public static byte[] MessageTransmissionHandler(Message message)
{
byte[] textBytes = new byte[0];
if (!String.IsNullOrEmpty(message.Text))
{
textBytes = Encoding.Unicode.GetBytes(message.Text);
}
byte[] dataBytes = new byte[0];
if (message.Data != null)
{
dataBytes = message.Data;
}
byte[] messageBytes = ByteHelper.ConcatinateArray(BitConverter.GetBytes(message.From), new byte[] { (byte)message.Type });
messageBytes = ByteHelper.ConcatinateArray(messageBytes, dataBytes, textBytes);
return(messageBytes);
}
public static void MessageTransmissionHandler(Message message)
{
byte[] messageBytes = ChatTwo_Protocol.MessageTransmissionHandler(message);
string sharedSecret;
if (message.Type == ChatTwo_Protocol.MessageType.CreateUser)
{
sharedSecret = ChatTwo_Protocol.DefaultSharedSecret;
}
else if (message.Type == ChatTwo_Protocol.MessageType.Login)
{
ServerSharedSecret = ByteHelper.GetHashString(messageBytes);
sharedSecret = ServerSharedSecret;
}
else if (message.To == ChatTwo_Protocol.ServerReserrvedUserID)
{
sharedSecret = ServerSharedSecret;
}
else
{
int userId = message.To;
sharedSecret = _contacts.Find(x => x.ID == userId).Secret;
// Testing!!!! REMOVE THIS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sharedSecret = ChatTwo_Protocol.DefaultSharedSecret;
}
messageBytes = ChatTwo_Protocol.AddSignatureAndMac(messageBytes, sharedSecret);
// Fire an OnMessageTransmission event.
PacketTransmissionEventArgs args = new PacketTransmissionEventArgs();
args.Destination = message.Ip;
args.PacketContent = messageBytes;
OnMessageTransmission(args);
}
private static void Keepalive() // Threaded looping method.
{
try
{
while (_loggedIn)
{
Thread.Sleep(500);
List <ContactObj> onlineContacts = _contacts.FindAll(x => x.Online == true);
byte[] contactIds = new byte[0];
foreach (ContactObj contact in onlineContacts)
{
byte[] contactId = BitConverter.GetBytes(contact.ID);
contactIds = ByteHelper.ConcatinateArray(contactIds, contactId);
}
ChatTwo_Client_Protocol.MessageToServer(ChatTwo_Protocol.MessageType.Status, contactIds, null);
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("### " + _threadKeepalive.Name + " has crashed:");
System.Diagnostics.Debug.WriteLine("### " + ex.Message);
System.Diagnostics.Debug.WriteLine("### " + ex.ToString());
}
}
private static string CreateMac(byte[] messageBytes, string sharedSecret)
{
return(ByteHelper.GetHashString(ByteHelper.ConcatinateArray(ByteHelper.GetHashBytes(messageBytes), Convert.FromBase64String(sharedSecret))));
}
public static byte[] RemoveSignatureAndMac(byte[] bytes)
{
bytes = ByteHelper.SubArray(bytes, SignatureByteLength + ByteHelper.HashByteLength); // Remove the signature, the version number and the MAC.
return(bytes);
}
public static void MessageReceivedHandler(object sender, PacketReceivedEventArgs args)
{
if (args.Data[0] == 0x92)
{
string sharedSecret;
// Position of the Type byte is 30 (SignatureByteLength + MacByteLength + TimezByteLength + UserIdByteLength).
ChatTwo_Protocol.MessageType type = (ChatTwo_Protocol.MessageType)args.Data[ChatTwo_Protocol.SignatureByteLength + ByteHelper.HashByteLength + 4 + 4];
// Position of the UserID bytes is 26 (SignatureByteLength + MacByteLength + TimezByteLength) with a length of 4.
int senderId = ByteHelper.ToInt32(args.Data, ChatTwo_Protocol.SignatureByteLength + ByteHelper.HashByteLength + 4);
if (type == ChatTwo_Protocol.MessageType.CreateUserReply)
{
sharedSecret = ChatTwo_Protocol.DefaultSharedSecret;
}
else if (senderId == 0)
{
sharedSecret = ServerSharedSecret;
}
else
{
sharedSecret = _contacts.Find(x => x.ID == senderId).Secret;
// Testing!!!! REMOVE THIS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sharedSecret = ChatTwo_Protocol.DefaultSharedSecret;
}
if (ChatTwo_Protocol.ValidateMac(args.Data, sharedSecret))
{
Message message = ChatTwo_Protocol.MessageReceivedHandler(args);
switch (message.Type)
{
case ChatTwo_Protocol.MessageType.CreateUserReply:
{
// Fire an OnCreateUserReply event.
