[C#] DarkOrbit Encoding/Decoding from Netty

Hello, today i bring you how to encode and decode the packets of the new darkorbit(which uses netty).

Dictionary:
Short - 2 bytes
Int - 4 bytes
Bool - 1 byte
Str or UTF - Short Length of String + String

The structure of the packets are:
1 - Short Length of all packet
2 - Short Packet ID
3 - Short version (normally 0)
4 - PACKET with shorts, ints, bools and strings (utf)

To encode/decode the bytes, you must use this functions:

Spoiler

And to read the packets or encode, you must use this 2 classes:

Spoiler

Code:

class packetBuilder
{
    List<byte> data;
    public packetBuilder(int ID)
    {
        data = new List<byte>();
        writeShort(ID);
    }

    public void writeInt(int num)
    {
        data.AddRange(Program.WriteInt(num));
    }

    public void writeShort(int num)
    {
        data.AddRange(Program.WriteShort(num));
    }

    public void writeBool(bool state)
    {
        data.Add(state ? (byte)1 : (byte)0);
    }

    public void writeString(string str)
    {
        if (str == null)
        {
            str = "";
        }

        byte[] byteStr = Encoding.UTF8.GetBytes(str);
        writeShort(byteStr.Length);

        data.AddRange(byteStr);
        byteStr = null;
    }

    public byte[] GetBytes()
    {
        List<byte> list = new List<byte>();
        list.AddRange(System.BitConverter.GetBytes(this.data.Count));
        list.Reverse();
        list.AddRange(data);

        System.Console.WriteLine(Encoding.UTF8.GetString(list.ToArray()));
        return list.ToArray();
    }
}


class packetParser
{
    private byte[] Body;
    private int Pointer = 0;
    public packetParser(byte[] Packet)
    {
        Body = Packet;
        this.Lenght = ReadShort();
        this.Id = ReadShort();
    }

    public short Lenght;
    public short Id;

    public short ReadShort()
    {
        return Convert.ToInt16(Program.ReadShort(
            new byte[] { 
                    Body[Pointer++], 
                    Body[Pointer++]
                }));
    }

    public int ReadInt()
    {
        return Program.ReadInt(
            new byte[] { 
                    Body[Pointer++], 
                    Body[Pointer++],
                    Body[Pointer++],
                    Body[Pointer++],
                });
    }

    public ushort ReadUShort()
    {
        return Convert.ToUInt16(Program.ReadShort(
            new byte[] { 
                    Body[Pointer++], 
                    Body[Pointer++]
                }));
    }

    public uint ReadUInt()
    {
        return Convert.ToUInt32(Program.ReadInt(
            new byte[] { 
                    Body[Pointer++], 
                    Body[Pointer++],
                    Body[Pointer++],
                    Body[Pointer++],
                }));
    }

    public string ReadString()
    {
        try
        {
            int Lenght = ReadShort();
            string data = Encoding.UTF8.GetString(Body, Pointer, Lenght);
            Pointer += Lenght;
            return data;
        }
        catch (System.Exception)
        {
            return "";
        }
    }
}

Example to use packetParser:
the first packet you receive from the client, apart from the policy, is id: 666.
To read:

Code:

int bytesRead = handler.EndReceive(ar);
if(bytesRead > 0)
{
    byte[] Body = new byte[bytesRead];
    Array.Copy(buffer, Body, bytesRead);

    packetParser packet = new packetParser(Body);
    if (packet.Id == 666)
    {
        Console.WriteLine(packet.ReadInt()); //Version Major
        Console.WriteLine(packet.ReadInt()); //Version Minor
        Console.WriteLine(packet.ReadInt()); //Version Build
    }
}

Example to use packetBuilder:
To respond to the version request (ID:666), you must build a packet like this:

Code:

packetBuilder enc = new packetBuilder(667);
enc.writeShort(0); // version
enc.writeBool(true);
enc.writeInt(0); //Version Major
enc.writeInt(0); //Version Minor
enc.writeInt(27); //Version Build

this.handler.Send(enc.GetBytes());

The Version Major, Minor and Build must be equal to which the client sent

SOMETHING INTERESTING:
To operate an upgraded server darkorbit is not necessary to start encryptions as ARC4 and IOW (InjectedObfuscationWrapper) because it are optional.

Credits
Me.
LittleJ.