powershell - Convert base64 string to file

Question

I'm trying to convert base64 strings back to the original files. The application from where I try to export these files will only allow me to export in base64 strings. This export returns the base64 string and the filetype.

How can I convert these strings back to the original files? I've been trying things like this, but I don't think this will work with different types of files?

[System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($file)) |
    Out-File C:IDdocument.$($extension)

Can anyone provide me some ideas on how to do this?

Answer 1

The FromBase64String() method converts a base64-encoded string to a byte array. All you need to do is write that byte array back to a file:

$b64      = 'AAAAAA...'
$filename = 'C:pathofile'

$bytes = [Convert]::FromBase64String($b64)
[IO.File]::WriteAllBytes($filename, $bytes)