auth.js

exports.AuthHelper = {
  /**
   * Authenticates a request using the login token
   * 
   * @param express request
   * @param express response
   * @param express next function
   */
  authFromLoginToken: function(req, res, next) {
    var cookie = JSON.parse(req.cookies.logintoken);
    LoginToken.findOne({ email: cookie.email, token: cookie.token, series: cookie.series }, function(err, token) {
      if (!token) {
        res.redirect('/');
        return;
      }
  
      User.findOne({ email: token.email }, function(err, user) {
        if (user) {
          req.session.user_id = user.id;
          req.currentUser = user;
          
          token.token = token.randomToken();
          token.save(function(){
            res.cookie('logintoken', token.cookieValue, { expires: new Date(Date.now() + 2 * 604800000), path: '/' });
            next();
          });
        } else {
          res.redirect('/login');
        }
      });
    });
  },
  
  /**
   * Loads the used for a request
   * 
   * @param express request
   * @param express response
   * @param express next function
   */
  loadUser: function(req, res, next) {
    if (app.set('disableAuthentication') === true)
      next();
    else {
      if (req.session.user_id) {
        User.findById(req.session.user_id, function(err, user) {
          if (user) {
            req.currentUser = user;
            next();
          } else {
            res.redirect('/');
          }
        });
      } else if (req.cookies.logintoken) {
        authFromLoginToken(req, res, next);
      } else {
        res.redirect('/');
      }
    }
  }
};