I was working on a secure site with sensitive video material that we needed strict members access to. Even though many plugins can make sure your direct permalinks can only be seen by logged in members, direct links to files in your wp-content directory are still accessible to others. They can even be hotlinked from other sites.
One way around this is to move the wp-content directory outside the web visible portion of your directory on the server, but even so WordPress can always link to such files. A better way is to tell your server not to give access to certain files (say ending with mp4 or mp3) and only allow access from your own domain.
We can use Apache Mod Rewrite for this – it’s a complex language that you can utilise in your .htaccess file within the wp-content folder.
Let me show you how to keep prying eyes out of your content.
The Problem
Say you had a PDF file that you’d like visitors on your own site to download.
However, if someone were to copy this link and call it from a browser window directly, or if they were to post the link to you PDF on another website then the document shall not be accessible. By default it is. Let’ fix that.
The Solution
Upload a .htaccess file into your wp-content folder. Have a look if one exists already, then append this code to the end of the file. If you don’t have one, just create a new blank file and add this code to it:
RewriteEngine On
RewriteCond %{HTTP_REFERER} !^http://(www\.)?yourwebsite\.com/ [NC]
RewriteCond %{REQUEST_URI} !hotlink\.(gif|png|jpg|doc|xls|pdf|html|htm|xlsx|docx|mp4|mov) [NC]
RewriteCond %{HTTP_COOKIE} !^.*wordpress_logged_in.*$ [NC]
RewriteRule .*\.(gif|png|jpg|doc|xls|pdf|html|htm|xlsx|docx|mp4|mov)$ http://yourwebsite.com/ [NC]
This rather strange sounding code is neither Linux nor PHP nor MySQL – it’s Apache (that’s the service which usually takes care of serving up those websites from a server). These are instructions that will tell Apache to do the following – I’ll explain this line by line:
- here are some instructions I’d like you to use in this directory
- IF someone comes from anywhere other than yourwebsite.com
- AND they ask for a direct file that ends with any of the following (gif, png, jpg, etc)
- AND they are not logged into WordPress on this domain
- THEN direct every link to such files to http://yourwebsite.com
If these conditions are not met, then give out the file – everyone’s happy.
Why do I need this?
To prevent people hotlinking to your files. One aspect is security: say you have sensitive material that you only want your direct visitors to see. Or imagine you had a members area and give out a PDF that you’d like only logged in visitors to see without an encrypted link.
The same goes for image files or videos hosted on your site which you’d like to embed into your own pages but not allow embedding on external sites.
I had a guy once hotlink one of my images as his MySpace profile, the background graphic came from my server. If you’re on a plan with bandwidth limitations this can get you into trouble.
What else do I need?
Make sure you have an Apache web server running on your website, and that user overrides (i.e. .htaccess directives) are allowed.
When I wrote this article in 2012 this was a given, but since then the internet landscape has changed slightly. Nowadays, other web servers such as NGINX are commonplace, with which the above code will not work. Your web hosting company will be able to tell you more about your hosting environment.
Usage Examples
You can use this solution to conserve load and bandwidth on your server. For example, other users won’t be able to embed images hosted on your server in their websites (unless they upload them to their own), and sensitive files can only be shared on your own website.
However, this does not mean that sensitive files cannot be accessed at all; they are still available for download if visitors come via your website. Here’s an example of how to this solution works
- you have a sensitive file at http://you.com/file.pdf
- users coming from http://anywhere.com and click on that link will be redirected to your home page
- users currently surfing http://whatever.com can paste your link into their browser bar will be redirected to your home page
- users currently surfing your own website http://you.com can paste the link into their browser bar and will also be redirected to your home page, unless they are logged in to WordPress
- if users are logged in to WordPress, and are currently surfing your website, and would paste the link to the file into their browser bar, they will get access
Alternatives
I’ve received many comments on this article over the years, with many suggested use cases and questions. It’s important to understand that while the above solution is a quick fix for preventing direct access sensitive files in certain cases, it is NOT a replacement for a full membership website.
If you’re selling anything downloadable and would like to make sure only authorised users have access to the files you provide, I suggest a membership plugin like WP eMember by Tips and Tricks HQ.
Further Reading
These articles discuss the same subject:
- http://top-frog.com/2010/07/01/a-simple-way-to-limit-file-downloads-to-only-logged-in-users-in-wordpress
- http://wordpress.stackexchange.com/questions/35226/the-best-way-to-protect-uploaded-media-in-wordpress
- http://wordpress.org/support/topic/how-to-protect-media-library-uploads-folder-within-a-membership-site
Let me know if it works, I’d be interested to know.
I must admit I’m (luckily) not in that situation. According to my Akismet stats, I’m getting roughly 10.000 spam comments every month in this site, but only a handful slip through (between 5 and 10) so it’s doing a good job. Which makes me curious as to what is causing spammers to get through on your site.
It’s not what is causing spam to get through, more about how it’s getting through to a WP site. I’ve narrowed it down to a hack targeting WP core files that could make it possible to programmatically post comments without going through the comment dialog of the blog and spam blocker plug-ins installed to reduce spam.
In the wp-comments-post.php source you’ll find:
if ( !comments_open($comment_post_ID) ) {
do_action(‘comment_closed’, $comment_post_ID);
wp_die( __(‘Sorry, comments are closed for this item.’) );
} elseif ( ‘trash’ == $status ) {
do_action(‘comment_on_trash’, $comment_post_ID);
exit;
} elseif ( !$status_obj->public && !$status_obj->private ) {
do_action(‘comment_on_draft’, $comment_post_ID);
exit;
} elseif ( post_password_required($comment_post_ID) ) {
do_action(‘comment_on_password_protected’, $comment_post_ID);
exit;
} else {
// * * * * * * * * * * * * * * * * * * * * * * * * *************
// **** THIS MAY BE THE PROGRAMMATIC HOOK
// * * * * * * * * * * * * * * * * * * * * * * * * *************
do_action(‘pre_comment_on_post’, $comment_post_ID);
}
I’m not wanting to comment this line out as other sources have suggested. Because it creates a maintenance vector that I don’t want to have to manage. Hence my search for hardened approach to blocking spambot posters. As you suggested, the volume of errant spam posts that sneak through are very very few. Only the ruthless seem to be able to bypass plugins designed to defeat them. But, I’m annoyed with even those few posts that go unblocked. I want open sites for visitor engagement and at the same time I want to eliminate all the spam.
Any rewrite is bounded to root, so a small correction to the code above is posted below …
RewriteEngine On
RewriteCond %{HTTP_REFERER} !^http://(www\.)?yoursite\.com/ [NC]
RewriteCond %{REQUEST_URI} !hotlink\.(wp-trackback.php|wp-comments-post.php) [NC]
RewriteCond %{HTTP_COOKIE} !^.*wordpress_logged_in.*$ [NC]
RewriteRule .*\.(wp-trackback.php|wp-comments-post.php)$ http://yoursite.com/ [NC]
Hey! Thanks for this code.
I’m trying to use it on a WP site — it doesn’t allow hotlinking, but it still allows direct access — if I put in the URL in a browser window it comes up with the file. Any idea what could be going on?