i usually use the standard POST form on my site, with fields that the user fills out, which POSTs directly to https://www.paypal.com/cgi-bin/webscr
what i would like to do now, is have the form submit to my own site, for my own internal programming purposes, and when that is done, my site would automatically forward the user to paypal, with the relevant field data in the URL, for example, to: https://www.paypal.com/cgi-bin/webscr?first_name=foo&last_name=bar& etc...
this would save me from having to put the intermediate stage of the form with the hidden fields, asking the user to "click here to complete your transaction on PayPal"
hope i'm understood....
thanks!
Sure, it'll work. But keep in mind that unless you involve the BMCreateButton or Express Checkout API's, the amount will be open to URL manipulation, so you must do a check on the paid amount afterwards.
For example; https://www.paypal.com/cgi-bin/webscr?cmd=_xclick&business=blah#blah2.com&amount=0.99¤cy_code=GBP&item_name=Blah+for+sale
Note: The GET redirect must be initiated on the browser-side or via a header() redirect. You can't use cURL for this, since that's a server-to-server communication.
Related
I have read a few questions on here about e-mail clients prefetching URLs in e-mails. An answer to this seems to be to add a new confirmation page, where the user has to click a button to confirm the desired action.
But, this answer states the following:
As of Feb 2017 Outlook (https://outlook.live.com/) scans emails
arriving in your inbox and it sends all found URLs to Bing, to be
indexed by Bing crawler.
This effectively makes all one-time use links like
login/pass-reset/etc useless.
(Users of my service were complaining that one-time login links don't
work for some of them and it appeared that BingPreview/1.0b is hitting
the URL before the user even opens the inbox)
Drupal seems to be experiencing the same problem:
https://www.drupal.org/node/2828034
My major concern is with this statement:
As of Feb 2017 Outlook (https://outlook.live.com/) scans emails
arriving in your inbox and it sends all found URLs to Bing, to be
indexed by Bing crawler.
If this is the case, any URL in an e-mail meant to confirm an action, e.g. confirming a login, subscription, or unsubscription, can end up searchable in a search engine, if that's whats meant by indexed in the quote above. In this case, it's Bing. Not even a dedicated confirmation page where the user confirms the desired action truly mitigates this.
Scenario #1
If I email the user a login link with a one-time token in the URL, that URL will end up in Bing. This token will have a short lifetime, lets say 5 minutes, so I doubt anyone will manage to search on Bing and find the URL before the user clicks it or it expires.
Scenario #2
The user gets an e-mail with a link to confirm a subscription. This link is perhaps valid for 24 hours. This might(?) be long enough for someone else to stumble over the link on a search engine and accidentally (or on purpose) confirm the subscription on behalf of the user.
Scenario #2 is not uncommon, it's even best practice to use double opt-in as far as I am aware.
Scenario #3
Unsubscribe URLs in the bottom of newsletters. Maybe valid for forever? You don't want this publicly searchable in an search engine.
Assume all the one-time confirmation links land on a confirmation page where the user confirms the desired action.
Is it truly the issue that URLs in e-mails are indexed by search engines, at least Bing? And will they actually end up publicly searchable? If not, what is meant by indexed in the quote above?
I'll add for the sake of completion that I don't think I've had much of a problem with this in my own use of the web, so my gut feeling is that this is unlikely the case.
Is it truly the issue that URLs in e-mails are indexed by search engines, at least Bing?
I can't definitely say if they are being indexed or not, only Bing could answer this question, but they are surely being visited, at least with a simple GET request. I just tested this sending myself a link to a page on my website that logs the requests that are made against it, and indeed I'm seeing a GET coming from 207.46.13.181 (reverse DNS says msnbot-207-46-13-181.search.msn.com), which suggests that an automated program from search.msn.com is crawling the link. This leads me to believe that yes, they are trying to index the link's content somehow, but it's only my opinion really.
And will they actually end up publicly searchable? If not, what is meant by "indexed" in the quote above?
Well, again, impossible to say unless you work for Bing. In any case, "indexing" means exactly what you think it does: parsing the content of a page to potentially include it in search results.
The real question here is: does this somehow represent a security problem or will it compromise my website's functionality?
It surely has the potential to: if your confirmation/reset/subscription/whatever process only relies on a single GET request with the appropriate GET parameter, then you should definitely revisit the strategy, as it obviously allows anyone to perform the action (even maliciously for example enumerating possible IDs for your GET parameters).
If the link you are trying to send contains sensible information or can be used to alter important data for an user of your website, then you should at least put it behind a login page only giving access to the interested user. This way, anyone who wants to access it (including search engines) will be redirected to a login page if not already logged in.
If the link you are trying to send is just some kind of harmless confirmation link (e.g. subscribe/unsubscribe from a newsletter), then at least use a form inside the web page to do the actual confirmation through a POST request (possibly also using a CSRF token), otherwise you will unequivocally end up with false positives.
We have a checkout page where the user enters their CC number, item they want to purchase, and they complete a challenge. When the form is submitted, the sever validates the challenge and then saves the payment and charges their card.
However, we want to change it to only prompt for the challenge when the person making the checkout is considered suspicious (and increase the difficulty of the challenge as they get more suspicious).
checkout button is pressed (POST)
server checks request data and compares it against previous checkouts
server determines if challenge is needed, if so, client needs to complete this and send back to the server
if challenge is not needed, checkout is accepted and CC is charged
What would be the RESTful way to do this?
What would be the RESTful way to do this?
How would you do it with web pages?
