Wordpress remote update checker

wp-fetch-updates-info.php

<?php
/**
 * Wordpress remote update checker
 * Written by Tomasz Klim, based on wp-admin code
 **

<Files wp-fetch-updates-info.php>
Order Deny,Allow
Deny from all
Allow from 1.2.3.4
Allow from 5.6.7.8
</Files>
*/

define('WP_ADMIN', true);

require_once(dirname(__FILE__) . '/wp-load.php');
require_once(ABSPATH . 'wp-admin/includes/update-core.php');
require_once(ABSPATH . 'wp-admin/includes/update.php');
require_once(ABSPATH . 'wp-admin/includes/plugin.php');
require_once(ABSPATH . 'wp-admin/includes/plugin-install.php');

$current = get_site_transient('update_core');
$last_update_check = false;
if ($current && isset($current->last_checked)) {
        $last_update_check = $current->last_checked + get_option('gmt_offset') * HOUR_IN_SECONDS;
}

$result = array();
$result["last_update_check"] = $last_update_check;

$query = wp_version_check(array(), true);
$result["wp_version_check"] = $query;

$updates = get_core_updates();
$result["core_updates"] = $updates;

$plugins = get_plugin_updates();
$result["plugin_updates"] = $plugins;

$themes = get_theme_updates();
$result["theme_updates"] = $themes;

$updates = wp_get_translation_updates();
$result["translation_updates"] = $updates;

$json = json_encode($result);
echo $json;