/// <summary>
/// Starts negotiating with the SOCKS server.
/// </summary>
/// <param name="connect">The bytes to send when trying to authenticate.</param>
/// <exception cref="ArgumentNullException"><c>connect</c> is null.</exception>
/// <exception cref="ArgumentException"><c>connect</c> is too small.</exception>
/// <exception cref="SocksProxyException">The proxy rejected the request.</exception>
/// <exception cref="SocketException">An operating system error occurs while accessing the Socket.</exception>
/// <exception cref="ObjectDisposedException">The Socket has been closed.</exception>
/// <exception cref="ProtocolViolationException">The proxy server uses an invalid protocol.</exception>
private void Negotiate(byte[] connect)
{
Authenticate();
Server.Send(connect);
var buffer = ReadBytes(4);
if (buffer[1] != 0)
{
Server.Close();
throw SocksProxyException.FromSocks5Error(buffer[1]);
}
switch (buffer[3])
{
case 1:
ReadBytes(6); //IPv4 address with port
break;
case 3:
buffer = ReadBytes(1);
ReadBytes(buffer[0] + 2); //domain name with port
break;
case 4:
ReadBytes(18); //IPv6 address with port
break;
default:
Server.Close();
throw new ProtocolViolationException();
}
}
/// <summary>
/// Starts negotiating with the SOCKS server.
/// </summary>
/// <param name="connect">The bytes to send when trying to authenticate.</param>
/// <exception cref="ArgumentNullException"><c>connect</c> is null.</exception>
/// <exception cref="ArgumentException"><c>connect</c> is too small.</exception>
/// <exception cref="SocksProxyException">The proxy rejected the request.</exception>
/// <exception cref="SocketException">An operating system error occurs while accessing the Socket.</exception>
/// <exception cref="ObjectDisposedException">The Socket has been closed.</exception>
private void Negotiate(byte [] connect)
{
if (connect == null)
{
throw new ArgumentNullException();
}
if (connect.Length < 2)
{
throw new ArgumentException();
}
Server.Send(connect);
var buffer = ReadBytes(8);
if (buffer[1] == 90)
{
return;
}
Server.Close();
throw SocksProxyException.FromSocks4Error(buffer[1]);
}