Question

I am testing integrating a website to Paypal, using Web Payments standard and HTML Variables.

I have written a simple PHP script to handle the IPN notifications.

According to the Paypal documentation, the Paypal server responds with a simple ‘VERIFIED‘ or ‘INVALID‘ response, once you ping the received data back to Paypal.

In my handler, I am doing a case sensitive string comparison for those two keywords, if either one of these known keywords is not found, then it is treated as an error.

<?php
  $fp = fsockopen ($socket_url, 80, $errno, $errstr, 10);

  if (!$fp){
     // SOCKET ERROR
     return false;
  }
  else {
         fputs ($fp, $header . $req);
         $is_ok = false;

         while (!feof($fp)) {
             $res = fgets ($fp, 1024);

             if (strcmp("VERIFIED",$this->ipn_response)==0) {
                //do something ...
             }
             // if the IPN POST was 'INVALID'
             else if (strcmp ($res, "INVALID") == 0) {
                 fclose ($fp);
                 return false;
             }
             else {
                echo "Unknown response from Paypal: $res";
                fclose ($fp);
                return false;
            }
         }

         fclose ($fp);
         return true;
   }
?>

My error message shows that I am receiving an ‘HTTP/1.1 200 OK’ response from Paypal.

Unknown response from Paypal:
‘HTTP/1.1 200 OK’

Has the PayPal API changed, or am I doing something wrong?

Answer 1

PayPal’s response is in the body of the HTTP response. You need to process the HTTP headers before you can get at the body. Or, alternately, just keep reading lines until you find a blank line, and the next line will be the body.