def testDecrypt(self):
"""Tests the Decrypt method."""
decrypter = des3_decrypter.DES3Decrypter(
cipher_mode=definitions.ENCRYPTION_MODE_CBC,
initialization_vector=self._DES3_INITIALIZATION_VECTOR,
key=self._DES3_KEY)
# Test full decryption.
decrypted_data, _ = decrypter.Decrypt(
b'e\x86k\t\x01W\xd7d\xe4\xa4\xb3~\x80\xd3\xc3\x7fq{E}:L\n '
b'.2\xd1\xcf\x8a\xf1\xa0!')
expected_decrypted_data = b'This is secret encrypted text!!!'
self.assertEqual(expected_decrypted_data, decrypted_data)
# Reset decrypter.
decrypter = des3_decrypter.DES3Decrypter(
cipher_mode=definitions.ENCRYPTION_MODE_CBC,
initialization_vector=self._DES3_INITIALIZATION_VECTOR,
key=self._DES3_KEY)
# Test partial decryption.
decrypted_data, encrypted_data = decrypter.Decrypt(
b'e\x86k\t\x01W\xd7d\xe4\xa4\xb3~\x80')
expected_decrypted_data = b'This is '
expected_encrypted_data = b'\xe4\xa4\xb3~\x80'
self.assertEqual(expected_decrypted_data, decrypted_data)
self.assertEqual(expected_encrypted_data, encrypted_data)
decrypted_data, encrypted_data = decrypter.Decrypt(
b'\xe4\xa4\xb3~\x80\xd3\xc3\x7fq{E}:L\n '
b'.2\xd1\xcf\x8a\xf1\xa0!')
expected_decrypted_data = b'secret encrypted text!!!'
expected_encrypted_data = b''
self.assertEqual(expected_decrypted_data, decrypted_data)
self.assertEqual(expected_encrypted_data, encrypted_data)
def testInitialization(self):
"""Tests the initialization method."""
# Test missing arguments.
with self.assertRaises(ValueError):
des3_decrypter.DES3Decrypter()
# Test unsupport block cipher mode.
with self.assertRaises(ValueError):
des3_decrypter.DES3Decrypter(cipher_mode='bogus',
key=self._DES3_KEY)
# Test missing initialization vector.
with self.assertRaises(ValueError):
des3_decrypter.DES3Decrypter(
cipher_mode=definitions.ENCRYPTION_MODE_CBC,
key=self._DES3_KEY)
# Test missing initialization vector with valid block cipher mode.
des3_decrypter.DES3Decrypter(
cipher_mode=definitions.ENCRYPTION_MODE_ECB, key=self._DES3_KEY)
# Test incorrect key size.
with self.assertRaises(ValueError):
des3_decrypter.DES3Decrypter(
cipher_mode=definitions.ENCRYPTION_MODE_ECB,
key='Wrong key size')
# Test incorrect initialization vector size.
with self.assertRaises(ValueError):
des3_decrypter.DES3Decrypter(
cipher_mode=definitions.ENCRYPTION_MODE_CBC,
initialization_vector='Wrong IV size',
key=self._DES3_KEY)
