隐藏 PHP

一般而言,通过隐藏的手段提高安全性被认为是作用不大的做法。但某些情况下,尽可能的多增加一份安全性都是值得的。

一些简单的方法可以帮助隐藏 PHP,这样做可以提高攻击者发现系统弱点的难度。在 php.ini 文件里设置 expose_php = off ,可以减少他们能获得的有用信息。

另一个策略就是让 web 服务器用 PHP 解析不同扩展名。无论是通过 .htaccess 文件还是 Apache 的配置文件,都可以设置能误导攻击者的文件扩展名:

Example #1 把 PHP 隐藏为另一种语言

# 使PHP看上去像其它的编程语言
AddType application/x-httpd-php .asp .py .pl
或者干脆彻底隐藏它:

Example #2 使用未知的扩展名作为 PHP 的扩展名

# 使 PHP 看上去像未知的文件类型
AddType application/x-httpd-php .bop .foo .133t
或者把它隐藏为 HTML 页面,这样所有的 HTML 文件都会通过 PHP 引擎,会为服务器增加一些负担:

Example #3 用 HTML 做 PHP 的文件后缀

# 使 PHP 代码看上去像 HTML 页面
AddType application/x-httpd-php .htm .html
要让此方法生效,必须把 PHP 文件的扩展名改为以上的扩展名。这样就通过隐藏来提高了安全性,虽然防御能力很低而且有些缺点。

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User Contributed Notes 27 notes

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14
marpetr at NOSPAM dot gmail dot com
8 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.
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7
anon at example dot com
10 months 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.
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9
mmj
10 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.
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10
CD001
4 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.
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9
rustamabd at google mail
7 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]
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8
Ryan
2 years ago
Another way to hide php is by removing the extension completely, like so:

Options +FollowSymlinks
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.+)$ /$1.php [L,QSA]

Hope this helps!
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2
php at vfmedia dot de
10 years ago
Ive found an easy way to hide php code and the uri is searchable by google and others...(only for unix or linux)

At first I have some rules in my hide.conf (i made an extra .conf for it (apache 2.0))

For example when I want to mask the index.php

<Files index>
ForceType application/x-httpd-php
</Files>

My problem is, that my code should be readable...

so I made an extra folder for example srv/www/htdocs/static_output

My phpcode is in the includefolder....(for ex. mnt/source/index.php)

Then I made a link in the shell  > ln mnt/source/index.php srv/www/htdocs/static_output/index

So the code is readable (with .php extension) in my includefolder and there is only the link in the srv folder without extension(which is called by the browser...).
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1
Anonymous
10 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.
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0
sandaimespaceman at gmail dot com
5 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");
?>
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0
Raz
7 years ago
May some servers not allow you to put this line (i.e this not work)

AddType application/x-httpd-php .asp .py .pl
or
DefaultType application/x-httpd-php

so, the alternative method that really a good one is:

1- In your .htaccess file write:

RewriteEngine  on
RewriteBase  /dire/ or just /
RewriteRule  securename   yourfile\.php  [T=application/x-httpd-php]

example: all url like
www.example.com/securename  parsed as
www.example.com/yourfile.php

2- but here the $_GET not work, but $_POST work, so for dynamic pages like
www.example.com/yourfile.php?page=1 you use
www.example.com/securename?page=1

now: instead of using $_GET use
<?php
$uri        
= $_SERVER['REQUEST_URI'];
$page        = strstr($uri, '=');
$page        = substr($page, 1);
$valid_pages = array('1', '2','...');
$page        = in_array($page, $valid_pages) ? $page : '1';
//....
?>

and for bad URL you can add this code to .htaccess file
of coarse below the first code in .htaccess
#--
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^.*$ http://www.example.com/securename [L]
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0
simon at carbontwelevedesign dot co dot uk
8 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];

...

?>
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0
ldemailly at qualysNOSPAM dot com
10 years ago
adding MultiViews to your apache Options config
lets you hide/omit .php in the url without any rewriting, etc...
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0
Anonymous
11 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.
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0
istvan dot takacsNOSPAM at hungax dot com
12 years ago
And use the
ServerTokens min
directive in your httpd.conf to hide installed PHP modules in apache.
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-1
jtw90210
9 years ago
In order to get the PATH_INFO to work in order to pass parameters using a hidden program/trailing slash/"pretty url" in more recent versions of PHP you MUST add "AcceptPathInfo On" to your httpd.conf.

AddType application/x-httpd-php .php .html
AcceptPathInfo On

Try it out with your phpinfo page and you'll be able to search for PATH_INFO.

http://example.com/myphpinfo.php/showmetheway

If you want to drop the .php use one or both of these:
DefaultType application/x-httpd-php
ForceType application/x-httpd-php
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-1
l0rdphi1 at liquefyr dot com
11 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 =)
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-1
Bryce Nesbitt at Obviously.COM
11 years ago
Using the .php extension for all your scripts is not necessary, and in fact can be harmful (by exposing too much information about your server, and by limiting what you can do in the future without breaking links). There are several ways to hide your .php script extension:

(1) Don't hard code file types at all.  Don't specify any dots, and most web servers will automatically find your .php, .html, .pdf, .gif or other matching file. This is called canonical URL format:
     www.xxxxxx.com/page
    www.xxxxxx.com/directory/
This gives you great flexibility to change your mind in the future, and prevents Windows browsers from making improper assumptions about the file type.

(2) In an Apache .htaccess file use:
    RewriteEngine on
    RewriteRule page.html page.php

(3) Force the webserver to interpret ALL .html files as .php:
    AddType application/x-httpd-php .php3 .php .html
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-1
yasuo_ohgaki at yahoo dot com
12 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)
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-2
Pyornide
6 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.
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-2
bminton at efn dot org
11 years ago
Another technique is to have every file be named index.php and be in it's own directory.  Then instead of using for instance http://example.com/foo.php you could use http://example.com/foo/ where foo is a directory with a file called index.php in it.
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-1
sth at panix dot com
12 years ago
The flipside to this is, if you're running a version of
PHP/Apache which is not known to have exploitable bugs (usually the latest stable version at the time), and an attacker sees this, they may give up before even trying. If they don't, they may continue to attempt their exploit(s).

It really depends on the type of attacker. The educated, security advisory reading attacker vs. script kiddie on the street.

If you're keeping up on patches, version exposition should not be a problem for you.
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-4
Kevin Vincent
11 years ago
Just a thought but if you have changed the extensions that php interprets I would assume you've also changed header.php and footer.php files to the new extension.

EG:

index.php, somefile.php, header.php, footer.php...

Change the Apache directive so PHP interprets .kev files and rename your files:

index.kev, somefile.kev, header.kev, footer.kev

If you leave header and footer as PHP files then it won't understand how to interpret them.
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-4
php at user dot net
10 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 :)
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-4
altan at javam dot org
4 years ago
You can use this trick for non-direct used PHP files, eg. setting, class, ajax-related ones.

For abcde.php:

<?php
if ('abcde.php' == basename($_SERVER['SCRIPT_FILENAME'])) die ('What?');
?>
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-5
benjamin at sonntag dot fr
9 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
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m1tk4 at hotmail dot com
12 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 .
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-7
Nikolai-Zujev-(at)-Gmail-dot-Com
10 years ago
Assign files w/o extension to php interpreter
without using ReWrite module

[clip httpd.conf]

<Files ~ "^[^\.]+$">
        ForceType application/x-httpd-php
</Files>

[/clip]
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