Stop an in-progress query-string-authorized download on Amazon S3?

Question

With Amazon S3, can I stop a query-string-authorized download that is in progress?

Are there other file download services that provide such a feature?

Answer 1

I'm not aware of anyone that allows this. In general, the authentication is only checked once, when you begin downloading, but not thereafter.

Can you describe what you're trying to do more broadly?

Answer 2

I'm not aware of a built in way to do this. If I understand your goal, you want to potentially stop an HTTP response mid-stream based on some custom rules you have. Is that right?

If so, perhaps you could write a very thin proxy to S3 that encapsulates this logic. If you ran the proxy on EC2 you wouldn't incur any additional bandwidth fees.

The downside is that you would have manage scaling the proxy (i.e. add more EC2 nodes based on traffic) so depending on your scaling requirements, this could require a bit of work. But the proxy script itself would probably be fairly trivial. Something like:

Make streaming HTTP request to S3 for object
for each x byte chunk in response from S3:
    Check auth condition.  Continue if valid.  Break if not.
    Send chunk to caller