/// <summary>
/// A client requested login.
/// </summary>
/// <param name="Client">NetworkClient instance.</param>
/// <param name="Packet">ProcessedPacket instance.</param>
public static void InitialClientConnect(NetworkClient Client, ProcessedPacket Packet)
{
Console.WriteLine("Server receives data - test 1");
//AES is used to encrypt all further communication between client and server.
AesCryptoServiceProvider AesCrypto = new AesCryptoServiceProvider();
AesCrypto.GenerateKey();
AesCrypto.GenerateIV();
AES AesEncryptor = new AES(AesCrypto.Key, AesCrypto.IV);
SessionKey = AesCrypto.Key;
IV = AesCrypto.IV;
Guid Nonce = new Guid(Packet.ReadPascalString());
//Username would normally be used to lookup client's public key in DB (only time such a use is valid).
string Username = Packet.ReadPascalString();
ECDiffieHellmanPublicKey ClientPub = StaticStaticDiffieHellman.ImportKey("ClientPublic.dat");
PacketStream EncryptedPacket = new PacketStream(0x02, 0);
EncryptedPacket.WriteHeader();
MemoryStream StreamToEncrypt = new MemoryStream();
BinaryWriter Writer = new BinaryWriter(StreamToEncrypt);
Writer.Write((byte)ChallengeResponse.ToByteArray().Length);
Writer.Write(ChallengeResponse.ToByteArray(), 0, ChallengeResponse.ToByteArray().Length);
Writer.Write((byte)SessionKey.Length);
Writer.Write(SessionKey, 0, SessionKey.Length);
Writer.Write((byte)IV.Length);
Writer.Write(IV, 0, IV.Length);
Writer.Flush();
byte[] EncryptedData = StaticStaticDiffieHellman.Encrypt(ServerKey, ClientPub, Nonce.ToByteArray(),
StreamToEncrypt.ToArray());
EncryptedPacket.WriteUInt16((ushort)(PacketHeaders.UNENCRYPTED + 1 + EncryptedData.Length));
EncryptedPacket.WriteByte((byte)EncryptedData.Length);
EncryptedPacket.Write(EncryptedData, 0, EncryptedData.Length);
Client.Send(EncryptedPacket.ToArray());
Console.WriteLine("Test 1: passed!");
}
/// <summary>
/// Initial response from server to client.
/// </summary>
/// <param name="Client">A NetworkClient instance.</param>
/// <param name="Packet">A ProcessedPacket instance.</param>
public static void HandleServerChallenge(NetworkClient Client, ProcessedPacket Packet)
{
Console.WriteLine("Client receives encrypted data - test 2");
byte[] PacketBuf = new byte[Packet.ReadByte()];
Packet.Read(PacketBuf, 0, (int)PacketBuf.Length);
ECDiffieHellmanPublicKey ServerPub = StaticStaticDiffieHellman.ImportKey("ServerPublic.dat");
MemoryStream DecryptedStream = new MemoryStream(StaticStaticDiffieHellman.Decrypt(ClientKey, ServerPub,
ClientNOnce.ToByteArray(), PacketBuf));
BinaryReader Reader = new BinaryReader(DecryptedStream);
Guid ChallengeResponse = new Guid(Reader.ReadBytes(Reader.ReadByte()));
SessionKey = Reader.ReadBytes(Reader.ReadByte());
IV = Reader.ReadBytes(Reader.ReadByte());
//Yay, we have key and IV, we can now start encryption with AES!
AES AesEncryptor = new AES(SessionKey, IV);
PacketStream EncryptedPacket = new PacketStream(0x03, 0);
EncryptedPacket.WriteHeader();
MemoryStream StreamToEncrypt = new MemoryStream();
BinaryWriter Writer = new BinaryWriter(StreamToEncrypt);
Writer.Write((byte)ChallengeResponse.ToByteArray().Length);
Writer.Write(ChallengeResponse.ToByteArray(), 0, ChallengeResponse.ToByteArray().Length);
//Encrypt data using key and IV from server, hoping that it'll be decrypted correctly at the other end...
byte[] EncryptedData = AesEncryptor.Encrypt(StreamToEncrypt.ToArray());
EncryptedPacket.WriteUInt16((ushort)(PacketHeaders.UNENCRYPTED + EncryptedData.Length + 1));
EncryptedPacket.WriteByte((byte)EncryptedData.Length);
EncryptedPacket.Write(EncryptedData, 0, EncryptedData.Length);
Client.Send(EncryptedPacket.ToArray());
Console.WriteLine("Test 2: passed!");
}