def make_signature(access_key_secret, date=None):
    if isinstance(date, bytes):
        date = date.decode("utf-8")
    if isinstance(date, int):
        date_gmt = http_date(date)
    elif date is None:
        date_gmt = http_date(int(time.time()))
    else:
        date_gmt = date

    data = str(access_key_secret) + "\n" + date_gmt
    return content_md5(data)