Digitally Sign PowerShell Scripts with a PFX Certificate

Nowadays you need to sign even PowerShell scripts.
I you have a bunch of them you may need a PowerShell script to sign all your PowerShell's. :-)

# Define the path to the self-signed certificate
$certificatePath = "C:\temp\Code Signing Cert.pfx"

# Define the folder path containing the PowerShell scripts
$scriptFolder = "C:\PS1"

# Prompt for the certificate password
$certificatePassword = Read-Host -Prompt "Enter the password for the certificate" -AsSecureString

# Get the certificate object
$certificate = New-Object System.Security.Cryptography.X509Certificates.X509Certificate2($certificatePath, $certificatePassword)

# Get all .ps1 files in the script folder
$scriptFiles = Get-ChildItem -Path $scriptFolder -Filter "*.ps1" -File

# Loop through each script file and sign it
foreach ($scriptFile in $scriptFiles) {
    # Check if the file already contains "signed" in its name
    if ($scriptFile.Name -notlike "*signed*") {
        # Generate the new filename with "signed" appended
        $newFileName = $scriptFile.Name.Replace(".ps1", "_signed.ps1")
        $newFilePath = Join-Path -Path $scriptFile.Directory.FullName -ChildPath $newFileName

        try {

            # Create a signed copy of the file with the "signed" filename
            Copy-Item -Path $scriptFile.FullName -Destination $newFilePath

            # Sign the script file
            Set-AuthenticodeSignature -FilePath $newFilePath -Certificate $certificate -TimestampServer "http://timestamp.digicert.com" -ErrorAction Stop

            Write-Host "Signed file created & signed: $newFileName"
        }
        catch {
            Write-Host "Failed to sign file: $newFileName"
            Write-Host "Error: $($_.Exception.Message)"
        }
    }
    else {
        Write-Host "File $($scriptFile.Name) already contains 'signed' in its name. Skipping..."
    }
}