How to generate URL authentication tokens and expiry with PHP on BunnyCDN (Bunny Net) URLs.

This means that URL’s fetched that do not have a valid token and expiry will return a 403 HTTP response.

Using token authentication on URLs makes traffic need to go through your website rather than directly accessing the media.

Here is a PHP function created with details from the Bunny net blog post.

function URLTokenGenerate(string $path, string $zone_url, int $expires_seconds = 3600): string
{
    $security_key = 'URL-TOKEN-AUTH-KEY-HERE';
    $expires = (time() + $expires_seconds);
    $hash_base = $security_key . $path . $expires;
    $token = md5($hash_base, true);
    $token = base64_encode($token);
    $token = strtr($token, '+/', '-_');
    $token = str_replace('=', '', $token);
    return "{$zone_url}{$path}?token={$token}&expires={$expires}";
}

Put in your token authentication key at $security_key

An example call:

$url = URLTokenGenerate('/images/banner.jpg', 'https://myweb.b-cdn.net', 300);

Will return similar to

https://myweb.b-cdn.net/images/banner.jpg?token=_AWA1k7ukqLqx2EyXUhrHA&expires=1627651686

This URL will be valid until 5 minutes (300 seconds) after creation.