Alexander01998 Alexander01998 - 16 days ago 9
PHP Question

PayPal IPN Always Returns "INVALID"

My problem



I set up an IPN listener in PHP, but it always returns
INAVLID
when testing with PayPal's IPN Simulator.

I know that this is a frequently asked question, but I have spent an entire weekend reading 50+ similar questions and trying out their solutions, but not a single one of them worked for me.

Note: I have to use fsock, my server does not support cURL.

What I tried




  • Ensured that my server is sending the request to
    www.sandbox.paypal.com
    and not
    www.paypal.com
    .

  • Ensured that my server uses SSL and port 443.

  • Ensured that the
    Host
    header is not missing.

  • Ensured that my response is equal to PayPal's request, prefixed with
    cmd=_notify-validate&
    .

  • Ensured that my server is parsing the
    VERIFIED
    /
    INVALID
    response correctly (PayPal's new system sends
    7\r\nINVALID\r\n0
    instead of just
    INVALID
    ).



My code



IPN listener class



<?php
/**
* PayPal IPN Listener
*
* A class to listen for and handle Instant Payment Notifications (IPN) from
* the PayPal server.
*
* Forked from the great Quixotix PayPal IPN script. This fork plans to
* fix the current issues with the original repo, as well as update the code
* for use according to PayPal's documentation, and today's standards.
*
* @package PHP-PayPal-IPN
* @link https://github.com/WadeShuler/PHP-PayPal-IPN
* @forked https://github.com/Quixotix/PHP-PayPal-IPN
* @author Wade Shuler
* @copyright Copyright (c) 2015, Wade Shuler
* @license http://choosealicense.com/licenses/gpl-2.0/
* @version 2.5.2
*/
class IpnListener
{
/**
* If true, the recommended cURL PHP library is used to send the post back
* to PayPal. If flase then fsockopen() is used. Default true.
*
* @var boolean
*/
public $use_curl = true;
/**
* If true, cURL will use the CURLOPT_FOLLOWLOCATION to follow any
* "Location: ..." headers in the response.
*
* @var boolean
*/
public $follow_location = false;
/**
* If true, the paypal sandbox URI www.sandbox.paypal.com is used for the
* post back. If false, the live URI www.paypal.com is used. Default false.
*
* @var boolean
*/
public $use_sandbox = false;
/**
* The amount of time, in seconds, to wait for the PayPal server to respond
* before timing out. Default 30 seconds.
*
* @var int
*/
public $timeout = 30;
/**
* If true, enable SSL certification validation when using cURL
*
* @var boolean
*/
public $verify_ssl = true;
private $_errors = array();
private $post_data;
private $rawPostData; // raw data from php://input
private $post_uri = '';
private $response_status = '';
private $response = '';
const PAYPAL_HOST = 'www.paypal.com';
const SANDBOX_HOST = 'www.sandbox.paypal.com';
/**
* Post Back Using cURL
*
* Sends the post back to PayPal using the cURL library. Called by
* the processIpn() method if the use_curl property is true. Throws an
* exception if the post fails. Populates the response, response_status,
* and post_uri properties on success.
*
* @todo add URL param so function is more dynamic
*
* @param string The post data as a URL encoded string
*/
protected function curlPost($encoded_data)
{
$uri = 'https://'.$this->getPaypalHost().'/cgi-bin/webscr';
$this->post_uri = $uri;
$ch = curl_init();
if ($this->verify_ssl) {
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($ch, CURLOPT_CAINFO, dirname(dirname(__FILE__)) . '/cert/api_cert_chain.crt');
}
curl_setopt($ch, CURLOPT_URL, $uri);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $encoded_data);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, $this->follow_location);
curl_setopt($ch, CURLOPT_TIMEOUT, $this->timeout);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, true);
$this->response = curl_exec($ch);
$this->response_status = strval(curl_getinfo($ch, CURLINFO_HTTP_CODE));
if ($this->response === false || $this->response_status == '0') {
$errno = curl_errno($ch);
$errstr = curl_error($ch);
throw new Exception("cURL error: [$errno] $errstr");
}
return $this->response;
}
/**
* Post Back Using fsockopen()
*
* Sends the post back to PayPal using the fsockopen() function. Called by
* the processIpn() method if the use_curl property is false. Throws an
* exception if the post fails. Populates the response, response_status,
* and post_uri properties on success.
*
* @todo add URL param so function is more dynamic
*
* @param string The post data as a URL encoded string
*/
protected function fsockPost($encoded_data)
{
$uri = 'ssl://'.$this->getPaypalHost();
$port = '443';
$this->post_uri = $uri.'/cgi-bin/webscr';
$fp = fsockopen($uri, $port, $errno, $errstr, $this->timeout);
if (!$fp) {
// fsockopen error
throw new Exception("fsockopen error: [$errno] $errstr");
}
$header = "POST /cgi-bin/webscr HTTP/1.1\r\n";
$header .= "Host: ".$this->getPaypalHost()."\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: ".strlen($encoded_data)."\r\n";
