I implemented a dynamic button "buy now" (not saved in my PayPal account) with IPN and it works fine (yeah!).
Now I have a doubt about his security, because if someone change with firebug (for example) the amount value, the transaction is valid for paypal also if my IPN listener says there is a problem with amount.
My question is "Can I encrypt the form with a php / codeigniter library?"
Because I tried to check amount in the IPN listener, but the transaction on paypal continue correctly and It isn't blocked from IPN.
Here, you find a part of my listener code:
private function isVerifiedIPN(){
$req = 'cmd=_notify-validate';
$posts = $this->input->post();
foreach ($posts as $key => $value){
$value = urlencode(stripslashes($value));
$req .= "&$key=$value";
}
if($this->config->item('SIMULATION'))
$url = $this->config->item('SIMULATION_URL');
else
$url = $this->config->item('PRODUCTION_URL');
if(!$this->isVerifiedAmmount() ||
!$this->isPrimaryPayPalEmail() ||
!$this->isNotProcessed()){
$req = '';
}
$header = "POST /cgi-bin/webscr HTTP/1.0\r\n";
$header .= "Host: $url\r\n"; //443
$header .= "Content-type: application/x-www-form-urlencoded\r\n";
$header .= "Content-length: " . strlen($req) . "\r\n\r\n";
$fp = fsockopen ("ssl://$url", 443, $errno, $errstr, 30);
if (!$fp)
{
$this->sendReport("Errore connessione socket");
return FALSE;
}
else
{
fputs ($fp, $header . $req);
while (!feof($fp))
{
$res = fgets ($fp, 1024);
if (strcmp($res, "VERIFIED") == 0)
{
// transizione valida
fclose ($fp);
return TRUE;
}
else if (strcmp ($res, "INVALID") == 0)
{
$this->sendReport('Transizione non valida');
fclose ($fp);
return FALSE;
}
}
}
}
You can dynamically encrypt buttons so that people with Firebug (or similar software) can't edit them. The PayPal API library has an example of this you can use, but I can't find it again right now.
This PayPal help file explains how to get the various keys you need using your server command line.
I also found a tutorial and a certificate builder (I didn't use, so can't confirm how secure it is...)
Once you've generated your key and certificate, you need to put them on your server and set DEFAULT_EWP_PRIVATE_KEY_PATH and DEFAULT_EWP_CERT_PATH to the relevant files.
Upload the public certificate to PayPal (instructions in linked tutorials), and set DEFAULT_CERT_ID to the Cert ID it gives you for that file. It'll also give you a file you can download - add that to your server and set PAYPAL_CERT_PATH to the path for that file.
For those who find it too hard to use a library to get the encryption going, or have hosting requirement issues with getting that working, the other trick is to not encrypt, but create a hash that you pass so that you can detect tampering, and then validate this hash when the IPN comes in for processing. I explain this here:
How do I make a PayPal encrypted buy now button with custom fields?
Related
So, no matter what I try to do, I seem to always get INVALID from my PayPal IPN process. I have found other pages that have similar issues, however either the solution has not worked for me or it was not solved.
Here is my current php code:
include_once($_SERVER['DOCUMENT_ROOT']."/api/static.php");
include_once($_SERVER['DOCUMENT_ROOT']."/api/api.php");
$req = 'cmd=_notify-validate';
foreach($_POST as $key => $value) {
$value = urlencode(stripslashes($value));
$req .= "&$key=$value";
}
$header = "POST /cgi-bin/webscr HTTP/1.0\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($req) . "\r\n\r\n";
$fp = fsockopen('ssl://www.paypal.com', 443, $errno, $errstr, 30);
if(!$fp) {
//There was an error.
$mccubedConnection->query("replace into testing (result) values (-2);");
} else {
fputs($fp, $header . $req);
while(!feof($fp)) {
$res = fgets($fp, 1024);
if(strcmp($res, "VERIFIED") == 0) {
//Valid
$mccubedConnection->query("replace into testing (result) values (1);");
} else if(strcmp($res, "INVALID") == 0) {
//Invalid
$mccubedConnection->query("replace into testing (result) values (-1);");
}
} fclose($fp);
}
$mccubedConnection->query("replace into testing (result) values (0);");
$mccubedConnection->close();
The MySQL queries are working fine, and in the database it's posting a -1 and a 0. Where my desire is for it to be posting a 1 and a 0 (This way is just temporary for my testing, I will be handling the transaction differently).
I am using the INP simulator here: https://developer.paypal.com/developer/ipnSimulator/
And supplying the correct url to where my php file is, as it is executing, but posting a -1 and 0 to the DB.
Thanks for your time!
