How does Stack Exchange's authorization works?

How does Stack Exchange's authorization works

• Possible Duplicate: http://meta.stackoverflow.com/questions/64260/how-does-sos-new-auto-login-feature-work After logging with an 3rd party account (facebook, google, ...), how does Stack Exchange Network save credentials? I signed up through an existing facebook account, I tried deleting cookies and cache for stackoverflow.com and refreshed the page to see if still logged in, and indeed I am still logged in. If not by cookies, how are the credentials saved (where)? What information is saved in the browser? No matter if OpenId or Oauth(1 or 2) is used, what information is saved in the database when retrieving the information through those protocols?

• Answer:

  It saves them using 2 storage methods: cookies and localStorage (html5), and this is probably what you forgot to delete. Without forgetting some kind of Switching Protocol (ws://sockets) Also, seems that it's been reinforced, by storing it's own credentials on stackauth.com and on every associated network. If not by cookies, how are the credentials saved (where)? localStorage (html5) What information is saved in the browser? some kind of cryptic identifier of you (for SSO) No matter if OpenId or Oauth(1 or 2) is used, what information is saved in the database when retrieving the information through those protocols? using oauth, anything that you previously have granted. That's the main motivation of the oauth protocol: you (as user) only have to enter your credentials only once to a protected authorization provider, and then, to have the right of grant (or not) to a third-party app a limited access of your personal information, to finally obtain an access_token; without sharing your credentials over the network again. Good luck!