17.7. Authentication and authorization in API's NodeJS: Implementation of role-based access control

Authentication and authorization are essential components in the construction of any API. In the context of NodeJS, there are several ways to implement these security aspects. In this chapter, we are going to discuss about implementing role-based access control (RBAC) in NodeJS APIs.

Before we dive into implementation, it's important to understand the difference between authentication and authorization. Authentication is the process of verifying a user's identity, usually through a username and password. Authorization, on the other hand, determines which resources an authenticated user can access.

A role-based access control (RBAC) system is one way to manage authorization. In an RBAC system, permissions are not assigned to individual users, but to roles. Users can then be assigned one or more roles, which gives them the permissions associated with those roles.

RBAC implementation in NodeJS

To implement RBAC in NodeJS, we need a module to handle authentication and another to handle authorization. For authentication, we can use Passport, an authentication middleware for Node.js. For authorization we can use node-acl, an ACL module for Node.js.

Passport

Passport is an extremely flexible and modular authentication middleware for Node.js. It is designed to serve a single purpose: authenticating requests. By providing a variety of authentication strategies, Passport allows applications to properly authenticate users, whether that be via a username and password, OAuth tokens, or even using Facebook or Google login.

To use Passport, we first need to install it using npm:

npm install passport

Next, we can configure Passport in our Node.js application. Here is an example of how we can do this:

const passport = require('passport');
app.use(passport.initialize());

Node-ACL

Node-ACL is an access control module for Node.js. It lets you control which users (or roles) can access which features in your app. To use node-acl we first need to install it using npm:

npm install acl

Next, we can configure node-acl in our Node.js application. Here is an example of how we can do this:

const acl = require('acl');
acl = new acl(new acl.memoryBackend());

With node-acl, we can create roles and assign permissions to them. Here is an example of how we can do this:

acl.allow('admin', 'videos', ['view', 'add', 'edit', 'delete']);
acl.allow('guest', 'videos', ['view']);

Next, we can assign users to roles:

acl.addUserRoles('john', 'admin');
acl.addUserRoles('jane', 'guest');

Finally, we can check a user's permissions:

acl.isAllowed('john', 'videos', 'delete', function(err, res){
    if(res){
        console.log("User is allowed to delete videos");
    }
});

This is just an overview of how we can implement role-based access control in Node.js APIs. There's so much more you can do with Passport and node-acl, including integrating with databases and creating custom authentication strategies.

In the next section, we'll explore how we can protect our Node.js APIs against common attacks such as Cross-Site Request Forgery (CSRF) and SQL Injection.