static void Main(string[] args)
{
server = new TcpListener(IPAddress.Any, 9999);
server.Start();
while (true)
{
client = server.AcceptTcpClient();
object my_lock = new object();
ns = client.GetStream();
Task.Factory.StartNew(() =>
{
Thread.Sleep(10000);
Console.Write(DateTime.Now);
lock (my_lock)
{
Console.Write(DateTime.Now);
client.Client.Close();
}
});
Task.Factory.StartNew(() =>
{
AES aes = null;
RSACryptoServiceProvider rsa = null;
while (true)
{
int messageType;
try
{
messageType = BitConverter.ToInt32(Receive(client, 4), 0);
}
catch (IOException e)
{
break;
}
lock (my_lock)
{
if (messageType == TCPConnection.GET_SESSION_KEY)
{
var lenBytes = BitConverter.ToInt32(Receive(client, 4), 0);
aes = GenerateSessionKey();
SendEcryptedSessionKey(aes, rsa);
}
if (messageType == TCPConnection.PUBLIC_KEY)
{
var lenBytes = BitConverter.ToInt32(Receive(client, 4), 0);
rsa = GetPublicKeyFromClient(client, lenBytes);
}
if (messageType == TCPConnection.LOGIN)
{
var lenBytes = BitConverter.ToInt32(Receive(client, 4), 0);
var msg = Receive(client, lenBytes);
byte[] loginLenArray = new byte[4];
Array.Copy(msg, 0, loginLenArray, 0, 4);
var loginLen = BitConverter.ToInt32(loginLenArray, 0);
byte[] loginArray = new byte[loginLen];
Array.Copy(msg, 4, loginArray, 0, loginLen);
loginArray = AES.Decrypt(loginArray, aes.rijndaelManaged.Key, aes.rijndaelManaged.IV);
var login = Encoding.Default.GetString(loginArray);
var passwordLen = msg.Length - 4 - loginLen;
byte[] passwordArray = new byte[passwordLen];
Array.Copy(msg, 4 + loginLen, passwordArray, 0, passwordLen);
passwordArray = AES.Decrypt(passwordArray, aes.rijndaelManaged.Key, aes.rijndaelManaged.IV);
var password = Encoding.Default.GetString(passwordArray);
if (checkUser(login, password))
{
Send(client, TCPConnection.LOGIN_APPROVED, null);
}
else
{
Send(client, TCPConnection.LOGIN_REJECTED, null);
}
}
else if (messageType == TCPConnection.FILENAME)
{
var lenBytes = BitConverter.ToInt32(Receive(client, 4), 0);
var msg = Receive(client, lenBytes);
var filename = Encoding.UTF8.GetString(AES.Decrypt(msg, aes.rijndaelManaged.Key, aes.rijndaelManaged.IV));
if (File.Exists(filename))
{
var text = File.ReadAllBytes(filename);
text = AES.Encrypt(text, aes.rijndaelManaged.Key, aes.rijndaelManaged.IV);
Send(client, TCPConnection.TEXT, text);
}
else
{
Send(client, TCPConnection.FILE_DO_NOT_EXISTS, null);
}
}
else if (messageType == TCPConnection.TEXT)
{
var lenBytes = BitConverter.ToInt32(Receive(client, 4), 0);
var msg = Receive(client, lenBytes);
byte[] filenameLenArray = new byte[4];
Array.Copy(msg, 0, filenameLenArray, 0, 4);
var filenameLen = BitConverter.ToInt32(filenameLenArray, 0);
byte[] filenameArray = new byte[filenameLen];
Array.Copy(msg, 4, filenameArray, 0, filenameLen);
filenameArray = AES.Decrypt(filenameArray, aes.rijndaelManaged.Key, aes.rijndaelManaged.IV);
var filename = Encoding.Default.GetString(filenameArray);
var textLen = msg.Length - 4 - filenameLen;
byte[] textArray = new byte[textLen];
Array.Copy(msg, 4 + filenameLen, textArray, 0, textLen);
textArray = AES.Decrypt(textArray, aes.rijndaelManaged.Key, aes.rijndaelManaged.IV);
File.WriteAllBytes(filename, textArray);
Send(client, TCPConnection.FILE_SAVED, null);
}
}
}
});
}
}
