Feature idea: Block uncropped image downloads from front-end

[bme-novaware]

I think it's a great idea that the Umbraco.CMS.Imaging.HMACSecretKey is now available, but would like to take that protection a step further by being able to block the downloading of uncropped images from the front-end altogether.

It is quite common for editors to upload full size photos from a professional camera into the media section, resulting in image files from 20MB all the way up to 50MB. We apply crops precisely for this reason: it keeps the response times low and prevents the visitor from downloading an enormous amount of data. However, the uncropped image files can still be downloaded directly by stripping all querystring parameters from the media URL. This is not normal operating procedure, but abuse of this possibility can incur extra bandwidth costs to the host. Preventing similar abuse of crops is exactly why the HMACSecretKey was introduced.

My suggestion is to introduce an Umbraco.CMS.Imaging.BlockUncroppedImageDownloads setting which prevents uncropped image downloads for everyone but authenticated users with access to the Media section. Of course the default would be false for backwards compatibility and the exception of access to the Media section makes sure that the original files are still available when loading items in the Media library.

What do you think?