User Authentication API

A RESTful API for user authentication with JWT-based token authentication.

Features

• User registration with password hashing
• JWT-based authentication
• Protected routes
• CORS enabled
• JSON-based communication

Getting Started

Prerequisites

• Node.js
• npm (Node Package Manager)

Installation

1. Clone the repository
2. Install dependencies:

   npm install

Environment Variables

Create a .env file with the following variables:

cp .env.example .env

PORT=your_port_number_here
JWT_SECRET=your_jwt_secret_key_here

API Endpoints

Register

• Endpoint: POST /register
• Description: Register a new user
• Request Body:

  {
    "username": "string",
    "password": "string"
  }

• Response:

  {
    "message": "User registered successfully"
  }

Login

• Endpoint: POST /login
• Description: Authenticate user and get JWT token
• Request Body:

  {
    "username": "string",
    "password": "string"
  }

• Response:

  {
    "token": "jwt_token"
  }

Profile

• Endpoint: GET /profile
• Description: Get user profile information
• Authentication: Requires JWT token in Authorization header
• Response:

  {
    "id": "string",
    "username": "string"
  }

Error Responses

The API returns appropriate HTTP status codes and error messages:

• 400: Bad Request (e.g., missing fields, invalid data)
• 401: Unauthorized (e.g., invalid credentials, missing token)
• 403: Forbidden (e.g., invalid token)
• 404: Not Found (e.g., user not found)
• 500: Internal Server Error

Security

• Passwords are hashed using bcrypt
• JWT tokens have a 15-minute expiration
• CORS is enabled for cross-origin requests
• Input validation is implemented

Running Tests

The API can be tested using tools like curl or Postman. Example curl commands:

# Register a new user
curl -X POST http://localhost:3000/register \
  -H "Content-Type: application/json" \
  -d '{"username":"testuser","password":"testpassword123"}'

# Login and get token
curl -X POST http://localhost:3000/login \
  -H "Content-Type: application/json" \
  -d '{"username":"testuser","password":"testpassword123"}'

# Access protected endpoint
curl -X GET http://localhost:3000/profile \
  -H "Authorization: Bearer your_jwt_token"