Elevating user credentials using runasuser verb - c#-4.0

Question

I'm trying to elevate the process of my application using "runasuser" verb of the ProcessStartInfo class but everytime I run the program, it automatically terminates.
here is my code for the main class:
private static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
//Application Events
Application.ThreadException += new ThreadExceptionEventHandler(Application_ThreadException);
//Check if the current user is a member of the administrator group
WindowsPrincipal principal = new WindowsPrincipal(WindowsIdentity.GetCurrent());
bool hasAdministrativeRights = principal.IsInRole(WindowsBuiltInRole.Administrator);
bool createdNew = false;
if (hasAdministrativeRights)
//Creating new mutex for single instance
using (Mutex mutex = new Mutex(true, "CpELabAppCopier", out createdNew))
{
if (createdNew)
Application.Run(new MainForm());
else
Application.Exit();
}
else
//Creating new mutex for single instance
using (Mutex mutex = new Mutex(true, "Elevated_CpELabAppCopier", out createdNew))
{
if (createdNew)
{
//Setting the startinfo
ProcessStartInfo newProcessInfo = new ProcessStartInfo();
newProcessInfo.FileName = Application.ExecutablePath;
newProcessInfo.Verb = "runasuser";
newProcessInfo.UseShellExecute = true;
//Starting new process
Process newProcess = new Process();
newProcess.StartInfo = newProcessInfo;
newProcess.Start();
//The Run As dialog box will show and close immediately.
}
}
}

Answer 1

Are you sure you want "runasuser" and not "runas"?
RunAs will attempt to run as an administrator, where RunAsUser will allow you to start a process as anybody.
If you really do want "runasuser", the problem seems to be that this verb will launch the username/password dialog in the same thread as the current process, but not block for a response. It also returns a null Process object in this case, so you can't query it's Respond/MainModule/... to see when it actually starts.
The only solution I've found is to enum all windows in the current process until you no longer see the username/password prompt dialog. Here's an example class; the only thing you may need/want to adjust is the trailing 500ms delay:
using System;
using System.Text;
using System.Threading;
using System.Diagnostics;
using System.Runtime.InteropServices;
namespace TestAsUser
{
public static class testClass
{
public delegate bool EnumThreadDelegate (IntPtr hwnd, IntPtr lParam);
[DllImport("user32.dll")] static extern bool EnumThreadWindows(uint threadId, EnumThreadDelegate lpfn, IntPtr lParam);
[DllImport("user32.dll")] static extern int GetWindowText(IntPtr hwnd, StringBuilder lpString, int nMaxCount);
[DllImport("user32.dll")] static extern int GetWindowTextLength(IntPtr hwnd);
private static bool containsSecurityWindow;
public static void Main(string[] args)
{
ProcessStartInfo psi = new ProcessStartInfo("c:\\windows\\system32\\notepad.exe");
psi.Verb = "runasuser";
Process.Start(psi);
containsSecurityWindow = false;
while(!containsSecurityWindow) // wait for windows to bring up the "Windows Security" dialog
{
CheckSecurityWindow();
Thread.Sleep(25);
}
while(containsSecurityWindow) // while this process contains a "Windows Security" dialog, stay open
{
containsSecurityWindow = false;
CheckSecurityWindow();
Thread.Sleep(50);
}
Thread.Sleep(500); // give some time for windows to complete launching the application after closing the dialog
}
private static void CheckSecurityWindow()
{
ProcessThreadCollection ptc = Process.GetCurrentProcess().Threads;
for(int i=0; i<ptc.Count; i++)
EnumThreadWindows((uint)ptc[i].Id, CheckSecurityThread, IntPtr.Zero);
}
private static bool CheckSecurityThread(IntPtr hwnd, IntPtr lParam)
{
if(GetWindowTitle(hwnd) == "Windows Security")
containsSecurityWindow = true;
return true;
}
private static string GetWindowTitle(IntPtr hwnd)
{
StringBuilder sb = new StringBuilder(GetWindowTextLength(hwnd) + 1);
GetWindowText(hwnd, sb, sb.Capacity);
return sb.ToString();
}
}
}