Add main domain to cookies

This apache2 module adds the main domain to each cookie set by the webserver or proxied HTTP response. Without the module, it is not possible to set the domain name for a cookie from a virtual host. You can set the domain name of a cookie to a fixed domain, but when there are multiple domains behind a single apache server, apache2 cannot set the domain name of the cookie to the hostname of the request.

This module solves the problem by splitting the value of HTTP header "Host:" by a dot, and taking the last two parts of the value. The last two parts are the domain set on each cookie.

This approaches allows a vhost to set cookies on a subdomain (for example the subdomain "m.example.com") and reuse those cookies when the user is accessing the main domain (in this case "example.com"), or another subdomain.

Usage

For compilation and installation of the apache2 modules, use:

make install

The compiled module will be copied to /usr/lib64/apache2/modules (Gentoo), or /usr/share/apache2/modules (Ubuntu).

You'll probable need root access to install the module there. Therefore, performing make followed by sudo make install is advised. The apache2 server has to be restarted in order to use the module.

Testing

For compilation, installation and testing the module, use:

TEST_URL="http://m.example.com/app/web/sb" make test

The module is successfully working when the cookie set by the HTTP server ends in "; Domain=.example.com".

Make sure to that mod_cookie_domain is loaded, and set as an output filter in one or more apache2 sites. The module can be loaded using:

LoadModule cookie_domain_module /usr/lib/apache2/modules/mod_cookie_domain.so

and, inside a <VirtualHost> section, set as output filter using:

SetOutputFilter cookie_domain

Note: This requires that the apache2 module directory is writable for the user performing make test. This will also restart apache2 to reload the installed module.