Express Auth Middleware Package

This package provides middleware for authentication in Express applications using JWT (JSON Web Tokens). It simplifies the process of verifying tokens and handling user authentication.

Installation

To install the package, use npm:

npm install express-auth-middleware



### Setting up Environment Variables

Create a `.env` file at the root directory of your project. 
Define the following environment variable:
JWT_SECRET=your_secret_key_here

import { authMiddleware } from "express-auth-middleware";

app.post("/verify", authMiddleware, (req, res) => {
  // Your route logic here
});

### Generating JWT Tokens

When generating JWT tokens using `jwt.sign()`, ensure the following:

-   The payload includes a property named  `user`  with any desired properties inside it can be an object or simply value as per convenience.
-   Use the environment variable `process.env.JWT_SECRET` as the secret key.

## Example:
const token = jwt.sign({ user }, process.env.JWT_SECRET, {
  expiresIn: Date.now() + 2 * 24 * 60 * 60 * 1000,
});

### Sending Tokens

When sending tokens, follow these conventions:

-   If sending cookies in headers, use the header `Authorization` with the token prefixed by `"Bearer "`.
-   If sending cookies as credentials, use the cookie named `access_token` while sending the cookie from the server to the client as shown below.

## Example:
res
  .status(200)
  .cookie("access_token", token, {
    httpOnly: true,
    expires: expiration time,
    // any other configuration
  })
  .json({ message: "Your message"});

### Handling Token Extraction

The middleware automatically extracts the token from the request headers or cookies or request body . If using cookies, ensure you have `cookie-parser` middleware set up in your Express app.

### Error Handling

The middleware handles unauthorized access and invalid tokens automatically. If the token is missing or invalid, it returns a 401 status with an appropriate error message.

## Dependencies

-   jsonwebtoken - For generating and verifying JWT tokens.
-   express - Core framework for building web applications in Node.js.
-   cookie-parser - For parsing cookies in Express applications.