/// <summary>
/// constructor that initializes the sniffer form
/// </summary>
public RawSockSnifferForm(TcpClient client, AesCrypto aes)
{
InitializeComponent();
pA = new PacketAnalyzer();
this.client = client;
this.aes = aes;
currentLocalPackets = new List <string[]>();
currentLocalPacketsTag = new List <byte[]>();
// Read data from the client async
data = new byte[client.ReceiveBufferSize];
// BeginRead will begin async read from the NetworkStream
// This allows the server to remain responsive and continue accepting new connections from other clients
// When reading complete control will be transfered to the ReviveMessage() function.
client.GetStream().BeginRead(data,
0,
System.Convert.ToInt32(client.ReceiveBufferSize),
ReceiveMessage,
null);
}
/// <summary>
/// recursive method that recieves a message from the server and handles it according to the request or response number
/// </summary>
/// <param name="ar"></param>
private void ReceiveMessage(IAsyncResult ar)
{
try
{
int bytesRead;
lock (client.GetStream())
{
// call EndRead to handle the end of an async read and read the data from the server
bytesRead = client.GetStream().EndRead(ar);
}
if (rsa.ServerPublicKey == null) // if RSA object is missing server's public key
{
rsa.SetServerPublicKey(ByteConverter.GetString(data).Split('#')[1]);
// creates an Aes instance for symmetric encryption and sends the key to the server
aes = new AesCrypto();
byte[] bytesArray = AesKeyAndIVBytesToSend(aes.GetKey(), aes.GetIV());
SendRsaEncryptedMessage(bytesArray);
}
else
{
byte[] arrived = new byte[bytesRead];
Array.Copy(data, arrived, bytesRead);
string messageReceived;
if (aes == null) // if AES object wasn't initialize yet
{
messageReceived = ByteConverter.GetString(arrived);
}
else
{
messageReceived = aes.DecryptStringFromBytes(arrived, aes.GetKey(), aes.GetIV());
}
Debug.WriteLine("received: " + messageReceived);
string[] arrayReceived = messageReceived.Split('#');
int requestNumber = Convert.ToInt32(arrayReceived[0]);
string text = arrayReceived[1];
if (requestNumber == registerStatusResponse)
{
if (text.Equals("ok"))
{
name = textBoxName.Text;
OpenSnifferForm();
return;
}
else if (text.Equals("not ok"))
{
MessageBox.Show("Wrong username or password\nPlease try again", "CAPCKET login error");
}
}
else if (requestNumber == EmailRequest)
{
string answer = CreateInteractionForm("Please enter the code that was sent to your email address:", "CAPCKET email verification");
string textToSend = text + "/" + answer;
SendAesEncryptedMessage(CodeResponse + "#" + textToSend + "#" + textToSend.Length);
}
else if (requestNumber == QuestionResponse)
{
string[] textArray = text.Split('/');
if (textArray.Length > 1)
{
MessageBox.Show("Wrong answer\nPlease try again", "CAPCKET login error");
}
string answer = CreateInteractionForm(textArray[0], "CAPCKET changing password");
SendAesEncryptedMessage(AnswerResponse + "#" + answer + "#" + answer.Length);
}
else if (requestNumber == PasswordRequest)
{
string password = CreateInteractionForm("Please enter a new password:"******"CAPCKET changing password");
if (!IsPasswordValid(password)) //checking password validity
{
//password isn't valid.
MessageBox.Show("The pasword isn't valid. Please try again.\nIt should be 6-8 charcters and contain both digits and letters.", "CAPCKET changing password");
}
else
{
// hash password
string hashpassword = HashString(password);
Debug.WriteLine("hash length: " + hashpassword.Length);
SendAesEncryptedMessage(PasswordResponse + "#" + hashpassword + "#" + password.Length);
}
}
else if (requestNumber == PasswordChangeStatusResponse)
{
if (text.Equals("ok"))
{
MessageBox.Show("Password changed successfully", "CAPCKET login · changing password");
}
else
{
string password = CreateInteractionForm("Please try again and enter a new password:"******"CAPCKET login error · changing password");
SendAesEncryptedMessage(PasswordResponse + "#" + password + "#" + password.Length);
}
}
else if (requestNumber == RSAPublicKeyTransfer)
{
rsa.SetServerPublicKey(text);
}
}
// continue reading
client.GetStream().BeginRead(data,
0,
System.Convert.ToInt32(client.ReceiveBufferSize),
ReceiveMessage,
null);
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}