void Connect()
{
IP = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9999);
client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
client.Connect(IP);
}
catch
{
MessageBox.Show("Không thể kết nối tới server", "Lỗi", MessageBoxButtons.OK, MessageBoxIcon.Error);
this.Close();
return;
}
byte[] nhandodai = new byte[1024];
client.Receive(nhandodai);
nhankey = new byte[BitConverter.ToInt32(nhandodai, 0)];
client.Receive(nhankey);
keypublic = Convert.ToBase64String(nhankey);
txtkeyserver.Text = keypublic;
TaoKey();
Diff.LayKhoaBiMat(nhankey);
khoabimat = Diff.aes.Key;
keysecret = Convert.ToBase64String(khoabimat);
txtFinalKey.Text = keysecret;
byte[] laydodai = BitConverter.GetBytes(khoapublic.Length);
client.Send(laydodai);
byte[] Keypublic = khoapublic;
client.Send(Keypublic);
Thread listen = new Thread(Receive);
listen.IsBackground = true;
listen.Start();
}
void Receive()
{
try
{
c : while (true)
{
byte[] data = new byte[1024];
client.Receive(data);
if (string.Equals(Encoding.UTF8.GetString(data), "guikey", StringComparison.InvariantCultureIgnoreCase))
{
txtServerKey.Clear();
txtFinalKey.Clear();
nhankeydadoi = new byte[140];
client.Receive(nhankeydadoi);
keypublic = Convert.ToBase64String(nhankeydadoi);
txtServerKey.Text = keypublic;
CreatePublicKey();
Diff.LayKhoaBiMat(nhankeydadoi);
khoabimat = Diff.aes.Key;
keysecret = Convert.ToBase64String(khoabimat);
txtFinalKey.Text = keysecret;
nhankey = nhankeydadoi;
guilaipublickey();
}
else if (string.Equals(Encoding.UTF8.GetString(data), "guikeytoclient", StringComparison.InvariantCultureIgnoreCase))
{
txtServerKey.Clear();
txtFinalKey.Clear();
nhankeydadoi = new byte[140];
client.Receive(nhankeydadoi);
keypublic = Convert.ToBase64String(nhankeydadoi);
txtServerKey.Text = keypublic;
Diff.LayKhoaBiMat(nhankeydadoi);
khoabimat = Diff.aes.Key;
keysecret = Convert.ToBase64String(khoabimat);
txtFinalKey.Text = keysecret;
nhankey = nhankeydadoi;
}
else
{
tinnhan = new byte[BitConverter.ToInt32(data, 0)];
client.Receive(tinnhan);
byte[] nhanvector = new byte[16];
client.Receive(nhanvector);
string message = Diff.GiaiMaDiffie(nhankey, tinnhan, nhanvector);
dateTimeIV = md5.maHoaMd5(DateTime.Now.ToString());
string time = dateTimeIV.Substring(0, 16);
dateTimeIv = Encoding.UTF8.GetBytes(time);
string a = txtFinalKey.Text.Substring(0, 32);
byte[] key = Encoding.ASCII.GetBytes(a);
string s = aes.DecryptString(message, key, dateTimeIv);
foreach (char c in s)
{
if (c.ToString() == ";")
{
string[] tokens = s.Trim().Split(';');
compare1 = tokens[1];
compare2 = md5.maHoaMd5(tokens[0]);
if (compare1 != compare2)
{
LstMS.Items.Add("Server: " + tokens[0]);
LstMS.Items.Add("Dữ liệu đã bị thay đổi trong quá trình chuyền:");
LstMS.Items.Add("Chuỗi mã trước:" + compare1);
LstMS.Items.Add("Chuỗi mã sau:" + compare2);
goto c;
}
}
}
LstMS.Items.Add("Server: " + s);
}
}
}catch
{
Close();
}
}