$header .= "Connection: Close\r\n\r\n";
fputs($fp, $header.$encoded_data."\r\n\r\n");
while(!feof($fp)) {
if (empty($this->response)) {
// extract HTTP status from first line
$this->response .= $status = fgets($fp, 1024);
$this->response_status = trim(substr($status, 9, 4));
} else {
$this->response .= fgets($fp, 1024);
}
}
fclose($fp);
return $this->response;
}
private function getPaypalHost()
{
return ($this->use_sandbox) ? self::SANDBOX_HOST : self::PAYPAL_HOST;
}
public function getErrors()
{
return $this->_errors;
}
private function addError($error)
{
$this->_errors[] .= $error;
}
public function getPostData()
{
return $this->post_data;
}
public function getRawPostData()
{
return $this->rawPostData;
}
/**
* Get POST URI
*
* Returns the URI that was used to send the post back to PayPal. This can
* be useful for troubleshooting connection problems. The default URI
* would be "ssl://www.sandbox.paypal.com:443/cgi-bin/webscr"
*
* @return string
*/
public function getPostUri()
{
return $this->post_uri;
}
/**
* Get Response
*
* Returns the entire response from PayPal as a string including all the
* HTTP headers.
*
* @return string
*/
public function getResponse()
{
return $this->response;
}
/**
* Get Response Status
*
* Returns the HTTP response status code from PayPal. This should be "200"
* if the post back was successful.
*
* @return string
*/
public function getResponseStatus()
{
return $this->response_status;
}
/**
* Get Text Report
*
* Returns a report of the IPN transaction in plain text format. This is
* useful in emails to order processors and system administrators. Override
* this method in your own class to customize the report.
*
* @return string
*/
public function getTextReport()
{
$r = '';
// date and POST url
for ($i=0; $i<80; $i++) { $r .= '-'; }
$r .= "\n[".date('m/d/Y g:i A').'] - '.$this->getPostUri();
if ($this->use_curl) {
$r .= " (curl)\n";
} else {
$r .= " (fsockopen)\n";
}
// HTTP Response
for ($i=0; $i<80; $i++) { $r .= '-'; }
$r .= "\n{$this->getResponse()}\n";
// POST vars
for ($i=0; $i<80; $i++) { $r .= '-'; }
$r .= "\n";
foreach ($this->post_data as $key => $value) {
$r .= str_pad($key, 25)."$value\n";
}
$r .= "\n\n";
return $r;
}
/**
* Process IPN
*
* Handles the IPN post back to PayPal and parsing the response. Call this
* method from your IPN listener script. Returns true if the response came
* back as "VERIFIED", false if the response came back "INVALID", and
* throws an exception if there is an error.
*
* @param array
*
* @return boolean
*/
public function processIpn($post_data=null)
{
try
{
$this->requirePostMethod(); // processIpn() should check itself if data is POST
// Read POST data
// reading posted data directly from $_POST causes serialization
// issues with array data in POST. Reading raw POST data from input stream instead.
if ($post_data === null) {
$raw_post_data = file_get_contents('php://input');
} else {
$raw_post_data = $post_data;
}
$this->rawPostData = $raw_post_data; // set raw post data for Class use
// if post_data is php input stream, make it an array.
if ( ! is_array($raw_post_data) ) {
$raw_post_array = explode('&', $raw_post_data);
$this->post_data = $raw_post_array; // use post array because it's same as $_POST
} else {
$this->post_data = $raw_post_data; // use post array because it's same as $_POST
}
$myPost = array();
if (isset($raw_post_array)) {
foreach ($raw_post_array as $keyval) {
$keyval = explode('=', $keyval);
if (count($keyval) == 2) {
$myPost[$keyval[0]] = urldecode($keyval[1]);
}
}
}
// read the post from PayPal system and add 'cmd'
$req = 'cmd=_notify-validate';
foreach ($myPost as $key => $value) {
if (function_exists('get_magic_quotes_gpc') && get_magic_quotes_gpc() == 1) {
$value = urlencode(stripslashes($value));
} else {
$value = urlencode($value);
}
$req .= "&$key=$value";
}

//XXX Debug log
$file = fopen('lastresponse.log', 'w');
fwrite($file, $req);
fclose($file);

if ($this->use_curl) {
$res = $this->curlPost($req);
} else {
$res = $this->fsockPost($req);
}
if (strpos($res, '200') === false) {
throw new Exception("Invalid response status: " . $res);
}
// Split response headers and payload, a better way for strcmp
$tokens = explode("\r\n\r\n", trim($res));
$res = trim(end($tokens));
if (strpos ($res, "VERIFIED") !== false) {
return true;
} else if (strpos ($res, "INVALID") !== false) {
return false;
} else {
throw new Exception("Unexpected response from PayPal: " . $res);
}
} catch (Exception $e) {
$this->addError($e->getMessage());
return false;
}
return false;
}
/**
* Require Post Method
*
* Throws an exception and sets a HTTP 405 response header if the request
* method was not POST.
*/
public function requirePostMethod()
{
// require POST requests
if ($_SERVER['REQUEST_METHOD'] && $_SERVER['REQUEST_METHOD'] != 'POST') {
header('Allow: POST', true, 405);
throw new Exception("Invalid HTTP request method.");
}
}
}


