Node Authentication using passport.js - Part 1

Authentication for a web application is difficult to setup manually.To make it easier, passport came into action.

What is Passport?

passport is an authentication middleware for node application. passport provides different set of strategies using a username and password, Facebook and Twitter.

The article is separated as two parts for better understanding of the passport authentication concepts

we can use different ways to login in a web application such as Facebook,Twitter, Google and local(username and password)

In this article, we will use local strategy for the web application and folder structure will looks like:

Project Structure :

Firstly, we are going to install all the dependencies needed for an application. Therefore, we install the packages needed for an application

1"dependencies": {
2    "bcrypt-nodejs": "0.0.3",
3    "body-parser": "^1.18.3",
4    "connect-flash": "^0.1.1",
5    "cookie-parser": "^1.4.4",
6    "cors": "^2.8.5",
7    "express": "^4.16.4",
8    "express-handlebars": "^3.0.2",
9    "express-session": "^1.16.1",
10    "method-override": "^3.0.0",
11    "mongoose": "^5.5.2",
12    "morgan": "^1.9.1",
13    "passport": "^0.4.0",
14    "passport-local": "^1.0.0"
15  },

Most importantly, passport and passport-local are the packages are used for passport authentication.

on the other hand, we need to create models which is nothing but Schema for user. create a file called user.schema.js

1const mongoose = require("mongoose")
2const bcrypt = require("bcrypt-nodejs")
3const Schema = mongoose.Schema
4
5let userschema = new Schema({
6  email: String,
7  password: String,
8})
9
10userschema.methods.generateHash = function(password) {
11  return bcrypt.hashSync(password, bcrypt.genSaltSync(8), null)
12}
13
14// checking if password is valid
15userschema.methods.validPassword = function(password) {
16  return bcrypt.compareSync(password, this.password)
17}
18
19let User = mongoose.model("User", userschema)
20
21module.exports = User

we need to create a file called passport where we need to setup the passport strategy. that is to say, create a file called config/passport.js .

Firstly, we will see how to setup the signup using passport authentication.Therefore, add the following code in the config/passport.js

1const LocalStrategy = require("passport-local").Strategy
2
3let User = require("../models/user.schema")
4
5module.exports = function(passport) {
6  // used to serialize the user for the session
7  passport.serializeUser(function(user, done) {
8    done(null, user.id)
9  })
10
11  // used to deserialize the user
12  passport.deserializeUser(function(id, done) {
13    User.findById(id, function(err, user) {
14      done(err, user)
15    })
16  })
17
18  passport.use(
19    "local-signup",
20    new LocalStrategy(
21      {
22        // by default, local strategy uses username and password, we will override with email
23        usernameField: "email",
24        passwordField: "password",
25        passReqToCallback: true, // allows us to pass back the entire request to the callback
26      },
27      function(req, email, password, done) {
28        // asynchronous
29        // User.findOne wont fire unless data is sent back
30        process.nextTick(function() {
31          // find a user whose email is the same as the forms email
32          // we are checking to see if the user trying to login already exists
33          User.findOne({ email: email }, function(err, user) {
34            // if there are any errors, return the error
35            if (err) return done(err)
36
37            // check to see if theres already a user with that email
38            if (user) {
39              return done(
40                null,
41                false,
42                req.flash("signupMessage", "That email is already taken.")
43              )
44            } else {
45              // if there is no user with that email
46              // create the user
47              var newUser = new User()
48
49              // set the user's local credentials
50
51              newUser.email = email
52              newUser.password = newUser.generateHash(password)
53
54              // save the user
55              newUser.save(function(err) {
56                if (err) throw err
57                return done(null, newUser)
58              })
59            }
60          })
61        })
62      }
63    )
64  )
65}

In the above file, we setup the passport local strategy for signup and insert the user into the database.

