How I can be sure that your version is not pirated? I've seen plenty of this licenses, keys and activators on torrent sites.
They are usually working fine and without problems but they are illegal. Is there a proof that your version is legit?
Sorry, I don't know how to proof it. Also I don't think that you can share licenses therefore it's unlikely that you'll find a working key for free.
But yes you could probably use an activator or cracker to use the software for free. (illegal)