I've been using the new [Synced Table](http://blog.cartodb.com/post/65639747344/synced-tables-create-real-time-maps-from-data-anywhere) feature of CartoDB, and it's working great. But some of the data I want to sync with is not public data. The data provider keeps it on S3, but requires authentication. Is there a way that I can use the sync tables if I have a password to access it? Can I plug that in to CartoDB somehow?