In this tutorial, we're gonna build a Node.js Express Login & Registration example that supports Token Based Authentication with JWT (JSONWebToken). You'll know:

Appropriate Flow for User Signup & User Login with JWT Authentication
Node.js Express Architecture with CORS, Authenticaton & Authorization middlewares & Sequelize
How to configure Express routes to work with JWT
How to define Data Models and association for Authentication and Authorization
Way to use Sequelize to interact with MySQL Database

Full Article: https://bezkoder.com/node-js-jwt-authentication-mysql/

Token Based Authentication

Comparing with Session-based Authentication that need to store Session on Cookie, the big advantage of Token-based Authentication is that we store the JSON Web Token (JWT) on Client side: Local Storage for Browser, Keychain for IOS and SharedPreferences for Android… So we don’t need to build another backend project that supports Native Apps or an additional Authentication module for Native App users.

There are three important parts of a JWT: Header, Payload, Signature. Together they are combined to a standard structure: header.payload.signature.

The Client typically attaches JWT in Authorization header with Bearer prefix:

Authorization: Bearer [header].[payload].[signature]

Or only in x-access-token header:

x-access-token: [header].[payload].[signature]

For more details, you can visit:
In-depth Introduction to JWT-JSON Web Token

Overview of Node.js Express Login & Registration example

We will build a Node.js Express application in that:

User can signup new account, or login with username & password.
By User's role (admin, moderator, user), we authorize the User to access resources

This is our Node.js application demo running with MySQL database and test Rest Apis with Postman.

These are APIs that we need to provide:

POST /api/auth/signup signup new account
POST /api/auth/signin login an account
GET /api/test/all retrieve public content
GET /api/test/user access User's content
GET /api/test/mod access Moderator's content
GET /api/test/admin access Admin's content

Flow for Signup & Login with JWT Authentication

The diagram shows flow of User Registration, User Login and Authorization process.

A legal JWT must be added to HTTP x-access-token Header if Client accesses protected resources.

You may need to implement Refresh Token like this:

More details at: https://bezkoder.com/jwt-refresh-token-node-js/

Node.js Express Architecture with Authentication & Authorization

You can have an overview of our Node.js Express App with the diagram below:

Via Express routes, HTTP request that matches a route will be checked by CORS Middleware before coming to Security layer.

Security layer includes:

JWT Authentication Middleware: verify SignUp, verify token
Authorization Middleware: check User's roles with record in database

If these middlewares throw any error, a message will be sent as HTTP response.

Controllers interact with MySQL Database via Sequelize and send HTTP response (token, user information, data based on roles…) to client.

For more details, implementation and Github, please visit:
https://bezkoder.com/node-js-jwt-authentication-mysql/

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Front-end that works well with this: