internal static void GetNullDaclSecurityDescriptor(out SECURITY_DESC sd)
 {
     if (InitializeSecurityDescriptor(out sd, 1))
     {
         if (!SetSecurityDescriptorDacl(ref sd, true, IntPtr.Zero, false))
         {
             throw new Win32Exception(Marshal.GetLastWin32Error());
         }
     }
     else
     {
         throw new Win32Exception(Marshal.GetLastWin32Error());
     }
 }
 private static extern bool InitializeSecurityDescriptor(out SECURITY_DESC sd, int dwRevision);
 private static extern bool SetSecurityDescriptorDacl(ref SECURITY_DESC sd, bool bDaclPresent, IntPtr Dacl, bool bDaclDefaulted);