protected void ClientThreadEntry()
{
try
{
TcpListener listenerV4 = new TcpListener(IPAddress.Any, PortNumber);
TcpListener listenerV6 = new TcpListener(IPAddress.IPv6Any, PortNumber);
listenerV4.Start(10);
listenerV6.Start(10);
// Start listening for connections.
Log.WriteLine("Listening for TCP connections on port " + PortNumber + "...\n", Severity.Debug);
while (!Stopping)
{
TcpClient ClientRequest;
try
{
if (listenerV4.Pending())
{
ClientRequest = listenerV4.AcceptTcpClient();
}
else if (listenerV6.Pending())
{
ClientRequest = listenerV6.AcceptTcpClient();
}
else
{
Thread.Sleep(250); continue;
}
Log.WriteLine("TCP Client accepted.\n", Severity.Debug);
NetworkStream = new SslStream(ClientRequest.GetStream(), false);
NetworkStream.AuthenticateAsServer(GetRemoteDesktopCertificate(), false, SslProtocols.Tls12, true);
if (!NetworkStream.IsAuthenticated)
{
NetworkStream = null;
Log.WriteLine("Unable to authenticate incoming connection from " + ((IPEndPoint)ClientRequest.Client.RemoteEndPoint).Address.ToString() + ".", Severity.Warning);
ClientRequest.Close();
continue;
}
if (!NetworkStream.IsEncrypted)
{
NetworkStream = null;
Log.WriteLine("Unable to encrypt incoming connection from " + ((IPEndPoint)ClientRequest.Client.RemoteEndPoint).Address.ToString() + ".", Severity.Warning);
ClientRequest.Close();
continue;
}
// Display the properties and settings for the authenticated stream.
Log.WriteLine("Authentication successful [host].\n", Severity.Debug);
#if DEBUG
DisplaySecurityLevel(Log, NetworkStream, Severity.Debug);
DisplaySecurityServices(Log, NetworkStream, Severity.Debug);
DisplayCertificateInformation(Log, NetworkStream, Severity.Debug);
DisplayStreamProperties(Log, NetworkStream, Severity.Debug);
#endif
// Transmit our version info as a hello.
System.Reflection.Assembly assembly = System.Reflection.Assembly.GetExecutingAssembly();
FileVersionInfo fvi = FileVersionInfo.GetVersionInfo(assembly.Location);
string version = fvi.FileVersion;
string XmlMsg = "<Portal-Version Core-Library=\"" + fvi.FileVersion + "\" />";
byte[] RawMsg = Encoding.Unicode.GetBytes(XmlMsg);
if (NetworkStream != null)
{
SendMessage(NetworkStream, RawMsg);
}
}
catch (Win32Exception ex)
{
Log.WriteLine("Exception accepting new connection: " + ex.ToString(), Severity.Debug);
if ((uint)ex.ErrorCode == 0x80004005)
{
// The credentials supplied to the pacakage were not recognized.
// This error comes up rom NetworkStream.AuthenticateAsServer() or GetRemoteDesktopCertificate() for localhost slave when there is no administrative access.
Log.WriteLine("This exception usually indicates that administrative access was required but not present.", Severity.Debug);
}
continue;
}
catch (Exception ex)
{
// Note: "The credentials supplied to the package were not recognized" is probably a sign that the code doesn't have Administrator access and can't access the subsystem or certificate it needs.
Log.WriteLine("Exception accepting new connection: " + ex.ToString(), Severity.Debug);
continue;
}
try
{
ServiceConnection(NetworkStream, ClientRequest, ClientRequest.GetStream());
}
catch (Exception ex)
{
Log.WriteLine("Exception servicing connection: " + ex.ToString(), Severity.Debug);
}
lock (ProcessLock)
{
// Setting ConnectedProcess to null before accepting a new connection is essential to security. It prevents access to the console without a new authentication and Connect-Terminal.
ConnectedProcess = null;
// If we aren't attached to a console, FreeConsole() would return ERROR_INVALID_PARAMETER.
ConsoleApi.FreeConsole();
Log.WriteLine("Closing connection in SlaveCore (if it isn't already).", Severity.Debug);
if (ClientRequest != null)
{
ClientRequest.Dispose(); ClientRequest = null;
}
if (Conin != null)
{
Conin.Dispose(); Conin = null;
}
if (CT != null)
{
CT.Dispose(); CT = null;
}
}
}
lock (ProcessLock)
{
ConnectedProcess = null;
foreach (var kvp in Processes)
{
kvp.Value.Dispose();
}
Processes.Clear();
}
}
catch (Exception e)
{
Log.WriteLine("Error: " + e.ToString(), Severity.Error);
}
}