Apache rewrites to control access to PHP files

There are certain PHP files that you want access to but don't want to make public.
Common examples of these are:

• PHPInfo.php
• APC.php
• memcache.php

You also don't really want to deploy these on all of your sites on a server nor have them in your git repositories for sites.

A neat way of dealing with this is to use rewriting in your web server config files (e.g. Apache, NGINX, IIS etc) to do the following:

• password protect these files
• deny access to all but a limited set of IP addresses
• point all requests to these files to a default set so they don't have to be duplicated in every site.

Blocking access to all php files other than index.php.

Note that this is specific to CMSs such as Drupal and Wordpress that pass all page requests through index.php.
Also in this example I refuse access to all TXT files other than robots.txt - This saves you having to delete them from your Drupal install as is often recommended for security - this saves you having to do that everytime you update core.

# require password for admin files or allow from an IP
#<FilesMatch "^(phpinfo.php|apc.php|memcache.php)$">
<FilesMatch "([^index].php|[^robots].*\.txt)$">
   AuthName "Development"
   AuthUserFile {location of your password file}
   AuthType basic
   Require valid-user
   Order deny,allow
   Deny from all
   Allow from {your-ip}
   Allow from 127.0.0.1
   Satisfy Any
</FilesMatch>

Use a default set of instrumentation files (phpinfo.php, apc.php etc

Next let's look at rewriting all requests to these standard php files to a set of default files.
Say we have site X (www.example.com)
/var/www/sitex/htdocs/ - this is your site root
and we have the default files in a folder:
/var/www/default/ - this contains phpinfo.php, apc.php etc

What we want is requests to www.example.com/phpinfo.php actually serve /var/www/default/phpinfo.php.
To do this, set up file aliases in Apache and rewrite all requests to the files to their defaults:

Alias /default-phpinfo.php /var/www/default/phpinfo.php
Alias /default-apc.php /var/www/default/apc.php
Alias /default-memcache.php /var/www/default/memcache.php

<FilesMatch "(apc\.php|memcache\.php|phpinfo.php)$">
        RewriteEngine on
        RewriteCond %{REQUEST_FILENAME} phpinfo\.php$ [NC]
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteRule .* /default-phpinfo.php [L]

        RewriteCond %{REQUEST_FILENAME} apc\.php$ [NC]
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteRule .* /default-apc.php [L]

        RewriteCond %{REQUEST_FILENAME} memcache\.php$ [NC]
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteRule .* /default-memcache.php [L]

</FilesMatch>

The rules say: If someone asks for phpinfo.php and it doesn't exist at the url they ask for it - return the default. This allows you to 'override' the rule by placing a phpinfo.php in the root of your site should you want to.

Using this technique means that any new site you have on your server will have access to these files without having to duplicate them. all over the place and they will be protected from general access.

Note: The files referred to in the aliases must exist or you will get a 500 error when you visit them.
These rules can go in .htaccess in the root of your site - but as always for performance reasons they are better placed in your vhosts / HTTPD.conf files is you have access to that.