If you want to block tough proxies like hidemyass.com, my previously posted .htaccess methods won’t work. Those methods will block quite a bit of proxy visits to your site, but won’t work on the stealthier proxies. Fortunately, we can use a bit of PHP to keep them out.

Block Tough Proxies with PHP

To stop tough proxy visits from sites like hidemyass.com, add the following slice of finely crafted PHP to the top of your header.php file:

<?php if(@fsockopen($_SERVER['REMOTE_ADDR'], 80, $errstr, $errno, 1))
die("Proxy access not allowed"); ?>

If you’re not using WordPress, just place the code at the top of your web page(s). No editing is necessary, so just add the code, upload the file, and done. You can check that it works by visiting your site via your favorite proxy service. If it works, access will be denied.

This method works for me on a Linux server running Apache 2.2.3, MySQL 5.0, and PHP 5.2.6. It should work on similar setups as well, but your results may vary depending on your server configuration.

Block Other Proxies with .htaccess

If for whatever reason you aren’t using the above PHP method, you can still block a majority of the “lesser” proxies by adding the following block of HTAccess code to your site’s root .htaccess file:

# BLOCK PROXY VISITS
# PerishablePress.com: http://bit.ly/12k6Uo
<ifModule mod_rewrite.c>
 RewriteEngine on
 RewriteCond %{HTTP:VIA}                 !^$ [OR]
 RewriteCond %{HTTP:FORWARDED}           !^$ [OR]
 RewriteCond %{HTTP:USERAGENT_VIA}       !^$ [OR]
 RewriteCond %{HTTP:X_FORWARDED_FOR}     !^$ [OR]
 RewriteCond %{HTTP:PROXY_CONNECTION}    !^$ [OR]
 RewriteCond %{HTTP:XPROXY_CONNECTION}   !^$ [OR]
 RewriteCond %{HTTP:HTTP_PC_REMOTE_ADDR} !^$ [OR]
 RewriteCond %{HTTP:HTTP_CLIENT_IP}      !^$
 RewriteRule .* - [F]
</ifModule>

This proxy-blocking technique is less-effective than the PHP method, but should help reduce overall proxy traffic to your site. Using HTAccess to filter proxies requires fewer system resources than the PHP method. So if you get tons of traffic or have lots of pages, you’re better off sticking with the HTAccess technique. It’s sort of a trade-off between effective proxy-blocking and optimum performance, which will vary depending on your needs and server configuration.

My Strategy

On most of my personal sites, I allow proxy access. I understand the need for privacy, but there are situations where denying proxy visits makes sense. Most often, the .htaccess code is a suitable solution. But for sites where anonymity isn’t an option, the PHP method is the way to go.