Corporate Firefox Deployment This site outlines steps for corporate deployment of the Mozilla Firefox browser and autoconfig.

Sunday, May 08, 2005

Firefox deployment in a corporate enviroment.

Firefox 1.0.3 browser Configuration

Configuration details for Firefox 1.0.3 browser to enable deployment and use within a corporate network, via proxies.

Using the distribution of the exe, additional configurations are added to allow access to proxies and to easy distribution to client PCs.


  • Firefox 1.0.3.exe from
  • A perl installation to generate encoded cfg files.
  • A way to package (such as nsis)
  • A way to deploy the package.
Firefox runs natively on the network, but needs a few settings for corporate usage, including turning off automatic updates, proxy settings, and minor but desirable issues such as network settings, security considerations such as popups, setting the default page and bookmarks etc.
A partial selection can be seen by reading the configuration files included on this website.
A full selection is found on the site.
Using "about:config" in the browser is also useful when deciding which directives to configure.

Firefox creates a profile for each user. Settings can be placed (by default) in the profile, but this is not desirable in a corporate environment, because it complicates and hinders the deployment process, as there may be multiple profiles on a PC, and the location of the live profile may not be predictable.
The process below puts the configuration files in the C:\Program Files structure and leaves the profile alone; this still allows user preferences to be saved in their profile.

Installation and configuration steps:

On a PC, remove the existing firefox in C:\Program Files\Firefox. (rename it if you wish to keep a backup). Be aware that older profiles will not work with later versions, but older bookmarks can always be imported.
Also remove the profile located in C:\Documents and Settings\user\Application Data\Mozilla (You may need to set explorer’s view folder options to see this directory.)
Run the mozilla version of firefox.exe. This will install the program into C:\Program Files\Mozilla Firefox
To make the relevant changes, change the files:
  • C:\Program Files\Mozilla Firefox\greprefs\all.js
The only line added is the following, which instructs the program where and which config file to use:
pref("general.config.filename", "firefox.cfg");
  • C:\Program Files\Mozilla Firefox\firefox.cfg (referenced above)
This file is generated by encoding from a text file called “firefox.txt”. The settings in this file have been tested thoroughly and were chosen with the assistance of the internet security community. The file is included on this website.

To generate a Firefox format file, the file must be encoded and renamed to “firefox.cfg”. The encoding is achieved by byte-shifting with an offset of 13. There are many byte-shifting programs for developers; the easiest way to accomplish this is to use the perl script “” from The script is included on this website.

Note that a future change is possible, to have one global configuration published on a website, as the proxy settings are, by the use of the "autoadmin.global_config_url" directive. This is not included in this configuration at this time.

The settings in this file can also be included in the file “user.js” in the profile, which is distributed in the default profile, however it's position in the profile makes it unfeasible to use in a corporate environment.
  • C:\Program Files\Mozilla Firefox\chrome\en-US.jar
This is a jar archive with NO compression.
Set cosmetic changes in here. The only archive file that I change is:
\locale\global\brand.dtd – Set the window title here. (Changed from Mozilla Firefox to Firefox)
A version number could be also entered here to display in the window title.
This change is for cosmetic and identification purposes only.
Beware when changing the archive contents that a second copy of the file is not created in the archive root, instead of changing the live file.
To manipulate the en-US.jar file, rename a copy to, extract the contents, make changes, create a new zip of the structure, with NO compression, and rename back to en-US.jar



Anonymous Anonymous said...

Well done.

8:24 PM  

Post a Comment

<< Home