tests/wycheproof/test_keywrap.py

# 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 binascii

import pytest

from cryptography.hazmat.backends.interfaces import CipherBackend
from cryptography.hazmat.primitives import keywrap


@pytest.mark.requires_backend_interface(interface=CipherBackend)
@pytest.mark.wycheproof_tests("kwp_test.json")
def test_keywrap_with_padding(backend, wycheproof):
    wrapping_key = binascii.unhexlify(wycheproof.testcase["key"])
    key_to_wrap = binascii.unhexlify(wycheproof.testcase["msg"])
    expected = binascii.unhexlify(wycheproof.testcase["ct"])

    result = keywrap.aes_key_wrap_with_padding(
        wrapping_key, key_to_wrap, backend
    )
    if wycheproof.valid or wycheproof.acceptable:
        assert result == expected

    if wycheproof.valid or (wycheproof.acceptable and not len(expected) < 16):
        result = keywrap.aes_key_unwrap_with_padding(
            wrapping_key, expected, backend
        )
        assert result == key_to_wrap
    else:
        with pytest.raises(keywrap.InvalidUnwrap):
            keywrap.aes_key_unwrap_with_padding(
                wrapping_key, expected, backend
            )


@pytest.mark.requires_backend_interface(interface=CipherBackend)
@pytest.mark.wycheproof_tests("kw_test.json")
def test_keywrap(backend, wycheproof):
    wrapping_key = binascii.unhexlify(wycheproof.testcase["key"])
    key_to_wrap = binascii.unhexlify(wycheproof.testcase["msg"])
    expected = binascii.unhexlify(wycheproof.testcase["ct"])

    if (
        wycheproof.valid or (
            wycheproof.acceptable and
            wycheproof.testcase["comment"] != "invalid size of wrapped key"
        )
    ):
        result = keywrap.aes_key_wrap(wrapping_key, key_to_wrap, backend)
        assert result == expected

    if wycheproof.valid or wycheproof.acceptable:
        result = keywrap.aes_key_unwrap(wrapping_key, expected, backend)
        assert result == key_to_wrap
    else:
        with pytest.raises(keywrap.InvalidUnwrap):
            keywrap.aes_key_unwrap(wrapping_key, expected, backend)