Linux in general does not have certificates of authenticity or product keys; there may a few commercial distros that are an exception. According to your comments it sounds like you want to extract the Windows product key, and certificate of authenticity.
New Windows systems running Windows 8, or newer no longer have a COA, but the product key is embedded into the UEFI, and the Windows installation's registry. You'll just need to install a keyfinder application to extract that information. I'm not personally familiar with any that you can install on Linux, but there probably are some (if not Wine might be an option).
Computer's that come with Windows 7, or earlier pre-installed have a COA, but it's a sticker on the computer, not a digital certificate, so there is no way to get that information using a script.