How to license EA. Is there a EA license management software?

Hello, 

I have a EA which I want to sell to my partners. My question is how can I give away the EA with licenses, say the user has to input a unique code to use the EA otherwise its useless.

Every user/EA has a unique code so they cant give it away to others. It would also be good if the code is restricted by time (30days, 3months, 1year...)

Is there a software where I can manage EA licenses? Or does someone of you know how to do it?

Best

Denis