Chrome Extension Programmer Needed - Add Licensing Functionality

I developed a Google Chrome Extension and require the ability to manage license both remotely and on a local network. Meaning I need two licensing structures: 1) For Online Computers 2) For Offline Computers The online computers would need to check a master "file" on my own server to see if the license is valid. Offline computers need a key generated by ME to activate the software that can only be used on one machine (prevent piracy). My Extension is already developed and you will need to be able to add this functionality to it. Thank you