public void sendMessage(string message, string receiver)
{
Chatmessage chatMessage = new Chatmessage();
chatMessage.Transmitter = _user;
chatMessage.Receiver = receiver;
chatMessage.Message = message;
byte[] msg = _clientEncryption.EncryptRijndael(Converter.fromObjectToByteArray(chatMessage));
sendMessage(msg);
}
public void openUserInfo(object sender, EventArgs e)
{
Chatmessage message = new Chatmessage();
message.MessageType = Chatmessage.MESSAGE_TYPE_USER_INFO;
message.Transmitter = txtUser.Text;
message.Receiver = listUser.SelectedItem.ToString();
message.Message = "userInfo";
_client.sendMessage(message);
}
public void InitializeConnection(string IP, string User)
{
_user = User;
IPAddress ipAddress = IPAddress.Parse(IP);
byte[] response;
byte[] answer;
// Check if IP is reachable
bool check = checkIfServerIsReachable(ipAddress);
if (check == false)
{
throw new Exception("Server ist zur Zeit nicht erreichbar!");
}
// erstmal verbinden
try {
_tcpServer = new TcpClient();
_tcpServer.Connect(ipAddress, _port);
}
catch (Exception)
{
_tcpServer = null;
throw new Exception("Server ist zur Zeit nicht erreichbar! (Antwortet nicht auf Anfragen)");
}
_swSender = new BinaryWriter(_tcpServer.GetStream());
_srReceiver = new BinaryReader(_tcpServer.GetStream());
// sende meinen public key zum server
byte[] myPubKey = Converter.fromStringToByteArray(_clientEncryption.getPublicKey());
sendMessage(myPubKey);
// empfange rij key + iv vom server (verschlüsselt mit meinem pub key)
Int32 length;
length = _srReceiver.ReadInt32();
response = new byte[length];
response = _srReceiver.ReadBytes(length);
byte[] rijKey = _clientEncryption.DecryptRSA(response);
length = _srReceiver.ReadInt32();
response = new byte[length];
response = _srReceiver.ReadBytes(length);
byte[] rijIV = _clientEncryption.DecryptRSA(response);
// setup rij für spätere kommunikation
_clientEncryption.setUpRijndael(rijKey, rijIV);
// sende chatmessage klasse mit signature, usernamen und willkommensnachricht
Library.Chatmessage message = new Library.Chatmessage();
message.Transmitter = User;
message.Message = "Welcome";
message.MessageType = Library.Chatmessage.MESSAGE_TYPE_CONNECT;
message.OperatingSystem = Environment.OSVersion;
answer = _clientEncryption.EncryptRijndael(Converter.fromObjectToByteArray(message));
sendMessage(answer);
_thrMessaging = new Thread(new ThreadStart(ReceiveMessages));
_thrMessaging.IsBackground = true;
_thrMessaging.Start();
connected = true;
}
public void sendMessage(Chatmessage message)
{
byte[] msg = _clientEncryption.EncryptRijndael(Converter.fromObjectToByteArray(message));
sendMessage(msg);
}
public StatusChangedEventArgs(Chatmessage message)
{
EventMsg = message;
}
public void closeConnection()
{
if (connected) {
connected = false;
Chatmessage message = new Chatmessage();
message.Transmitter = _user;
message.Receiver = "global";
message.Message = "Goodbye";
message.MessageType = Chatmessage.MESSAGE_TYPE_DISCONNECT;
sendMessage(message);
}
_users.Clear();
}
public StatusChangedEventArgs(Chatmessage message)
{
EventMsg = message;
}
private void AcceptClient()
{
srReceiver = new System.IO.BinaryReader(tcpClient.GetStream());
swSender = new System.IO.BinaryWriter(tcpClient.GetStream());
byte[] answer;
byte[] response;
Int32 length;
// lese laenge von pub key von client
length = srReceiver.ReadInt32();
// empfange client pub key
response = new byte[length];
response = srReceiver.ReadBytes(length);
