R – UAC: Manifest file is ignored

As of 2017, an easy method to achieve this is the following:

import ctypes, sys

def is_admin():
    try:
        return ctypes.windll.shell32.IsUserAnAdmin()
    except:
        return False

if is_admin():
    # Code of your program here
else:
    # Re-run the program with admin rights
    ctypes.windll.shell32.ShellExecuteW(None, "runas", sys.executable, " ".join(sys.argv), None, 1)

If you are using Python 2.x, then you should replace the last line for:

ctypes.windll.shell32.ShellExecuteW(None, u"runas", unicode(sys.executable), unicode(" ".join(sys.argv)), None, 1)

Also note that if you converted you python script into an executable file (using tools like py2exe, cx_freeze, pyinstaller) then you should use sys.argv[1:] instead of sys.argv in the fourth parameter.

Some of the advantages here are:

• No external libraries required. It only uses ctypes and sys from standard library.
• Works on both Python 2 and Python 3.
• There is no need to modify the file resources nor creating a manifest file.
• If you don't add code below if/else statement, the code won't ever be executed twice.
• You can get the return value of the API call in the last line and take an action if it fails (code <= 32). Check possible return values here.
• You can change the display method of the spawned process modifying the sixth parameter.

Documentation for the underlying ShellExecute call is here.

The method I finally settled on depends on the fact that Vista and Windows 2008 have the whoami.exe utility, and it detects the integrity level of the user who owns the process. A couple of screenshots help here:

WHOAMI, normal and elevated, on Vista http://lh3.ggpht.com/_Svunm47buj0/SQ6ql4iNjPI/AAAAAAAAAeA/iwbcSrAZqRg/whoami%20-%20adminuser%20-%20groups%20-%20cropped.png?imgmax=512

You can see that when cmd is running elevated, whoami /groups reports a "High" mandatory integrity level and a different SID than when running non-elevated. In the pic, the top session is normal, the one underneath is running elevated after UAC prompt.

Knowing that, here is the code I used. It essentially checks the OS version, and if it is Vista or Server 2008, calls CheckforElevation which runs whoami.exe /groups, and looks for the string S-1-16-12288 in the output. In this example I just echo status; in the real script I branch to different actions based on the result.

sub GetOSVersion
Dim strComputer, oWMIService, colOSInfo, oOSProperty, strCaption, strOSFamily
strComputer = "."
Set oWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
Set colOSInfo = oWMIService.ExecQuery("Select * from Win32_OperatingSystem")
'I hate looping through just to get one property. But dunno another way!
For Each oOSProperty in colOSInfo 
  strCaption = oOSProperty.Caption 
Next
If InStr(1,strCaption, "Vista", vbTextCompare) Then strOSFamily = "Vista"
If InStr(1,strCaption, "2008", vbTextCompare) Then strOSFamily = "2008"
If InStr(1,strCaption, "XP", vbTextCompare) Then strOSFamily = "XP"
If InStr(1,strCaption, "2003", vbTextCompare) Then strOSFamily = "2003"
If InStr(1,strCaption, "2000", vbTextCompare) Then strOSFamily = "2000"
If strOSFamily = "" Then 
    Wscript.Echo "No known OS found. (Script can detect Windows 2000, 2003, XP, Vista, 2008.)" 
Else 
    Wscript.Echo "OS Family = " & strOSFamily
End If
Select Case strOSFamily 'if Vista/2008 then call CheckforElevation
Case "Vista"
    CheckforElevation
Case "2008"
    CheckforElevation
Case Else
    Exit Sub
End Select
end sub

sub CheckforElevation 'test whether user has elevated token 
Dim oShell, oExecWhoami, oWhoamiOutput, strWhoamiOutput, boolHasElevatedToken
Set oShell = CreateObject("WScript.Shell")
Set oExecWhoami = oShell.Exec("whoami /groups")
Set oWhoamiOutput = oExecWhoami.StdOut
strWhoamiOutput = oWhoamiOutput.ReadAll
If InStr(1, strWhoamiOutput, "S-1-16-12288", vbTextCompare) Then boolHasElevatedToken = True
If boolHasElevatedToken Then
    Wscript.Echo "Current script is running with elevated privs."
Else
    Wscript.Echo "Current script is NOT running with elevated privs."
End If
end sub