From 7c1d0b17773dc9478365bc18566bdbda1b816013 Mon Sep 17 00:00:00 2001
From: "tyler.montney" <tyler.montney@wast3dgeneration.com>
Date: Sun, 24 Dec 2023 21:57:25 -0600
Subject: [PATCH] Simplified process by passing script as encoded string,
 including arguments

---
 PS in Batch.ps1      | 117 +++++++++++++------------------------------
 Sample PS Script.ps1 |  19 +++----
 2 files changed, 43 insertions(+), 93 deletions(-)

diff --git a/PS in Batch.ps1 b/PS in Batch.ps1
index 13392db..fc31a88 100644
--- a/PS in Batch.ps1	
+++ b/PS in Batch.ps1	
@@ -1,92 +1,44 @@
-function ConvertTo-BatchWrapped([String]$PSScriptPath, [Hashtable]$Arguments) {
-    $PSScriptContents = Get-Content -Path $PSScriptPath -Raw -ErrorAction Stop
-    $BatchBase64 = ConvertTo-MultilineBatchBase64 -VarName "TargetScript" -VarText $PSScriptContents
-
-    $TempBase64OutputLine = @()
-    for ($i = 1; $i -le $BatchBase64.VarCount; $i++) {
-        $TempBase64OutputLine += "echo !TargetScript$i! > %TempBase64Output%"
+function ConvertTo-PSBatchScript {
+    [CmdletBinding()]
+    param (
+        [Parameter(Mandatory = $true)]
+        [String]
+        $PSScriptContents,
+        [Parameter(Mandatory = $false)]
+        [String[]]
+        $Arguments = @(),
+        # Consider using delayed expansion on variables
+        # If you explicitly specify $env:TEMP and run this as another user, it will map to the wrong user's temp folder
+        [Parameter(Mandatory = $false)]
+        [String]
+        $CurrentWorkingDirectory = "%TEMP%"
+    )
+    
+    try 
+    { [void]([ScriptBlock]::Create($PSScriptContents)) }
+    catch 
+    { Write-Warning -Message "There was a problem parsing 'PSScriptContents' as a PowerShell script."; Write-Error $_; return }
+
+    if ($Arguments.Count -gt 0) {
+        $ArgumentsAL = [System.Collections.ArrayList]::new()
+        $ArgumentsAL.AddRange($Arguments)
+
+        $cliXml = [System.Management.Automation.PSSerializer]::Serialize($ArgumentsAL)
+        $ArgsBase64 = "-EncodedArguments " + ([Convert]::ToBase64String([System.Text.Encoding]::Unicode.GetBytes($cliXml)))
     }
 
-    $InvokePSLine = "%WINDIR%\System32\WindowsPowerShell\v1.0\powershell.exe -ExecutionPolicy Bypass -File ""%TempTargetScript%"""
-    if ($Arguments) {
-        $Arguments.Keys | ForEach-Object {
-            if ($Arguments[$_] -is [String]) {
-                $InvokePSLine += " -$_ ""$($Arguments[$_])"""
-            }
-            else {
-                $InvokePSLine += " -$_ $($Arguments[$_])"
-            }
-        }
-    }
+    $BatchBase64 = [Convert]::ToBase64String([System.Text.Encoding]::Unicode.GetBytes($PSScriptContents))
+    $InvokePSLine = "%WINDIR%\System32\WindowsPowerShell\v1.0\powershell.exe -ExecutionPolicy Bypass -EncodedCommand $BatchBase64 $ArgsBase64"
 
-    $BatchContents = @"
+    return @"
 @echo off
-setlocal EnableDelayedExpansion
-set LF=^
-
-
-REM !!! Do not remove the two lines above this; required to make a newline variable !!!
-
-REM To generate the following, use certutil -decode or ConvertTo-MultilineBatchBase64 in PowerShell.Common.psm1
-REM At this time, it isn't possible to decode with certutil using Base64 encoded by [System.Convert]::ToBase64String
-REM certutil appears to keep lines to ~64 characters; recommended maximium line length is 127
 
-REM Set the Base64 of the target script
-$($BatchBase64.Var)
+REM Set current working directory to a temporary folder
+cd $CurrentWorkingDirectory
 
