h):
          
          ctr = Crypto.Util.Counter.new(128, initial_value=0)
          cipher = Crypto.Cipher.AES.new(h,
                                         Crypto.Cipher.AES.MODE_CTR, counter=ctr)
          buf = cipher.encrypt(b'\0' * self.order_len_bin)
          return self._buf_to_exponent(buf)
docs: Converts a 32 byte hash to an exponent