jwtverify.php

<?php
$token = $_COOKIE['token'];

$parts = explode('.', $token);
$signature = base64UrlEncode(
    hash_hmac('sha256', $parts[0].'.'.$parts[1], 'segredinho_rs', true)
);

if($signature == $parts[2]){
    $payload = json_decode(
        base64_decode($parts[1])
    );
    
} else{
    header('Location: /login.php');
};
?>