def test_cipher(self):
for mode in ['AES-128/CTR-BE', 'Serpent/GCM', 'ChaCha20Poly1305']:
enc = botan2.SymmetricCipher(mode, encrypt=True)
if mode == 'AES-128/CTR-BE':
self.assertEqual(enc.algo_name(), 'CTR-BE(AES-128)')
elif mode == 'Serpent/GCM':
self.assertEqual(enc.algo_name(), 'Serpent/GCM(16)')
else:
self.assertEqual(enc.algo_name(), mode)
(kmin, kmax) = enc.key_length()
self.assertLessEqual(kmin, kmax)
rng = botan2.RandomNumberGenerator()
iv = rng.get(enc.default_nonce_length())
key = rng.get(kmax)
pt = rng.get(21)
enc.set_key(key)
enc.start(iv)
update_result = enc.update('')
assert not update_result
ct = enc.finish(pt)
dec = botan2.SymmetricCipher(mode, encrypt=False)
dec.set_key(key)
dec.start(iv)
decrypted = dec.finish(ct)
self.assertEqual(decrypted, pt)
def decrypt(iv, key, ctxt):
cipher = botan.SymmetricCipher('AES-256/GCM', False)
cipher.set_key(key)
cipher.start(iv)
ptxt = cipher.finish(ctxt)
cipher.clear()
return ptxt.decode('utf-8')
def encrypt(key, ptxt):
iv = botan.RandomNumberGenerator().get(16)
cipher = botan.SymmetricCipher('AES-256/GCM')
cipher.set_key(key)
cipher.start(iv)
ctxt = cipher.finish(ptxt.encode('utf-8'))
cipher.clear()
return (iv, ctxt)
