How to authenticate the VAPID public key on the server?

Question

PHP

The js script on the client side stores the VAPID public key as a string, but sends it to the server by passing it through the urlBase64ToUint8Array function

urlBase64ToUint8Array Function

function urlBase64ToUint8Array(base64String) {
    const padding = '='.repeat((4 - (base64String.length % 4)) % 4);
    const base64 = (base64String + padding).replace(/\-/g, '+').replace(/_/g, '/');

    const rawData = window.atob(base64);
    const outputArray = new Uint8Array(rawData.length);

    for (let i = 0; i < rawData.length; ++i) {
      outputArray[i] = rawData.charCodeAt(i);
    }
    return outputArray;
  }

It is not clear how to match on the server the key from the settings and the key received in the request. The keys themselves are created using a php script https://github.com/web-push-libs/web-push-php/blob...

Answer 1

The urlBase64ToUint8Array() function sends encrypted keys to a third-party server (on behalf of which notifications will be sent to the user's browser), and not to your server ( the demo code of the author of this package), you need to get these keys raw on the backend yourself (in fact - read from file). You do not need to convert the keys on the backend yourself, this is decided at the level of the vendor code.