We have an application behind our firewall that we want to push content to a content type on our external Drupal site. Our internal application will need to create new nodes, update existing nodes, and delete existing nodes as needed. It would also have to have some kind of authentication method that would be used by the application.
What modules/process (services maybe) are best for doing this type of action on the Drupal site? What type of custom programming will need to be done on the Drupal side to allow this?