README

This system is built to handle either authentication or authorization, or both. A common usage for this system is for storing temporary tokens for changing passwords: a user requests that their password get changed, so they are sent an email with a link containing some weird complicated hash. This is the system that handles the logic of creating the tokens and storing them in the database, along with handling automatic expiration.

What Are Tokens For?

Imagine you've got a web application, and there's authentication involved. You're going to create a "simple" system wherein a user can click something and generate a "lost password" request. Since you want to be user-friend and security-conscious, your system generates an email with a link for them to follow. With CS Auth Token, you can create one that:

• only works for the specified user's account
• expires after a single (successful) use
• expires after a given period of time
• is cryptographically secure

How Do I Use It?

I could explain it, but really, it's easier just to show you:

$x = new cs_authToken($db, $uidOfUser);
$hash = $x->create_token($email);

The email might look something like:

Hello {friendlyName},

To reset your password, please click this link:

http://www.cs.local/lost?hash={hash}?key={email}

The code to handle verification looks like:

$x = new cs_authToken($db);

$authData = $x->authenticate_token($hash, $key);

if($authData['result'] == true) {
	//authenticated! use 'stored_value' to help in resetting their password
	$myData = $authData['stored_value'];
}

Expiration Possibilities

Currently, there are a number of ways that a token can be expired:

• a given number of maximum uses (e.g. 1 use)
• an specific date of expiration (e.g. 15 minutes from when it was created)
• a limited number of uses + a specific expiration date (e.g. 1 use in the next 15 minutes)
• no specific expiration (the token will never be automatically removed)

Some things these tokens could be used for (they're just ideas):

• token API calls
  • 1000 uses until token expires
  • 30 days until token expires
  • limit of 1000 uses during the next 30 days
• sessions:
  • 1000 page views before need to login again
  • must expire before a certain date
  • 1000 page views OR until a certain date (whichever comes first)
• licensing (requires something to keep token from being destroyed, depending upon implementation)
  • 5 allowed licenses for 1 year
  • unlimited users for 1 year
  • 5 users, no expiration
  • unlimited users for 1 year