I want to use S3 to store user uploaded excel files - obviously I only want that S3 file to be accessible by that user.
Right now my application accomplishes this by checking if the user is correct, then hitting the URL https://s3.amazonaws.com/datasets.mysite.com/1243 via AJAX. I can use CORS to allow this AJAX only from https://www.mysite.com.
However if you just type https://s3.amazonaws.com/datasets.mysite.com/1243 into the browser, you can get any file :P
How do I stop S3 from serving files directly, and only enable it to be served via ajax (where I already control access with CORS)?