Compile Powershell script into interpreted code - powershell

Question

Please pardon me if I have misstated the title, but here is what I am looking for:
Let's say I have this script:
$secureCiphers = #(
'AES 128/128',
'AES 256/256'
)
foreach ($secureCipher in $secureCiphers) {
$key = (Get-Item HKLM:\).OpenSubKey('SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers', $true).CreateSubKey($secureCipher)
New-ItemProperty -path "HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\$secureCipher" -name 'Enabled' -value '0xffffffff' -PropertyType 'DWord' -Force | Out-Null
$key.close()
Write-Host "Strong cipher $secureCipher has been enabled."
}
Is there something out there will unroll the loop, make assignments for each iteration and say the above code is equivalent to:
$key = (Get-Item HKLM:\).OpenSubKey('SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers', $true).CreateSubKey('AES 128/128')
New-ItemProperty -path "HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\AES 128/128" -name 'Enabled' -value '0xffffffff' -PropertyType 'DWord' -Force | Out-Null
$key.close()
Write-Host "Strong cipher AES 128/128 has been enabled."
$key = (Get-Item HKLM:\).OpenSubKey('SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers', $true).CreateSubKey('AES 256/256')
New-ItemProperty -path "HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\AES 256/256" -name 'Enabled' -value '0xffffffff' -PropertyType 'DWord' -Force | Out-Null
$key.close()
Write-Host "Strong cipher AES 256/256 has been enabled."
I can then write an automated test to say the script was supposed to set these registry keys and the system has the expected values for those registry keys. Does this request make sense? The scripts are more complicated and have functions and a lot of if-else statements.

Answer 1

I think instead what might serve you better is to abstract the logic of what you're trying to do into functions (preferably in a module), which take parameters for the things that change. So in this case, you'd have a function that takes a particular "secure cipher" and does what it needs to do.
Once you've got the logic in a function, you can write tests around the function, that ensure it works as expected, that it fails as expected when passed invalid entries, etc.
PowerShell has a testing framework called Pester that is helpful for writing tests.
Now you've got re-usable function, with tests to prove it works.
Your script should then become:
$secureCiphers = #(
'AES 128/128',
'AES 256/256'
)
foreach ($secureCipher in $secureCiphers) {
Set-MySecureCipher -Cipher $secureCipher
}
Or, if you wrote your function to be able to accept pipeline input, it may be:
$secureCiphers | Set-MySecureCipher
I've left out the meaty details of a lot of this in favor of explaining at a high-level, but you can continue to research each of those areas:
Writing functions
Writing PowerShell modules
Writing Pester tests
Writing advanced functions (accepting pipeline input, supporting ShouldProcess for -WhatIf support)