Limit access to website based on referrer

We use suphp on this server and here was the solution. In the user’s public_html file we created a .htaccess with the following:


SetEnv PHPRC /home/$user/public_html/php.ini


Then a php.ini file with:
auto_prepend_file = /home/$user/public_html/checkrefer.php

checkrefer.php


<?php
session_start();
echo $_SESSION['allowme'];

//First we check to see if a valid session exists
if ($_SESSION[‘allowme’]==1){
//keep going and allow access
}
else {
$domain=$_SERVER[“HTTP_REFERER”];
$domainref = parse_url($domain, PHP_URL_HOST);
//check to see what the referrer is
if ($domainref==”$validreferdomain”){
//start session and allow access
$_SESSION[‘allowme’] = 1; // store session data
}

//block access bad referrer and no session
else{
print “Access Forbidden. Please visit this page for further information.”;
exit;
}

}
?>

On this script you have to set $validreferdomain = to the referrer you want the visitor to come from.

Limitation – this only effects php pages and not images or other file types. You can get it to lock down html pages by setting the site to parse html as php.