First iteration improved multiplatform support

Lidgren.Network/Encryption/NetCryptoProviderEncryption.cs

@@ -0,0 +1,59 @@
+using System;
+using System.IO;
+using System.Security.Cryptography;
+
+namespace Lidgren.Network
+{
+	public abstract class NetCryptoProviderEncryption : NetEncryption
+	{
+		public NetCryptoProviderEncryption(NetPeer peer)
+			: base(peer)
+		{
+		}
+
+		protected abstract CryptoStream GetEncryptStream(MemoryStream ms);
+
+		protected abstract CryptoStream GetDecryptStream(MemoryStream ms);
+
+		public override bool Encrypt(NetOutgoingMessage msg)
+		{
+			int unEncLenBits = msg.LengthBits;
+
+			var ms = new MemoryStream();
+			var cs = GetEncryptStream(ms);
+			cs.Write(msg.m_data, 0, msg.LengthBytes);
+			cs.Close();
+
+			// get results
+			var arr = ms.ToArray();
+			ms.Close();
+
+			msg.EnsureBufferSize((arr.Length + 4) * 8);
+			msg.LengthBits = 0; // reset write pointer
+			msg.Write((uint)unEncLenBits);
+			msg.Write(arr);
+			msg.LengthBits = (arr.Length + 4) * 8;
+
+			return true;
+		}
+
+		public override bool Decrypt(NetIncomingMessage msg)
+		{
+			int unEncLenBits = (int)msg.ReadUInt32();
+
+			var ms = new MemoryStream(msg.m_data, 4, msg.LengthBytes - 4);
+			var cs = GetDecryptStream(ms);
+
+			var result = m_peer.GetStorage(unEncLenBits);
+			cs.Read(result, 0, NetUtility.BytesToHoldBits(unEncLenBits));
+			cs.Close();
+
+			// TODO: recycle existing msg
+
+			msg.m_data = result;
+			msg.m_bitLength = unEncLenBits;
+
+			return true;
+		}
+	}
+}