Aidan Findlater

The sample code supplied by PayPal for using their Instant Payment Notification (IPN) system does not work for me.

A post in their forums has the solution that fixed my code. Boanerges provided the solution: instead of directly opening a socket using fsockopen (as in the sample), use cURL to make the call. mondunet isolated the problem to cookie handling: apparently the PayPal sandbox requires you to accept cookies, which is not something that the direct socket connection does.

Here is the working code:

// read the post from PayPal system and add 'cmd'
if($_SERVER['REQUEST_METHOD']!="POST") die("No data");
$req = 'cmd=_notify-validate';
foreach ($_POST as $key => $value) {
    $value = urlencode(stripslashes($value));
    $req .= "&$key=$value";
}

// post back to PayPal system to validate
$url=(!isset($_POST['test_ipn'])) ? 'https://www.paypal.com/cgi-bin/webscr' : 'https://www.sandbox.paypal.com/cgi-bin/webscr';

$curl_result = $curl_err = '';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/x-www-form-urlencoded", "Content-Length: " . strlen($req)));
curl_setopt($ch, CURLOPT_HEADER , 0);
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_TIMEOUT, 30);

$curl_result = @curl_exec($ch);
$curl_err = curl_error($ch);
curl_close($ch);

//are we verified? If so, let's process the IPN
if (strpos($curl_result, "VERIFIED")!==false)
{
    //do your IPN stuff here
}

Aidan Findlater Impersonal paypal, php, web development