Actual IPN listener



<?php

ini_set("log_errors", 1);
ini_set("error_log", "php-error.log");

$file = fopen('lastrequest.log', 'w');
fwrite($file, file_get_contents('php://input'));
fclose($file);

require_once $_SERVER['DOCUMENT_ROOT'] . '/_includes/ipnlistener.php';

$listener = new IpnListener();
$listener->use_sandbox = true;
$listener->use_curl = false;
header('HTTP/1.1 200 OK');

if ($verified = $listener->processIpn())
{
// Valid IPN
/*
1. Check that $_POST['payment_status'] is "Completed"
2. Check that $_POST['txn_id'] has not been previously processed
3. Check that $_POST['receiver_email'] is your Primary PayPal email
4. Check that $_POST['payment_amount'] and $_POST['payment_currency'] are correct
*/
$transactionRawData = $listener->getRawPostData(); // raw data from PHP input stream
$transactionData = $listener->getPostData(); // POST data array
// Feel free to modify path and filename. Make SURE THE DIRECTORY IS WRITEABLE!
// For security reasons, you should use a path above/outside of your webroot
file_put_contents('ipn_success.log', print_r($transactionData, true) . PHP_EOL, LOCK_EX | FILE_APPEND);
} else {
// Invalid IPN
$errors = $listener->getErrors();
// Feel free to modify path and filename. Make SURE THE DIRECTORY IS WRITEABLE!
// For security reasons, you should use a path above/outside of your webroot
file_put_contents('ipn_errors.log', print_r($errors, true) . PHP_EOL, LOCK_EX | FILE_APPEND);
}

file_put_contents("verified.log", $verified ? "VERIFIED" : "INVALID");


My logs



PayPal's request



payment_type=instant&payment_date=Sun%20Dec%2006%202015%2020%3A05%3A21%20GMT%2B0100%20%28Mitteleurop%C3%A4ische%20Zeit%29&payment_status=Completed&address_status=confirmed&payer_status=verified&first_name=John&last_name=Smith&payer_email=buyer%40paypalsandbox.com&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&business=seller%40paypalsandbox.com&receiver_email=seller%40paypalsandbox.com&receiver_id=seller%40paypalsandbox.com&residence_country=US&item_name1=something&item_number1=AK-1234&tax=2.02&mc_currency=USD&mc_fee=0.44&mc_gross=12.34&mc_gross1=12.34&mc_handling=2.06&mc_handling1=1.67&mc_shipping=3.02&mc_shipping1=1.02&txn_type=cart&txn_id=936522821&notify_version=2.1&custom=xyz123&invoice=abc1234&test_ipn=1&verify_sign=AFcWxV21C7fd0v3bYYYRCpSSRl31A61b6KnaHJWRwuKxRGWvWo2Bos20


My server's response



cmd=_notify-validate&payment_type=instant&payment_date=Sun+Dec+06+2015+20%3A05%3A21+GMT%2B0100+%28Mitteleurop%C3%A4ische+Zeit%29&payment_status=Completed&address_status=confirmed&payer_status=verified&first_name=John&last_name=Smith&payer_email=buyer%40paypalsandbox.com&payer_id=TESTBUYERID01&address_name=John+Smith&address_country=United+States&address_country_code=US&address_zip=95131&address_state=CA&address_city=San+Jose&address_street=123+any+street&business=seller%40paypalsandbox.com&receiver_email=seller%40paypalsandbox.com&receiver_id=seller%40paypalsandbox.com&residence_country=US&item_name1=something&item_number1=AK-1234&tax=2.02&mc_currency=USD&mc_fee=0.44&mc_gross=12.34&mc_gross1=12.34&mc_handling=2.06&mc_handling1=1.67&mc_shipping=3.02&mc_shipping1=1.02&txn_type=cart&txn_id=936522821&notify_version=2.1&custom=xyz123&invoice=abc1234&test_ipn=1&verify_sign=AFcWxV21C7fd0v3bYYYRCpSSRl31A61b6KnaHJWRwuKxRGWvWo2Bos20

Answer

I've spent almost 2 days on this issue and thought I would share with people what have worked for me hopefully It can help a few others who faced the same issue.

Problem

PayPal IPN simulator gives INVALID IPN response always.

Solution

When simulating change the payment_date in simulator fields to NULL and everything should start working if your setup is correct.