php jwt login storage

Question

I'm building a web app with CodeIgniter 4 where I implemented a REST API for register and login and a profile page just a test my login.

I have a login form that sends a javascript fetch post request to my api and I receives a jwt token. This is working.

Now I am in the situation where I think I did not understand the principle. I want that the user stays logged in and doesn't need to re-login every time. The token expires after 12h.

And I want to use php (if possible) as the entire app runs on php.

Currently, I have a little javascript function to store my token:

const store = {};
store.setJWT = (data) => {
    this.JWT = data;
};

But this is not secure against page reload.

Additionally I am creating a cookie with php, when the user logs in:

helper('cookie');
set_cookie([
    'name' => 'login',
    'value' => $token,
    'expire' => $exp,
    'httponly' => true,
    'secure' => true,
]);

I am able to fetch data from the API using the cookie or the store object.


const token = getCookie('login');

const res = await fetch('/profile', {
    headers: {
        'Authorization': `Bearer ${token}` // or store.JWT
    }
});

So.... what I want is: The user goes to a protected url e.g. https://myapp.com/profile and if he is logged in, he has access. If not, he gets redirect to the login page.

Is using the cookie to store the jwt a good idea? Or did I completely misunderstood the idea of JWT and it is not used to be used for a login?

Additionally: I still don't know if biulding the login as an API was the best idea.

user_2457191 · Answer

First of all there is nothing wrong with building "login with API". It is common practice. And JWT is perfectly suited for auth.

You sure can store JWT token inside a cookie, but it is a little bit wrong in my opinion. Usually JWT tokens are stored in the local storage on the client side. It will persist after page reload.

Set token in the local storage:

localStorage.setItem('token', token);

Get token from the local storage:

token = localStorage.getItem('token');

To better understand the conception of the JWT you can copy some token (without Bearer) and paste it in jwt.io. Basically JWT contain all the required information about the user and server can trust this information.

And when you set the cookie like this

set_cookie([
    'name' => 'login',
    'value' => $token,
    'expire' => $exp,
    'httponly' => true,
    'secure' => true,
]);

It is an overkill. JWT possible already contains all this information and you can extract it from the token.

php jwt login storage

1 Answers