JWT Token Based Authentication API in NodeJs

Welcome, programming, buddies! Today, In this tutorial, we are going to learn how to build a secure token-based user authentication REST APIs using JWT (JSON web token), bcrypt, Node, Express, and MongoDB.

Creating authentication REST API with Node Js is merely effortless. We will be taking the help of Express js to create the authentication endpoints and also make the MongoDB connection to store the user’s data in it.

Click on the below button to get the complete code of this project on GitHub.

What are JSON Web Tokens (JWT)?

JSON Web Token (JWT) is a JSON object that is described in RFC 7519 as a safe approach to transfer a set of information between two parties. The claims in a JWT are encoded as a JSON object that is used as the payload of a JSON Web Signature (JWS) structure or as the plaintext of a JSON Web Encryption (JWE) structure, enabling the claims to be digitally signed or integrity protected with a Message Authentication Code (MAC) and/or encrypted.
– Internet Engineering Task Force (IETF)

Authentication Workflow with JSON Web Tokens

Let’s understand from the below diagram how does the secure authentication system work with JSON web token.

• A client makes the API call and sends the user information such as username and password to the webserver.
• On successful authentication a webserver generates a string-based token and returns to the client system.
• A client can store this token in the browser’s local storage or in a session.
• Client sets this token in a header something like “Bearer xxx.xxx.xxx”.
• On next API call JWT token communicateS with the server, and after the successful verification, the server returns the response to the client.

Initiate Node Token-Based Authentication Project

Create a project folder to build secure user authentication REST API, run the following command.

mkdir server

Get inside the project folder.

cd server

Let’s start the project by first creating the package.json file by running the following command.

npm init

Install NPM Packages to Create Secure Auth API

Next, install the NPM dependencies for the authentication API by running the given below command.

npm install express jsonwebtoken bcryptjs body-parser 
cors mongoose-unique-validator mongoose --save

Next, install the nodemon NPM module, it helps in starting the node server when any change occurs in the server files.

npm install nodemon --save-dev

--save-dev saves the package for development purpose.

Define Mongoose Schema

Next, we are going to define user schema using mongoose ODM. It allows us to retrieve the data from the database.

Create a folder and name it models inside the project directory, create a file User.js in it.

To prevent storing the duplicate email id in MongoDB database install mongoose-unique-validator package. Below we will learn how to use in mongoose schema to validate duplicate email id from MongoDB database.

npm i mongoose-unique-validator --save

Next, add the following code in models/User.js file:

// models/User.js

const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const uniqueValidator = require('mongoose-unique-validator');

let userSchema = new Schema({
    name: {
        type: String
    },
    email: {
        type: String,
        unique: true
    },
    password: {
        type: String
    }
}, {
    collection: 'users'
})

userSchema.plugin(uniqueValidator, { message: 'Email already in use.' });
module.exports = mongoose.model('User', userSchema)

• The userSchema.plugin(uniqueValidator) method won’t let duplicate email id to be stored in the database.
• The unique: true property in email schema does the internal optimization to enhance the performance.

Implement MongoDB Database in Node App

Create database folder in the project folder and create a new file database/db.js in it.

module.exports = {
    db: 'mongodb://localhost:27017/meanauthdb'
}

Create Secure Token-based Authentication REST API in Node

To build secure user authentication endpoints in node, create routes folder, and auth.routes.js file in it.

Here, we will define CRUD Restful APIs using the npm packages for log-in, sign-up, update-user, and delete-user.

