def test_state_dump_to_bytes(self):
"""Tests dumping State to bytes."""
data = bytearray(self.data)
state_ = state.State.load(data, self.offset)
steps.add_round_key(state_, self.key.schedule, current_round=2)
state_.dump(data, self.offset)
self.assertNotEqual(bytearray(self.data), data)
def test_dump(self):
"""Tests dumping state to file."""
key = Key.load(self.key)
for test in range(self.tests):
offset = test * self.size
state = State.load(self.file, offset)
steps.add_round_key(state, key.schedule, current_round=2)
with self.subTest(offset=offset):
state.dump(self.file, offset)
self.assertNotEqual(state, State.load(self.file, offset))
def test_add_round_key(self):
"""Tests adding current_round keys."""
previous = copy.deepcopy(self.state)
current_round = random.randrange(constants.ROUNDS[self.key.size])
steps.add_round_key(self.state,
self.key.schedule,
current_round=current_round)
for row_id, row in enumerate(previous):
for col_id, elem in enumerate(row):
key_schedule_col_id = 4 * current_round + col_id
with self.subTest(ids=(row_id, col_id)):
self.assertEqual(
elem ^ self.key.schedule[row_id][key_schedule_col_id],
self.state[row_id][col_id])
def test_state_dump_to_file(self):
"""Tests dumping State to files."""
file_mock = mock.MagicMock(spec=pathlib.Path)
open_mock = mock.mock_open(file_mock, self.data)
file_handler_mock = open_mock.return_value
with mock.patch('builtins.open', open_mock):
state_ = state.State.load(file_mock, self.offset)
steps.add_round_key(state_, self.key.schedule, current_round=2)
state_.dump(file_mock, self.offset)
self.assertEqual(2, open_mock.call_count)
open_mock.assert_any_call(file_mock, 'rb')
open_mock.assert_any_call(file_mock, 'rb+')
self.assertEqual(2, file_handler_mock.seek.call_count)
file_handler_mock.seek.assert_any_call(self.offset)
file_handler_mock.read.assert_called_once_with(self.size)
self.assertEqual(4, file_handler_mock.write.call_count)
file_handler_mock.write.assert_any_call(bytes(c[0] for c in state_))
file_handler_mock.write.assert_any_call(bytes(c[1] for c in state_))
file_handler_mock.write.assert_any_call(bytes(c[2] for c in state_))
file_handler_mock.write.assert_any_call(bytes(c[3] for c in state_))
def decrypt(state, key):
"""Decrypts state."""
rounds = constants.ROUNDS[key.size]
steps.add_round_key(state, key.schedule, current_round=rounds)
for current_round in range(rounds - 1, 0, -1):
steps.shift_rows(state, inverse=True)
steps.sub_bytes(state, inverse=True)
steps.add_round_key(state, key.schedule, current_round=current_round)
steps.mix_columns(state, inverse=True)
steps.shift_rows(state, inverse=True)
steps.sub_bytes(state, inverse=True)
steps.add_round_key(state, key.schedule, current_round=0)
def encrypt(state, key):
"""Encrypts state."""
rounds = constants.ROUNDS[key.size]
steps.add_round_key(state, key.schedule, current_round=0)
for current_round in range(1, rounds):
steps.sub_bytes(state)
steps.shift_rows(state)
steps.mix_columns(state)
steps.add_round_key(state, key.schedule, current_round=current_round)
steps.sub_bytes(state)
steps.shift_rows(state)
steps.add_round_key(state, key.schedule, current_round=rounds)