/// <summary>
/// Builds the message HMAC or MAC
/// </summary>
/// <returns>HMAC or MAC.</returns>
/// <param name="data">Data.</param>
/// <param name="messageAuthAlg">Algorithm to create the HMAC or MAC.</param>
/// <param name="key">Key to create the HMAC or MAC.</param>
/// <param name="algo">Algorithm ID.</param>
static byte[] BuildMessageAuthAlgo(byte[] data, MessageAuthAlgo messageAuthAlg, byte[] key, out Int16 algo)
{
switch (messageAuthAlg)
{
case MessageAuthAlgo.HMACSHA256:
algo = 1;
return(SHA256hmac.ComputeHMAC(data, key));
case MessageAuthAlgo.NOALGO:
algo = -1;
return(null);
default:
throw new PacketGenerationException("Message Auth Algorithm not implemented");
}
}
public ClientEventArgs(Int16 packetType,
bool isEncrypted,
bool hasMessageAuth,
CipherAlgo cipherAlgo,
byte[] cipherIV,
MessageAuthAlgo messageAuthAlgo,
byte[] messageAuthenticationCode,
byte[] data)
{
PacketType = packetType;
IsEncrypted = isEncrypted;
HasMessageAuth = hasMessageAuth;
CipherAlgorithm = cipherAlgo;
CipherIV = cipherIV;
MessageAuthenticationAlgorithm = messageAuthAlgo;
MessageAuthentication = messageAuthenticationCode;
Data = data;
}
/// <summary>
/// Starts listening for messages from the user
/// </summary>
void StartListening()
{
int requestCount = 0;
requestCount = 0;
while (!stop)
{
try
{
requestCount = requestCount + 1;
NetworkStream stream = Socket.GetStream();
byte[] dataLength = new byte[4];
stream.Read(dataLength, 0, 4);
int dLength = BitConverter.ToInt32(dataLength, 0);
byte[] packetType = new byte[2];
stream.Read(packetType, 0, 2);
Int16 pType = BitConverter.ToInt16(packetType, 0);
byte[] isEnc = new byte[1];
stream.Read(isEnc, 0, 1);
bool isEncrypted = isEnc[0] != 0b0;
byte[] hasMac = new byte[1];
stream.Read(hasMac, 0, 1);
bool hasMessageAuth = isEnc[0] != 0b0;
Int16 cipherAlgorithm = 0;
byte[] cipherIV = null;
if (isEncrypted)
{
byte[] ciptherAlgo = new byte[2];
stream.Read(ciptherAlgo, 0, 2);
cipherAlgorithm = BitConverter.ToInt16(ciptherAlgo, 0);
byte[] cipherIvSize = new byte[4];
stream.Read(cipherIvSize, 0, 4);
cipherIV = new byte[BitConverter.ToInt32(cipherIvSize, 0)];
stream.Read(cipherIV, 0, BitConverter.ToInt32(cipherIvSize, 0));
}
CipherAlgo cAlgo = CipherAlgo.NOALGO;
if (isEncrypted)
{
switch (cipherAlgorithm)
{
case 0:
cAlgo = CipherAlgo.AES256;
break;
}
}
Int16 macAlgorithm = 0;
byte[] msgMac = null;
if (hasMessageAuth)
{
byte[] macAlgo = new byte[2];
stream.Read(macAlgo, 0, 2);
macAlgorithm = BitConverter.ToInt16(macAlgo, 0);
byte[] macSize = new byte[4];
stream.Read(macSize, 0, 4);
msgMac = new byte[BitConverter.ToInt32(macSize, 0)];
stream.Read(msgMac, 0, BitConverter.ToInt32(macSize, 0));
}
MessageAuthAlgo algo = MessageAuthAlgo.NOALGO;
if (hasMessageAuth)
{
switch (macAlgorithm)
{
case 0:
algo = MessageAuthAlgo.HMACSHA256;
break;
}
}
byte[] data = new byte[dLength];
stream.Read(data, 0, dLength);
ClientEventArgs e = new ClientEventArgs(pType, isEncrypted, hasMessageAuth, cAlgo, cipherIV, algo, msgMac, data);
MessageReceived(this, e);
}
catch (Exception)
{
if (!stop)
{
ConnectionLost(this, null);
stop = true;
}
}
}
}
/// <summary>
/// Starts listening for incoming connections
/// </summary>
/// <param name="ip">Ip.</param>
/// <param name="port">Port.</param>
void StartListening(IPAddress ip, int port)
{
TcpListener serverSocket = new TcpListener(ip, port);
TcpClient clientSocket = default(TcpClient);
int counter = 0;
serverSocket.Start();
while (!stop)
{
if (serverSocket.Pending())
{
counter += 1;
clientSocket = serverSocket.AcceptTcpClient();
NetworkStream stream = clientSocket.GetStream();
byte[] dataLength = new byte[4];
stream.Read(dataLength, 0, 4);
