public static void DecryptPacket(Socket socket, ClientState state, byte[] packet)
{
int messageId = BitConverter.ToInt32(new byte[2].Concat(packet.Take(2)).Reverse().ToArray(), 0);
int payloadLength = BitConverter.ToInt32(new byte[1].Concat(packet.Skip(2).Take(3)).Reverse().ToArray(), 0);
int unknown = BitConverter.ToInt32(new byte[2].Concat(packet.Skip(2).Skip(3).Take(2)).Reverse().ToArray(), 0);
byte[] cipherText = packet.Skip(2).Skip(3).Skip(2).ToArray();
byte[] plainText;
if (messageId == 20100)
{
plainText = cipherText;
}
else if (messageId == 20104)
{
byte[] nonce = GenericHash.Hash(state.nonce.Concat(state.clientKey.PublicKey).Concat(state.serverKey).ToArray(), null, 24);
plainText = PublicKeyBox.Open(cipherText, nonce, state.clientKey.PrivateKey, state.serverKey);
state.serverState.nonce = plainText.Take(24).ToArray();
state.serverState.sharedKey = plainText.Skip(24).Take(32).ToArray();
plainText = plainText.Skip(24).Skip(32).ToArray();
}
else
{
state.serverState.nonce = Utilities.Increment(Utilities.Increment(state.serverState.nonce));
plainText = SecretBox.Open(new byte[16].Concat(cipherText).ToArray(), state.serverState.nonce, state.serverState.sharedKey);
}
Console.WriteLine("[SERVER]{0} "+Environment.NewLine+"{1}", PacketInfos.GetPacketName(messageId), Utilities.BinaryToHex(packet.Take(7).ToArray()) + Utilities.BinaryToHex(plainText));
ServerCrypto.EncryptPacket(state.serverState.socket, state.serverState, messageId, unknown, plainText);
}
public static void EncryptPacket(Socket socket, ClientState state, int messageId, int unknown, byte[] plainText)
{
byte[] cipherText;
if (messageId == 10100)
{
cipherText = plainText;
}
else if (messageId == 10101)
{
byte[] nonce = GenericHash.Hash(state.clientKey.PublicKey.Concat(state.serverKey).ToArray(), null, 24);
plainText = state.serverState.sessionKey.Concat(state.nonce).Concat(plainText).ToArray();
cipherText = PublicKeyBox.Create(plainText, nonce, state.clientKey.PrivateKey, state.serverKey);
cipherText = state.clientKey.PublicKey.Concat(cipherText).ToArray();
}
else
{
// nonce was already incremented in ServerCrypto.DecryptPacket
cipherText = SecretBox.Create(plainText, state.nonce, state.serverState.sharedKey).Skip(16).ToArray();
}
byte[] packet = BitConverter.GetBytes(messageId).Reverse().Skip(2).Concat(BitConverter.GetBytes(cipherText.Length).Reverse().Skip(1)).Concat(BitConverter.GetBytes(unknown).Reverse().Skip(2)).Concat(cipherText).ToArray();
socket.BeginSend(packet, 0, packet.Length, 0, new AsyncCallback(SendCallback), state);
}
public static void DecryptPacket(Socket socket, ClientState state, byte[] packet)
{
int messageId = BitConverter.ToInt32(new byte[2].Concat(packet.Take(2)).Reverse().ToArray(), 0);
int payloadLength = BitConverter.ToInt32(new byte[1].Concat(packet.Skip(2).Take(3)).Reverse().ToArray(), 0);
int unknown = BitConverter.ToInt32(new byte[2].Concat(packet.Skip(2).Skip(3).Take(2)).Reverse().ToArray(), 0);
byte[] cipherText = packet.Skip(2).Skip(3).Skip(2).ToArray();
byte[] plainText;
if (messageId == 20100 || (messageId == 20103 && state.serverState.sharedKey == null))
{
plainText = cipherText;
}
else if (messageId == 20103 || messageId == 20104)
{
byte[] nonce = GenericHash.Hash(state.nonce.Concat(state.clientKey.PublicKey).Concat(state.serverKey).ToArray(), null, 24);
plainText = PublicKeyBox.Open(cipherText, nonce, state.clientKey.PrivateKey, state.serverKey);
state.serverState.nonce = plainText.Take(24).ToArray();
state.serverState.sharedKey = plainText.Skip(24).Take(32).ToArray();
plainText = plainText.Skip(24).Skip(32).ToArray();
}
else
{
state.serverState.nonce = Utilities.Increment(Utilities.Increment(state.serverState.nonce));
plainText = SecretBox.Open(new byte[16].Concat(cipherText).ToArray(), state.serverState.nonce, state.serverState.sharedKey);
}
try
{
JObject decoded = state.decoder.decode(messageId, unknown, plainText);
Console.WriteLine("{0}: {1}", decoded["name"], decoded["fields"]);
}
catch (Exception e)
{
Console.WriteLine(e.Message);
Console.WriteLine("{0} {1}", messageId, Utilities.BinaryToHex(BitConverter.GetBytes(messageId).Reverse().Skip(2).Concat(BitConverter.GetBytes(plainText.Length).Reverse().Skip(1)).Concat(BitConverter.GetBytes(unknown).Reverse().Skip(2)).Concat(plainText).ToArray()));
}
ServerCrypto.EncryptPacket(state.serverState.socket, state.serverState, messageId, unknown, plainText);
}