7.12. Working with Routes in ExpressJS: Working with JWT Authentication on Routes

7.12 Working with Routes in ExpressJS: Working with JWT Authentication on Routes

ExpressJS is a web application framework for Node.js that provides a robust way to build web servers and APIs. One of the key concepts when working with ExpressJS is the concept of routes. Routes are the path the server must follow to respond to a specific request from the client.

To secure routes and ensure that only authenticated users can access them, we can use JWT (JSON Web Token) authentication. JWT is a standard (RFC 7519) that defines a compact and secure way to pass information between parties as a JSON object. This information can be verified and trusted because it is digitally signed.

Implementing JWT Authentication in Routes

To implement JWT authentication on ExpressJS routes, we first need to install the 'jsonwebtoken' package using npm (Node Package Manager). The command to install this package is 'npm install jsonwebtoken'.

Next, we need to create a middleware that verifies the JWT token on every request. A middleware is a function that has access to the request object (req), the response object (res), and the next middleware function in the application's request/response cycle. The next middleware function is commonly denoted by a variable called 'next'.

Here is an example of what a JWT authentication middleware might look like:

const jwt = require('jsonwebtoken');

function authenticateToken(req, res, next) {
  const authHeader = req.headers['authorization'];
  const token = authHeader && authHeader.split(' ')[1];

  if (token == null) return res.sendStatus(401); // if there is no token, return a 401 error

  jwt.verify(token, process.env.ACCESS_TOKEN_SECRET, (err, user) => {
    if (err) return res.sendStatus(403); // if the token is invalid, return a 403 error
    req.user = user;
    next(); // pass the execution to the next middleware
  });
}

The 'authenticateToken' middleware extracts the token from the authorization header of the request, verifies that the token is present, and then verifies that the token is valid using the 'verify' function of the 'jsonwebtoken' package. If the token is valid, it adds the user to the request object and passes the execution to the next middleware.

Now, to secure a route with this middleware, all we need to do is add 'authenticateToken' as an argument to the route function, like in this example:

app.get('/protected', authenticateToken, (req, res) => {
  res.send('This is a protected route');
});

In this example, the '/protected' route can only be accessed if the client sends a valid JWT token in the authorization header of the request.

Conclusion

Working with routes in ExpressJS is a fundamental part of API development. Adding JWT authentication to routes allows you to secure certain parts of the API and ensure that only authenticated users can access them. While implementing JWT authentication may seem complex at first, it becomes quite straightforward once you understand the basics of how JWT tokens and middleware work.

We hope this chapter has provided a clear overview of how to work with routes and JWT authentication in ExpressJS. In the next chapter, we'll explore more advanced ExpressJS features and how they can be used to create more robust and secure APIs.

Next page of the Free Ebook:

59Working with Routes in ExpressJS: Working with Route Authorization

3 minutes