public void GetHostEntryCallback(IAsyncResult ar)
{
DNSCbContext ct = (DNSCbContext)ar.AsyncState;
IPHostEntry ipHostInfo = Dns.EndGetHostEntry(ar);
IPAddress ipAddress = ipHostInfo.AddressList[0];
DNSCache.GetInstence().Put(ct.host, ipAddress);
IPEndPoint remoteEP = new IPEndPoint(ipAddress, ct.port);
remote = new Socket(ipAddress.AddressFamily,
SocketType.Stream, ProtocolType.Tcp);
remote.BeginConnect(remoteEP,
new AsyncCallback(remoteConnectCallback), null);
}
private void handshakeReceiveCallback(IAsyncResult ar)
{
try
{
int bytesRead = connection.EndReceive(ar);
//Console.WriteLine("bytesRead" + bytesRead.ToString() + " stage" + stage.ToString());
if (stage == 0)
{
//recv numbers of ivlen data
byte[] iv = encryptor.Decrypt(this.connetionBuffer, bytesRead);
//Decrypt sucessful
//iv
stage = 1;
connection.BeginReceive(this.connetionBuffer, 0, 1, 0,
new AsyncCallback(handshakeReceiveCallback), null);
}
else if (stage == 1)
{
byte[] buff = encryptor.Decrypt(this.connetionBuffer, bytesRead);
//Decrypt sucessful
//addrtype
char addrtype = (char)buff[0];
if (addrtype == 1)
{
//type of ipv4
stage = 4;
connection.BeginReceive(this.connetionBuffer, 0, 4, 0,
new AsyncCallback(handshakeReceiveCallback), null);
}
else if (addrtype == 3)
{
//type of url
stage = 3;
connection.BeginReceive(this.connetionBuffer, 0, 1, 0,
new AsyncCallback(handshakeReceiveCallback), null);
}
else if (addrtype == 4)
{
//type of ipv6
stage = 4;
connection.BeginReceive(this.connetionBuffer, 0, 16, 0,
new AsyncCallback(handshakeReceiveCallback), null);
}
else
{
throw new Exception("Error Socket5 AddrType");
}
}
else if (stage == 3)
{
//addr len
byte[] buff = encryptor.Decrypt(this.connetionBuffer, bytesRead);
stage = 4;
//recv addr
connection.BeginReceive(this.connetionBuffer, 0, buff[0], 0,
new AsyncCallback(handshakeReceiveCallback), null);
}
else if (stage == 4)
{
//addr
byte[] buff = encryptor.Decrypt(this.connetionBuffer, bytesRead);
destAddr = ASCIIEncoding.Default.GetString(buff);
stage = 5;
connection.BeginReceive(this.connetionBuffer, 0, 2, 0,
new AsyncCallback(handshakeReceiveCallback), null);
}
else if (stage == 5)
{
//port
byte[] buff = encryptor.Decrypt(this.connetionBuffer, bytesRead);
int port = (int)(buff[0] << 8) + (int)buff[1];
stage = 6;
//Begin to connect remote
IPAddress ipAddress;
bool parsed = IPAddress.TryParse(destAddr, out ipAddress);
if (!parsed)
{
IPAddress cache_ipAddress = DNSCache.GetInstence().Get(destAddr);
if (cache_ipAddress == null)
{
DNSCbContext ct = new DNSCbContext(destAddr, port);
Dns.BeginGetHostEntry(destAddr, new AsyncCallback(GetHostEntryCallback), ct);
return;
}
ipAddress = cache_ipAddress;
}
IPEndPoint remoteEP = new IPEndPoint(ipAddress, port);
remote = new Socket(ipAddress.AddressFamily,
SocketType.Stream, ProtocolType.Tcp);
remote.BeginConnect(remoteEP,
new AsyncCallback(remoteConnectCallback), null);
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
this.Close();
}
}
