1

Has anybody got a controller (or whatever plugin aparatus is needed) to process Paypal IPN?

Edit: Years later, I have accomplished this, and have some information which could be helpful if someone else wants PayPal IPN to function within a controller. There is a trick regarding CSRF, for example.

#1 CSRF PayPal is not going to send a Craft CSRF token, so unless you want to disable CSRF (not recommended), then your config/general.php needs a line similar to this:

'enableCsrfProtection' => (!isset($_SERVER['REQUEST_URI']) || $_SERVER['REQUEST_URI'] != '/actions/livestream/main/paypalipn'),

where the plugin is called livestream, the controller is Main, and the controller function is actionPaypalipn

#2 Not logged in PayPal will also not be logged in to Craft, so the controller requires this:

protected $allowAnonymous = true;

or I suppose this:

protected $allowAnonymous = ['paypalipn'];

Again, the quotes 'paypalipn' are because the controller function is actionPaypalipn.

Full Code (cleaned up a bit)

So those are the main bits. For those who want to look at someone else's code, it's here. Over at PayPal, the IPN Notification URL is set to https://mywebsite.org/actions/livestream/main/paypalipn. The plugin happens to be called Livestream.

class MainController extends Controller
{
    protected $allowAnonymous = true;

    public function actionPaypalipn() {
        $request = Craft::$app->request->getBodyParams();

        // Go handshake with PayPalIPN to verify the transaction. 
        $success = Livestream::$plugin->paypal->verifyIPN($request);
        if ($success) {
            //It worked! Now do our business-side processing(emails,etc).
            Livestream::$plugin->otherservice->processSuccessfulPayment($request);
            return "IPN Verified";
        } else {
            return "IPN Failed";
        }
    }

And the service:

class Paypal extends Component
{

    /***********************************************************
    *                                                          *
    * Helper functions for the PayPal IPN verification process *
    *                                                          *
    ***********************************************************/

    /** @var bool Indicates if the sandbox endpoint is used. */
    private $use_sandbox = false;
    /** @var bool Indicates if the local certificates are used. */
    private $use_local_certs = true;

    /** Production Postback URL */
    const VERIFY_URI = 'https://ipnpb.paypal.com/cgi-bin/webscr';
    /** Sandbox Postback URL */
    const SANDBOX_VERIFY_URI = 'https://ipnpb.sandbox.paypal.com/cgi-bin/webscr';

    /** Response from PayPal indicating validation was successful */
    const VALID = 'VERIFIED';
    /** Response from PayPal indicating validation failed */
    const INVALID = 'INVALID';

    /**
     * Sets the IPN verification to sandbox mode (for use when testing,
     * should not be enabled in production).
     * @return void
     */
    public function useSandbox()
    {
        $this->use_sandbox = false;
    }

    /**
     * Sets curl to use php curl's built in certs (may be required in some
     * environments).
     * @return void
     */
    public function usePHPCerts()
    {
        $this->use_local_certs = false;
    }

    /**
     * Determine endpoint to post the verification data to.
     *
     * @return string
     */
    public function getPaypalUri()
    {
        if ($this->use_sandbox) {
            return self::SANDBOX_VERIFY_URI;
        } else {
            return self::VERIFY_URI;
        }
    }

    /***********************************************************
    * Main function for the PayPal IPN verification process    *
    * Sends the incoming post data back to PayPal using the    *
    * cURL library.                                            *
    *                                                          *
    * @return bool                                             *
    ***********************************************************/

    public function verifyIPN($raw_post_array) {


        /**************************************************
        * Verify the validity of the request with PayPal. *
        **************************************************/

        // BUILD THE QUERY TO POST BACK TO PAYPAL
        $req = 'cmd=_notify-validate&' . http_build_query($raw_post_array, '', '&');

        //Log it as we go.
        file_put_contents(SOME_PATH . "log.txt", "\n". date(DATE_RSS)."\n$req\n", FILE_APPEND);

        // Post the data back to PayPal, using curl. Throw exceptions if errors occur.
        $ch = curl_init($this->getPaypalUri());
        curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
        curl_setopt($ch, CURLOPT_SSLVERSION, 6);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);

        // This is often required if the server is missing a global cert bundle, or is using an outdated one.
        if ($this->use_local_certs) {
            curl_setopt($ch, CURLOPT_CAINFO, __DIR__ . "/cert/cacert.pem");
        }
        curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array(
            'User-Agent: PHP-IPN-Verification-Script',
            'Connection: Close',
        ));
        $res = curl_exec($ch);
        if ( ! ($res)) {
            $errno = curl_errno($ch);
            $errstr = curl_error($ch);
            curl_close($ch);
            error_log("cURL error: [$errno] $errstr", 3 , $errorLog );
        }

        $info = curl_getinfo($ch);
        $http_code = $info['http_code'];
        if ($http_code != 200) {
            error_log("PayPal responded with http code $http_code", 3 , $errorLog );
        }

        curl_close($ch);

        /************************************
        * Report what we found from PayPal. *
        ************************************/

        // Check if PayPal verified the IPN data, and if so, return true.
        if ($res == self::VALID) {
            return true;
        } else {
            return false;
        }
    }
  • 1
    I'm not the downvoter, but I'd imagine it's because the question "does not show any research effort". This would have been a much better question for Slack (for future reference). – Lindsey D Sep 21 '15 at 5:23
  • Thank you, Lindsey. I appreciate you've been helpful before too. In this case, the whole point was to not invest much research effort. For me Paypal IPN is a clunky hassle to work out once every several years, and then forget. But now I'm thinking it probably doesn't need to be done in Craft at all. Just a file or two somewhere on the public part of the website. Anyway, it has to wait a couple of weeks. – kr37 Sep 27 '15 at 6:57
  • 1
    I'm voting to close this question as off-topic because although I was intending to do this through Craft CMS, there is no need to have it within the CMS, so it is not really a Craft question. – kr37 Nov 5 '16 at 20:41
1

Here's a full list of all publicly known plugins...

https://straightupcraft.com/craft-plugins

Not the answer you're looking for? Browse other questions tagged or ask your own question.