Hiding PHP

In general, security by obscurity is one of the weakest forms of security. But in some cases, every little bit of extra security is desirable.

A few simple techniques can help to hide PHP, possibly slowing down an attacker who is attempting to discover weaknesses in your system. By setting expose_php to off in your php.ini file, you reduce the amount of information available to them.

Another tactic is to configure web servers such as apache to parse different filetypes through PHP, either with an .htaccess directive, or in the apache configuration file itself. You can then use misleading file extensions:

Example #1 Hiding PHP as another language

# Make PHP code look like other code types AddType application/x-httpd-php .asp .py .pl
Or obscure it completely:

Example #2 Using unknown types for PHP extensions

# Make PHP code look like unknown types AddType application/x-httpd-php .bop .foo .133t
Or hide it as HTML code, which has a slight performance hit because all HTML will be parsed through the PHP engine:

Example #3 Using HTML types for PHP extensions

# Make all PHP code look like HTML AddType application/x-httpd-php .htm .html
For this to work effectively, you must rename your PHP files with the above extensions. While it is a form of security through obscurity, it's a minor preventative measure with few drawbacks.
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User Contributed Notes 25 notes

28
rustamabd at google mail
15 years ago
So far I haven't seen a working rewriter of /foo/bar into /foo/bar.php, so I created my own. It does work in top-level directory AND subdirectories and it doesn't need hardcoding the RewriteBase.

.htaccess:

RewriteEngine on

# Rewrite /foo/bar to /foo/bar.php
RewriteRule ^([^.?]+)$ %{REQUEST_URI}.php [L]

# Return 404 if original request is /foo/bar.php
RewriteCond %{THE_REQUEST} "^[^ ]* .*?\.php[? ].*$"
RewriteRule .* - [L,R=404]

# NOTE! FOR APACHE ON WINDOWS: Add [NC] to RewriteCond like this:
# RewriteCond %{THE_REQUEST} "^[^ ]* .*?\.php[? ].*$" [NC]
14
anon at example dot com
8 years ago
The session name defaults to PHPSESSID.  This is used as the name of the session cookie that is sent to the user's web browser / client. (Example: PHPSESSID=kqjqper294faui343o98ts8k77).

To hide this, call session_name() with the $name parameter set to a generic name, before calling session_start().  Example:

session_name("id");
session_start();

Cheers.
Anonymous
18 years ago
Keep in mind, if your really freaked out over hiding PHP, GD will expose you.

Go ahead - make an image with GD and open with a text editor.. Somewhere in there you'll see a comment with gd & php all over it.
CD001
12 years ago
It's a good idea to "hide" PHP anyway so you can write a RESTful web application.

Using Apache Mod Rewrite:

RewriteEngine On
RewriteRule ^control/([^/]+)/(.*)$ sitecontroller.php?control=$1&query=$2

You then use a function like the following as a way to retrieve data (in a zero indexed fashion) from the $_GET superglobal.

<?php
function myGET() {
 
$aGet = array();

  if(isset(
$_GET['query'])) {
   
$aGet = explode('/', $_GET['query']);
  }

  return
$aGet;
}
?>

This is only a really basic example of course - you can do a lot with Mod Rewrite and a custom 'GET' function.
Pyornide
13 years ago
The idea of hiding the X-Powered-By in PHP is a flawed attempt at establishing security. As the manual indicates, obscurity is not security. If I were exploiting a site, I wouldn't check what scripting language the site runs on, because all that would matter to me is exploiting it. Hiding the fact that you use [x] language isn't going to prevent me from bypassing poor security.
mmj
18 years ago
You can see if somebody's using PHP just by adding the following to the end of the URL:
?=PHPB8B5F2A0-3C92-11d3-A3A9-4C7B08C10000
If the page is using PHP, this will show the PHP credits.

Setting expose_php to Off in php.ini prevents this.
ldemailly at qualysNOSPAM dot com
18 years ago
adding MultiViews to your apache Options config
lets you hide/omit .php in the url without any rewriting, etc...
marpetr at NOSPAM dot gmail dot com
16 years ago
I think the best way to hide PHP on Apache and Apache itself is this:

httpd.conf
-------------
# ...
# Minimize 'Server' header information
ServerTokens Prod
# Disable server signature on server generated pages
ServerSignature Off
# ...
# Set default file type to PHP
DefaultType application/x-httpd-php
# ...

php.ini
------------
; ...
expose_php = Off
; ...