string clientPubKey = Converter.fromByteArrayToString(response);
Encryption clientEncryption = new Encryption(clientPubKey);
// sende mit client pub key verschlüsselt rij key + iv
answer = clientEncryption.EncryptRSA(serverEncryption.getRijKey());
sendMessage(answer);
answer = clientEncryption.EncryptRSA(serverEncryption.getRijIV());
sendMessage(answer);
// empfange chatmessage objekt mit usernamen signature und message
length = srReceiver.ReadInt32();
response = new byte[length];
response = srReceiver.ReadBytes(length);
Chatmessage message = (Chatmessage) Converter.fromByteArrayToObject(serverEncryption.DecryptRijndael(response));
int pos = 0;
if (message.Signature != _acceptedSignature)
{
pos = -1;
}
currUser = message.Transmitter;
if (currUser != "")
{
Chatmessage serverResponse = new Chatmessage();
serverResponse.Transmitter = "Administrator";
serverResponse.Receiver = currUser;
if (pos == -1)
{
serverResponse.Message = "0|Wrong Client.";
byte[] msg = serverEncryption.EncryptRijndael(Converter.fromObjectToByteArray(serverResponse));
sendMessage(msg);
CloseConnection();
return;
}
else if (ChatServer.userInfos.ContainsKey(currUser) == true)
{
serverResponse.Message = "0|This username already exists.";
byte[] msg = serverEncryption.EncryptRijndael(Converter.fromObjectToByteArray(serverResponse));
sendMessage(msg);
CloseConnection();
return;
}
else if (currUser == "Administrator")
{
serverResponse.Message = "0|This username is reserved.";
byte[] msg = serverEncryption.EncryptRijndael(Converter.fromObjectToByteArray(serverResponse));
sendMessage(msg);
CloseConnection();
return;
}
else
{
serverResponse.Message = "1|Connected Successfully";
byte[] msg = serverEncryption.EncryptRijndael(Converter.fromObjectToByteArray(serverResponse));
sendMessage(msg);
// send actual user list
MemoryStream stream = new MemoryStream();
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(stream, ChatServer.users);
msg = stream.ToArray();
sendMessage(msg);
// add new user
ChatServer.AddUser(tcpClient, currUser, serverEncryption, message.OperatingSystem);
}
}
else
{
CloseConnection();
return;
}
try
{
while ((length = Convert.ToInt32(srReceiver.ReadInt32())) != 0)
{
response = new byte[length];
response = srReceiver.ReadBytes(length);
var rawResponse = Converter.fromByteArrayToObject(serverEncryption.DecryptRijndael(response));
Chatmessage chatResponse = (Chatmessage) rawResponse;
switch (chatResponse.MessageType) {
case Chatmessage.MESSAGE_TYPE_DISCONNECT:
// client wants do disconnect
ChatServer.RemoveUser(currUser);
break;
case Chatmessage.MESSAGE_TYPE_USER_INFO:
// send user info of a user to client
ChatServer.SendMessage(currUser, chatResponse.Message, chatResponse.Receiver, Chatmessage.MESSAGE_TYPE_USER_INFO);
break;
case Chatmessage.MESSAGE_TYPE_MESSAGE:
default:
// normal chat message or default behaviour
if (chatResponse.Message.Length > 0) {
ChatServer.SendMessage(currUser, chatResponse.Message, chatResponse.Receiver, Chatmessage.MESSAGE_TYPE_MESSAGE);
} else {
ChatServer.RemoveUser(currUser);
}
break;
}
}
}
catch
{
ChatServer.RemoveUser(currUser);
}
}
protected static void sendMessage(Chatmessage message, User user)
{
BinaryWriter swSender;
try
{
Encryption tmp = user.Encryption;
swSender = new BinaryWriter(user.TcpClient.GetStream());
byte[] sendMessage = tmp.EncryptRijndael(Converter.fromObjectToByteArray(message));
swSender.Write(sendMessage.Length);
