Amazon_S3_And_CloudFront::sanitize_custom_domain PHP Method

    function sanitize_custom_domain($domain)
    {
        $domain = preg_replace('@^[a-zA-Z]*:\\/\\/@', '', $domain);
        $domain = preg_replace('@[^a-zA-Z0-9\\.\\-]@', '', $domain);
        return $domain;
    }