So it appears to me that this is an issue with PayPal's simulator specifically. I have done even more research and found this post, where they mention that it works on live servers, but not within sandbox. I really hate to make assumptions and to just assume it works and to push it, but if anyone else can confirm this is true, please let me know! (btw this has been an issue on that github for almost 2 months now... quite incredible)
I know that there have been a few changes to the PayPal IPN system as of May 15th, 2018. I happen to be in the middle of implementing my first IPN listener; and I'm not sure if I'm lost because of my resources (including SO posts, some dating back to 2009 on this subject) have been obsolesced by PayPal's changes, or merely because I am inexperienced in this field.
My suspicion is that I am pointing to the incorrect PayPal address:
$fh = fsockopen('ssl://www.paypal.com',443,$errno,$errstr,30);
//$fh = fsockopen('https://www.sandbox.paypal.com',80,$errno,$errstr,30);
//$fh = fsockopen('https://ipnpb.sandbox.paypal.com/cgi-bin/webscr',80,$errno,$errstr,30);
The first address completes in a successful handshake with PayPal, but returns INVALID as the IPN response. The second two handshake, but don't pass the if (!$fh) test.
I have tried both the code below, and the CURL code found in Chris Muench's answer here: PayPal IPN returns invalid in sandbox
<?php
// Paypal IPN code
header('HTTP/1.1 200 OK'); // send header
$resp = 'cmd=_notify-validate';
foreach ($_POST as $parm => $var){
$var = urlencode(stripslashes($var));
$resp .= "&$parm=$var";
}
$httphead = "POST /cgi-bin/webscr HTTP/1.1\r\n";
$httphead .= "Content-Type: application/x-www-form-urlencoded\r\n";
$httphead .= "Content-Length: " . strlen($resp) . "\r\n\r\n";
// create a ="file handle" for writing to a URL to paypal.com on Port 443 (the IPN port)
$errno ='';
$errstr='';
$fh = fsockopen('ssl://www.paypal.com',443,$errno,$errstr,30);
//$fh = fsockopen('https://www.sandbox.paypal.com',443,$errno,$errstr,30);
//$fh = fsockopen('https://ipnpb.sandbox.paypal.com/cgi-bin/webscr',443,$errno,$errstr,30);
if (!$fh) {
// if-fh does not work - cnxn FAILED
}
else{
// Connection opened, so spit back the response and get PayPal's view whether it was an authentic notification
fputs ($fh,$httphead.$resp);
while (!feof($fh)){
$readresp = fgets ($fh, 1024);
if (strcmp(trim($readresp),"VERIFIED") == 0){
// if-fh works - cnxn OPEN';
// WE ALL WIN!!
}
else if(strcmp(trim($readresp),"INVALID") == 0){
// A possible hacking attempt, or
// In my case, a possible hacking false-positive
}
}
fclose ($fh);
}
?>
I'm testing using the IPN simulator in my sandbox account.
None of the SO recommended solutions have worked.
Please help!
For the record, this url seems to be working fine: https://www.paypal.com/cgi-bin/webscr
this is the first time I am using Paypal to process a payment. I have set up a developer account, created some test merchant/buyer accounts and successfully created a cart that I sent to paypal sandbox. Here, using one of my buyers accounts, I can, again, successfully complete the purchase. In the account history of paypal, it shows that the transaction was completed. All good till now.
The problem lays in the return url, where I get the IPN. Here is the code I copied from paypal website.
<?php
include($_SERVER['WROOT'].'core/init.php');
//Put together postback info
$postback = 'cmd=_notify-validate';
foreach($_POST as $key =>$value){
$postback .= "&$key=$value";
}
// EMAIL $postback
// build the header string to post back to PayPal system to validate
$header = "POST /cgi-bin/webscr HTTP/1.1\r\n";
$header .= "Host: www.sandbox.paypal.com\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($postback) . "\r\n\r\n";
// also tried with $fp = fsockopen ('ssl://www.sandbox.paypal.com', 443, $errno, $errstr, 30);
$fp = fsockopen ('www.sandbox.paypal.com', 80, $errno, $errstr, 30);
if(!$fp){ //no conn
die();
}
//post data back
fputs($fp, $header . $postback);
while(!feof($fp)){
$res=stream_get_contents($fp, 1024);
if((strcmp($res, "VERIFIED")) == 0){
// EMAIL with a success notification
// update the database - THIS IS ONLY A SMALL TEST TO SEE IF THE TRANSACTION IS SUCCESSFUL -
$new = $dbh->prepare(" ISNERT INTO orders(txn_id) VALUES(:txn_id) ");
$new->execute(array( 'txn_id' => $_POST['txn_id'] ));
} else if ( strcmp ($res, "INVALID") == 0 ) {
// EMAIL with a error notification
// LOG THE ERROR TO A FILE
}
}
?>
Ok, first of all I don't do any check to see if the email, gross amount and other parameters are valid, that is something I will do after I can solve this problem.
