IPN error -- IPN URL encoded -- where do I find this?

[jgold723]

Sorry about that. The text of the email from PayPal is below. A little more background information:

-- there is an ipn_main_handler.php file in the sub directory referenced by the url -- in fact if you decode the url, it points correctly to the ipn_main_handler.php file;

-- the PayPal module does have a reference to a url to this file - but it is an instruction to place that URL in my PayPal account information (on the PayPal site) and not an editable path

Here's the error email:

Hello xxxxxx,

Please check your server that handles PayPal Instant Payment Notifications (IPN). IPNs sent to the following URL(s) are failing:

https%3A%2F%2Fbrooklyntweed.net%2Fstore%2Fipn_main_handler.php

If you do not recognize this URL, you may be using a service provider that is using IPN on your behalf. Please contact your service provider with the above information. If this problem continues, IPNs may be disabled for your account.

Thank you for your prompt attention to this issue.


Thanks,

PayPal

[mc12345678]

Sorry about that. The text of the email from PayPal is below. A little more background information:

-- there is an ipn_main_handler.php file in the sub directory referenced by the url -- in fact if you decode the url, it points correctly to the ipn_main_handler.php file;

-- the PayPal module does have a reference to a url to this file - but it is an instruction to place that URL in my PayPal account information (on the PayPal site) and not an editable path

Here's the error email:

Hello xxxxxx,

Please check your server that handles PayPal Instant Payment Notifications (IPN). IPNs sent to the following URL(s) are failing:

https%3A%2F%2Fbrooklyntweed.net%2Fstore%2Fipn_main_handler.php

If you do not recognize this URL, you may be using a service provider that is using IPN on your behalf. Please contact your service provider with the above information. If this problem continues, IPNs may be disabled for your account.

Thank you for your prompt attention to this issue.


Thanks,

PayPal

Good, so, file exists where it should, error message from paypal seems to indicate that there is some issue getting to/accessing the file. Do you have ipn handling activated in PayPal and has the appropriate directory been provided to PayPal?

I tried the decoded path and had no redirect away from that area.so the next question, is there more than one version of the store installed at/near that directory? (Assuming the above request has already been done before posting this and no problem(s) were found)
So, even if the above path exists, is it going to a somewhat "inactive" store that won't be able to do anything with the information?

[jgold723]

That is the active store -- there isn't any other. And yes, IPN handling has been activated in PayPay and the correct address to that file has been entered there (https://www.brooklyntweed.net/store/...in_handler.php).

It seems that PayPal is trying to use an encoded version of the url

(https%3A%2F%2Fbrooklyntweed.net%2Fstore%2Fipn_main_handler.php)

which doesn't work -- I just can't figure out where it would get that.

[lhungil]

I "believe" by default the older IPN paypal modules for Zen Cart use PayPal's "Name-Value Pair" API. This API indicates all values sent via a POST must be urlencoded.

If PayPal's API is sent a "NOTIFYURL" it will use the URL sent. If one is not sent, the notification URL from your Merchant Profile (on PayPal) is used.

Zen Cart does send "NOTIFYURL" to PayPal (correctly urlencoded as per PayPal's documentation)... Sounds like possibly an error on PayPal's side (not correctly decoding the value)? You might also want to double check what is configured as the notification URL in your PayPal Merchant Profile.

One quick workaround may be to stop using PayPal IPN and use PayPal Express Checkout...

[jgold723]

Hmmm, you just brought up an interesting point that I hadn't considered.

We actually are using the two modules below:

PayPal Website Payments Pro (USA) PayPal 0 Processing Info
PayPal Express Checkout via Payflow Pro PayPal 0 Processing

And not website payments standard
PayPal Website Payments Standard - IPN PayPal Info

So why would we be getting error notices regarding IPN? Can I/should I disable IPN on the Paypal side? Is that the problem?

[lhungil]

Not sure... I was just looking at the code + API (v1.3.9h and 1.5.1)... Typically the notification URL is how an IPN method tells your store the transaction posted (if my memory is correct). Maybe someone more knowledgeable will have the answers?

You may also want to check out this thread on PayPal Communications (and some tools for debugging IPN).

One other item I should note... If you are really running 1.3.9a, you should probably upgrade at least to 1.3.9h... In the long term, it may be worth just upgrading to Zen Cart 1.5.x... If I am remembering correctly Zen Cart 1.5.x includes (among many other changes) updates to the PayPal modules...

[jgold723]

Another interesting point -- someone stated here that URLs are supposed to be encoded, per PayPal's API instructions. Yet, the answer we got from PayPal would seem to indicate otherwise:

=====
However, when I checked the transaction that you are doing, you are passing the variable:

paymentrequest_0_notifyurl="https%3A%2F%2Fbrooklyntweed.net%2Fstore%2Fipn_main_h andler.php"

when doing the DoExpressCheckoutPayment API call. This is causing the error. It seems that the URL was encoded. Can you please check with your developer to see if they had accidentally encoded the value when passing it to our server during the call?
========

[lhungil]

PayPal has multiple APIs. The Zen Cart modules include support for Payflow and NVP (the default).

From your later post it appears you have your site configured to use PayPal Express Checkout via Payflow Pro (also known as Payments Pro and Website Payments Pro). So in your case, PayPal is correct the URL should not be encoded.

Payflow does not require encoded values. NVP does require encoded values. Looking at the source code for "paypal_curl.php" in Zen Cart 1.3.9h and Zen Cart 1.5.1 the included PayPal modules follow those (and other) requirements.

I would highly suggest upgrading your copy of Zen Cart to a newer version. Version 1.3.9a is over 3.5 years old and things change (including the APIs used by 3rd parties such as PayPal). There is a good chance more up to date versions of Zen Cart will play better with PayPal.

What was the result of running the PayPal IPN debugging tools?

Notes:

You can enable logging (as well as PAYPAL_DEV_MODE) to record (and later review) the entire process and see what is being sent to PayPal. This will let you verify the data being sent by Zen Cart (including the NOTIFYURL).

Zen Cart's included PayPal modules (1.3.9h - 1.5.1) for PayFlow populate "NOTIFYURL" for "DoExpressCheckoutPayment" as per the Payflow API (not "paymentrequest_0_notifyurl").