CKFinder is a plugin-based application and as such it can be extended relatively easily.
Enabling JavaScript Plugins
To add a plugin to CKFinder, upload it to the plugins folder and enable it by using the extraPlugins configuration option in the config.js file:
CKFinder.customConfig = function( config )
{
config.extraPlugins = 'dummy';
};
Enabling PHP Plugins
To add a plugin to CKFinder, upload it to the plugins folder and add an include_once/require_once statement in the PHP configuration file (config.php):
include_once "plugins/imageresize/plugin.php";