The OneBox module is configured as an external module for the Google Search Appliance. When a user issues a search request to the Google Search Appliance, asking for secure as well as public content, the Google Search Appliance calls each configured external module, asking for authentication credentials where required. Each module performs its own search based on the given credentials and query values and returns the results to the Google Search Appliance in a standard format including a name and a URL that can display the search result.
When the OneBox module receives a search request, it authenticates the user submitting the request, then checks if that user already has a session open. If not, a session is created. The OneBox module then submits the search request to the Search Service and sends the results back to the Google Search Appliance in the standard format. The module includes the user's single-sign-on token so the documents returned in the results can be opened from the search results without having to log in again.