C++ – Requesting administrator privileges at run time

cuacwindows

Is it possible to get a C++ application running in Windows to request administrator privileges from the operating system at run time?

I know it can be done at compile time, but can't seem to find anywhere whether it can be done at run time.

Thanks for your help!

EDIT: What if I want the current instance to have elevated privileges? For example, I might have data stored in memory which I want to keep.

Best Answer

If you want the application to always elevate, you can give it a manifest, either by building one in (not compiling technically) or by putting an external manifest in the same folder as the exe. If you want to decide, as a person, to run it elevated, you right click the exe or short cut and choose Run As Administrator. If you are launching it from code, then as @vcsjones comments, you use the runas verb when you launch that process. For example:

ShellExecute( NULL, 
    "runas",  
    "c:\\windows\\notepad.exe",  
    " c:\\temp\\report.txt",     
    NULL,                        // default dir 
    SW_SHOWNORMAL  
);

Related Solutions

Python – How to run a Python script as a service in Windows

Yes you can. I do it using the pythoncom libraries that come included with ActivePython or can be installed with pywin32 (Python for Windows extensions).

This is a basic skeleton for a simple service:

import win32serviceutil
import win32service
import win32event
import servicemanager
import socket


class AppServerSvc (win32serviceutil.ServiceFramework):
    _svc_name_ = "TestService"
    _svc_display_name_ = "Test Service"

    def __init__(self,args):
        win32serviceutil.ServiceFramework.__init__(self,args)
        self.hWaitStop = win32event.CreateEvent(None,0,0,None)
        socket.setdefaulttimeout(60)

    def SvcStop(self):
        self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING)
        win32event.SetEvent(self.hWaitStop)

    def SvcDoRun(self):
        servicemanager.LogMsg(servicemanager.EVENTLOG_INFORMATION_TYPE,
                              servicemanager.PYS_SERVICE_STARTED,
                              (self._svc_name_,''))
        self.main()

    def main(self):
        pass

if __name__ == '__main__':
    win32serviceutil.HandleCommandLine(AppServerSvc)

Your code would go in the main() method—usually with some kind of infinite loop that might be interrupted by checking a flag, which you set in the SvcStop method

C++ – Dropping privileges in C++ on Windows

Yes, you can use AdjustTokenPrivileges to remove unneeded and dangerous privileges from your token. You can either disable if not immediately needed (the privilege can be enabled later) or remove a privilege from your token altogether.

You can also create a restricted token via CreateRestrictedToken and relaunch your application running with that restricted token. CreateRestrictedToken can be used to disable privileges and remove groups (like Administrators Group) from a token.

You may be able to use AdjustTokenGroups to remove the administrator group from the token of your running process, but I've never tried this on an already running process.

Note that write-access to the Windows directory is not covered by a privilege. Resources in the system have ACL's which govern who has access. System and administrators have write-access to the Windows directory.

Best Answer

Related Solutions

Python – How to run a Python script as a service in Windows

C++ – Dropping privileges in C++ on Windows

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