Now the URLs will look like this:
http://my.server.com/forums/post?forumid=15

Now hacker knows only that you are using Apache.
yasuo_ohgaki at yahoo dot com
20 years ago
To hide PHP, you need following php.ini settings

expose_php=Off
display_errors=Off

and in httpd.conf

ServerSignature Off
(min works, but I prefer off)
sandaimespaceman at gmail dot com
13 years ago
Set INI directive "expose_php" to "off" will also help.
You can spoof your PHP to ASP.NET by using:
<?php
error_reporting
(0);
header("X-Powered-By: ASP.NET");
?>
Anonymous
19 years ago
PS. If you want to use pretty URLs (i.e. hide your .php extensions) AND you have safe-mode=on, the previous example (ForceType) won't work for you.  The problem is that safe-mode forces Apache to honor trailing characters in a requested URL.  This means that:

http://www.example.com/home

would still be processed by the home script in our doc root, but for:

http://www.example.com/home/contact_us.html

apache would actually look for the /home/contact_us.html file in our doc root.

The best solution I've found is to set up a virtual host (which I do for everything, even the default doc root) and override the trailing characters handling within the virtual host.  So, for a virtual host listening on port 8080, the apache directives would look like this:

<VirtualHost *:8080>
    DocumentRoot /web/doc_root
    Alias /home "/web/doc_root/home.php"
    AcceptPathInfo On
</VirtualHost>

Some people might question why we are overriding the trailing characters handling (with the AcceptPathInfo directive) instead of just turning safe-mode=off.  The reason is that safe mode sets global limitations on the entire server, which can then be turned on or left off for each specific virtual host.  This is the equivilent of blocking all connections on a firewall, and then opening up only the ones you want, which is a lot safer than leaving everything open globally, and assuming your programmers will never overlook a possible security hole.
benjamin at sonntag dot fr
17 years ago
In response to the previous messages, for apache, there is a easier way to set files without "." to be executed by PHP, just put this in a ".htaccess" file :

DefaultType  application/x-httpd-php
info at frinteractives dot com
7 years ago
try this
RewriteEngine On

# Unless directory, remove trailing slash
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([^/]+)/$ http://example.com/folder/$1 [R=301,L]

# Redirect external .php requests to extensionless url
RewriteCond %{THE_REQUEST} ^(.+)\.php([#?][^\ ]*)?\ HTTP/
RewriteRule ^(.+)\.php$ http://example.com/folder/$1 [R=301,L]

# Resolve .php file for extensionless php urls
RewriteRule ^([^/.]+)$ $1.php [L]
l0rdphi1 at liquefyr dot com
19 years ago
More fun includes files without file extensions.

Simply add that ForceType application/x-httpd-php bit to an Apache .htaccess and you're set.

Oh yea, it gets even better when you play with stuff like the following:

<?php
substr
($_SERVER['PATH_INFO'],1);
?>

e.g. www.example.com/somepage/55

And:

<?php
foreach ( explode('/',$_SERVER['PATH_INFO']) as $pair ) {
    list(
$key,$value) = split('=',$pair,2);
   
$param[$key] = stripslashes($value);
}
?>

e.g. www.example.com/somepage/param1=value1/param2=value2/etc=etc

Enjoy =)
m1tk4 at hotmail dot com
20 years ago
I usually do:

<code>
RewriteEngine on<br>
RewriteOptions inherit<br>
RewriteRule (.*)\.htm[l]?(.*) $1.php$2 [nocase]<br>
</code>

in .htaccess. You'll need mod_rewrite installed for this .
istvan dot takacsNOSPAM at hungax dot com
20 years ago
And use the
ServerTokens min
directive in your httpd.conf to hide installed PHP modules in apache.
php at user dot net
18 years ago
What about this in a .htaccess file :

RewriteEngine on
RewriteRule    ^$    /index.php    [L]
RewriteRule    ^([a-zA-Z0-9\-\_/]*)/$    /$1/index.php    [L]
RewriteRule    ^([a-zA-Z0-9\-\_/]*)\.(html|htm)$    /$1.php    [L]
RewriteRule    ^([a-zA-Z0-9\-\_/]*)$    /$1.php    [L]

Typing "sub.domain.foo/anything" loads "/anything/index.php" if 'anything' is a directory, else it loads "/anything.php".

I'm sure you can find mutch better, but it works great on my site :)
-2
simon at carbontwelevedesign dot co dot uk
16 years ago
I use the following in the .htaccess document

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

then the following simple code

<?php

$permalinks
= explode("/",$_SERVER['REQUEST_URI']);

$varone = $permalinks[1];
$vartwo = $permalinks[2];

...

?>