sudo.ps1

# Copyright (c) Microsoft Corporation.
# Licensed under the MIT License.

# open question - Should -NoProfile be used when invoking PowerShell
BEGIN {
	if ($__SUDO_TEST -ne $true) {
		$SUDOEXE = "sudo.exe"
	}
	else {
		if ($null -eq $SUDOEXE) {
			throw "variable SUDOEXE has not been set for testing"
		}
	}

	if ([Environment]::OSVersion.Platform -ne "Win32NT") {
		throw "This script works only on Microsoft Windows"
	}

	if ($null -eq (Get-Command -Type Application -Name "$SUDOEXE" -ErrorAction Ignore)) {
		throw "'$SUDOEXE' cannot be found."
	}

	$psProcess = Get-Process -id $PID
	if (($null -eq $psProcess) -or ($psProcess.Count -ne 1)) {
		throw "Cannot retrieve process for '$PID'"
	}

	$thisPowerShell = $psProcess.MainModule.FileName
	if ($null -eq $thisPowerShell) {
		throw "Cannot determine path to '$psProcess'"
	}

	function convertToBase64EncodedString([string]$cmdLine) {
		$bytes = [System.Text.Encoding]::Unicode.GetBytes($cmdLine)
		[Convert]::ToBase64String($bytes)
	}

	$MI = $MyInvocation
}

END {
	$cmdArguments = $args

	# short-circuit if the user provided a scriptblock, then we will use it and ignore any other arguments
	if ($cmdArguments.Count -eq 1 -and $cmdArguments[0] -is [scriptblock]) {
		$scriptBlock = $cmdArguments[0]
		$encodedCommand = convertToBase64EncodedString -cmdLine ($scriptBlock.ToString())
		if (($psversiontable.psversion.major -eq 7) -and ($__SUDO_DEBUG -eq $true)) {
			Trace-Command -PSHOST -name param* -Expression { & $SUDOEXE "$thisPowerShell" -e $encodedCommand }
		}
		else {
			& $SUDOEXE "$thisPowerShell" -e $encodedCommand
		}
		return
	}

	$cmdLine = $MI.Line
	$sudoOffset = $cmdLine.IndexOf($MI.InvocationName)
	$cmdLineWithoutScript = $cmdLine.SubString($sudoOffset + 5)
	$cmdLineAst = [System.Management.Automation.Language.Parser]::ParseInput($cmdLineWithoutScript, [ref]$null, [ref]$null)
	$commandAst = $cmdLineAst.Find({$args[0] -is [System.Management.Automation.Language.CommandAst]}, $false)
	$commandName = $commandAst.GetCommandName()
	$isApplication = Get-Command -Type Application -Name $commandName -ErrorAction Ignore | Select-Object -First 1
	$isCmdletOrScript = Get-Command -Type Cmdlet,ExternalScript -Name $commandName -ErrorAction Ignore | Select-Object -First 1

	# if the command is a native command, just invoke it
	if ($null -ne $isApplication) {
		if (($psversiontable.psversion.major -eq 7) -and ($__SUDO_DEBUG -eq $true)) {
			trace-command -PSHOST -name param* -Expression { & $SUDOEXE $cmdArguments }
		}
		else {
			& $SUDOEXE $cmdArguments
		}
	}
	elseif ($null -ne $isCmdletOrScript) {
		$encodedCommand = convertToBase64EncodedString($cmdLineWithoutScript)
		if (($psversiontable.psversion.major -eq 7) -and ($__SUDO_DEBUG -eq $true)) {
			trace-command -PSHOST -name param* -Expression { & $SUDOEXE -nologo -e $encodedCommand }
		}
		else {
			& $SUDOEXE $thisPowerShell -nologo -e $encodedCommand
		}
	}
	else {
		throw "Cannot find '$commandName'"
	}
}