RichieMN RichieMN - 5 months ago 38
Ajax Question

Paypal Payflow Transparent Redirect, SecureToken with AJAX?

I'm working on a C# VS2012 Framework 4.5 MVC application that is trying to become PCI compliant using Payflow Pro (https://pilot-payflowpro.paypal.com). We've been using PayflowPro for years, and this is what I have to use. From my reading it seems that I should use the Transparent Redirect so I'm not posting anything private to my webserver, though I don't know if I need that with how I'm hoping to handle this. I also have a few questions...

How I think this all works:
My understanding is that you need a securetoken (communication to Paypal, trip 1). Then you post the secure data (CC, exp, security code) including the securetoken (communication to Paypal, trip 2) and receive the authorization and transactionID of the sale.

How I'm hoping to do it:
I'm intending on having a form that will have all the info (user details, shipping details, and CC info), and when the user presses the purchase button, I'll use AJAX to process trip 1 to my server (no secure user info sent). Here I'll create the URL + params and send paypal my un/pw info to retrieve the token (all from my server). The response will be returned to the client and, if successful, I'll then directly communicate via AJAX to Paypal's Gateway server, this time sending the secure CC info + token (trip #2). Based on the response to trip #2, I'll let the user know what's up with their purchase. Trip 2 shouldn't need my Paypal UN/PW info as it could easily be see on the client, and I'm including the SecureToken which SHOULD identify the original transaction. From what I've explained I don't see a need for Transparent Redirect. Or am I missing something here?

Also, what Transaction Type do I want to use? Create an 'Authorization' for trip #1, then a 'Sale' for trip #2?

So here's the nitty gritty coding type stuff:
For my R&D testing I'm building my own name/value pair parameter string (see below) and communicating to the gateway server via WebRequest through their sandbox/test url (pilot-payflowpro.paypal.com). I do get a successful response and SECURETOKEN back. Initial request (shown below) for secure token is TRXTYPE = A (Authorization), no card info is sent. Do I want to authorize first?

Here are my parameters (might include shipto info as well, but it's not listed below):

USER=myAuthUserName
&VENDOR=myAuthUserName
&PARTNER=myPartner
&PWD=myPassword
&AMT=21.43
&BILLTOFIRSTNAME=FName
&BILLTOLASTNAME=LName
&BILLTOSTREET=123 Main Street
&BILLTOSTREET2=Apt 203B
&BILLTOCITY=MyCity
&BILLTOSTATE=CA
&BILLTOZIP=77777
&BILLTOPHONENUM=4444444444
&EMAIL=myemail@somedomain.com
&CURRENCY=USD
**&TRXTYPE=A**
&SILENTTRAN=TRUE
&CREATESECURETOKEN=Y
&SECURETOKENID=a99998afe2474b1b82c8214c0824df99


As I said, I get a successful response and move to the next step of sending the secure data (CC#, EXPDATE, security code). When I remove my UN/PW/VENDOR/Partner info from the params I get an error due to invalid user authentication. But, seeing I'm dynamically building this 2nd call I can't have my paypal un/pw there. What am I missing? Anyone offer assistance with this or the other questions from above?

Please let me know if I need any clarification to be added. Thanks in advance for your time!

Answer

I was able to use RichieMN's answer to get a working Transparent Redirect happening. However, the problem with doing a redirect with window.location.replace in the SendCCDetailsToPaypal function is that you're passing the data on a GET string.

This works on the PayFlow Gateway side, but when they send the customer's browser back to your ResponseURL, your Apache logs will show the whole payflowlink.paypal.com URL, including the GET string as the referrer in your Apache access logs! That GET string includes the Credit Card number and now you have just lost your PCI compliance!

To alleviate this problem, you can either put the SecureToken and SecureTokenID into your Credit Card entry form, and POST it directly to payflowlink.paypal.com, or you can rewrite the SendCCDetailsToPaypal function to build a form and submit it, like this:

function SendCCDetailsToPaypal() {
    var parameters = {
        "SECURETOKEN": secureToken,
        "SECURETOKENID": secureTokenID,
        "ACCT": $("#ccNumber").val(),
        "EXPDATE": $("#expMonth").val() + $("#expYear").val(),
        "CSC": $("#ccSecurityCode").val()
    };
    var form = $('<form></form>');
    form.attr("method", "post");
    form.attr("action", "https://pilot-payflowlink.paypal.com");
    $.each(parameters, function(key, value) {
        var field = $('<input></input>');
        field.attr("type", "hidden");
        field.attr("name", key);
        field.attr("value", value);
        form.append(field);
    });
    $(document.body).append(form);
    form.submit();
}

Since that form transfers the data via POST, when your server gets the result POST back, the referrer does not contain any sensitive data, and your PCI compliance is maintained.

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