Safari 3rd party cookie iframe trick no longer working?

Question

So this is the umteenth revenge of the "how do I get 3rd party cookies to work in Safari" question but I'm asking again because I think the playing field has changed, perhaps after February 2012. One of the standard tricks to get 3rd party cookies in Safari was as follows: use some javascript to POST to a hidden iframe. It (used to) trick Safari into thinking that the user had interacted with the 3rd party content and so then allow cookies to be set.

I think this loophole has been closed in the wake of the mild scandal where it was revealed that Google was using that trick with its ads. At the very least, while using this trick I have been completely unable to set cookies in Safari. I unearthed some random internet postings that claimed that Apple was working on closing the loophole but I haven't found any official word.

As a fallback I even tried redesigning the main third party frame so that you had to click on a button before the content would load but even that level of direct interaction was not enough to melt Safari's cold cold heart.

So does anyone know for certain if Safari has indeed closed this loophole? If so, are there other workarounds (other than manually including a session ID in every request)?

Answer 1

Just wanted to leave a simple working solution here that does not require user interaction.

As I stated in a post I made:

Basically all you need to do is load your page on top.location, create the session and redirect it back to facebook.

Add this code in the top of your index.php and set $page_url to your application final tab/app URL and you’ll see your application will work without any problem.

<?php
    // START SAFARI SESSION FIX
    session_start();
    $page_url = "http://www.facebook.com/pages/.../...?sk=app_...";
    if (isset($_GET["start_session"]))
        die(header("Location:" . $page_url));

    if (!isset($_GET["sid"]))
        die(header("Location:?sid=" . session_id()));
    $sid = session_id();
    if (empty($sid) || $_GET["sid"] != $sid):
?>
   <script>
        top.window.location="?start_session=true";
    </script>
<?php
    endif;
    // END SAFARI SESSION FIX
?>

Note: This was made for facebook, but it would actually work within any other similar situations.

---

Edit 20-Dec-2012 - Maintaining Signed Request:

The above code does not maintain the requests post data, and you would loose the signed_request, if your application relies on signed request feel free to try the following code:

Note: This is still being tested properly and may be less stable than the first version. Use at your own risk / Feedback is appreciated.

(Thanks to CBroe for pointing me into the right direction here allowing to improve the solution)

// Start Session Fix
session_start();
$page_url = "http://www.facebook.com/pages/.../...?sk=app_...";
if (isset($_GET["start_session"]))
    die(header("Location:" . $page_url));
$sid = session_id();
if (!isset($_GET["sid"]))
{
    if(isset($_POST["signed_request"]))
       $_SESSION["signed_request"] = $_POST["signed_request"];
    die(header("Location:?sid=" . $sid));
}
if (empty($sid) || $_GET["sid"] != $sid)
    die('<script>top.window.location="?start_session=true";</script>');
// End Session Fix