codekingpro/portable-devtools

1# This file is dual licensed under the terms of the Apache License, Version2# 2.0, and the BSD License. See the LICENSE file in the root of this repository3# for complete details.4 5from __future__ import annotations6 7import abc8 9from cryptography.utils import Buffer10 11 12class KeyDerivationFunction(metaclass=abc.ABCMeta):13    @abc.abstractmethod14    def derive(self, key_material: bytes) -> bytes:15        """16        Deterministically generates and returns a new key based on the existing17        key material.18        """19 20    @abc.abstractmethod21    def derive_into(self, key_material: bytes, buffer: Buffer) -> None:22        """23        Deterministically generates a new key based on the existing key24        material and stores it in the provided buffer.25        """26 27    @abc.abstractmethod28    def verify(self, key_material: bytes, expected_key: bytes) -> None:29        """30        Checks whether the key generated by the key material matches the31        expected derived key. Raises an exception if they do not match.32        """33