You can bypass any action from security token validation (CSRF Token).

<?php
function my_component_init(){
		ossn_add_hook('action', 'validate:bypass', 'my_component_hook');
}
function my_component_hook($hook, $type, array $actions){
		  //bypass user/login action from validation of security tokens
		  $actions[] = 'user/login';
		  return $actions;
}
ossn_register_callback('ossn', 'init', 'my_component_init');