After that, we need to create a route file where we need to handle the signup url.So,create a file called routes/index.js

1module.exports = function(app, passport) {
2  app.get("/", isLoggedIn, (req, res) => {
3    console.log("req user", req.user)
4    res.render("home", {
5      user: req.user,
6    })
7  })
8
9  app.get("/signup", (req, res) => {
10    res.render("signup")
11  })
12
13  app.post(
14    "/signup",
15    passport.authenticate("local-signup", {
16      successRedirect: "/", // redirect to the secure profile section
17      failureRedirect: "/signup", // redirect back to the signup page if there is an error
18      failureFlash: true, // allow flash messages
19    })
20  )
21
22  app.get("/logout", function(req, res) {
23    req.logout()
24    res.redirect("/")
25  })
26
27  // route middleware to make sure a user is logged in
28  function isLoggedIn(req, res, next) {
29    // if user is authenticated in the session, carry on
30    if (req.isAuthenticated()) return next()
31
32    // if they aren't redirect them to the home page
33    res.redirect("/login")
34  }
35}

So far, we added the route for signup and after successful signup, we redirect them to home page. So, we need to create view files for signup and home page.

create a folder called views and add the the following files

1- views
2       - layouts
3        ------ main.handlebars  <!-- show our home page with
4    ------ home.handlebars    <!-- show our home -->
5    ------ login.handlebars   <!-- show our login form -->

that is to say, main.hanldebars should looks like

1<!DOCTYPE html>
2<html>
3  <head>
4    <meta charset="utf-8" />
5    <title>Worker App</title>
6    <link rel="icon" href="/images/favicon.png" />
7    <link
8      rel="stylesheet"
9      href="https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.4.1/semantic.min.css"
10    />
11  </head>
12  <body>
13    {{{body}}}
14  </body>
15</html>

signup.handlebars should looks like

1{{#if message }}
2        <div class="ui negative message transition hidden">
3            <i class="close icon"></i>
4            <div class="header">
5                {{message}}
6            </div>
7        </div>
8    {{/if}}
9    <div class="ui middle aligned center aligned grid container">
10        <div class="column">
11            <h2 class="ui teal image header">
12                <img src="/images/favicon.png" alt="cloudnweb" class="image"/>
13                <div class="content">
14                    Cloudnweb.dev
15                </div>
16            </h2>
17            <form action="/signup" method="POST" class="ui large form">
18                <div class="ui stacked segment">
19
20
21                    <div class="field">
22                        <div class="ui left icon input">
23                            <i class="user icon"></i>
24                            <input type="text" name="email" placeholder="Enter Email Address"/>
25                        </div>
26                    </div>
27                    <div class="field">
28                        <div class="ui left icon input">
29                            <i class="lock icon"></i>
30                            <input type="password" name="password" placeholder="Enter Password"/>
31                        </div>
32                    </div>
33                    <input type="submit" class="ui fluid large teal submit button" value="Sign Up">                </div>
34            </form>
35
36        </div>
37    </div>

home.handlebars should look like

1<div class="ui small menu">
2  <a href="" class="active item">
3    Home
4  </a>
5  <div class="right menu">
6    <div class="item">
7      <h4>{{user.email}}</h4>
8    </div>
9    <div class="item">
10        <a href="/logout" class="ui primary button">Log Out</a>
11    </div>
12  </div>
13</div>

Finally, add the following code in the app.js

1const express = require("express")
2const exphbs = require("express-handlebars")
3const mongoose = require("mongoose")
4const app = express()
5const passport = require("passport")
6const flash = require("connect-flash")
7const morgan = require("morgan")
8const cookieParser = require("cookie-parser")
9const bodyParser = require("body-parser")
10const session = require("express-session")
11
12require("dotenv").config()
13
14app.engine("handlebars", exphbs({ defaultLayout: "main" }))
15app.set("view engine", "handlebars")
16
17app.use(morgan("dev"))
18app.use(cookieParser())
19app.use(bodyParser.urlencoded({ extended: true }))
20app.use(bodyParser.json())
21
22const MONGODB_URI = process.env.MONGODB_URL
23
24mongoose.connect(MONGODB_URI, { useNewUrlParser: true })
25
26var db = mongoose.connection
27db.on("error", console.error.bind(console, "connection error:"))
28db.once("open", function() {
29  console.log("connected")
30})
31
32app.use(session({ secret: "ilearnnodejs" }))
33app.use(passport.initialize())
34app.use(passport.session())
35app.use(flash())
36
37require("./config/passport")(passport)
38require("./routes/index")(app, passport)
39
40const PORT = process.env.PORT
41
42app.listen(PORT, () => {
43  console.log(`app is listening to port ${PORT}`)
44})