totp.py 文件源码

def _decode_bytes(key, format):
    """
    internal TOTP() helper --
    decodes key according to specified format.
    """
    if format == "raw":
        if not isinstance(key, bytes):
            raise exc.ExpectedTypeError(key, "bytes", "key")
        return key
    # for encoded data, key must be either unicode or ascii-encoded bytes,
    # and must contain a hex or base32 string.
    key = to_unicode(key, param="key")
    key = _clean_re.sub("", key).encode("utf-8") # strip whitespace & hypens
    if format == "hex" or format == "base16":
        return base64.b16decode(key.upper())
    elif format == "base32":
        return b32decode(key)
    # XXX: add base64 support?
    else:
        raise ValueError("unknown byte-encoding format: %r" % (format,))

#=============================================================================
# OTP management
#=============================================================================

#: flag for detecting if encrypted totp support is present