php - PayPal IPN simulator returning "INVALID" but I've followed the rules

Question

So I have a PHP service that's only job is to accept PayPal IPN connections. I'm using PSR7 $request->getBody()->getContents() to get the following from PayPal IPN simulator request.

payment_type=echeck&payment_date=Tue%20Jun%2007%202016%2012%3A56%3A47%20GMT+0100%20%28BST%29&payment_status=Completed&address_status=confirmed&payer_status=verified&first_name=John&last_name=Smith&[email protected]&payer_id=TESTBUYERID01&address_name=John%20Smith&address_country=United%20States&address_country_code=US&address_zip=95131&address_state=CA&address_city=San%20Jose&address_street=123%20any%20street&[email protected]&[email protected]&[email protected]&residence_country=US&item_name=something&item_number=AK-1234&quantity=1&shipping=3.04&tax=2.02&mc_currency=USD&mc_fee=0.44&mc_gross=12.34&mc_gross_1=12.34&txn_type=web_accept&txn_id=787223012&notify_version=2.1&custom=xyz123&invoice=abc1234&test_ipn=1&verify_sign=AFcWxV21C7fd0v3bYYYRCpSSRl31AfBnnvbsi0E9urbgYYn51fFWPj23

So when I post this back using Guzzle 6 POSTing to https://www.sandbox.paypal.com/cgi-bin/webscr using the following body.

cmd=_notify-validate&payment_type=echeck&payment_date=Tue%20Jun%2007%202016%2012%3A56%3A47%20GMT+0100%20%28BST%29&payment_status=Completed&address_status=confirmed&payer_status=verified&first_name=John&last_name=Smith&[email protected]&payer_id=TESTBUYERID01&address_name=John%20Smith&address_country=United%20States&address_country_code=US&address_zip=95131&address_state=CA&address_city=San%20Jose&address_street=123%20any%20street&[email protected]&[email protected]&[email protected]&residence_country=US&item_name=something&item_number=AK-1234&quantity=1&shipping=3.04&tax=2.02&mc_currency=USD&mc_fee=0.44&mc_gross=12.34&mc_gross_1=12.34&txn_type=web_accept&txn_id=787223012&notify_version=2.1&custom=xyz123&invoice=abc1234&test_ipn=1&verify_sign=AFcWxV21C7fd0v3bYYYRCpSSRl31AfBnnvbsi0E9urbgYYn51fFWPj23

I get INVALID for a response. I don't know if it coming from a different IP address to the server that handles the SSL termination is the issue or if I'm just going mad.

I've ran a diff on PayPal's simulator request body to the body I send back without the cmd variable and there is no difference.

Answer 1

It would seem the new IPN Simulator interface is using javascript Dates in the payment_date field. If you set this manually to something like today it works OK. Whether this is an encoding/decoding issue on the IPN Simulator side, or in your IPN listener, I am not sure.