async Task <Socket> ConnectAsync(string host, int port, bool doAsync, CancellationToken cancellationToken)
{
Socks5AddressType addrType;
IPAddress ip;
ValidateArguments(host, port);
addrType = GetAddressType(host, out ip);
cancellationToken.ThrowIfCancellationRequested();
var socket = await SocketUtils.ConnectAsync(ProxyHost, ProxyPort, null, doAsync, cancellationToken).ConfigureAwait(false);
var method = ProxyCredentials != null ? Socks5AuthMethod.UserPassword : Socks5AuthMethod.Anonymous;
byte[] domain = null, addr = null;
int bufferSize = 6;
switch (addrType)
{
case Socks5AddressType.Domain:
domain = Encoding.UTF8.GetBytes(host);
bufferSize += 1 + domain.Length;
break;
case Socks5AddressType.IPv6:
bufferSize += 16;
break;
case Socks5AddressType.IPv4:
bufferSize += 4;
break;
}
try {
method = NegotiateAuthMethod(socket, cancellationToken, method);
switch (method)
{
case Socks5AuthMethod.UserPassword:
Authenticate(socket, cancellationToken);
break;
case Socks5AuthMethod.Anonymous:
break;
default:
//throw new ProxyProtocolException ("Failed to negotiate authentication method with the proxy server.");
break;
}
// +----+-----+-------+------+----------+----------+
// |VER | CMD | RSV | ATYP | DST.ADDR | DST.PORT |
// +----+-----+-------+------+----------+----------+
// | 1 | 1 | X'00' | 1 | Variable | 2 |
// +----+-----+-------+------+----------+----------+
var buffer = new byte[bufferSize];
int nread, n = 0;
buffer [n++] = (byte)SocksVersion;
buffer[n++] = (byte)Socks5Command.Connect;
buffer[n++] = 0x00;
buffer[n++] = (byte)addrType;
switch (addrType)
{
case Socks5AddressType.Domain:
buffer[n++] = (byte)domain.Length;
Buffer.BlockCopy(domain, 0, buffer, n, domain.Length);
n += domain.Length;
break;
case Socks5AddressType.IPv6:
addr = ip.GetAddressBytes();
Buffer.BlockCopy(addr, 0, buffer, n, addr.Length);
n += 16;
break;
case Socks5AddressType.IPv4:
addr = ip.GetAddressBytes();
Buffer.BlockCopy(addr, 0, buffer, n, addr.Length);
n += 4;
break;
}
buffer[n++] = (byte)(port >> 8);
buffer[n++] = (byte)port;
SocketUtils.Poll(socket, SelectMode.SelectWrite, cancellationToken);
socket.Send(buffer, 0, n, SocketFlags.None);
// +-----+-----+-------+------+----------+----------+
// | VER | REP | RSV | ATYP | BND.ADDR | BND.PORT |
// +-----+-----+-------+------+----------+----------+
// | 1 | 1 | X'00' | 1 | Variable | 2 |
// +-----+-----+-------+------+----------+----------+
// Note: We know we'll need at least 4 bytes of header + a minimum of 1 byte
// to determine the length of the BND.ADDR field if ATYP is a domain.
int need = 5;
n = 0;
do
{
SocketUtils.Poll(socket, SelectMode.SelectRead, cancellationToken);
if ((nread = socket.Receive(buffer, 0 + n, need - n, SocketFlags.None)) > 0)
{
n += nread;
}
} while (n < need);
if (buffer[1] != (byte)Socks5Reply.Success)
{
throw new ProxyProtocolException(string.Format("Failed to connect to {0}:{1}: {2}", host, port, GetFailureReason(buffer[1])));
}
addrType = (Socks5AddressType)buffer[3];
switch (addrType)
{
case Socks5AddressType.Domain: need += buffer[4] + 2; break;
case Socks5AddressType.IPv6: need += (16 - 1) + 2; break;
case Socks5AddressType.IPv4: need += (4 - 1) + 2; break;
default: throw new ProxyProtocolException("Proxy server returned unknown address type.");
}
do
{
SocketUtils.Poll(socket, SelectMode.SelectRead, cancellationToken);
if ((nread = socket.Receive(buffer, 0 + n, need - n, SocketFlags.None)) > 0)
{
n += nread;
}
} while (n < need);
// TODO: do we care about BND.ADDR and BND.PORT?
return(socket);
} catch (OperationCanceledException) {
socket.Disconnect(false);
socket.Dispose();
throw;
} catch {
socket.Dispose();
throw;
}
}
async Task <Socket> ConnectAsync(string host, int port, bool doAsync, CancellationToken cancellationToken)
{
byte[] addr, domain = null;
IPAddress ip;
ValidateArguments(host, port);
if (!IPAddress.TryParse(host, out ip))
{
domain = Encoding.UTF8.GetBytes(host);
addr = InvalidIPAddress;
}
else
{
if (ip.AddressFamily != AddressFamily.InterNetwork)
{
throw new ArgumentException(nameof(host));
}
addr = ip.GetAddressBytes();
}
cancellationToken.ThrowIfCancellationRequested();
var socket = await SocketUtils.ConnectAsync(ProxyHost, ProxyPort, null, doAsync, cancellationToken).ConfigureAwait(false);
var user = ProxyCredentials != null?Encoding.UTF8.GetBytes(ProxyCredentials.UserName) : new byte[0];
try {
// +----+-----+----------+----------+----------+-------+--------------+-------+
// |VER | CMD | DST.PORT | DST.ADDR | USERID | NULL | DST.DOMAIN | NULL |
// +----+-----+----------+----------+----------+-------+--------------+-------+
// | 1 | 1 | 2 | 4 | VARIABLE | X'00' | VARIABLE | X'00' |
// +----+-----+----------+----------+----------+-------+--------------+-------+
int bufferSize = 9 + user.Length + (domain != null ? domain.Length + 1 : 0);
var buffer = new byte[bufferSize];
int nread, n = 0;
buffer[n++] = (byte)SocksVersion;
buffer[n++] = (byte)Socks4Command.Connect;
buffer[n++] = (byte)(port >> 8);
buffer[n++] = (byte)port;
Buffer.BlockCopy(addr, 0, buffer, n, 4);
n += 4;
Buffer.BlockCopy(user, 0, buffer, n, user.Length);
n += user.Length;
buffer[n++] = 0x00;
if (domain != null)
{
Buffer.BlockCopy(domain, 0, buffer, n, domain.Length);
n += domain.Length;
buffer[n++] = 0x00;
}
SocketUtils.Poll(socket, SelectMode.SelectWrite, cancellationToken);
socket.Send(buffer, 0, n, SocketFlags.None);
// +-----+-----+----------+----------+
// | VER | REP | BND.PORT | BND.ADDR |
// +-----+-----+----------+----------+
// | 1 | 1 | 2 | 4 |
// +-----+-----+----------+----------+
n = 0;
do
{
SocketUtils.Poll(socket, SelectMode.SelectRead, cancellationToken);
if ((nread = socket.Receive(buffer, 0 + n, 8 - n, SocketFlags.None)) > 0)
{
n += nread;
}
} while (n < 8);
if (buffer[1] != (byte)Socks4Reply.RequestGranted)
{
throw new ProxyProtocolException(string.Format("Failed to connect to {0}:{1}: {2}", host, port, GetFailureReason(buffer[1])));
}
// TODO: do we care about BND.ADDR and BND.PORT?
return(socket);
} catch (OperationCanceledException) {
socket.Disconnect(false);
socket.Dispose();
throw;
} catch {
socket.Dispose();
throw;
}
}
