PHP Ghost Admin Token Generator

ghost.php

<?php
use Firebase\JWT\JWT;

class Ghost
{
    /**
     * @param string $admin_api_key The Ghost Admin API Key
     * @param int $ttl Token validity in minutes
     */
    public static function adminToken($admin_api_key, $ttl = 5)
    {
        [$id, $secret] = explode(':', $admin_api_key);
        
        $secretBinary = hex2bin($secret);
        $payload = [
            'aud' => '/admin/',
            'iat' => time(),
            'exp' => time() + ($ttl * 60),
        ];

        $headers = [
            'kid' => $id,
        ];

        return JWT::encode($payload, $secretBinary, 'HS256', null, $headers);
    }
}