// routes/auth.routes.js

const express = require("express");
const jwt = require("jsonwebtoken");
const bcrypt = require("bcrypt");
const router = express.Router();
const userSchema = require("../models/User");


// Sign-up
router.post("/register-user", (req, res, next) => {
    bcrypt.hash(req.body.password, 10).then((hash) => {
        const user = new userSchema({
            name: req.body.name,
            email: req.body.email,
            password: hash
        });
        user.save().then((response) => {
            res.status(201).json({
                message: "User successfully created!",
                result: response
            });
        }).catch(error => {
            res.status(500).json({
                error: error
            });
        });
    });
});


// Sign-in
router.post("/signin", (req, res, next) => {
    let getUser;
    userSchema.findOne({
        email: req.body.email
    }).then(user => {
        if (!user) {
            return res.status(401).json({
                message: "Authentication failed"
            });
        }
        getUser = user;
        return bcrypt.compare(req.body.password, user.password);
    }).then(response => {
        if (!response) {
            return res.status(401).json({
                message: "Authentication failed"
            });
        }
        let jwtToken = jwt.sign({
            email: getUser.email,
            userId: getUser._id
        }, "longer-secret-is-better", {
            expiresIn: "1h"
        });
        res.status(200).json({
            token: jwtToken,
            expiresIn: 3600,
            msg: getUser
        });
    }).catch(err => {
        return res.status(401).json({
            message: "Authentication failed"
        });
    });
});

// Get Users
router.route('/').get((req, res) => {
    userSchema.find((error, response) => {
        if (error) {
            return next(error)
        } else {
            res.status(200).json(response)
        }
    })
})

// Get Single User
router.route('/user-profile/:id').get((req, res, next) => {
    userSchema.findById(req.params.id, (error, data) => {
        if (error) {
            return next(error);
        } else {
            res.status(200).json({
                msg: data
            })
        }
    })
})

// Update User
router.route('/update-user/:id').put((req, res, next) => {
    userSchema.findByIdAndUpdate(req.params.id, {
        $set: req.body
    }, (error, data) => {
        if (error) {
            return next(error);
            console.log(error)
        } else {
            res.json(data)
            console.log('User successfully updated!')
        }
    })
})


// Delete User
router.route('/delete-user/:id').delete((req, res, next) => {
    userSchema.findByIdAndRemove(req.params.id, (error, data) => {
        if (error) {
            return next(error);
        } else {
            res.status(200).json({
                msg: data
            })
        }
    })
})

module.exports = router;

• To secure the password, we are using the bcryptjs, It stores the hashed password in the database.
• In the signin API, we are checking whether the assigned and retrieved passwords are the same or not using the bcrypt.compare() method.
• In the signin API, we set the JWT token expiration time. Token will be expired within the defined duration.

Verify Node Authentication REST API

Next, we will verify the auth API using the JWT token. Create a middlewares folder and create a auth.js file inside of it, then include the following code in it.

// middlewares/auth.js

const jwt = require("jsonwebtoken");

module.exports = (req, res, next) => {
    try {
        const token = req.headers.authorization.split(" ")[1];
        jwt.verify(token, "longer-secret-is-better");
        next();
    } catch (error) {
        res.status(401).json({ message: "Authentication failed!" });
    }
};

Now, we will learn to implement JWT verification in the /user-profile endpoint. Import the following auth.js file from middlewares folder.

// Get User Profile
router.route('/user-profile/:id').get(authorize, (req, res, next) => {
    userSchema.findById(req.params.id, (error, data) => {
        if (error) {
            return next(error);
        } else {
            res.status(200).json({
                msg: data
            })
        }
    })
})

We added the authorize variable inside the user-profile API. It won’t render the data unless it has the valid JWT token. As you can see in the below screenshot, we have not defined the JWT token in get request, so we are getting the “No token provided” error.

Adding Input Validation in Express RESTful API

Next, we will learn to implement validation in Express auth API using POST body request. Install express-validator npm library to validate name, email and password.

The express-validator is an express.js middleware for validating POST body requests.

Run the below command to install the express-validator package.

npm install express-validator --save

Add the following code in the middlewares/auth.routes.js file.

