Passport strategy for authenticating based on a remember me cookie.

This module lets you authenticate using a remember me cookie (aka persistent login) in your Node.js applications. By plugging into Passport, remember me authentication can be easily and unobtrusively integrated into any application or framework that supports Connect-style middleware, including Express.

$ npm install passport-remember-me

The remember me authentication strategy authenticates users using a token stored in a remember me cookie. The strategy requires a verify callback, which consumes the token and calls done providing a user.

The strategy also requires an issue callback, which issues a new token. For security reasons, remember me tokens should be invalidated after being used. The issue callback supplies a new token that will be stored in the cookie for next use.

passport.use(new RememberMeStrategy(
  function(token, done) {
    Token.consume(token, function (err, user) {
      if (err) { return done(err); }
      if (!user) { return done(null, false); }
      return done(null, user);
    });
  },
  function(user, done) {
    var token = utils.generateToken(64);
    Token.save(token, { userId: user.id }, function(err) {
      if (err) { return done(err); }
      return done(null, token);
    });
  }
));

Use passport.authenticate(), specifying the 'remember-me' strategy, to authenticate requests.

This is typically used in an application's middleware stack, to log the user back in the next time they visit any page on your site. For example:

app.configure(function() {
  app.use(express.cookieParser());
  app.use(express.bodyParser());
  app.use(express.session({ secret: 'keyboard cat' }));
  app.use(passport.initialize());
  app.use(passport.session());
  app.use(passport.authenticate('remember-me'));
  app.use(app.router);
});

Note that passport.session() should be mounted above remember-me authentication, so that tokens aren't exchanged for currently active login sessions.

If the user enables "remember me" mode, an initial cookie should be set when they login.

app.post('/login', 
  passport.authenticate('local', { failureRedirect: '/login', failureFlash: true }),
  function(req, res, next) {
    // issue a remember me cookie if the option was checked
    if (!req.body.remember_me) { return next(); }

    var token = utils.generateToken(64);
    Token.save(token, { userId: req.user.id }, function(err) {
      if (err) { return done(err); }
      res.cookie('remember_me', token, { path: '/', httpOnly: true, maxAge: 604800000 }); // 7 days
      return next();
    });
  },
  function(req, res) {
    res.redirect('/');
  });

If not managed correctly, using a "remember me" cookie for automatic authentication increases a service's exposure to potential security threats. There are a number of techniques to reduce and mitigate these threats, and it is a matter of application-level policy to asses the level of risk and implement appropriate counter measures.

The following list is recommended reading for understanding these risks:

• The definitive guide to forms based website authentication
• Persistent Login Cookie Best Practice
• Improved Persistent Login Cookie Best Practice (archive)

For a complete, working example, refer to the login example.

$ npm install
$ make test

• Jared Hanson

The MIT License

Copyright (c) 2013 Jared Hanson <http://jaredhanson.net/>