User Authentication System with JWT in Node.js Express

This is a simple user authentication system implemented in a Node.js Express application using JSON Web Tokens (JWT). It allows users to register, login, and access protected routes using JWT for authentication.

Features

• User registration with unique username and secure password storage
• User login with verification of credentials and issuance of JWT
• Access to protected routes requiring a valid JWT
• Secure logout mechanism that revokes issued tokens
• Optional features:
  • Token expiration for enhanced security
  • Refresh token mechanism to obtain a new JWT without logging in again

Technologies Used

• Node.js
• Express.js
• JSON Web Tokens (JWT)
• bcrypt (for password hashing)
• SQLite (for database)
• Axios (for HTTP requests in the React front end)

Installation

1. Clone the repository:

   git clone <repository-url>

2. Navigate to the project directory:

   cd <project-directory>

3.Install dependencies:

npm install

4.Set up environment variables:Create a .env file in the root directory and add the following variables:

PORT=3000
JWT_SECRET=<your-secret-key>

5.Run the application:

npm start

6.Access the application in your browser:Open http://localhost:3000 to view it.

Usage Register a new user by providing a unique username and a secure password. Login with the registered username and password to obtain a JWT. Access protected routes by providing the JWT in the Authorization header. Logout to invalidate the token.

Folder Structure:

. ├── controllers # Controllers for handling application logic ├── models # Models representing data structures and interacting with the database ├── routes # Routes mapping HTTP requests to controller actions ├── app.js # Main application file ├── .env # Environment variables └── README.md # Project documentation

Contributions are welcome! Feel free to open issues or submit pull requests.