// routes/auth.routes.js

const express = require("express");
const jwt = require("jsonwebtoken");
const bcrypt = require("bcrypt");
const router = express.Router();
const userSchema = require("../models/User");
const authorize = require("../middlewares/auth");
const { check, validationResult } = require('express-validator');

// Sign-up
router.post("/register-user",
    [
        check('name')
            .not()
            .isEmpty()
            .isLength({ min: 3 })
            .withMessage('Name must be atleast 3 characters long'),
        check('email', 'Email is required')
            .not()
            .isEmpty(),
        check('password', 'Password should be between 5 to 8 characters long')
            .not()
            .isEmpty()
            .isLength({ min: 5, max: 8 })
    ],
    (req, res, next) => {
        const errors = validationResult(req);
        console.log(req.body);

        if (!errors.isEmpty()) {
            return res.status(422).jsonp(errors.array());
        }
        else {
            bcrypt.hash(req.body.password, 10).then((hash) => {
                const user = new userSchema({
                    name: req.body.name,
                    email: req.body.email,
                    password: hash
                });
                user.save().then((response) => {
                    res.status(201).json({
                        message: "User successfully created!",
                        result: response
                    });
                }).catch(error => {
                    res.status(500).json({
                        error: error
                    });
                });
            });
        }
    });


// Sign-in
router.post("/signin", (req, res, next) => {
    let getUser;
    userSchema.findOne({
        email: req.body.email
    }).then(user => {
        if (!user) {
            return res.status(401).json({
                message: "Authentication failed"
            });
        }
        getUser = user;
        return bcrypt.compare(req.body.password, user.password);
    }).then(response => {
        if (!response) {
            return res.status(401).json({
                message: "Authentication failed"
            });
        }
        let jwtToken = jwt.sign({
            email: getUser.email,
            userId: getUser._id
        }, "longer-secret-is-better", {
            expiresIn: "1h"
        });
        res.status(200).json({
            token: jwtToken,
            expiresIn: 3600,
            _id: getUser._id
        });
    }).catch(err => {
        return res.status(401).json({
            message: "Authentication failed"
        });
    });
});

// Get Users
router.route('/').get((req, res) => {
    userSchema.find((error, response) => {
        if (error) {
            return next(error)
        } else {
            res.status(200).json(response)
        }
    })
})

// Get Single User
router.route('/user-profile/:id').get(authorize, (req, res, next) => {
    userSchema.findById(req.params.id, (error, data) => {
        if (error) {
            return next(error);
        } else {
            res.status(200).json({
                msg: data
            })
        }
    })
})

// Update User
router.route('/update-user/:id').put((req, res, next) => {
    userSchema.findByIdAndUpdate(req.params.id, {
        $set: req.body
    }, (error, data) => {
        if (error) {
            return next(error);
            console.log(error)
        } else {
            res.json(data)
            console.log('User successfully updated!')
        }
    })
})


// Delete User
router.route('/delete-user/:id').delete((req, res, next) => {
    userSchema.findByIdAndRemove(req.params.id, (error, data) => {
        if (error) {
            return next(error);
        } else {
            res.status(200).json({
                msg: data
            })
        }
    })
})

module.exports = router;

We Passed the validation array with the check() method inside the post() method as a second argument. Next, we called the validationResult() method to validate errors, and it returns the errors if found any.

Following validation we implemented in ("/register-user") api.

• Check if the value is required.
• Check min and max character’s length.

Final auth.routes.js

// routes/auth.routes.js

const express = require("express");
const jwt = require("jsonwebtoken");
const bcrypt = require("bcrypt");
const router = express.Router();
const userSchema = require("../models/User");
const authorize = require("../middlewares/auth");
const { check, validationResult } = require('express-validator');


// Sign-up
router.post("/register-user",
    [
        check('name')
            .not()
            .isEmpty()
            .isLength({ min: 3 })
            .withMessage('Name must be atleast 3 characters long'),
        check('email', 'Email is required')
            .not()
            .isEmpty(),
        check('password', 'Password should be between 5 to 8 characters long')
            .not()
            .isEmpty()
            .isLength({ min: 5, max: 8 })
    ],
    (req, res, next) => {
        const errors = validationResult(req);
        console.log(req.body);

        if (!errors.isEmpty()) {
            return res.status(422).jsonp(errors.array());
        }
        else {
            bcrypt.hash(req.body.password, 10).then((hash) => {
                const user = new userSchema({
                    name: req.body.name,
                    email: req.body.email,
                    password: hash
                });
                user.save().then((response) => {
                    res.status(201).json({
                        message: "User successfully created!",
                        result: response
                    });
                }).catch(error => {
                    res.status(500).json({
                        error: error
                    });
                });
            });
        }
    });


// Sign-in
router.post("/signin", (req, res, next) => {
    let getUser;
    userSchema.findOne({
        email: req.body.email
    }).then(user => {
        if (!user) {
            return res.status(401).json({
                message: "Authentication failed"
            });
        }
        getUser = user;
        return bcrypt.compare(req.body.password, user.password);
    }).then(response => {
        if (!response) {
            return res.status(401).json({
                message: "Authentication failed"
            });
        }
        let jwtToken = jwt.sign({
            email: getUser.email,
            userId: getUser._id
        }, "longer-secret-is-better", {
            expiresIn: "1h"
        });
        res.status(200).json({
            token: jwtToken,
            expiresIn: 3600,
            msg: getUser
        });
    }).catch(err => {
        return res.status(401).json({
            message: "Authentication failed"
        });
    });
});

// Get Users
router.route('/').get(authorize, (req, res) => {
    userSchema.find((error, response) => {
        if (error) {
            return next(error)
        } else {
            res.status(200).json(response)
        }
    })
})

// Get Single User
router.route('/user-profile/:id').get((req, res, next) => {
    userSchema.findById(req.params.id, (error, data) => {
        if (error) {
            return next(error);
        } else {
            res.status(200).json({
                msg: data
            })
        }
    })
})

// Update User
router.route('/update-user/:id').put((req, res, next) => {
    userSchema.findByIdAndUpdate(req.params.id, {
        $set: req.body
    }, (error, data) => {
        if (error) {
            return next(error);
            console.log(error)
        } else {
            res.json(data)
            console.log('User successfully updated!')
        }
    })
})


// Delete User
router.route('/delete-user/:id').delete((req, res, next) => {
    userSchema.findByIdAndRemove(req.params.id, (error, data) => {
        if (error) {
            return next(error);
        } else {
            res.status(200).json({
                msg: data
            })
        }
    })
})

module.exports = router;

Node Server Configuration

Create a server.js file in the token-based authentication project’s folder and paste the following code in it.

const express = require('express');
const mongoose = require('mongoose');
const cors = require('cors');
const bodyParser = require('body-parser');
const dbConfig = require('./database/db');

// Express APIs
const api = require('./routes/auth.routes');

// MongoDB conection
mongoose.Promise = global.Promise;
mongoose.connect(dbConfig.db, {
    useNewUrlParser: true,
    useUnifiedTopology: true
}).then(() => {
    console.log('Database connected')
},
    error => {
        console.log("Database can't be connected: " + error)
    }
)

// Remvoe MongoDB warning error
mongoose.set('useCreateIndex', true);


// Express settings
const app = express();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
    extended: false
}));
app.use(cors());

// Serve static resources
app.use('/public', express.static('public'));

app.use('/api', api)

// Define PORT
const port = process.env.PORT || 4000;
const server = app.listen(port, () => {
    console.log('Connected to port ' + port)
})

// Express error handling
app.use((req, res, next) => {
    setImmediate(() => {
        next(new Error('Something went wrong'));
    });
});

app.use(function (err, req, res, next) {
    console.error(err.message);
    if (!err.statusCode) err.statusCode = 500;
    res.status(err.statusCode).send(err.message);
});

In this file we defined mongoDB database, express routes, PORT and errors.

Start Node Server

Now, we have placed everything at its place, and now it’s time to start the Node server. Open the terminal and run the given below commands to start the Node server and mongoDB:

Start the MongoDB database:

mongod

Start the nodemon server:

nodemon

You can test Node server on the following URL:
http://localhost:4000/api

Here, are the user authentication CRUD REST APIs built with Node.js.

I hope you liked this tutorial, please share it with others, thanks for reading!