Powershell start-process script calls a second scr

Question

I have a powershell script that accepts parameters in the form of "sender-ip=10.10.10.10" and that runs perfectly with elevated credentials

#script.ps1

$userID=$NULL
$line_array = @()
$multi_array = @()
[hashtable]$my_hash = @{}

foreach ($i in $args){
   $line_array+= $i.split(" ")
}

foreach ($j in $line_array){
    $multi_array += ,@($j.split("="))
}

foreach ($k in $multi_array){
    $my_hash.add($k[0],$k[1])
}

$Sender_IP = $my_hash.Get_Item("sender-ip")


<#Gather information on the computer corresponding to $Sender_IP#>
$Win32OS = Get-WmiObject -Class Win32_OperatingSystem -ComputerName $Sender_IP 

<#Determine the build number#>
$Build = $Win32OS.BuildNumber


<#Running Windows Vista with SP1 and later, i.e. $Build is greater than or equal to 6001#>
if($Build -ge 6001){
    $Win32User = Get-WmiObject -Class Win32_UserProfile -ComputerName $Sender_IP
    $Win32User = $Win32User | Sort-Object -Property LastUseTime -Descending
    $LastUser = $Win32User | Select-Object -First 1
    $UserSID = New-Object System.Security.Principal.SecurityIdentifier($LastUser.SID)
    $userId = $UserSID.Translate([System.Security.Principal.NTAccount])
    $userId = $userId.Value
}

<#Running Windows Vista without SP1 and earlier, i.e $Build is less than or equal to 6000#>
elseif ($Build -le 6000){
    $SysDrv = $Win32OS.SystemDrive
    $SysDrv = $SysDrv.Replace(":","$")
    $ProfDrv = "\\" + $Sender_IP + "\" + $SysDrv
    $ProfLoc = Join-Path -Path $ProfDrv -ChildPath "Documents and Settings"
    $Profiles = Get-ChildItem -Path $ProfLoc
    $LastProf = $Profiles | ForEach-Object -Process {$_.GetFiles("ntuser.dat.LOG")}
    $LastProf = $LastProf | Sort-Object -Property LastWriteTime -Descending | Select-Object -First 1
    $userId = $LastProf.DirectoryName.Replace("$ProfLoc","").Trim("\").ToUpper()
}

else{
    $userId = "Unknown/UserID"
}

if ($userId -ne $NULL){
    return "userId=" + $userId
}
elseif ($userID -eq $NULL)
{
    $userId = "Unknown/UserID"
    return "userId=" + $userId
}

Since this script will be invoked by a third party program that doesn't use elevated credentials, I had to create a second powershell script that includes the elevated privileges (which the third party program will invoke)

#elevated.ps1

[string]$abc = $args

<#Previously created password file in C:\Script\cred.txt, read-host -assecurestring | convertfrom-securestring | out-file C:\Script\cred.txt#>

$password = get-content C:\Script\cred.txt | convertto-securestring
$credentials = new-object -typename System.Management.Automation.PSCredential -argumentlist "DOMAIN\Username",$password


[string]$output = start-process powershell -Credential $credentials -ArgumentList '-noexit','-File', 'C:\script\script.ps1', $abc

return $output

And I can manually invoke elevated.ps1 with

.\elevated.ps1 "sender-ip=10.10.10.10"

Instead of having two scripts, i.e. one script with the start-process calling the other script, how to make this in one single script? I believe this would simplify the parameter passing because the third party program has to call elevate.ps1 which calls script.ps1 and some error is happening somewhere.

Answer 1

Contrary to my man Dilbert, I say this can be done. Just use the builtin "$myInvocation.MyCommand.Definition" which is the secret variable to get the full path of a running script. Write a loop statement to verify if running as Admin, then if not, start-process with the $myIvocation.MyCommand.Definition as an argument.

Plop this at the top of your script. If in UAC mode you will get a confirmation prompt. Add your elevated scripts at the end where the Write-Host starts.

$WID=[System.Security.Principal.WindowsIdentity]::GetCurrent();
$WIP=new-object System.Security.Principal.WindowsPrincipal($WID);
$adminRole=[System.Security.Principal.WindowsBuiltInRole]::Administrator;
If ($WIP.IsInRole($adminRole)){
}else {
  $newProcess = new-object System.Diagnostics.ProcessStartInfo 'PowerShell';
  $newProcess.Arguments = $myInvocation.MyCommand.Definition
  $newProcess.Verb = 'runas'
  [System.Diagnostics.Process]::Start($newProcess);Write-Host 'Prompting for Elevation'
  exit
}

Write-Host 'ElevatedCodeRunsHere';
Write-Host 'Press any key to continue...'
$null = $Host.UI.RawUI.ReadKey('NoEcho,IncludeKeyDown')

Here are some more start process examples

Answer 2

Windows does not allow a process to elevate while running. There are some tricks but in one way or another they will spawn a new process with the elevated rights. See here for more info. So the easiest way for PowerShell is still using one script to Start-Process the other script elevated.