/// <summary>
/// Starts the synchronous authentication process.
/// </summary>
/// <exception cref="SocksProxyException">Authentication with the proxy server failed.</exception>
/// <exception cref="ProtocolViolationException">The proxy server uses an invalid protocol.</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 Authenticate()
{
Server.Send(new byte[] { 5, 2, 0, 2 });
var buffer = ReadBytes(2);
if (buffer[1] == 255)
{
throw new SocksProxyException("No authentication method accepted.");
}
// Detect authentication type
IAuthProtocol authenticate;
switch (buffer[1])
{
case 0:
authenticate = new AuthNoneSocket(Server);
break;
case 2:
authenticate = new AuthUserPassSocket(Server, new NetworkCredential(Username, Password));
break;
default:
throw new ProtocolViolationException();
}
// Attempt to authenticate
authenticate.Authenticate();
}
/// <summary>
/// Called when an authentication reply has been received.
/// </summary>
/// <param name="ar">Stores state information for this asynchronous operation as well as any user-defined data.</param>
private void OnAuthReceive(IAsyncResult ar)
{
try
{
Received += Server.EndReceive(ar);
if (Received <= 0)
{
throw new SocketException();
}
}
catch (Exception e)
{
handShakeComplete(e);
return;
}
try
{
if (Received < 2)
{
Server.BeginReceive(Buffer, Received, Buffer.Length - Received, SocketFlags.None, OnAuthReceive,
Server);
}
else
{
IAuthProtocol authenticate;
switch (Buffer[1])
{
case 0:
authenticate = new AuthNoneSocket(Server);
break;
case 2:
var credential = new NetworkCredential(Username, Password);
authenticate = new AuthUserPassSocket(Server, credential);
break;
default:
handShakeComplete(new SocketException());
return;
}
authenticate.BeginAuthenticate(OnAuthenticated);
}
}
catch (Exception e)
{
handShakeComplete(e);
}
}