Middlewares for Authentication and Authorization

Authentication and authorization are critical components of many web applications. Authentication verifies the user's identity, while authorization determines if that user has permissions to perform a specific action. In this module, you will learn how to implement middlewares to manage authentication and authorization in a Node.js application.

Authentication

Authentication is the process of verifying who the user is. The most common form of authentication is the use of credentials like a username and password.

Authentication Middleware

Let's create a simple middleware that simulates authentication token verification.

Basic Example

javascript

In this example, the verificarAutenticacion middleware checks if the authorization token in the request headers is correct. If it is, it allows access to the /privado route; otherwise, it responds with a 401 (Unauthorized) status.

Authorization

Authorization is the process of determining if an authenticated user has permissions to access a specific resource or perform a particular action.

Authorization Middleware

Let's create an authorization middleware that checks if the user has the appropriate role to access a specific route.

Basic Example

javascript

In this example, the verificarAutenticacion middleware adds a simulated user to the request. Then, the verificarAutorizacion authorization middleware checks if the user has the necessary role to access the route. If the user does not have the required role, a 403 (Forbidden) status is sent in the response.

[Insert image here: Diagram showing the flow of a request through authentication and authorization middlewares before reaching protected routes.]

Using middlewares for authentication and authorization helps you protect sensitive resources and ensures that only the appropriate users can access certain parts of your application. In the next module, we will see how to handle sensitive data and configuration through middlewares.