title: Facebook login in Opencart
body: <p>I want to implement Facebook login in OC 1.5. More particular - I have Facebook login button on my site and i ask for extended permissions. But after i have user's email I'm not able to log it in my site, because i don't have the password (it is hashed). </p>
  
  <p>What's the secret behind this Facebook auto login for websites? How can i log user in Opencart, using only email?    </p>
  
  <p>Again, sorry if I'm missing something obvious. I'm not familiar with OC and MVC-L model but may be there is also way to log user if i pass only email to /catalog/controller/account/login.php.</p>