Authenticate Users with Passport js: A Beginner’s Guide

Passport.js is a popular authentication middleware for Node.js that helps developers authenticate users in their web applications. It is a modular system that supports a wide range of authentication strategies, including OAuth, OpenID, and local authentication.

Introduction

Passport.js is an authentication middleware for Node.js that makes it easy to authenticate users in web applications. It is a flexible, modular system that supports a wide range of authentication strategies, including OAuth, OpenID, and local authentication.

Setting up Passport.js

To get started with Passport.js, you’ll first need to install it in your project. Use the following command to install Passport.js via npm

npm install passport

Once you’ve installed Passport.js, you’ll need to require it in your application and configure it. Here’s an example of how to do this

const passport = require('passport');
app.use(passport.initialize());
app.use(passport.session());

Adding an Authentication Strategy

Passport.js comes with a wide range of authentication strategies, including OAuth, OpenID, and local authentication. To use a specific strategy, we’ll need to install the corresponding package and configure it.For example, here is how to use the Local Strategy

const LocalStrategy = require('passport-local').Strategy;
passport.use(new LocalStrategy(
function(username, password, done)
 {    
User.findOne({ username: username } function (err, user) {   
   if (err) { return done(err); } 
     if (!user) { return done(null, false); }   
   if (!user.verifyPassword(password)) { return done(null, false); }   
   return done(null, user);  
  }); 
 }));

Protecting Routes

Once you’ve set up Passport.js and added an authentication strategy, you can use it to protect your routes. To do this, you’ll need to use the passport.authenticate() function.

app.post('/login',   passport.authenticate('local', {failureRedirect: '/login' }),  function(req, res) {   
 res.redirect('/');  });

Conclusion

Passport.js is a popular and flexible authentication middleware for Node.js that makes it easy to authenticate users in web applications. It supports a wide range of authentication strategies, including OAuth, OpenID, and local authentication, and it’s easy to set up and use. you can easily protect your routes and ensure that only authenticated users can access them.

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