Probably - you would present the user with a form, the user would fill in the form and submit it. If the user looks innocent, then you would process the checkout as is, and send back a response that represents the checkout action.
If the user looks suspicious, then rather than processing that form, you would send the user a response that says we can't process your payment because you are suspicious; use this alternative form to make progress. The user would submit the alternative form, and then you would evaluate whether or not the user had met the security challenge.
That's the RESTful way to do it; you give the client forms to submit, and links to follow. Clients that recognize the semantics provided in the representations can make progress, those that cannot stop.
looking for a little advice on HTML emails and GDPR re-permission.
With the new GDPR regulations I have to create an email to send out to an existing list requesting their consent to continue contacting them.
My intention is to have an 'I'm in' button in the email, which when clicked takes the user to another page/url which has a simple form on it requesting the users email address and checkbox for them to tick to opt in.
My question is can I achieve this another more simple way. For example in the email itself when the user clicks the 'I'm in' button, can a post submission be made automatically with their email address, that gets sent to clients email, and they then just get re-directed to a standard success message. Is something like this possible? It would save having to create a form somewhere and make the process easier for the user.
I don't normally do HTML emails so I'm a little unsure - any help on this would be greatly appreciated, thanks in advance
Yes, you could embed their email in the query string of the URL and then have a webapp at that URL pick up their email from the querystring and process it. Obviously you'd need to code the webapp side accordingly.
E.g:
I'm in!
If you can still send an email to the user, the collection of consent can be quite simple. It will be sufficient to send each user an email containing a link to accept the newsletter (e.g. "Yes, I want to receive the newsletter"). The email should also contain the terms and conditions of the service, and the privacy policy. What come next can be either automated, or handled manually.
The best option would be to automate the process. This can be done in multiple way, the simplest being with a customized link for each user pointing to a website capable of interpreting the data transmitted by the link itself. To achieve this result, the link contained in each email should contain an identification code - which should be anonymized where possible - so that it will be possible to link the new consent to each user. In this way, when the user clicks the link, he or she will be taken to the website. At that point, the backend will be able to collect the code passed by the link, identify the user and, finally, re-subscribe the user to the newsletter.
In practical terms, in the email there could be a link with a value to be passed as a `GET« parameter:
Yes, I want to receive the newsletter
The server-side logic could be as follows (in PHP synthax):
// re-subscribe.php
$uuid = $_GET['uuid'];
$user = getUserByUUID($uuid); // assumed function that gets the user infos by a UUID
subscribeUser($user); // assumed function that re-subscribes user to the newsletter
echo 'Thank you!'
This could even be accomplished manually, provided that a link tracker service/tool is used.
In this – less ideal – case, in the email there should only be a single clickable link, the one required to express consent (e.g. "Yes, I want to receive the newsletter"). This link could take the user wherever deemed most appropriate. What matters, in this case, is the ability, through the tracker service/tool, to know which users have clicked the link. As long as there is only one link in the email, this would inform us that the user has expressed his or her consent, and thus we could manually re-subscribe them to the newsletter. In this case, the link to the terms and conditions and to the privacy policy should be included as static text, and not as an actual clickable link.
For more info, check out our blog post, inspired by this question, at blog.autoprivacy.eu/2018/05/newsletters-after-gdpr-existing-and-new.html
I'm developing a site for a client, and he wants people to be able to buy licenses/support contracts via PayPal. What I'm stumped on is how I can make the payments secure. My current idea is to generate a random string using MD5 or whatever, plug this into a database, and send it along with the rest of the PayPal button code. When the payment is completed, the user is redirected to a PHP page where there is code to update their information in the database. The only thing stopping a hacker giving themselves a license/whatever without paying is the random hash, which can be found out using a sniffer of some sort, and plugged into the POST data returned by the PayPal code.
So. My question is this: How do I execute custom PHP code only on a successful PayPal payment, without leaving any loopholes open for the more evil users of the interwebs?
I think you should use a Payment Gateway such as PayFlow
if you're on the website ready to pay, there maybe a session already with your user logged in?
in this scenario, when the user returns back to the website, you can check you have a particular session variable and if it exists, you do the following
1) check your session, do you have a user logged in? should still be logged in if you just visited paypal a few minutes ago.
2) does the session contain your sale_id?
3) if no, dump the user on the home page, remember to header("Location..."); die("DEAD"). the die() part is important
4) if yes, check the sale_id was paid, the notify url should have caught the POSTED payment data, if valid, allow them to update the data
5) if yes, but not valid, allow them to repay using another method, this means to redirect them to another page to attempt to pay again, but don't let them access the "change details" page, the only way you get there, is by strictly validating the payment was successful.
how does that work for you ?
Advice needed for backend form submission to aweber and get response.
Scenario
When customer signup at my form, I will
1. insert the customer details into my own database,
2. send them a welcome email from my system,
3. at the same time I want the email to be added into aweber (this should run in the background, so that customer no need to fill in details for second time)
If I use the php curl call alone, is it a good solution?
I want to submit form value to aweber, so that aweber add the new email into their system, and then response to my backend script?
I have seen many versions outside, which may include:
http://scripts.incutio.com/httpclient/
http://freshmeat.net/projects/curl_http_client/
http://snoopy.sourceforge.net/
Are they having any special benefit over the normal php curl call to pass in data?
I have done this successfully before just using just a cURL request, but I couldn't get aweber to accept the submission without sending the person a confirmation message of their own. Basically it acts as if you have "confirmed opt-in" turned on, even if you turn it off.
Also, aweber addlead.pl script doesn't return anything, so if you had something in mind for that it won't go anywhere.
Hope this helps!