private SocksHttpWebResponse InternalGetResponse()
{
Uri requestUri = RequestUri;
int redirects = 0;
const int maxAutoredirectCount = 10;
while (redirects++ < maxAutoredirectCount)
{
// Loop while redirecting
var proxyUri = Proxy.GetProxy(requestUri);
var ipAddress = GetProxyIpAddress(proxyUri);
var response = new List <byte>();
using (var client = new TcpClient(ipAddress.ToString(), proxyUri.Port))
{
int timeout = Timeout;
if (timeout == 0)
{
timeout = 30 * 1000;
}
client.ReceiveTimeout = timeout;
client.SendTimeout = timeout;
var networkStream = client.GetStream();
// auth
var buf = new byte[300];
buf[0] = 0x05; // Version
buf[1] = 0x01; // NMETHODS
buf[2] = 0x00; // No auth-method
networkStream.Write(buf, 0, 3);
networkStream.Read(buf, 0, 2);
if (buf[0] != 0x05)
{
throw new IOException("Invalid Socks Version");
}
if (buf[1] == 0xff)
{
throw new IOException("Socks Server does not support no-auth");
}
if (buf[1] != 0x00)
{
throw new Exception("Socks Server did choose bogus auth");
}
// connect
var destIP = Dns.GetHostEntry(requestUri.DnsSafeHost).AddressList[0];
var index = 0;
buf[index++] = 0x05; // version 5 .
buf[index++] = 0x01; // command = connect.
buf[index++] = 0x00; // Reserve = must be 0x00
buf[index++] = 0x01; // Address is full-qualified domain name.
var rawBytes = destIP.GetAddressBytes();
rawBytes.CopyTo(buf, index);
index += (ushort)rawBytes.Length;
var portBytes = BitConverter.GetBytes(Uri.UriSchemeHttps == requestUri.Scheme ? 443 : 80);
for (var i = portBytes.Length - 3; i >= 0; i--)
{
buf[index++] = portBytes[i];
}
networkStream.Write(buf, 0, index);
networkStream.Read(buf, 0, 4);
if (buf[0] != 0x05)
{
throw new IOException("Invalid Socks Version");
}
if (buf[1] != 0x00)
{
throw new IOException($"Socks Error {buf[1]:X}");
}
var rdest = string.Empty;
switch (buf[3])
{
case 0x01: // IPv4
networkStream.Read(buf, 0, 4);
var v4 = BitConverter.ToUInt32(buf, 0);
rdest = new IPAddress(v4).ToString();
break;
case 0x03: // Domain name
networkStream.Read(buf, 0, 1);
if (buf[0] == 0xff)
{
throw new IOException("Invalid Domain Name");
}
networkStream.Read(buf, 1, buf[0]);
rdest = Encoding.ASCII.GetString(buf, 1, buf[0]);
break;
case 0x04: // IPv6
var octets = new byte[16];
networkStream.Read(octets, 0, 16);
rdest = new IPAddress(octets).ToString();
break;
default:
throw new IOException("Invalid Address type");
}
networkStream.Read(buf, 0, 2);
var rport = (ushort)IPAddress.NetworkToHostOrder((short)BitConverter.ToUInt16(buf, 0));
Stream readStream = null;
if (Uri.UriSchemeHttps == requestUri.Scheme)
{
var ssl = new SslStream(networkStream);
ssl.AuthenticateAsClient(requestUri.DnsSafeHost);
readStream = ssl;
}
else
{
readStream = networkStream;
}
string requestString = BuildHttpRequestMessage(requestUri);
var request = Encoding.ASCII.GetBytes(requestString);
readStream.Write(request, 0, request.Length);
readStream.Flush();
var buffer = new byte[client.ReceiveBufferSize];
var readlen = 0;
do
{
readlen = readStream.Read(buffer, 0, buffer.Length);
response.AddRange(buffer.Take(readlen));
} while (readlen != 0);
readStream.Close();
}
var webResponse = new SocksHttpWebResponse(requestUri, response.ToArray());
if (webResponse.StatusCode == HttpStatusCode.Moved || webResponse.StatusCode == HttpStatusCode.MovedPermanently)
{
string redirectUrl = webResponse.Headers["Location"];
if (string.IsNullOrEmpty(redirectUrl))
{
throw new WebException("Missing location for redirect");
}
requestUri = new Uri(requestUri, redirectUrl);
if (AllowAutoRedirect)
{
continue;
}
return(webResponse);
}
if ((int)webResponse.StatusCode < 200 || (int)webResponse.StatusCode > 299)
{
throw new WebException(webResponse.StatusDescription, null, WebExceptionStatus.UnknownError, webResponse);
}
return(webResponse);
}
throw new WebException("Too many redirects", null, WebExceptionStatus.ProtocolError, SocksHttpWebResponse.CreateErrorResponse(HttpStatusCode.BadRequest));
}