def pad_encoded_str(encoded_string):
    """Return padded encoded string with zero
       to full byte if missing
    """
    extra_zero = 8 - len(encoded_string) % 8
    padded_encoded_string = '0' * extra_zero + encoded_string
    extra_zero_info = '{0:08b}'.format(extra_zero)
    padded_encoded_string = extra_zero_info + padded_encoded_string
    return padded_encoded_string
