def cast_byte_decrypt(self, input_byte, encrypt_key):
pbk = PBKDF2HMAC(hashes.SHA256, self.__salt_size, self.__salt, self.__iteration_count, self._backend)
pbk_key = pbk.derive(encrypt_key.encode())
decryptor = Cipher(
CAST5(pbk_key), modes.CBC(self.__IV[0:8]), self._backend
).decryptor()
cipher_text = decryptor.update(input_byte) + decryptor.finalize()
un_padder = padding.PKCS7(CAST5.block_size).unpadder()
un_padded_data = un_padder.update(cipher_text) + un_padder.finalize()
return un_padded_data
def test_invalid_key_type(self):
with pytest.raises(TypeError, match="key must be bytes"):
CAST5(u"0" * 10)
def test_invalid_key_size(self):
with pytest.raises(ValueError):
CAST5(binascii.unhexlify(b"0" * 34))
def test_key_size(self, key, keysize):
cipher = CAST5(binascii.unhexlify(key))
assert cipher.key_size == keysize
def test_invalid_key_type(self):
with pytest.raises(TypeError, match="key must be bytes"):
CAST5("0" * 10) # type: ignore[arg-type]
def _make_cipher(self, passphrase):
key = self.make_key(passphrase)
iv = self.make_iv(passphrase)
cipher = Cipher(CAST5(key), CBC(iv), backend=default_backend())
return cipher