int dLength = BitConverter.ToInt32(dataLength, 0);
byte[] packetType = new byte[2];
stream.Read(packetType, 0, 2);
Int16 pType = BitConverter.ToInt16(packetType, 0);
byte[] isEnc = new byte[1];
stream.Read(isEnc, 0, 1);
bool isEncrypted = isEnc[0] != 0b0;
byte[] hasMac = new byte[1];
stream.Read(hasMac, 0, 1);
bool hasMessageAuth = isEnc[0] != 0b0;
Int16 cipherAlgorithm = 0;
byte[] cipherIV = null;
if (isEncrypted)
{
byte[] ciptherAlgo = new byte[2];
stream.Read(ciptherAlgo, 0, 2);
cipherAlgorithm = BitConverter.ToInt16(ciptherAlgo, 0);
byte[] cipherIvSize = new byte[4];
stream.Read(cipherIvSize, 0, 4);
cipherIV = new byte[BitConverter.ToInt32(cipherIvSize, 0)];
stream.Read(cipherIV, 0, BitConverter.ToInt32(cipherIvSize, 0));
}
CipherAlgo cAlgo = CipherAlgo.NOALGO;
if (isEncrypted)
{
switch (cipherAlgorithm)
{
case 0:
cAlgo = CipherAlgo.AES256;
break;
}
}
Int16 macAlgorithm = 0;
byte[] msgMac = null;
if (hasMessageAuth)
{
byte[] macAlgo = new byte[2];
stream.Read(macAlgo, 0, 2);
macAlgorithm = BitConverter.ToInt16(macAlgo, 0);
byte[] macSize = new byte[4];
stream.Read(macSize, 0, 4);
msgMac = new byte[BitConverter.ToInt32(macSize, 0)];
stream.Read(msgMac, 0, BitConverter.ToInt32(macSize, 0));
}
MessageAuthAlgo algo = MessageAuthAlgo.NOALGO;
if (hasMessageAuth)
{
switch (macAlgorithm)
{
case 0:
algo = MessageAuthAlgo.HMACSHA256;
break;
}
}
byte[] data = new byte[dLength];
stream.Read(data, 0, dLength);
ClientEventArgs _e = new ClientEventArgs(pType, isEncrypted, hasMessageAuth, cAlgo, cipherIV, algo, msgMac, data);
ClientConnected(data, clientSocket, _e);
}
}
/*BroadcastShutdownToClients();
* foreach (DictionaryEntry item in clientHandlers)
* ((ClientHandler)item.Value).Disconnect();
* if (clientSocket != null)
* clientSocket.Close();
* serverSocket.Stop();*/
}
/// <summary>
/// Builds the network packet
/// </summary>
/// <returns>The packet.</returns>
/// <param name="message">Byte array that contains the data.</param>
/// <param name="cipherKey">Cipher key.</param>
/// <param name="cipherIv">Cipher iv.</param>
/// <param name="cipherAlgo">Cipher algo, to enable encryption change CipherAlgo to other algorithm.</param>
/// <param name="messageAuthAlgoKey">Key to generate HMAC and MAC.</param>
/// <param name="messageAuthAlgo">Algorithm used to create the HMAC or MAC to disable the MessageAuth use MessageAuthAlgo.NOALGO.</param>
/// <param name="type">Type.</param>
public static byte[] BuildPacket(byte[] message,
byte[] cipherKey = null,
byte[] cipherIv = null,
CipherAlgo cipherAlgo = CipherAlgo.NOALGO,
byte[] messageAuthAlgoKey = null,
MessageAuthAlgo messageAuthAlgo = MessageAuthAlgo.NOALGO,
Int16 type = -1)
{
if (messageAuthAlgo != MessageAuthAlgo.NOALGO)
{
if (messageAuthAlgoKey == null)
{
throw new PacketGenerationException("Missing MAC/HMAC Key");
}
}
if (cipherAlgo != CipherAlgo.NOALGO)
{
if (cipherKey == null)
{
throw new PacketGenerationException("Missing encryption key");
}
}
// packet information
byte[] packetType = BitConverter.GetBytes(type);
byte[] isEncrypted = new byte[1];
isEncrypted[0] = cipherAlgo != CipherAlgo.NOALGO ? (byte)0b1 : (byte)0b0;
byte[] hasAuth = new byte[1];
hasAuth[0] = messageAuthAlgo != MessageAuthAlgo.NOALGO ? (byte)0b1 : (byte)0b0;
byte[] macAlgo = new byte[2];
byte[] encAlgo = new byte[2];
//packet data
Int16 cipherAlgoId = 0;
byte[] data = (cipherAlgo != CipherAlgo.NOALGO) ? BuildEncryptedMessage(message, cipherKey, cipherAlgo, out cipherAlgoId, cipherIv) : message;
Int16 msgAuthAlgo = 0;
byte[] mac = (messageAuthAlgo != MessageAuthAlgo.HMACSHA256) ? BuildMessageAuthAlgo(data, messageAuthAlgo, messageAuthAlgoKey, out msgAuthAlgo) : null;
// update packet information
