def _cases_cipher(key_size, mult_keys, mult_state, mode='encrypt'): # noqa
if mult_keys:
keys = np.random.randint(0,
255, (number_of_keys, key_size),
dtype='uint8')
if mult_state:
state = np.random.randint(0,
255, (number_of_keys, 8),
dtype='uint8')
expected = np.empty((number_of_keys, 8), dtype='uint8')
for i, key in enumerate(keys):
if key_size == 8:
ciphertext = crypto_des.DESCipher(key)
elif key_size == 16 or key_size == 24:
ciphertext = crypto_des3.DES3Cipher(key)
expected[i] = np.frombuffer(getattr(ciphertext,
mode)(state[i]),
dtype='uint8')
else:
state = np.random.randint(0, 255, (8), dtype='uint8')
expected = np.empty((number_of_keys, 8), dtype='uint8')
for i, key in enumerate(keys):
if key_size == 8:
ciphertext = crypto_des.DESCipher(key)
elif key_size == 16 or key_size == 24:
ciphertext = crypto_des3.DES3Cipher(key)
expected[i] = np.frombuffer(getattr(ciphertext, mode)(state),
dtype='uint8')
else:
keys = np.random.randint(0, 255, (key_size), dtype='uint8')
if key_size == 8:
ciphertext = crypto_des.DESCipher(keys)
elif key_size == 16 or key_size == 24:
ciphertext = crypto_des3.DES3Cipher(keys)
if mult_state:
state = np.random.randint(0,
255, (number_of_keys, 8),
dtype='uint8')
expected = np.empty((number_of_keys, 8), dtype='uint8')
for i, s in enumerate(state):
expected[i] = np.frombuffer(getattr(ciphertext, mode)(s),
dtype='uint8')
else:
state = np.random.randint(0, 255, (8), dtype='uint8')
expected = np.frombuffer(getattr(ciphertext, mode)(state),
dtype='uint8')
return {
'keys': keys,
'state': state,
'key_size': key_size,
'expected': expected
}
def test_get_master_key_retrieves_des_master_key_able_to_decrypt_the_ciphertext(
):
des_key = np.random.randint(256, size=8, dtype=np.uint8)
plaintext = np.random.randint(256, size=8, dtype=np.uint8)
expected_ciphertext = des.encrypt(plaintext, des_key)
des_key_schedule = des.key_schedule(des_key)
for round_index, round_key in enumerate(des_key_schedule):
found_master_key = des.get_master_key(round_key, round_index,
plaintext, expected_ciphertext)
assert found_master_key is not None
plaintext_from_found_key = np.frombuffer(crypto_des.DESCipher(
found_master_key).decrypt(expected_ciphertext),
dtype='uint8')
assert np.array_equal(plaintext_from_found_key, plaintext)