# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.

from __future__ import absolute_import, division, print_function

import abc

import six


@six.add_metaclass(abc.ABCMeta)
class MACContext(object):
    @abc.abstractmethod
    def update(self, data):
        """
        Processes the provided bytes.
        """

    @abc.abstractmethod
    def finalize(self):
        """
        Returns the message authentication code as bytes.
        """

    @abc.abstractmethod
    def copy(self):
        """
        Return a MACContext that is a copy of the current context.
        """

    @abc.abstractmethod
    def verify(self, signature):
        """
        Checks if the generated message authentication code matches the
        signature.
        """