if (messageAuthAlgo != MessageAuthAlgo.NOALGO)
{
macAlgo = BitConverter.GetBytes(msgAuthAlgo);
}
if (cipherAlgo != CipherAlgo.NOALGO)
{
encAlgo = BitConverter.GetBytes(cipherAlgoId);
}
// packet size calculation
int packetSize = 4;
if (cipherAlgo != CipherAlgo.NOALGO)
{
packetSize += 6;
packetSize += cipherIv != null ? cipherIv.Length : 0;
}
if (messageAuthAlgo != MessageAuthAlgo.NOALGO)
{
packetSize += 6;
packetSize += mac.Length;
}
packetSize += data.Length;
byte[] size = BitConverter.GetBytes(data.Length);
byte[] packet = new byte[packetSize + 4];
// merge all information to one array
Array.Copy(size, packet, 4);
Array.Copy(packetType, 0, packet, 4, 2);
Array.Copy(isEncrypted, 0, packet, 6, 1);
Array.Copy(hasAuth, 0, packet, 7, 1);
if (cipherAlgo != CipherAlgo.NOALGO)
{
int civl = cipherIv != null ? cipherIv.Length : 0;
Array.Copy(encAlgo, 0, packet, 8, 2);
Array.Copy(BitConverter.GetBytes(civl), 0, packet, 10, 4);
if (cipherIv != null)
{
Array.Copy(cipherIv, 0, packet, 14, cipherIv.Length);
}
// if it also contains Message Auth
if (messageAuthAlgo != MessageAuthAlgo.NOALGO)
{
Array.Copy(macAlgo, 0, packet, 14 + civl, 2);
Array.Copy(BitConverter.GetBytes(mac.Length), 0, packet, 16 + civl, 4);
Array.Copy(mac, 0, packet, 20 + civl, mac.Length);
Array.Copy(data, 0, packet, 20 + civl + mac.Length, data.Length);
}
else
{
Array.Copy(data, 0, packet, 14 + civl, data.Length);
}
}
else
{
if (messageAuthAlgo != MessageAuthAlgo.NOALGO)
{
Array.Copy(macAlgo, 0, packet, 8, 2);
Array.Copy(BitConverter.GetBytes(mac.Length), 0, packet, 10, 4);
Array.Copy(mac, 0, packet, 14, mac.Length);
Array.Copy(data, 0, packet, 14 + mac.Length, data.Length);
}
else
{
Array.Copy(data, 0, packet, 8, data.Length);
}
}
return(packet);
}
void GetMessage()
{
while (IsListening)
{
try {
serverStream = clientSocket.GetStream();
byte[] dataLength = new byte[4];
serverStream.Read(dataLength, 0, 4);
int dLength = BitConverter.ToInt32(dataLength, 0);
byte[] packetType = new byte[2];
serverStream.Read(packetType, 0, 2);
Int16 pType = BitConverter.ToInt16(packetType, 0);
byte[] isEnc = new byte[1];
serverStream.Read(isEnc, 0, 1);
bool isEncrypted = isEnc[0] != 0b0;
byte[] hasMac = new byte[1];
serverStream.Read(hasMac, 0, 1);
bool hasMessageAuth = isEnc[0] != 0b0;
Int16 cipherAlgorithm = 0;
byte[] cipherIV = null;
if (isEncrypted)
{
byte[] ciptherAlgo = new byte[2];
serverStream.Read(ciptherAlgo, 0, 2);
cipherAlgorithm = BitConverter.ToInt16(ciptherAlgo, 0);
byte[] cipherIvSize = new byte[4];
serverStream.Read(cipherIvSize, 0, 4);
cipherIV = new byte[BitConverter.ToInt32(cipherIvSize, 0)];
serverStream.Read(cipherIV, 0, BitConverter.ToInt32(cipherIvSize, 0));
}
CipherAlgo cAlgo = CipherAlgo.NOALGO;
if (isEncrypted)
{
switch (cipherAlgorithm)
{
case 0:
cAlgo = CipherAlgo.AES256;
break;
}
}
Int16 macAlgorithm = 0;
byte[] msgMac = null;
if (hasMessageAuth)
{
byte[] macAlgo = new byte[2];
serverStream.Read(macAlgo, 0, 2);
macAlgorithm = BitConverter.ToInt16(macAlgo, 0);
byte[] macSize = new byte[4];
serverStream.Read(macSize, 0, 4);
msgMac = new byte[BitConverter.ToInt32(macSize, 0)];
serverStream.Read(msgMac, 0, BitConverter.ToInt32(macSize, 0));
}
MessageAuthAlgo algo = MessageAuthAlgo.NOALGO;
if (hasMessageAuth)
{
switch (macAlgorithm)
{
case 0:
algo = MessageAuthAlgo.HMACSHA256;
break;
}
}
byte[] data = new byte[dLength];
serverStream.Read(data, 0, dLength);
ClientEventArgs e = new ClientEventArgs(pType, isEncrypted, hasMessageAuth, cAlgo, cipherIV, algo, msgMac, data);
if (pType == -1234)
{
Connected(this, e);
}
else
{
MessageReceived(this, e);
}
}
catch (Exception) {
IsListening = false;
ConnectionLost(this, null);
}
}
}
