Powershell: Prevent Users To View and Change Input or Config Files That Are Used by a Script

Often, I use .xml or .ini files to store settings that a PowerShell script uses. When I distribute my scripts to end users, sometimes, I want to make sure users cannot manually view or change the content of these config files.

Below is what I did to achieve the goal:

  1. Create a password protected zip file that contains the config file (.xml or .ini).
  2. rename the zip file from xxxxxx.zip to xxxxxx.bin
  3. In powershell script, use ICSharpCode.SharpZipLib.dll to unzip renamed zip file
  4. compile powershell script to exe so users cannot view the script to figure out the zip file password.
  5. read the content of the extracted config file
  6. delete extracted config file

To compile the powershell script, I can use one of these tools:

Below is a sample Powershell script (Zip-Test.PS1) I have written to read a xml file inside a renamed zip file:

param ([string]$FilePath)
$ziplib = Join-Path $FilePath "ICSharpCode.SharpZipLib.dll"
[System.Reflection.Assembly]::LoadFrom("$ziplib") | Out-Null
$ZipName = "Health-Check.bin"
$XmlName = "Health-Check.xml"
$xmlPath = Join-Path $FilePath $XmlName
$ZipPath = Join-Path $FilePath $ZipName
$objZip = New-Object ICSharpCode.SharpZipLib.Zip.FastZip
$objZip.Password = "password"
$objzip.ExtractZip($ZipPath, $FilePath, $XmlName)
if ((Test-Path $xmlPath))
{
$xml = (get-content $xmlPath)
Remove-Item $xmlPath -Force
}
$xml.configuration

The script extracts and reads the health-check.xml file and deletes health-check.xml straightaway, it happens so fast, it won’t be possible for end users to access the file. Below is the output from above sample code (content of my XML file):

image

One thing to keep in mind: in most of my scripts, I use

$thisScript = Split-Path $myInvocation.MyCommand.Path -Leaf
$scriptRoot = Split-Path (Resolve-Path $myInvocation.MyCommand.Path)

To determine the script name and location. $MyInvocation does not work anymore after I converted the Powershell script to EXE. Therefore, from my above example, I’m actually passing the directory location into the script as a parameter.

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