Engine.Integration/Engine.Integration.LiteNetLib/LiteNetLibClient.cs

@@ -11,6 +11,7 @@ namespace Engine.Systems.Network;
 public class LiteNetLibClient : LiteNetLibCommunicatorBase, INetworkCommunicatorClient
 {
     private readonly NetDataWriter netDataWriter = new();
+    private readonly NetDataWriter netDataWriterEncrypted = new();
 
     private CancellationTokenSource? cancellationTokenSource = null;
 
@@ -42,7 +43,20 @@ public class LiteNetLibClient : LiteNetLibCommunicatorBase, INetworkCommunicator
     public INetworkCommunicatorClient SendToServer<T>(T packet, PacketDelivery packetDelivery) where T : class, new()
     {
         netDataWriter.Reset();
-        netPacketProcessor.Write(netDataWriter, packet);
+        netDataWriterEncrypted.Reset();
+
+        if (packet is INetworkPacketEncrypted)
+        {
+            netPacketProcessor.Write(netDataWriterEncrypted, packet);
+            byte[] encryptedData = cryptor.Encrypt(netDataWriterEncrypted.CopyData());
+            netDataWriter.Put(true);
+            netDataWriter.PutBytesWithLength(encryptedData);
+        }
+        else
+        {
+            netDataWriter.Put(false);
+            netPacketProcessor.Write(netDataWriter, packet);
+        }
 
         switch (packetDelivery)
         {

Engine.Integration/Engine.Integration.LiteNetLib/LiteNetLibCommunicatorBase.cs

@@ -12,6 +12,7 @@ namespace Engine.Systems.Network;
 public abstract class LiteNetLibCommunicatorBase : Behaviour, IEnterUniverse, IExitUniverse, INetworkCommunicator
 {
     protected readonly NetPacketProcessor netPacketProcessor = new();
+    protected readonly PacketCryptor cryptor = new("At4ywW9PGoWH3g==", "NmpMFTvd3pvUbA=="); // TODO implement public key exchange
 
     private readonly Dictionary<Type, Event<IConnection, object>> listeners = [];
     private readonly Dictionary<string, IConnection> _connections = [];
@@ -54,7 +55,20 @@ public abstract class LiteNetLibCommunicatorBase : Behaviour, IEnterUniverse, IE
 
     private void NetworkReceiveEvent(NetPeer peer, NetPacketReader reader, byte channel, DeliveryMethod deliveryMethod)
     {
-        try { netPacketProcessor.ReadAllPackets(reader, peer); }
+        try
+        {
+            bool isEncrypted = reader.GetBool();
+            if (isEncrypted) // TODO performance improvements 
+            {
+                byte[] encryptedData = reader.GetBytesWithLength();
+                byte[] decryptedData = cryptor.Decrypt(encryptedData);
+                NetDataReader innerReader = new(decryptedData);
+                netPacketProcessor.ReadAllPackets(innerReader, peer);
+                return;
+            }
+
+            netPacketProcessor.ReadAllPackets(reader, peer);
+        }
         catch (Exception exception) { logger?.LogException(this, exception, force: true); }
     }
 

Engine.Integration/Engine.Integration.LiteNetLib/LiteNetLibServer.cs

@@ -13,6 +13,7 @@ public class LiteNetLibServer : LiteNetLibCommunicatorBase, INetworkCommunicator
     public int Port { get; private set; } = 8888;
 
     private readonly NetDataWriter netDataWriter = new();
+    private readonly NetDataWriter netDataWriterEncrypted = new();
 
     public LiteNetLibServer() : this(8888, 2) { }
     public LiteNetLibServer(int port, int maxConnectionCount) : base()
@@ -53,11 +54,25 @@ public class LiteNetLibServer : LiteNetLibCommunicatorBase, INetworkCommunicator
     public INetworkCommunicatorServer SendToClient<T>(IConnection connection, T packet, PacketDelivery packetDelivery) where T : class, new()
     {
         netDataWriter.Reset();
-        netPacketProcessor.Write(netDataWriter, packet);
 
         if (Manager.ConnectedPeerList.FirstOrDefault(p => p.Id.ToString().CompareTo(connection.Id) == 0) is not NetPeer netPeer)
             throw new($"Peer {connection} couldn't be found.");
 
+        if (packet is INetworkPacketEncrypted) // TODO performance improvements 
+        {
+            netDataWriterEncrypted.Reset();
+            netPacketProcessor.Write(netDataWriterEncrypted, packet);
+            byte[] encryptedData = cryptor.Encrypt(netDataWriterEncrypted.CopyData());
+
+            netDataWriter.Put(true);
+            netDataWriter.PutBytesWithLength(encryptedData);
+        }
+        else
+        {
+            netDataWriter.Put(false);
+            netPacketProcessor.Write(netDataWriter, packet);
+        }
+
         switch (packetDelivery)
         {
             case PacketDelivery.ReliableInOrder: netPeer.Send(netDataWriter, DeliveryMethod.ReliableOrdered); break;
@@ -75,6 +90,23 @@ public class LiteNetLibServer : LiteNetLibCommunicatorBase, INetworkCommunicator
         netDataWriter.Reset();
         netPacketProcessor.Write(netDataWriter, packet);
 
+        if (packet is INetworkPacketEncrypted)
+        {
+            netDataWriterEncrypted.Reset();
+
+            logger?.Log($"Encrypted Packet Sending");
+            netPacketProcessor.Write(netDataWriterEncrypted, packet);
+            byte[] encryptedData = cryptor.Encrypt(netDataWriterEncrypted.CopyData());
+            netDataWriter.PutBytesWithLength(encryptedData);
+            netDataWriter.Put(true);
+        }
+        else
+        {
+            logger?.Log($"Regular Packet Sending");
+            netPacketProcessor.Write(netDataWriter, packet);
+            netDataWriter.Put(false);
+        }
+
         switch (packetDelivery)
         {
             case PacketDelivery.ReliableInOrder: Manager.SendToAll(netDataWriter, DeliveryMethod.ReliableOrdered); break;

Engine.Integration/Engine.Integration.LiteNetLib/PacketCryptor.cs

@@ -0,0 +1,26 @@
+using System.Security.Cryptography;
+using System.Text;
+
+namespace Engine.Systems.Network;
+
+public class PacketCryptor // TODO performance improvements 
+{
+    private readonly Aes aes = null!;
+
+    private readonly ICryptoTransform encrpytor = null!;
+    private readonly ICryptoTransform decryptor = null!;
+
+    public byte[] Encrypt(byte[] data) => encrpytor.TransformFinalBlock(data, 0, data.Length);
+    public byte[] Decrypt(byte[] data) => decryptor.TransformFinalBlock(data, 0, data.Length);
+
+    public PacketCryptor(string key, string initializationVector)
+    {
+        aes = Aes.Create();
+
+        aes.Key = Encoding.UTF8.GetBytes(key);
+        aes.IV = Encoding.UTF8.GetBytes(initializationVector);
+
+        encrpytor = aes.CreateEncryptor();
+        decryptor = aes.CreateDecryptor();
+    }
+}

Engine.Systems/Network/Abstract/INetworkPacketEncrypted.cs

@@ -0,0 +1,3 @@
+namespace Engine.Systems.Network;
+
+public interface INetworkPacketEncrypted : INetworkPacket;