def http_parse_auth(s):
    """https://tools.ietf.org/html/rfc7235#section-2.1
    """
    scheme, rest = s.split(" ", 1)
    result = {}
    while True:
        m = httplib2.WWW_AUTH_RELAXED.search(rest)
        if not m:
            break
        if len(m.groups()) == 3:
            key, value, rest = m.groups()
            result[key.lower()] = httplib2.UNQUOTE_PAIRS.sub(r"\1", value)
    return result