#
#  SelfTest/Cipher/DES3.py: Self-test for the Triple-DES cipher
#
# Written in 2008 by Dwayne C. Litzenberger <dlitz@dlitz.net>
#
# ===================================================================
# The contents of this file are dedicated to the public domain.  To
# the extent that dedication to the public domain is not available,
# everyone is granted a worldwide, perpetual, royalty-free,
# non-exclusive license to exercise all rights associated with the
# contents of this file for any purpose whatsoever.
# No rights are reserved.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
# ===================================================================

"""Self-test suite for Crypto.Cipher.DES3"""

from binascii import hexlify, unhexlify

import pytest

from Crypto.Cipher import DES3
from Crypto.SelfTest.Cipher.common import make_block_tests
from Crypto.SelfTest.loader import load_test_vectors
from Crypto.Util.strxor import strxor_c

# This is a list of (plaintext, ciphertext, key, description) tuples.
test_data = [
    # Test vector from Appendix B of NIST SP 800-67
    # "Recommendation for the Triple Data Encryption Algorithm (TDEA) Block
    # Cipher"
    # http://csrc.nist.gov/publications/nistpubs/800-67/SP800-67.pdf
    (
        "54686520717566636b2062726f776e20666f78206a756d70",
        "a826fd8ce53b855fcce21c8112256fe668d5c05dd9b6b900",
        "0123456789abcdef23456789abcdef01456789abcdef0123",
        "NIST SP800-67 B.1",
    ),
    # This test is designed to test the DES3 API, not the correctness of the
    # output.
    ("21e81b7ade88a259", "5c577d4d9b20c0f8", "9b397ebf81b1181e282f4bb8adbadc6b", "Two-key 3DES"),
]

# NIST CAVP test vectors

nist_tdes_mmt_files = ("TECBMMT2.rsp", "TECBMMT3.rsp")

for tdes_file in nist_tdes_mmt_files:
    test_vectors = (
        load_test_vectors(
            ("Cipher", "TDES"), tdes_file, "TDES ECB (%s)" % tdes_file, {"count": lambda x: int(x)}
        )
        or []
    )

    for index, tv in enumerate(test_vectors):
        # The test vector file contains some directive lines
        if isinstance(tv, str):
            continue

        key = tv.key1 + tv.key2 + tv.key3
        test_data_item = (
            hexlify(tv.plaintext).decode("latin-1"),
            hexlify(tv.ciphertext).decode("latin-1"),
            hexlify(key).decode("latin-1"),
            "%s (%s)" % (tdes_file, index),
        )
        test_data.append(test_data_item)


class TestCheckParity:
    def test_parity_option2(self):
        before_2k = unhexlify("CABF326FA56734324FFCCABCDEFACABF")
        after_2k = DES3.adjust_key_parity(before_2k)
        assert after_2k == unhexlify("CBBF326EA46734324FFDCBBCDFFBCBBF")

    def test_parity_option3(self):
        before_3k = unhexlify("AAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCC")
        after_3k = DES3.adjust_key_parity(before_3k)
        assert after_3k == unhexlify("ABABABABABABABABBABABABABABABABACDCDCDCDCDCDCDCD")

    def test_degradation(self):
        sub_key1 = bytes([1]) * 8
        sub_key2 = bytes([255]) * 8

        # K1 == K2
        with pytest.raises(ValueError):
            DES3.adjust_key_parity(sub_key1 * 2 + sub_key2)

        # K2 == K3
        with pytest.raises(ValueError):
            DES3.adjust_key_parity(sub_key1 + sub_key2 * 2)

        # K1 == K2 == K3
        with pytest.raises(ValueError):
            DES3.adjust_key_parity(sub_key1 * 3)

        # K1 == K2 (with different parity)
        with pytest.raises(ValueError):
            DES3.adjust_key_parity(sub_key1 + strxor_c(sub_key1, 1) + sub_key2)


class TestDegenerateToDES:
    def test(self):
        sub_key1 = bytes([1]) * 8
        sub_key2 = bytes([255]) * 8

        # K1 == K2
        with pytest.raises(ValueError):
            DES3.new(sub_key1 * 2 + sub_key2, DES3.MODE_ECB)

        # K2 == K3
        with pytest.raises(ValueError):
            DES3.new(sub_key1 + sub_key2 * 2, DES3.MODE_ECB)

        # K1 == K2 == K3
        with pytest.raises(ValueError):
            DES3.new(sub_key1 * 3, DES3.MODE_ECB)

        # K2 == K3 (parity is ignored)
        with pytest.raises(ValueError):
            DES3.new(sub_key1 + sub_key2 + strxor_c(sub_key2, 0x1), DES3.MODE_ECB)


class TestOutput:
    def test(self):
        # Encrypt/Decrypt data and test output parameter

        cipher = DES3.new(b"4" * 8 + b"G" * 8 + b"T" * 8, DES3.MODE_ECB)

        pt = b"5" * 16
        ct = cipher.encrypt(pt)

        output = bytearray(16)
        res = cipher.encrypt(pt, output=output)
        assert ct == output
        assert res is None

        res = cipher.decrypt(ct, output=output)
        assert pt == output
        assert res is None

        output = memoryview(bytearray(16))
        cipher.encrypt(pt, output=output)
        assert ct == output

        cipher.decrypt(ct, output=output)
        assert pt == output

        with pytest.raises(TypeError):
            cipher.encrypt(pt, output=b"0" * 16)
        with pytest.raises(TypeError):
            cipher.decrypt(ct, output=b"0" * 16)

        shorter_output = bytearray(7)
        with pytest.raises(ValueError):
            cipher.encrypt(pt, output=shorter_output)
        with pytest.raises(ValueError):
            cipher.decrypt(ct, output=shorter_output)


TestVectors = make_block_tests(DES3, "DES3", test_data)