Anyway, after a buyer pays, my database should update, but it does not.
What I did ?
First of all, I email me the $postback variable as soon as it's created and it worked. I got the email with a huge string of response and all the data was correct.
But the $res variable is not either VERIFIED or INVALID so anything past the fsockopen() does not work.
As I said, the payment on the paypal website is successfull. The documentation is fairly poor and I can't get an answer.
The one thing I want to add is that my website does NOT have a SSL certificate, but I do not store any of the customer data, everything is processed on the secure paypal website. Do I need a SSL certificate ?
One last thing. I tried using this class https://github.com/Quixotix/PHP-PayPal-IPN and the error log message is Invalid response status: 302
I have the same issue like PayPal Instant Payment Notification Warning. I have two sites. I have the ipn url set in paypal account to site1. But I'm sending notify_url in paypal form for current site. My verification code on both sites:
public function paymentCheck()
{
$request = 'cmd=_notify-validate';
foreach ($_POST as $key => $value) {
$value = urlencode(stripslashes($value));
$request .= "&$key=$value";
}
$header = "POST /cgi-bin/webscr HTTP/1.1\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($request) . "\r\n\r\n";
$fp = fsockopen ('ssl://www.paypal.com', 443, $errno, $errstr, 30);
if (!$fp)
return false;
else {
fputs ($fp, $header . $request);
while (!feof($fp)) {
$res = fgets ($fp, 1024);
if (strcmp ($res, "INVALID") == 0) {
return false;
}
}
fclose ($fp);
}
return true;
}
My sites handle ipn. All working fine. But some of paypal messages is failing and they turned it off. Do you have any ideas, what can cause warnings?
It means that for some reason PayPal is getting something other than a 200 OK response back from your script. If it looks like your script is working it could mean that all of the tasks are completing, but then an issue at the very end causes a failure that you don't even see other than the fact that PayPal isn't getting a good response back.
You need to check your web server logs for the times when your IPN script was hit and look at the results. You'll probably find a bunch of them that show 500 or something other than 200. You should also be able to see the error details there, too, and get it resolved.
Having made a newbe error let me try again.
The website is for a non-profit and I added a PayPal "donation" page couple of years ago; done as a shopping cart (3 types of donations and/or membership). PP returns to a php script that uses the PDT data to build a thank-you page and set cookies for a double-opt-in mailing list. IPN sends the thank-you email, opt-in email, database, etc. works fine.
Now adding a PayPal option to ticket reservation pages. Again, a shopping cart that calls PayPal and seems to work fine in the sandbox; PayPal screen is as expected, and the two foo emails look correct. I pass a different return URL which gets called but bombs on the hand shake. The code is cut&past from the previous effort and based on the PayPal PDT example.
// read the post from PayPal system and add 'cmd'
$req = 'cmd=_notify-synch';
$header = "";
$tx_token = $_GET['tx'];
$req .= "&tx=$tx_token&at=$auth_token"; // see header for def of auth_token
// post back to PayPal system to validate
$header .= "POST /cgi-bin/webscr HTTP/1.0\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($req) . "\r\n\r\n";
// If possible, securely post back to paypal using HTTPS
// Your PHP server will need to be SSL enabled
$fp = fsockopen ($socket, $port, $errno, $errstr, 30); // see header
if (!$fp)
{
// HTTP ERROR
mail($email, "PDT Error", "fsockopen error " . $errno . ": " . $errstr);
}
else
{
fputs ($fp, $header . $req);
// read the body data
$res = '';
$headerdone = false;
while (!feof($fp))
{
$line = fgets ($fp, 1024);
echo $line . "<br>";
if (strcmp($line, "\r\n") == 0)
{
// read the header
$headerdone = true;
}
else if ($headerdone)
{
// header has been read. now read the contents
$res .= $line;
}
}
The results from the added echo are:
HTTP/1.0 302 Found
Location: https://www.sandbox.paypal.com
Server: BigIP
Connection: close
Content-Length: 0
The var $auth_token, $socket and $port are set up with a "if ($test)" to switch between the sandbox and live. Obviously with 0 length payload, nothing else works.
I read here that about the new Auth_token. There are some other nits about testing for SUCCESS that I haven't gotten to, with no data to play with..
I can't remember, does the sandbox trigger the IPN? I'm getting nothing there either - set for the sandbox. Thanks for any suggestions about where to look.