private void CheckHeartbeat(Object source, ElapsedEventArgs e)
{
if (!HeartbeatReceived)
{
ClientMsgReceivedHandler?.Invoke(this, "\t\theartbeat timeout");
}
else
{
WriteToClient("echo **HEARTBEAT");
HeartbeatReceived = false;
}
}
/// <summary>
/// Handles messages received from the client.
/// </summary>
protected virtual void OnClientMsgReceived(string e)
{
string trimString = e.TrimEnd('\0');
if (trimString.StartsWith("**HEARTBEAT"))
{
HeartbeatReceived = true;
}
else
{
ClientMsgReceivedHandler?.Invoke(this, trimString);
}
}
/// <summary>
/// Launches the paexec.exe service. Calling this method will prompt for elevated credentials because the program runs in two different user contexts.
/// </summary>
/// <param name="paexec_EXE">The full path to the "paexec.exe" binary.</param>
/// <param name="testComputer">The name of the test computer to launch paexec.exe on."</param>
/// <param name="elevatedUsername">
/// The username of the elevated account that will be used to launch paexec. Should include the account domain.
/// <para/>E.g. <paramref name="elevatedUsername"/> = @"domain\\administrator.account"
/// </param>
/// <param name="elevatedContext_EXE">The full path to the ElevatedProcess.exe binary.</param>
public bool StartService(string paexec_EXE, string testComputer, string elevatedUsername, string elevatedContext_EXE)
{
string pipeName = Guid.NewGuid().ToString();
try
{
// configure pipe security
PipeSecurity pipeSecurity = new PipeSecurity();
pipeSecurity.AddAccessRule(new PipeAccessRule(elevatedUsername, PipeAccessRights.FullControl, AccessControlType.Allow));
pipeSecurity.AddAccessRule(new PipeAccessRule(pipeUser, PipeAccessRights.FullControl, AccessControlType.Allow));
// launch server first
server = new NamedPipeServerStream(pipeName, PipeDirection.InOut, 2, PipeTransmissionMode.Message,
PipeOptions.Asynchronous, MaxLen, MaxLen, pipeSecurity)
{
ReadMode = PipeTransmissionMode.Message
};
// this is the admin/elevated process that runs paexec.exe and acts as a pipe client
clientProcess = new Process
{
StartInfo = new ProcessStartInfo(elevatedContext_EXE)
{
Verb = "RunAs", Arguments = string.Join("", "\"", paexec_EXE, "\" ", pipeName, " \"\\\\", testComputer.Trim(), " -h cmd\"")
}
};
ClientMsgReceivedHandler?.Invoke(this, "Prompting for elevated credentials needed to launch paexec.exe wrapper.\r\n");
clientProcess.Start(); // will prompt for credentials, due to "RunAs" verb
Thread.Sleep(500);
// Async await for connection. if shut down flag is set, it will stop
ShouldRun = true;
serverconnect:
while (ShouldRun)
{
try
{
IAsyncResult asyncResult = server.BeginWaitForConnection(HandleConnection, server);
int waitResult = WaitHandle.WaitAny(new[] { asyncResult.AsyncWaitHandle });
if (waitResult == 0)
{
server.EndWaitForConnection(asyncResult);
IsRunning = true;
break;
}
}
catch (Exception)
{
ClientMsgReceivedHandler?.Invoke(this, "Server connection error. Retrying... \r\n\r\n");
IsRunning = false;
server.Close();
continue;
}
}
// after connection is made, await messages over the pipe.
try
{
new Task(ReadFromClientTask).Start();
new Task(WriteToClientTask).Start();
StartHeartbeatTimer(60);
ClientMsgReceivedHandler?.Invoke(this, "Connected to paexec.exe wrapper. Redirecting output...\r\n\r\n");
return(true);
}
catch (Exception)
{
server.Close();
IsRunning = false;
ClientMsgReceivedHandler?.Invoke(this, "Pipe exception. Resetting server... \r\n");
Thread.Sleep(1500);
goto serverconnect;
}
}
catch (Exception e)
{
System.Windows.Forms.MessageBox.Show("Error launching the paexec.exe pipe service. \r\n\r\n" + e.ToString());
if (server.IsConnected)
{
server.Close();
}
return(false);
}
}