Passport authentication using basic credentials.

passport_session.js

passport.use(new LocalStrategy( // a new Local instance
  function(username, password, done) { // passing in a function
    User.findOne({ username: username }, function (err, user) { // Mongo interface
      if (err) { return done(err); } // generic error
      if (!user) { return done(null, false); } // user not found
      if (!user.verifyPassword(password)) { return done(null, false); } // wrong password
      return done(null, user); // authenticated, returns 'user'
    });
  }
));