void Undo()
{
// PreSharp Bug: Call 'Marshal.GetLastWin32Error' or 'Marshal.GetHRForLastWin32Error' before any other interop call.
#pragma warning suppress 56523 // The LastWin32Error can be ignored here.
Fx.Assert(this.threadHandle == SafeNativeMethods.GetCurrentThread(), "");
// We are in the Dispose method. If a failure occurs we just have to ignore it.
// PreSharp Bug: Call 'Marshal.GetLastWin32Error' or 'Marshal.GetHRForLastWin32Error' before any other interop call.
// #pragma warning suppress 56523 // The LastWin32Error can be ignored here.
if (!SafeNativeMethods.SetCurrentThreadToken(IntPtr.Zero, this.tokenHandle))
{
int error = Marshal.GetLastWin32Error();
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new SecurityException(SR.GetString(SR.RevertImpersonationFailure,
new Win32Exception(error).Message)));
}
tokenHandle.Close();
}
// This api simply check if the calling thread is process primary thread.
// We are not trying to be smart if the impersonation to the same user as
// process token since privileges could be different.
bool IsImpersonatedContext()
{
SafeCloseHandle tokenHandle = null;
if (!SafeNativeMethods.OpenCurrentThreadToken(
SafeNativeMethods.GetCurrentThread(),
TokenAccessLevels.Query,
true,
out tokenHandle))
{
int error = Marshal.GetLastWin32Error();
Utility.CloseInvalidOutSafeHandle(tokenHandle);
if (error == (int)Win32Error.ERROR_NO_TOKEN)
{
return(false);
}
System.ServiceModel.Dispatcher.ErrorBehavior.ThrowAndCatch(new Win32Exception(error));
return(true);
}
tokenHandle.Close();
return(true);
}