made encryption optional, put server params into config, default is server = off

ClientServerLib/ClientServerLib/CConnection.cs

@@ -13,6 +13,7 @@ namespace ClientServerLib
     internal class CConnection
     {
         private bool keySet;
+        private bool encryption;
         private CDiffieHellman dh;
         private UTF8Encoding encoder;
         private int connectionID;
@@ -29,17 +30,23 @@ namespace ClientServerLib
             get { return connectionID; }
         }
 
-        public CConnection(TcpClient client, int ConnectionID)
+        public CConnection(TcpClient client, int ConnectionID, bool Encryption = false)
         {
             TcpClient = client;
             client.NoDelay = true;
             keySet = false;
+            encryption = Encryption;
             connectionID = ConnectionID;
             encoder = new UTF8Encoding();
         }
 
         public byte[] GetKeyParams()
         {
+            if (!encryption)
+            {
+                return encoder.GetBytes("NO ENCRYPTION");
+            }
+
             if (dh == null)
                 dh = new CDiffieHellman(256).GenerateRequest();
 
@@ -51,34 +58,65 @@ namespace ClientServerLib
             if (serverParam == null)
                 return null;
 
-            dh = new CDiffieHellman(256).GenerateResponse(
-                encoder.GetString(serverParam, 0, serverParam.Length));
+            string response = encoder.GetString(serverParam, 0, serverParam.Length);
+            if (response == "NO ENCRYPTION")
+            {
+                encryption = false;
+                keySet = true;
+                return encoder.GetBytes(response);
+            }
+
+            dh = new CDiffieHellman(256).GenerateResponse(response);
 
             keySet = true;
+            encryption = true;
             return encoder.GetBytes(dh.ToString());
         }
 
         public void CreateServerKey(byte[] clientResponse)
         {
+            string response = encoder.GetString(clientResponse, 0, clientResponse.Length);
+
+            if (response == "NO ENCRYPTION")
+            {
+                keySet = true;
+                return;
+            }
+
             if (dh == null)
                 return;
 
-            dh.HandleResponse(encoder.GetString(clientResponse, 0, clientResponse.Length));
+            dh.HandleResponse(response);
             keySet = true;
         }
 
         public byte[] Encrypt(byte[] Data)
         {
-            if (Data == null || !keySet)
+            if (Data == null || (!keySet && encryption))
                 return Data;
 
+            byte[] dataLength = BitConverter.GetBytes(Data.Length);
+
+            if (!encryption)
+            {
+                int len = 4 + dataLength.Length + Data.Length;
+                byte[] messageLength = BitConverter.GetBytes(len);
+
+                using (var stream = new MemoryStream())
+                {
+                    stream.Write(messageLength, 0, messageLength.Length);
+                    stream.Write(dataLength, 0, dataLength.Length);
+                    stream.Write(Data, 0, Data.Length);
+
+                    return stream.ToArray();
+                }
+            }
+
             using (Aes aes = new AesManaged())
             {
                 aes.Key = dh.Key;
                 aes.GenerateIV();
 
-                byte[] dataLength = BitConverter.GetBytes(Data.Length);
-
                 using (var encryptor = aes.CreateEncryptor(aes.Key, aes.IV))
                 using (var memoryStream = new MemoryStream())
                 using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
@@ -91,32 +129,47 @@ namespace ClientServerLib
                     int len = 4 + aes.IV.Length + dataLength.Length + encrypted.Length;
                     byte[] messageLength = BitConverter.GetBytes(len);
 
-                    MemoryStream stream = new MemoryStream();
-                    stream.Write(messageLength, 0, messageLength.Length);
-                    stream.Write(aes.IV, 0, aes.IV.Length);
-                    stream.Write(dataLength, 0, dataLength.Length);
-                    stream.Write(encrypted, 0, encrypted.Length);
+                    using (var stream = new MemoryStream())
+                    {
+                        stream.Write(messageLength, 0, messageLength.Length);
+                        stream.Write(aes.IV, 0, aes.IV.Length);
+                        stream.Write(dataLength, 0, dataLength.Length);
+                        stream.Write(encrypted, 0, encrypted.Length);
 
-                    return stream.ToArray();
+                        return stream.ToArray();
+                    }
                 }
             }
         }
 
         public byte[] Decrypt(byte[] Data)
         {
-            if (Data == null || !keySet)
+            if (Data == null || (!keySet && encryption))
                 return Data;
 
-            if (Data.Length < 25)
-                return null;
-
+            
             int messageLength = BitConverter.ToInt32(Data, 0);
             if (messageLength > Data.Length)
                 return null;
 
+            int dataLength;
+
+            if (!encryption)
+            {
+                dataLength = BitConverter.ToInt32(Data, 4);
+
+                byte[] message = new byte[dataLength];
+                Array.Copy(Data, 8, message, 0, dataLength);
+                return message;
+            }
+            
+            if (Data.Length < 25)
+                return null;
+
             byte[] IV = new byte[16];
             Array.Copy(Data, 4, IV, 0, 16);
-            int dataLength = BitConverter.ToInt32(Data, 20);
+
+            dataLength = BitConverter.ToInt32(Data, 20);
 
             using (Aes aes = new AesManaged())
             {

ClientServerLib/ClientServerLib/CServer.cs

@@ -13,6 +13,7 @@ namespace ClientServerLib
         private TcpListener tcpListener;
         private Thread listenThread;
         private int port;
+        private bool encryption;
         private int bufferLength = 8192;
         private bool running;
 
@@ -21,11 +22,12 @@ namespace ClientServerLib
         private Dictionary<int, CConnection> clients;
         private  Queue<int> ids;
 
-        public CServer(HandleRequest RequestCallback, int Port = 3000)
+        public CServer(HandleRequest RequestCallback, int Port = 3000, bool Encryption = false)
         {
             port = Port;
             running = false;
             requestCallback = RequestCallback;
+            encryption = Encryption;
 
             clients = new Dictionary<int, CConnection>();
             ids = new Queue<int>(1000);
@@ -90,7 +92,7 @@ namespace ClientServerLib
                 if (client != null)
                 {
                     int id = ids.Dequeue();
-                    CConnection connection = new CConnection(client, id);
+                    CConnection connection = new CConnection(client, id, encryption);
 
                     lock (clients)
                     {