Force HTTPS. How is it possible?

Question

I've got just one page that I want to force as an HTTPS page (PHP on Apache). How do I do this without making the whole directory require HTTPS? Or, if you submit a form to an HTTPS page from an HTTP page, does it send it by HTTPS instead of HTTP?

Here is my example:

http://www.mysite.com/buyCrap.php

needs to only be accessed through:

https://www.mysite.com/buyCrap.php

Sure, I can put all of the links to this page pointed at the HTTPS version, but that doesn't stop some fool from accessing it through HTTP on purpose...

One thing I thought was putting a redirect in the header of the PHP file to check to be sure that they are accessing the HTTPS version:

if($_SERVER["SCRIPT_URI"] == "http://www.mysite.com/buyCrap.php"){ header('Location: https://www.mysite.com/buyCrap.php'); }

But that can't be the right way can it?

BTW, please pay no attention to the URL. I know that if it were actually a page where there was a shopping cart, etc. you would do it a different way. Think of it as a page from a site that sells one item for one price where you type in your credit card info to be submitted to a payment gateway on an external site for the express purpose of charging your card one time.

Answer 1

You could do it with a directive and mod_rewrite on Apache:

<Location /buyCrap.php>
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
</Location>

You could make the Location smarter over time using regular expressions if you want.

Answer 2

Use $_SERVER['HTTPS'] to tell if it is SSL, and redirect to the right place if not.

And remember, the page that displays the form does not need to be fed via HTTPS, it's the post back URL that needs it most.

Edit: yes, as is pointed out below, it's best to have the entire process in HTTPS. It's much more reassuring - I was pointing out that the post is the most critical part. Also, you need to take care that any cookies are set to be secure, so they will only be sent via SSL. The mod_rewrite solution is also very nifty, I've used it to secure a lot of applications on my own website.

Answer 3

The way I've done it before is basically like what you wrote, but doesn't have any hardcoded values:

if($_SERVER["HTTPS"] != "on")
{
    header("Location: https://" . $_SERVER["HTTP_HOST"] . #_SERVER["REQUEST_URI"]);
}

Answer 4

Don't mix HTTP and HTTPS on the same page. If you have a form page that is served up via HTTP, I'm going to be nervous about submitting data -- I can't see if the submit goes over HTTPS or HTTP without doing a View Source and hunting for it.

Serving up the form over HTTPS along with the submit link isn't that heavy a change for the advantage.

Answer 5

You shouldn't for security reasons. Especially if cookies are in play here. It leaves you wide open to cookie-based replay attacks.

Either way, you should use Apache control rules to tune it.

Then you can test for HTTPS being enabled and redirect as-needed where needed.

You should redirect to the pay page only using a FORM POST (no get), and accesses to the page without a POST should be directed back to the other pages. (This will catch the people just hot-jumping.)

http://joseph.randomnetworks.com/archives/2004/07/22/redirect-to-ssl-using-apaches-htaccess/

Is a good place to start, apologies for not providing more. But you really should shove everything through SSL.

It's over-protective, but at least you have less worries.