/// <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>
public void ReceiveMessage(IAsyncResult ar)
{
int bytesRead;
try
{
lock (client.GetStream())
{
// call EndRead to handle the end of an async read.
bytesRead = client.GetStream().EndRead(ar);
}
Console.WriteLine("in receive server");
if (rsa == null) // RSA object wasn't initialized yet
{
string key = ByteConverter.GetString(data, 0, bytesRead).Split('#')[1];
// an Rsa crypto object is created
rsa = new RsaCrypto(key);
Console.WriteLine("created rsa object");
// sends the RSA object public key to the client
string messageToSend = RSAPublicKeyTransfer + "#" + rsa.GetServerPublicKey() + "#" + rsa.GetServerPublicKey().Length;
SendMessage(ByteConverter.GetBytes(messageToSend));
}
else
{
byte[] arrived = new byte[bytesRead];
Array.Copy(data, arrived, bytesRead);
string messageReceived = "";
int requestNumber;
int keyLength, ivLength;
byte[] key = null, iv = null;
string details = null;
string[] detailsArray = null;
if (aes == null) // AES object wasn't initialized yet
{
byte[] decrypted = rsa.RSADecrypt(arrived);
Console.WriteLine("AES details: " + BytesToString(decrypted));
AnalyzingAesKeyAndIvMessage(decrypted, out requestNumber, out keyLength, out ivLength, out key, out iv);
}
else
{
messageReceived = aes.DecryptStringFromBytes(arrived, aes.GetKey(), aes.GetIV());
Console.WriteLine("received: " + messageReceived);
string[] arrayReceived = messageReceived.Split('#');
requestNumber = Convert.ToInt32(arrayReceived[0]);
details = arrayReceived[1];
detailsArray = details.Split('/');
}
string status = "ok";
if (requestNumber == signUpRequest)
{
detailsArray[1].Replace("\u200B", "");
//detailsArray[1].Replace(detailsArray[1], @"^[\s,]+|[\s,]+$");
// inserts to the SQL table
bool b = sql.Insert(detailsArray[0], detailsArray[1], detailsArray[2], detailsArray[3], detailsArray[4], 0);
if (!b)
{
status = "not ok";
SendAesEncryptedMessage(RegisterStatusResponse + "#" + status + "#" + status.Length);
}
else
{
// ok, email verification is needed
name = detailsArray[0];
email = detailsArray[2];
string code = EmailVerification(email);
SendAesEncryptedMessage(EmailRequest + "#" + code + "#" + code.Length);
}
}
else if (requestNumber == signInRequest)
{
// checks if a player is in the table
int check = sql.IsExist(detailsArray[0], detailsArray[1]);
if (check == 0)
{
status = "not ok";
}
else
{
name = detailsArray[0];
}
Console.WriteLine(status + " 2");
if (check != 1)
{
SendAesEncryptedMessage(RegisterStatusResponse + "#" + status + "#" + status.Length);
}
else
{
string code = EmailVerification(sql.GetEmail(name));
SendAesEncryptedMessage(EmailRequest + "#" + code + "#" + code.Length);
}
if (check == 2)
{
//opens a new object that handles the logs of the sniffer
SnifferLogs snifferLogs = new SnifferLogs(client, name, aes);
return;
}
}
else if (requestNumber == QuestionRequest)
{
string question = sql.GetQuestion(details);
name = details;
SendAesEncryptedMessage(QuestionResponse + "#" + question + "#" + question.Length);
}
else if (requestNumber == CodeResponse)
{
string originalCode = detailsArray[0].Trim();
string answer = detailsArray[1].Trim();
bool compare = originalCode.Equals(answer);
if (compare)
{
sql.ChangeEmailConfirmed(name);
SendAesEncryptedMessage(RegisterStatusResponse + "#" + "ok" + "#2");
//opens a new object that handles the logs of the sniffer
SnifferLogs snifferLogs = new SnifferLogs(client, name, aes);
return;
}
else
{
// sends another email
string code = EmailVerification(sql.GetEmail(name));
SendAesEncryptedMessage(EmailRequest + "#" + code + "#" + code.Length);
}
}
else if (requestNumber == AnswerResponse)
{
bool checkAnswer = sql.GetAnswer(name).Equals(details);
if (checkAnswer)
{
//let the user invent a new password
SendAesEncryptedMessage(PasswordRequest + "##0");
}
else
{
// the answer was incorrect, the client need to try again
string question = sql.GetQuestion(details);
name = details;
SendAesEncryptedMessage(QuestionResponse + "#" + question + "/" + "#" + question.Length);
}
}
else if (requestNumber == PasswordResponse)
{
bool b = sql.SetPassword(name, details);
string isChanged = "ok";
if (!b)
{
isChanged = "not ok";
}
SendAesEncryptedMessage(PasswordChangeStatusResponse + "#" + isChanged + "#" + isChanged.Length);
}
else if (requestNumber == RSAPublicKeyTransfer)
{
// an Rsa crypto object is created
rsa = new RsaCrypto(details);
string messageToSend = RSAPublicKeyTransfer + "#" + rsa.GetServerPublicKey() + "#" + rsa.GetServerPublicKey().Length;
SendMessage(ByteConverter.GetBytes(messageToSend));
}
else if (requestNumber == AesKeyTransfer)
{
// initializes the AES object
aes = new AesCrypto(key, iv);
Console.WriteLine("received- Key: {0}\nIV: {1}", BytesToString(key), BytesToString(iv));
Console.WriteLine("aes object- Key: {0}\nIV: {1}", BytesToString(aes.GetKey()), BytesToString(aes.GetIV()));
}
}
lock (client.GetStream())
{
// continue reading from the client
client.GetStream().BeginRead(data, 0, System.Convert.ToInt32(client.ReceiveBufferSize), ReceiveMessage, null);
}
}
catch (Exception ex)
{
Console.WriteLine("catch recieve");
Console.WriteLine(ex.ToString());
}
}
/// <summary>
/// gets a string message, encrypts it using Aes protocol and sends it to the client
/// </summary>
/// <param name="message">string to encrypt and send to the server</param>
private void SendAesEncryptedMessage(string message)
{
Console.WriteLine("sending aes: " + message);
SendMessage(aes.EncryptStringToBytes(message, aes.GetKey(), aes.GetIV()));
}