Scratch Auth integration for Express

• Plug and play, minimal setup required
• Easy to use

Installation

npm install sa-express

Usage

const express = require('express');
const scratchauth = require('sa-express');

const app = express();

const needsAuth = scratchauth(app, {
  secret: 'SuperSecret1234',
  appName: 'My Cool Express App',
  succeeded(req, res) {
    res.redirect('/welcome');
  },
  failed(req, res) {
    res.redirect('/authfailed');
  },
});

Options

Name	Description	Default
secret	Secret that cookie-session will use. It should be stored securely in an environment variable.	No default; this option is required
appName	Name for Scratch Auth to use on the login page.	''
loginRoute	Route for redirecting the user to Scratch Auth.	'/auth/login'
verifyRoute	Route for verifying Scratch Auth's repsonse.	'/auth/verify'
logoutRoute	Route for logging the user out.	'/auth/logout'
logoutRedirect	Route to redirect to after logging out.	'/'
domain	The domain of your app. This is only needed if your app unexpectedly redirects to localhost instead of your app's domain. It should not include http[s]:// or a trailing slash.	''
succeeded	Called when the user has been logged in successfully.	(req, res) => res.redirect('/')
failed	Called when auth has failed.	(req, res) => res.send('Auth failed')
cookie	More options here.	By default lasts 7 days with sameSite: lax.

Using Auth/Protected Routes

Calling scratchauth returns a middleware for protected routes. It will redirect the user if they are not logged in. By default, the redirect route is whatever you passed for loginRoute.

app.get('/dashboard', needsAuth(), (req, res) => {
  res.send(`Welcome to your dashboard, ${res.locals.username}!`);
});

You can manually implement protected routes by using res.locals.loggedIn:

app.get('/dashboard', (req, res) => {
  if (res.locals.loggedIn) {
    res.send(`Welcome to your dashboard, ${res.locals.username}!`);
  } else {
    res.redirect('/auth/login');
  }
});

In fact, needsAuth uses res.locals.loggedIn under the hood, so both of the methods are equivalent.

Demo Application

A demo can be found in demo/.