Full-Stack Web Development with Vue.js and Node

Building Authentication with passport.js Chapter 6

Introduction to passport.js

passport.js is a middleware provided by Node.js for authentication. The functionality of

passport.js is to authenticate the requests that are made to the server. It provides several

strategies for authentication. passport.js provides strategies to such as local strategy,

Facebook strategy, Google strategy, Twitter strategy, and JWT strategy. In this chapter, we
will focus on using the JWT strategy.

JWT

JWT is a way of authenticating the requests using a token-based approach. There are two

methods of authenticating requests: cookie-based authentication, and token-based
authentication. The cookie-based authentication mechanism saves the user's session ID in

the browser's cookie, whereas the token-based mechanism uses a signed token that will
look like this:

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6IjVhNjhhNDMzMDJkMWNlZDU5YjExND

g3MCIsImlhdCI6MTUxNzI0MjM1M30.5xY59iTIjpt9ukDmxseNAGbOdz6weWL1drJkeQzoO3M

This token is then validated on every request that we make to the controllers.

For our application, we will use a combination of both. When a user requests to log in to the

app, we will create a signed token for them and then add that token to the browser's cookie.
The next time when the user logs in, we will read that token from the cookie and validate

that token using the passport-jwt module in the server, and then decide whether or not

to log that user in.

If you look at the preceding token carefully, you will see that the token has three parts
separated by a period (.); each part has its own meaning:

The first part represents the header

The second part represents the payload

The third part represents the signature

To be able to use this JWT, we will need to add a package. To do that, we can just run the

following command:

$ npm install jsonwebtoken --save