CreateUserReplyEventArgs argsCreateUser = new CreateUserReplyEventArgs();
argsCreateUser.Success = message.Data[0] == 0x00;
switch (message.Data[0])
{
case 0: // Success.
break;
case 1: // Username already exist.
argsCreateUser.Message = "A user already exist with that name.";
break;
case 2:
argsCreateUser.Message = "Username is too short or too long.";
break;
}
OnCreateUserReply(argsCreateUser);
break;
}
case ChatTwo_Protocol.MessageType.LoginReply:
{
// Fire an OnLoginReply event.
LoginReplyEventArgs argsLogin = new LoginReplyEventArgs();
argsLogin.Success = message.Data[0] == 0x00;
switch (message.Data[0])
{
case 0: // Success.
int userId = ByteHelper.ToInt32(message.Data, 1);
string username = Encoding.Unicode.GetString(ByteHelper.SubArray(message.Data, 5));
LogIn(userId);
_user.Name = username;
argsLogin.Name = username;
break;
case 1: // Wrong password.
argsLogin.Message = "Wrong username or password.";
break;
case 2: // Already online.
argsLogin.Message = "That user is already online.";
break;
}
OnLoginReply(argsLogin);
break;
}
case ChatTwo_Protocol.MessageType.ContactRequestReply:
{
// Fire an OnAddContactReply event.
AddContactReplyEventArgs argsAddContact = new AddContactReplyEventArgs();
argsAddContact.Success = message.Data[0] == 0x00;
switch (message.Data[0])
{
case 0: // Success.
break;
case 1: // No user with that name.
argsAddContact.Message = "No user with that name.";
break;
case 2: // You can't add your self.
argsAddContact.Message = "You can't add your self.";
break;
case 3: // User is already a contact.
argsAddContact.Message = "User is already a contact.";
break;
}
OnAddContactReply(argsAddContact);
break;
}
case ChatTwo_Protocol.MessageType.ContactStatus:
{
int contactId = ByteHelper.ToInt32(message.Data, 0);
int nameLength = ((31 & message.Data[4]) * 2);
ContactObj contact;
if (_contacts.Any(x => x.ID == contactId))
{
contact = _contacts.Find(x => x.ID == contactId);
}
else
{
contact = new ContactObj();
contact.ID = contactId;
contact.Name = Encoding.Unicode.GetString(message.Data, 5, nameLength);
_contacts.Add(contact);
}
contact.Online = ByteHelper.CheckBitCodeIndex(message.Data[4], 7);
contact.RelationshipTo = ByteHelper.CheckBitCodeIndex(message.Data[4], 6);
contact.RelationshipFrom = ByteHelper.CheckBitCodeIndex(message.Data[4], 5);
if (contact.Online)
{
int port = ByteHelper.ToInt32(message.Data, 5 + nameLength);
contact.Socket = new IPEndPoint(new IPAddress(ByteHelper.SubArray(message.Data, 5 + nameLength + 4)), port);
}
// Fire an OnContactUpdate event.
OnContactUpdate();
break;
}
case ChatTwo_Protocol.MessageType.Message:
{
ContactObj contact;
if (_contacts.Any(x => x.ID == message.From && x.RelationshipTo && x.RelationshipFrom))
{
contact = _contacts.Find(x => x.ID == message.From);
OpenChat(contact.ID);
message.Text = Encoding.Unicode.GetString(message.Data);
contact.ChatWindow.ReceiveMessage(message.Text);
}
else
#if DEBUG
{ throw new NotImplementedException("You received a message from someone that isn't your contact?"); }
#else
{ return; }
#endif
break;
}
}
}
#if DEBUG
else
{
throw new NotImplementedException("Could not validate the MAC of received message.");
}
// Need to add a simple debug message here, but this works as a great breakpoint until then.
#endif
}
#if DEBUG
else
{
throw new NotImplementedException("Could not validate the signature of the received message. The signature was \"0x" + args.Data[0] + "\" but only \"0x92\" is allowed.");
}
// Need to add a simple debug message here, but this works as a great breakpoint until then.
#endif
}
/// <summary>
/// This is a threaded method that keeps looping while _online is true.
/// It will receive UDP messages on the UdpClient's port number and forward them to the OnPacketReceived event.
/// </summary>
public void ReceivePacket() // Threaded looping method.
