Manual:Securing database passwords

LocalSettings.php

LocalSettings.php contains MySQL database user IDs and passwords. Keeping these passwords in LocalSettings.php is risky because php files can be served as plain text under several different conditions revealing your wiki admin account to the world. If you want to keep your admin account a secret remove them from LocalSettings.php

LocalSettings.php can be served as plain text if:

• Php is disabled on the server
• Php itself breaks
• You have cgi search.pl (a common cgi search script) anywhere in that domain. Description of exploit.

Verify that apache can gain access to this file, and only administrators have access to this file when logged in.

Fix (Theory)

Check with your distro for what the apache user is (this varies, examples include "apache", "nobody","httpd"). Then set the permissions for the folder you have installed mediawiki into (in this example "mediawikifolder") like so:

chown apache mediawikifolder
chgrp apache mediawikifolder
chmod o-rxw mediawikifolder  (removes the access rights from other)
(probably repeat with g-rxw ... for LocalSettings.php )
make sure that u has r (or chmod 400 LocalSettings.php)

Note: The fix above only works if you are granted rights to change your wiki-folder owner and group to the apache's owner and group. If you do execute the above you get: Access denied. To prevent this, do:

chmod 710 "mediawikifolder"

Rights then required for LocalSettings.php are:

chmod 400 LocalSettings.php

or depending on your hosting

chmod 755 "mediawikifolder"

and

chmod 404 LocalSettings.php

In both cases there is no need for the executable bit.

Note: "mediawikifolder" is the folder where you put your mediawiki-installation (e.g. /var/www/mediawiki)

Example

There is no total security but having apache access the files as "other" is far away from being secure.

Default permissions set for mediawiki are root:root -rw-rw-r-- and lookup for directories.
I recommend setting ownership as above to apache (or as it must be named on your server). Now you either can set the group to apache also or to a group of very few people who shall be allowed to access the data. Remember: Don't act as root if possible! Instead act as a normal user who is in this group staff

Now make group staff or as you may want to name it. If it exists already you'll get an error.

kuser &               #on KDE with a gui, very simple
groupadd staff        #or on posix-terminal add per hand
addgroup putYourNameHere staff   #add him to staff
addgroup putNextNameHere staff   #add him to staff
addgroup root staff   #add him to staff

I recommend this setting (you can type these command one after one):

export mediawikifolder="/var/www/mw6" #put your setting here
export apacheID="www-data"            #put your setting here, see above for examples
export groupID="staff"                #example, name it as you like or as you've set it earlier
chown -R "$apacheID":"$groupID" $mediawikifolder
chmod -R 460 $mediawikifolder         #user can read, group can read and write others are not allowed 
                                      #- be careful, directories come later
chmod -R 660 $mediawikifolder/images  #we need write access for user(=apache) and group - you see, 
                                      #noone else allowed
chmod 660 $mediawikifolder/config     # Allow write access for installation, 
chmod -R u+X $mediawikifolder         #only user and staff can lookup (x on dirs)
chmod -R g+X $mediawikifolder

later set

chmod 060 $mediawikifolder/config     # Only staff

At this moment I can't see, why group apache has to be set. If you get problems with some modules or extensions you can do this:

export mediawikifolder="/var/www/mw6" #put your setting here
export groupID="apache"               #be sure to take right groupname that apache needs
chgroup -R $groupID $mediawikifolder

Keep Mysql Passwords Out Of Webroot

You should never put your mysql passwords in a text file that is within the web root. You can avoid doing so by doing this:

1. Make a directory outside your web root. For example, if your website is located at "/htdocs/www-wiki", then make a directory called "external_includes" outside of your webroot:
   1. mkdir /external_includes
2. Create a file in the directory you just made called something like "mysql_pw" and place a variable on a separate line for each of your mysql user name, password, hostname, and database name, each variable being set to the real values. For example, using vi as your editor:
   1. vi /external_includes/mysql_pw
   2. i (vi command for insert)
   3. Type the following lines using the real values of course in place of the bracketed "mysql_" fillers:
      1. $db_host="[mysql_host]";
      2. $db_name="[mysql_db_name]";
      3. $db_user="[mysql_user]";
      4. $db_password="[mysql_password]";

<?php
  $db_host="[mysql_host]"; 
  $db_name="[mysql_db_name]"; 
  $db_user="[mysql_user]";  
  $db_password="[mysql_password]";

1. Take care to leave no whitespace (blank lines) after the text.
2. Save the file. In vi this is: [Escape Key]ZZ
3. Chmod and/or chown this file as explained in the previous example for LocalSettings.php so apache can read it. Usually something like:

chown apache /htdocs/external_includes/mysql_pw 
chmod o-rw /htdocs/external_includes/mysql_pw

• Edit your LocalSettings.php file and add the following line in the beginning of the file:

require_once("[FULL ABSOLUTE PATH TO mysql_pw]") (in our example this would be: require_once ("/external_includes/mysql_pw");

• Now instead of your real password, user name, database name, and host name do this in LocalSettings.php:

 $wgDBserver         = $db_host;
 $wgDBname           = $db_name;
 $wgDBuser           = $db_user;
 $wgDBpassword       = $db_password;

This way if somebody is able to access and display LocalSettings.php, all they will see is the variables rather than the real password, username, etc. to your mysql database and the real file containing that information is off limits to the web server. You still need to make sure LocalSettings.php is only readonly to the apache user as described above.

NOTE. If you are doing these changes and do not have access to the users because you web server provider does not let you, then, from ftp the minimum rights you have to set for your "external_includes" are: "rwxr-xr-x" (755). For the file "mysql_pw" you will have to set "rwxr-xr--" (754), otherwise your wiki will not run. Still, your password is secure because the file with critical info is out of world access.

PHP breakage security problems

If your php breaks, it will serve LocalSettings.php as a regular file, giving the world your wiki database password!

Fix

(may break elsewhere!)

<IfModule !sapi_apache2.c>
    <Files ~ '\.php$'>
        Order allow,deny
        Deny from all
        Allow from none
    </Files>
    <Files ~ '\.phps'>
        Order deny,allow
        Allow from all
    </Files>
</IfModule>

Replace sapi_apache2.c with mod_php4.c for apache 1.3

Replace sapi_apache2.c with mod_php5.c for apache 2

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