Authentication Middleware

A reusable authentication middleware for validating JWT tokens and ensuring user authorization. This middleware checks for the presence of a JWT token in the request, verifies the token, and fetches the user details. It supports custom error messages for multiple languages.

Features

• Verifies JWT tokens in Authorization headers.
• Handles language-specific error messages using the translator object.
• Ensures the user account is active before allowing access to protected routes.
• Can be easily linked as an NPM package for use across multiple projects.

Installation

Step 1: Install Dependencies

Make sure that your project has the necessary dependencies installed, such as jsonwebtoken for token verification:

npm install jsonwebtoken

Usage

Import the middleware into your project and use it as a route handler for authentication:

const AuthenticationMiddleware = require('jwt-authen');

// Example usage in an Express or Fastify app const authMiddleware = AuthenticationMiddleware({ secret: process.env.SECRET_TOKEN, getUserById: async (userId) => { // Replace with your service to fetch user by ID return await someService.getUserById(userId); }, translator: { en: { Authentication: { UnAuthorized: 'Unauthorized access.', InvalidJWT: 'Invalid or missing token.', InactiveAccount: 'Your account is inactive. Please reactivate it.' } }, });

// Use the middleware on your routes app.use(authMiddleware);

Parameters

The AuthenticationMiddleware function accepts an options object with the following properties:

secret (string): The secret key used to verify the JWT token.
getUserById (Function): A function that takes a userId and returns the corresponding user details (e.g., from a database or service).
translator (Object): A dictionary containing the translations for error messages in different languages.
    translator[lang]: Language-specific translations for the Authentication messages.
        UnAuthorized: The error message when the user is unauthorized.
        InvalidJWT: The error message when the JWT token is invalid or missing.
        InactiveAccount: The error message when the user’s account is inactive.

Example Configuration

const authMiddleware = AuthenticationMiddleware({ secret: process.env.SECRET_TOKEN, getUserById: async (userId) => { // Fetch user from database or service return await userService.getUserById(userId); }, translator: { en: { Authentication: { UnAuthorized: 'Unauthorized access.', InvalidJWT: 'Invalid token.', InactiveAccount: 'Your account has been deactivated. Please reactivate to log in.' } }, // u can add other languages });

License

MIT License - See LICENSE file for details.