Authentication

For the Authentication we have an api available at: /api/authentication, this authentication api comes from Auth0 and is integrated into NextJS.

Overview

This guide outlines the necessary steps to integrate Auth0 for user authentication within a Next.js application. It focuses on authenticating users and then deferring authorization logic to a custom backend API. This documentation is far from complete, but gives an overal example on how such implementation could be done.

Prerequisites

1. An existing Auth0 account and application.

2. A Next.js project ready for integration.

3. The @auth0/nextjs-auth0 package installed.

4. Environment variables for Auth0: AUTH0_SECRET, AUTH0_BASE_URL, AUTH0_ISSUER_BASE_URL, AUTH0_CLIENT_ID, AUTH0_CLIENT_SECRET.

Step 1: Environment Configuration

Set up the following environment variables in your .env.local file:

plaintextCopy codeAUTH0_SECRET=YOUR_AUTH0_SECRET
AUTH0_BASE_URL=http://localhost:3000
AUTH0_ISSUER_BASE_URL=https://YOUR_DOMAIN.auth0.com
AUTH0_CLIENT_ID=YOUR_AUTH0_CLIENT_ID
AUTH0_CLIENT_SECRET=YOUR_AUTH0_CLIENT_SECRET

Replace the placeholders with your Auth0 application's specific details.

Step 2: Auth0 SDK Setup

Initialize the Auth0 SDK in a utils/auth0.js file:

import { initAuth0 } from '@auth0/nextjs-auth0';

export const auth0 = initAuth0({
  secret: process.env.AUTH0_SECRET,
  baseURL: process.env.AUTH0_BASE_URL,
  issuerBaseURL: process.env.AUTH0_ISSUER_BASE_URL,
  clientID: process.env.AUTH0_CLIENT_ID,
  clientSecret: process.env.AUTH0_CLIENT_SECRET,
  routes: {
    callback: '/api/authentication',
    postLogoutRedirect: '/'
  }
});

Step 3: Authentication API Route

Create the /api/authentication endpoint in pages/api/authentication.js:

import { auth0 } from '../../utils/auth0';

export default async function callback(req, res) {
  try {
    await auth0.handleCallback(req, res, {
      // Here you can perform actions after successful authentication
      // such as setting a cookie, session management, etc.
      // but we're not redirecting to the custom authorization logic
      onUserLoaded: async (req, res, session, state) => {
        // You might want to replace this with your custom logic
        console.log('Authentication successful. User:', session.user);
        // Redirect to the user's homepage or dashboard after login
        return res.redirect('/user/home');
      }
    });
  } catch (error) {
    console.error(error);
    res.status(error.status || 500).end(error.message);
  }
}

Step 4: Login and Logout Endpoints

Implement login and logout functionalities in their respective API routes (/api/login and /api/logout):

Login (pages/api/login.js):

import { auth0 } from '../../utils/auth0';

export default async function login(req, res) {
  try {
    await auth0.handleLogin(req, res);
  } catch (error) {
    console.error(error);
    res.status(error.status || 500).end(error.message);
  }
}

Logout (pages/api/logout.js):

import { auth0 } from '../../utils/auth0';

export default async function logout(req, res) {
  await auth0.handleLogout(req, res);
}

Step 5: Testing the Authentication Flow

Run your Next.js application:

bashCopy codenpm run dev
# or
yarn dev

Test the authentication flow by navigating to /api/login and /api/logout. Be reminded that for every user action, a user needs it's capabilities checked on: /api/authorization/check.

Conclusion

By following these steps, you have successfully added Auth0 authentication to your Next.js application. Your application will authenticate users and delegate the authorization process to your custom API, allowing you to control access based on account types, user roles, and other capabilities as needed.

Ensure to thoroughly test your custom authorization logic and handle any edge cases specific to your application's requirements.

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This implementation provides the flexibility needed to accommodate your custom authorization strategy while leveraging Auth0 for robust authentication. Remember to secure your authorization endpoint and use HTTPS in production to protect sensitive data.