Checking the validity of admin users with Passport JS

Question

Checking the validity of admin users with Passport JS

I'm currently working on a Node.js and Express application with EJS as the front end.

One challenge I am facing is implementing a middleware function using Passport that needs to run before all create, edit, and delete routes.

function isLoggedIn(req, res, next) {
    if (req.isAuthenticated()) {
        if (req.user._id != "12345") {
            res.redirect("/error");
        }
        return next();
    }
    res.redirect("/error");
}

I have been trying to ensure that only my admin user can access certain routes by checking their user id in MongoDB with req.user._id

Are there any alternative methods or best practices for handling admin user access control within routes and HTML components?

node.js express passport.js ejs

Answer 1

Answer №1

From my perspective, this appears to be on the right track. It's crucial to acknowledge the distinction between two layers: authentication and authorization.

Authentication essentially boils down to a yes or no question: is the user authenticated? The function req.isAuthenticated() should logically return either true or false, indicating whether the user is currently logged in.

Authorization can manifest in various ways but at its core, it's another binary query: does this user have the necessary credentials to access this particular resource?

While authentication is typically handled efficiently within middleware that runs before reaching "the endpoint," authorization is more complex. Each endpoint may grant or deny operations based on the user's privileges.

This conversation delves deep into roles and permissions discussions.

In your application, there are two primary requirements: the user must be authenticated, and possibly, the user needs admin privileges.

The solution would likely involve determining the simplest approach to fulfill these requirements.

In my view, adhering to SOLID principles suggests having one middleware responsible for checking if the user is authenticated. For additional conditions like verifying admin status, consider implementing a separate middleware - perhaps named isAdmin - that applies to endpoints requiring such verification. This segregation ensures cleaner code that is easier to reuse and compose.

An isAdmin middleware could prove beneficial. Alternatively, you might incorporate an admin check directly within each endpoint where needed. The key decision factor here revolves around simplicity: which method minimizes code complexity while maintaining clarity?

Given the context of roles and permissions, consider a robust mechanism for identifying admin users. Instead of relying on conditional statements like if (req.user._id === 12345) {}, which are prone to errors, introduce a designated column like is_admin within the user table. This way, you can streamline checks using if (req.user.is_admin) {}.

Building upon this concept, you could create a middleware function such as:

function isAdmin(req, res, next) {
    if (req.isAuthenticated() && (req.user.is_admin === 1)) {
        return next();
    }
    return res.redirect(403, "/error");
}

Alternatively, instead of a simple binary value like 'is_admin,' use a broader classification like 'role' with varying levels of authority. This allows for nuanced privilege management:

function hasAuthorization(req, res, next) {
    if (req.isAuthenticated() && (req.user.role >= 2)) {
        return next();
    }
    return res.redirect(403, "/error");
}

Employing such logic enables progressive escalation of user roles, enhancing administrative control. However, beware of potential pitfalls when adjusting route structures or role definitions, as overlooking even a single instance can compromise system security.

Rather than relying on generic operators (<, >), favor explicit role checks:

if ((req.user.role === 'ADMIN') || (req.user.role === 'MANAGER')) {}

To determine the optimal approach, evaluate whether consolidating admin routes under an isAdmin middleware or embedding authorization checks within individual routes better aligns with your project's simplicity and maintainability.

Consider this example:

import isAdmin from '../auth/isAdmin.js'

app.get('/admin', (req, res) => {
    if (!isAdmin(req.user)) {
        return res.redirect(403, '/error')
    }

    return res.render('admin')
})

Although slightly more labor-intensive, this method offers finer granularity and enhanced control over user permissions.

app.get('/foobars', (req, res) => {
    if (isAdmin(req.user)) {
        return res.json(/* all foobar records from all accounts */)
    }

    if (isManager(req.user)) {
        return res.json(/* all foobar records from the user's account */)
    }

    return res.json({ error: 'Insufficient privileges for this operation' })
})

In conclusion, segregate user authentication and authorization checks into distinct functions, then integrate them either within a middleware stack or individual routes to ensure seamless functionality. Additionally, explore more reliable means of self-identification beyond static identifiers like user IDs, considering potential scenarios involving platform migrations and database modifications.

Answer 2