| # 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 KeyDerivationFunction(object): |
| @abc.abstractmethod |
| def derive(self, key_material): |
| """ |
| Deterministically generates and returns a new key based on the existing |
| key material. |
| """ |
| |
| @abc.abstractmethod |
| def verify(self, key_material, expected_key): |
| """ |
| Checks whether the key generated by the key material matches the |
| expected derived key. Raises an exception if they do not match. |
| """ |