json_util.py 文件源码

def decode_b64jose(data, size=None, minimum=False):
    """Decode JOSE Base-64 field.

    :param unicode data:
    :param int size: Required length (after decoding).
    :param bool minimum: If ``True``, then `size` will be treated as
        minimum required length, as opposed to exact equality.

    :rtype: bytes

    """
    error_cls = TypeError if six.PY2 else binascii.Error
    try:
        decoded = b64.b64decode(data.encode())
    except error_cls as error:
        raise errors.DeserializationError(error)

    if size is not None and ((not minimum and len(decoded) != size) or
                             (minimum and len(decoded) < size)):
        raise errors.DeserializationError(
            "Expected at least or exactly {0} bytes".format(size))

    return decoded