swSender.Flush();
swSender.Write(sendMessage);
swSender.Flush();
swSender = null;
}
catch
{
RemoveUser(user.Username);
}
}
public static void SendMessage(string From, string Message, string Receiver, string MessageType)
{
// overwrite message with specific user info message
if (MessageType == Chatmessage.MESSAGE_TYPE_USER_INFO) {
Message = "Login: "******" "
+ ChatServer.userInfos[From].LoginTime.ToLongTimeString()
+ Environment.NewLine
+ "Operating System: " + ChatServer.userInfos[From].OperatingSystem.VersionString;
}
Chatmessage userMessage = new Chatmessage(From, Receiver, Message, MessageType);
e = new StatusChangedEventArgs(userMessage);
OnStatusChanged(e);
if (Receiver == "global")
{
foreach (KeyValuePair<string, User> entry in ChatServer.userInfos)
{
sendMessage(userMessage, entry.Value);
}
}
else
{
sendMessage(userMessage, ChatServer.userInfos[Receiver]);
}
}
public static void SendAdminMessage(string Message)
{
Chatmessage adminMessage = new Chatmessage("Administrator", "global", Message, Library.Chatmessage.MESSAGE_TYPE_MESSAGE);
e = new StatusChangedEventArgs(adminMessage);
OnStatusChanged(e);
foreach (KeyValuePair<string, User> entry in ChatServer.userInfos) {
sendMessage(adminMessage, entry.Value);
}
}
public void InitializeConnection(string IP, string User)
{
_user = User;
IPAddress ipAddress = IPAddress.Parse(IP);
byte[] response;
byte[] answer;
// Check if IP is reachable
bool check = checkIfServerIsReachable(ipAddress);
if (check == false)
{
throw new Exception("Server ist zur Zeit nicht erreichbar!");
}
// erstmal verbinden
try {
_tcpServer = new TcpClient();
_tcpServer.Connect(ipAddress, _port);
}
catch (Exception)
{
_tcpServer = null;
throw new Exception("Server ist zur Zeit nicht erreichbar! (Antwortet nicht auf Anfragen)");
}
_swSender = new BinaryWriter(_tcpServer.GetStream());
_srReceiver = new BinaryReader(_tcpServer.GetStream());
// sende meinen public key zum server
byte[] myPubKey = Converter.fromStringToByteArray(_clientEncryption.getPublicKey());
sendMessage(myPubKey);
// empfange rij key + iv vom server (verschlüsselt mit meinem pub key)
Int32 length;
length = _srReceiver.ReadInt32();
response = new byte[length];
response = _srReceiver.ReadBytes(length);
byte[] rijKey = _clientEncryption.DecryptRSA(response);
length = _srReceiver.ReadInt32();
response = new byte[length];
response = _srReceiver.ReadBytes(length);
byte[] rijIV = _clientEncryption.DecryptRSA(response);
// setup rij für spätere kommunikation
_clientEncryption.setUpRijndael(rijKey, rijIV);
// sende chatmessage klasse mit signature, usernamen und willkommensnachricht
Library.Chatmessage message = new Library.Chatmessage();
message.Transmitter = User;
message.Message = "Welcome";
message.MessageType = Library.Chatmessage.MESSAGE_TYPE_CONNECT;
message.OperatingSystem = Environment.OSVersion;
answer = _clientEncryption.EncryptRijndael(Converter.fromObjectToByteArray(message));
sendMessage(answer);
_thrMessaging = new Thread(new ThreadStart(ReceiveMessages));
_thrMessaging.IsBackground = true;
_thrMessaging.Start();
connected = true;
}
private void UpdateStatus(Chatmessage message)
{
if (message.MessageType == Chatmessage.MESSAGE_TYPE_USER_INFO) {
return;
}
if (message.Transmitter == "Administrator") {
UpdateStatus(message.Message);
} else {
if (System.Configuration.ConfigurationManager.AppSettings["LogUserMessages"] == "true") {
UpdateStatus(message.Message);
}
}
}
