How to ask for administer privileges on Windows with Go

What I want to achieve for my application, is to not need to right click and choose Run as administrator each time I want to run it. I want Windows to prompt me to gain admin permissions as with other windows applications.

consider the following code:

package main

import (
	"fmt"
	"io/ioutil"
	"time"
)

func main() {
	err := ioutil.WriteFile("C:/Windows/test.txt", []byte("TESTING!"), 0644)
	if err != nil {
		fmt.Println(err.Error())
		time.Sleep(time.Second * 3)
	}
}

If you compile it and double click on it it will print:

> open: C:\Windows\test.txt: Access is denied.

But if you right-click and run as administrator, it will create and write the file.

How to make it ask for the admin permission just by double clicking on it?

You need to embed a manifest file which will tell Windows that you want elevated privileges.

The example from that page is:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity
    version="9.0.0.0"
    processorArchitecture="x86"
    name="myapp.exe"
    type="win32"
/>
<description>My App</description>
<trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
    <security>
        <requestedPrivileges>
            <requestedExecutionLevel level="requireAdministrator" uiAccess="false"/>
        </requestedPrivileges>
    </security>
</trustInfo>
</assembly>

This go-nuts post suggests that using rsrc should do the trick for you.

This is the technique that I use to detect if I am running as administrator, and if not relaunch myself with a UAC prompt. This allows me to run as a standard user in most cases, and only elevate when needed. I use this in command line tools where most functions don't need admin rights, but functions like -install or -uninstall do since they're writing to HKLM in the registry or Program Files. No manifest is necessary with this method.

package main

import (
	"fmt"
	"golang.org/x/sys/windows"
	"os"
	"syscall"
	"time"
)

func main() {
	// if not elevated, relaunch by shellexecute with runas verb set
	if !amAdmin() {
		runMeElevated()
	}
	time.Sleep(10*time.Second)

}

func runMeElevated() {
	verb := "runas"
	exe, _ := os.Executable()
	cwd, _ := os.Getwd()
	args := strings.Join(os.Args[1:], " ")
	
	verbPtr, _ := syscall.UTF16PtrFromString(verb)
	exePtr, _ := syscall.UTF16PtrFromString(exe)
	cwdPtr, _ := syscall.UTF16PtrFromString(cwd)
	argPtr, _ := syscall.UTF16PtrFromString(args)
	
	var showCmd int32 = 1 //SW_NORMAL
	
	err := windows.ShellExecute(0, verbPtr, exePtr, argPtr, cwdPtr, showCmd)
	if err != nil {
		fmt.Println(err)
	}
}

func amAdmin() bool {
	_, err := os.Open("\\\\.\\PHYSICALDRIVE0")
	if err != nil {
		fmt.Println("admin no")
		return false
	}
	fmt.Println("admin yes")
	return true
}

More details available here:
https://gist.github.com/jerblack/d0eb182cc5a1c1d92d92a4c4fcc416c6