public static void DecryptPacket(ServerState state, byte[] packet)
{
using (var reader = new Reader(packet))
{
var ID = reader.ReadUInt16();
reader.Seek(3, SeekOrigin.Current);
var Version = reader.ReadUInt16();
byte[] cipherText = reader.ReadAllBytes, plainText;
var Name = Packet_Names.GetName(ID);
switch (ID)
{
case 10100:
{
plainText = cipherText;
break;
}
case 10101:
{
state.ClientKey = cipherText.Take(32).ToArray();
var nonce = GenericHash.Hash(state.ClientKey.Concat(state.ServerKey.PublicKey).ToArray(), null,
24);
cipherText = cipherText.Skip(32).ToArray();
plainText = PublicKeyBox.Open(cipherText, nonce, state.ServerKey.PrivateKey, state.ClientKey);
state.SessionKey = plainText.Take(24).ToArray();
state.ClientState.Nonce = plainText.Skip(24).Take(24).ToArray();
plainText = plainText.Skip(24).Skip(24).ToArray();
break;
}
default:
{
state.ClientState.Nonce = Utilities.Increment(Utilities.Increment(state.ClientState.Nonce));
plainText = SecretBox.Open(new byte[16].Concat(cipherText).ToArray(), state.ClientState.Nonce,
state.SharedKey);
break;
}
}
ClientCrypto.EncryptPacket(state.ClientState, ID, Version, plainText);
Console.WriteLine(
$"[{DateTime.Now.ToLongTimeString()}, CLIENT, {ID}] {Resources.Definition.Decode(new Reader(plainText), ID)}");
Logger.Write(BitConverter.ToString(plainText).Replace("-", string.Empty), $"{ID}_{Name}",
LogType.PACKET);
}
}
public static void ReceiveCallback(IAsyncResult Result)
{
try
{
var state = Result.AsyncState as State;
var socket = state.Socket;
int bytesAvailable, bytesNeeded, bytesRead = 0, bytesReceived = socket.EndReceive(Result);
while (bytesRead < bytesReceived)
{
bytesAvailable = bytesReceived - bytesRead;
if (bytesReceived > 0 && state.Packet.Length >= 7)
{
var payloadLength =
BitConverter.ToInt32(new byte[1].Concat(state.Packet.Skip(2).Take(3)).Reverse().ToArray(),
0);
bytesNeeded = payloadLength - (state.Packet.Length - 7);
if (bytesAvailable >= bytesNeeded)
{
state.Packet = state.Packet.Concat(state.Buffer.Skip(bytesRead).Take(bytesNeeded))
.ToArray();
bytesRead += bytesNeeded;
bytesAvailable -= bytesNeeded;
if (state.GetType() == typeof(ClientState))
{
ClientCrypto.DecryptPacket(state as ClientState, state.Packet);
}
else if (state.GetType() == typeof(ServerState))
{
ServerCrypto.DecryptPacket(state as ServerState, state.Packet);
}
state.Packet = new byte[0];
}
else
{
state.Packet = state.Packet.Concat(state.Buffer.Skip(bytesRead).Take(bytesAvailable))
.ToArray();
bytesRead = bytesReceived;
bytesAvailable = 0;
}
}
else if (bytesAvailable >= 7)
{
state.Packet = state.Packet.Concat(state.Buffer.Skip(bytesRead).Take(7)).ToArray();
bytesRead += 7;
bytesAvailable -= 7;
}
else
{
state.Packet = state.Packet.Concat(state.Buffer.Skip(bytesRead).Take(bytesAvailable)).ToArray();
bytesRead = bytesReceived;
bytesAvailable = 0;
}
}
socket.BeginReceive(state.Buffer, 0, 2048, 0, ReceiveCallback, state);
}
catch (Exception)
{
}
}