-REM Set the temporary file paths
-set "TempBase64Output=%temp%\TargetScript.%random%.txt"
-set "TempTargetScript=%temp%\TargetScript.%random%.ps1"
-
-REM Decode the TargetScript variable
-$($TempBase64OutputLine -join "`n")
-certutil -decode %TempBase64Output% %TempTargetScript% > NUL
-
-REM Execute TargetScript
+REM Execute PowerShell script
 $InvokePSLine
-
-REM Clean up temporary files
-del %TempBase64Output%
-del %TempTargetScript%
 "@
-
-    Set-Content -Path "$Script:ScriptCWD\$(([System.IO.Path]::GetFileNameWithoutExtension($PSScriptPath))).bat" -Value $BatchContents -Force
-}
-
-function ConvertTo-MultilineBatchBase64([String]$VarName, [String]$VarText) {
-    #$VarBase64 = [System.Convert]::ToBase64String([System.Text.Encoding]::Unicode.GetBytes($Text))
-
-    $VarTextTempFile = New-TemporaryFile
-    $VarBase64TempFile = New-TemporaryFile
-    Set-Content -Path $VarTextTempFile -Value $VarText
-    [void](certutil.exe -f -encode $VarTextTempFile $VarBase64TempFile)
-
-    $Var = @()
-    $VarCount = 1
-    $VarBase64 = Get-Content -Path $VarBase64TempFile | Select-Object -Skip 1 | Select-Object -SkipLast 1
-
-    Remove-Item -Path $VarTextTempFile -Force -ErrorAction SilentlyContinue
-    Remove-Item -Path $VarBase64TempFile -Force -ErrorAction SilentlyContinue
-
-    if ($VarBase64) {
-        $Var = @("set $VarName$VarCount=$($VarBase64[0])!LF!")
-        if ($VarBase64.Length -gt 1) {
-            for ($i = 1; $i -lt $VarBase64.Length; $i++) {
-                if ($i % 100 -eq 0) {
-                    $VarCount += 1
-                    $Var += "set $VarName$VarCount=$($VarBase64[$i])!LF!"
-                }
-                else {
-                    $Var += "set $VarName$VarCount=!$VarName$VarCount!$($VarBase64[$i])!LF!"
-                }
-            }
-        }
-    }
-
-    return [PSCustomObject]@{
-        VarCount = $VarCount
-        Var      = ($Var -join "`n")
-    }
 }
 
 ####################
@@ -101,4 +53,5 @@ else {
     throw "Cannot determine script's working directory"
 }
 
-ConvertTo-BatchWrapped -PSScriptPath "$Script:ScriptCWD\Sample PS Script.ps1" -Arguments @{"Message" = "Hello world!" }
\ No newline at end of file
+$PSScriptContents = Get-Content -Path "$Script:ScriptCWD\Sample PS Script.ps1" -Raw
+ConvertTo-PSBatchScript -PSScriptContents $PSScriptContents -Arguments @("Hello world!") | Set-Content -LiteralPath "$Script:ScriptCWD\Sample PS Script.bat" -Force
\ No newline at end of file
diff --git a/Sample PS Script.ps1 b/Sample PS Script.ps1
index d0107cf..262108d 100644
--- a/Sample PS Script.ps1	
+++ b/Sample PS Script.ps1	
@@ -1,19 +1,16 @@
 [CmdletBinding()]
 param (
-    [Parameter(Mandatory = $true)]
+    [Parameter(Mandatory = $false)]
     [String]
-    $Message
+    $Message = "Hello"
 )
 
-if ($MyInvocation.MyCommand.Path) {
-    $ScriptCWD = (Get-Item -Path $MyInvocation.MyCommand.Path).Directory.FullName
-}
-elseif ($PSScriptRoot) {
-    $ScriptCWD = $PSScriptRoot
-}
-else {
-    throw "Cannot determine script's working directory"
-}
+# For whatever reason it wasn't changed in the batch script
+# We don't want to dirty up System32
+if ((Get-Location).Path -eq "$env:WINDIR\System32")
+{ Set-Location -Path $env:TEMP }
+
+$ScriptCWD = (Get-Location).Path
 
 Write-Output -InputObject "Script current working directory: $ScriptCWD"