{
while (_online)
{
try
{
IPEndPoint remoteSender = new IPEndPoint(IPAddress.Any, 0);
byte[] receivedBytes = _client.Receive(ref remoteSender);
if (receivedBytes != null && receivedBytes.Length != 0)
{
if (receivedBytes.Length == ByteHelper.HashByteLength + 2 && receivedBytes[0] == 0xCE && receivedBytes[receivedBytes.Length - 1] == 0xCE)
{
if (_messageSendingControlList.Count != 0)
{
// The received message is a ACK message.
string hash = OpenAck(receivedBytes);
ControlledPacket packet = _messageSendingControlList.Find(x => x.Hash == hash);
if (packet != null)
{
_messageSendingControlList.Remove(packet);
}
}
}
else if (receivedBytes.Length == 1 && receivedBytes[0] == 0xEC)
{
// Fire an OnEtherConnectionReply event.
OnEtherConnectionReply(null);
}
else
{
// Send back an ACK packet.
string hash = ByteHelper.GetHashString(receivedBytes);
byte[] ackBytes = CreateAck(hash);
_client.Send(ackBytes, ackBytes.Length, remoteSender);
// Check if the message is a duplicate.
if (!_messageReceivingControlList.Any(x => x == hash))
{
// Add the message's hash to a list so we don't react on the same message twice.
_messageReceivingControlList.Add(hash);
if (_messageReceivingControlList.Count > 5) // Only keep the latest 5 messages.
{
_messageReceivingControlList.RemoveAt(0);
}
// Fire an OnPacketReceived event.
PacketReceivedEventArgs args = new PacketReceivedEventArgs();
args.Sender = remoteSender;
args.Data = receivedBytes;
OnPacketReceived(args);
}
}
}
}
catch (SocketException ex)
{
if (ex.SocketErrorCode != SocketError.TimedOut)
{
System.Diagnostics.Debug.WriteLine("### " + _threadPacketListener.Name + " has crashed:");
System.Diagnostics.Debug.WriteLine("### " + ex.Message);
System.Diagnostics.Debug.WriteLine("### " + ex.ToString());
break;
}
else
{
continue;
}
}
}
}
/// <summary>
/// Create an ACK packet from a base64 hash string.
/// </summary>
/// <param name="hash">Base64 hash string to be used.</param>
protected byte[] CreateAck(string hash)
{
byte[] ackTag = new byte[] { 0xCE }; // 0xCE = 206
byte[] ackBytes = ByteHelper.ConcatinateArray(ackTag, Convert.FromBase64String(hash), ackTag);
return(ackBytes);
}
private void btnRegister_Click(object sender, EventArgs e)
{
ResetWindow();
// If there is no username entered.
if (tbxUsername.Text == "")
{
lblUsername.ForeColor = Color.Red;
tbxUsername.ForeColor = Color.Red;
lblResult.ForeColor = Color.Red;
lblResult.Text = "You did not enter a username.";
return;
}
// If the username is too long.
if (tbxUsername.Text.Length > 30)
{
lblUsername.ForeColor = Color.Red;
tbxUsername.ForeColor = Color.Red;
lblResult.ForeColor = Color.Red;
lblResult.Text = "The username is too long. Please use 30 or less characters.";
return;
}
// If there is no password entered.
if (tbxPassword1.Text == "")
{
lblPassword1.ForeColor = Color.Red;
tbxPassword1.ForeColor = Color.Red;
lblResult.ForeColor = Color.Red;
lblResult.Text = "You did not enter a password.";
return;
}
// If the password and the confirm password textboxes aren't the same.
if (tbxPassword1.Text != tbxPassword2.Text)
{
lblPassword2.ForeColor = Color.Red;
tbxPassword2.ForeColor = Color.Red;
lblResult.ForeColor = Color.Red;
lblResult.Text = "The two passwords are not the same.";
return;
}
// If the password is too short.
// (I hate strict password rules! If it is not a bank or social security thing, don't force the uesr to make insane passwords.)
if (tbxPassword1.Text.Length < 4)
{
lblPassword1.ForeColor = Color.Red;
tbxPassword1.ForeColor = Color.Red;
lblResult.ForeColor = Color.Red;
lblResult.Text = "The password is too short. Please use 4 or more characters.";
return;
}
btnRegister.Enabled = false;
btnCancel.Enabled = false;
tbxUsername.ReadOnly = true;
tbxPassword1.ReadOnly = true;
tbxPassword2.ReadOnly = true;
lblResult.Text = "Contacting server...";
_waitingForCreateUserReply = true;
byte[] passwordHash = ByteHelper.GetHashBytes(Encoding.Unicode.GetBytes(tbxPassword1.Text));
ChatTwo_Client_Protocol.MessageToServer(ChatTwo_Protocol.MessageType.CreateUser, passwordHash, tbxUsername.Text);
timer1.Start();
}