private void OutputSizeTests()
{
byte[] K = new byte[32];
byte[] A = null;
byte[] N = new byte[12];
AeadParameters parameters = new AeadParameters(new KeyParameter(K), 16 * 8, N, A);
ChaCha20Poly1305 cipher = InitCipher(true, parameters);
if (cipher.GetUpdateOutputSize(0) != 0)
{
Fail("incorrect getUpdateOutputSize for initial 0 bytes encryption");
}
if (cipher.GetOutputSize(0) != 16)
{
Fail("incorrect getOutputSize for initial 0 bytes encryption");
}
cipher.Init(false, parameters);
if (cipher.GetUpdateOutputSize(0) != 0)
{
Fail("incorrect getUpdateOutputSize for initial 0 bytes decryption");
}
// NOTE: 0 bytes would be truncated data, but we want it to fail in the doFinal, not here
if (cipher.GetOutputSize(0) != 0)
{
Fail("fragile getOutputSize for initial 0 bytes decryption");
}
if (cipher.GetOutputSize(16) != 0)
{
Fail("incorrect getOutputSize for initial MAC-size bytes decryption");
}
}
private void RandomTest(SecureRandom random)
{
int kLength = 32;
byte[] K = new byte[kLength];
random.NextBytes(K);
int pHead = random.Next(256);
int pLength = random.Next(65536);
int pTail = random.Next(256);
byte[] P = new byte[pHead + pLength + pTail];
random.NextBytes(P);
int aLength = random.Next(256);
byte[] A = new byte[aLength];
random.NextBytes(A);
int saLength = random.Next(256);
byte[] SA = new byte[saLength];
random.NextBytes(SA);
int nonceLength = 12;
byte[] nonce = new byte[nonceLength];
random.NextBytes(nonce);
AeadParameters parameters = new AeadParameters(new KeyParameter(K), 16 * 8, nonce, A);
ChaCha20Poly1305 cipher = InitCipher(true, parameters);
int ctLength = cipher.GetOutputSize(pLength);
byte[] C = new byte[saLength + ctLength];
Array.Copy(SA, 0, C, 0, saLength);
int split = NextInt(random, saLength + 1);
cipher.ProcessAadBytes(C, 0, split);
cipher.ProcessAadBytes(C, split, saLength - split);
int predicted = cipher.GetUpdateOutputSize(pLength);
int len = cipher.ProcessBytes(P, pHead, pLength, C, saLength);
if (predicted != len)
{
Fail("encryption reported incorrect update length in randomised test");
}
len += cipher.DoFinal(C, saLength + len);
if (ctLength != len)
{
Fail("encryption reported incorrect length in randomised test");
}
byte[] encT = cipher.GetMac();
byte[] tail = new byte[ctLength - pLength];
Array.Copy(C, saLength + pLength, tail, 0, tail.Length);
if (!AreEqual(encT, tail))
{
Fail("stream contained wrong mac in randomised test");
}
cipher.Init(false, parameters);
int decPHead = random.Next(256);
int decPLength = cipher.GetOutputSize(ctLength);
int decPTail = random.Next(256);
byte[] decP = new byte[decPHead + decPLength + decPTail];
split = NextInt(random, saLength + 1);
cipher.ProcessAadBytes(C, 0, split);
cipher.ProcessAadBytes(C, split, saLength - split);
predicted = cipher.GetUpdateOutputSize(ctLength);
len = cipher.ProcessBytes(C, saLength, ctLength, decP, decPHead);
if (predicted != len)
{
Fail("decryption reported incorrect update length in randomised test");
}
len += cipher.DoFinal(decP, decPHead + len);
if (!AreEqual(P, pHead, pHead + pLength, decP, decPHead, decPHead + decPLength))
{
Fail("incorrect decrypt in randomised test");
}
byte[] decT = cipher.GetMac();
if (!AreEqual(encT, decT))
{
Fail("decryption produced different mac from encryption");
}
//
// key reuse test
//
cipher.Init(false, AeadTestUtilities.ReuseKey(parameters));
decPHead = random.Next(256);
decPLength = cipher.GetOutputSize(ctLength);
decPTail = random.Next(256);
decP = new byte[decPHead + decPLength + decPTail];
split = NextInt(random, saLength + 1);
cipher.ProcessAadBytes(C, 0, split);
cipher.ProcessAadBytes(C, split, saLength - split);
len = cipher.ProcessBytes(C, saLength, ctLength, decP, decPHead);
len += cipher.DoFinal(decP, decPHead + len);
if (!AreEqual(P, pHead, pHead + pLength, decP, decPHead, decPHead + decPLength))
{
Fail("incorrect decrypt in randomised test");
}
decT = cipher.GetMac();
if (!AreEqual(encT, decT))
{
Fail("decryption produced different mac from encryption");
}
}