Integrating facebook sign in with php website

I am currently developing a PHP website for a start up company. They want a feature added so that a business can sign up using their Business Facebook account and pull all the information like business category, business name and opening times etc and have it sorted on their account for this website.
Firstly is it possible to pull info from Facebook and store it ?
And If so, Is this legal ?
any help would be appreciated as I'm having difficulty finding an answer