private void FakeEncrypt(OutgoingPacket packet, byte[] mac)
{
packet.BuildHeader();
packet.Raw = new byte[packet.Data.Length + MacLen + OutHeaderLen];
// Copy the Mac from [Mac...] to [Mac..., Header..., Data...]
Array.Copy(mac, 0, packet.Raw, 0, MacLen);
// Copy the Header from packet.Header to [Mac..., Header..., Data...]
Array.Copy(packet.Header, 0, packet.Raw, MacLen, OutHeaderLen);
// Copy the Data from packet.Data to [Mac..., Header..., Data...]
Array.Copy(packet.Data, 0, packet.Raw, MacLen + OutHeaderLen, packet.Data.Length);
// Raw is now [Mac..., Header..., Data...]
}
internal void Encrypt(OutgoingPacket packet)
{
if (packet.PacketType == PacketType.Init1)
{
FakeEncrypt(packet, TS3InitMac);
return;
}
if (packet.UnencryptedFlag)
{
FakeEncrypt(packet, fakeSignature);
return;
}
var keyNonce = GetKeyNonce(false, packet.PacketId, packet.GenerationId, packet.PacketType);
packet.BuildHeader();
ICipherParameters ivAndKey = new AeadParameters(new KeyParameter(keyNonce.Item1), 8 * MacLen, keyNonce.Item2, packet.Header);
byte[] result;
int len;
lock (eaxCipher)
{
eaxCipher.Init(true, ivAndKey);
result = new byte[eaxCipher.GetOutputSize(packet.Size)];
try
{
len = eaxCipher.ProcessBytes(packet.Data, 0, packet.Size, result, 0);
len += eaxCipher.DoFinal(result, len);
}
catch (Exception ex) { throw new Ts3Exception("Internal encryption error.", ex); }
}
// result consists of [Data..., Mac...]
// to build the final TS3/libtomcrypt we need to copy it into another order
// len is Data.Length + Mac.Length
packet.Raw = new byte[OutHeaderLen + len];
// Copy the Mac from [Data..., Mac...] to [Mac..., Header..., Data...]
Array.Copy(result, len - MacLen, packet.Raw, 0, MacLen);
// Copy the Header from packet.Header to [Mac..., Header..., Data...]
Array.Copy(packet.Header, 0, packet.Raw, MacLen, OutHeaderLen);
// Copy the Data from [Data..., Mac...] to [Mac..., Header..., Data...]
Array.Copy(result, 0, packet.Raw, MacLen + OutHeaderLen, len - MacLen);
// Raw is now [Mac..., Header..., Data...]
}
