public static int Encrypt(byte[] plaintext, int offset, int len, byte[] additionalData, byte[] nonce, byte[] key, byte[] outBuffer)
{
lock (mutex) {
if (cipher == null)
{
cipher = new ChaCha7539Engine();
}
else
{
cipher.Reset();
}
if (_encryptKey == null)
{
_encryptKey = new KeyParameter(key);
}
else
{
_encryptKey.Reset();
_encryptKey.SetKey(key);
}
if (_temp_Params == null)
{
_temp_Params = new ParametersWithIV(_encryptKey, nonce);
}
else
{
_temp_Params.Reset();
_temp_Params.Set(_encryptKey, nonce);
}
cipher.Init(true, _temp_Params);
byte[] firstBlock = BufferPool.GetBuffer(64);
KeyParameter macKey = GenerateRecordMacKey(cipher, firstBlock);
cipher.ProcessBytes(plaintext, offset, len, outBuffer, 0);
byte[] mac = BufferPool.GetBuffer(16);
int macsize = CalculateRecordMac(macKey, additionalData, outBuffer, 0, len, mac);
Array.Copy(mac, 0, outBuffer, len, macsize);
BufferPool.ReturnBuffer(mac);
BufferPool.ReturnBuffer(firstBlock);
return(len + 16);
}
}
private void Reset(bool clearMac, bool resetCipher)
{
Array.Clear(mBuf, 0, mBuf.Length);
if (clearMac)
{
Array.Clear(mMac, 0, mMac.Length);
}
this.mAadCount = 0UL;
this.mDataCount = 0UL;
this.mBufPos = 0;
switch (mState)
{
case State.DecInit:
case State.EncInit:
break;
case State.DecAad:
case State.DecData:
case State.DecFinal:
this.mState = State.DecInit;
break;
case State.EncAad:
case State.EncData:
case State.EncFinal:
this.mState = State.EncFinal;
return;
default:
throw new InvalidOperationException();
}
if (resetCipher)
{
mChacha20.Reset();
}
InitMac();
if (null != mInitialAad)
{
ProcessAadBytes(mInitialAad, 0, mInitialAad.Length);
}
}