I built a proof of concept project that was a lot like transfer.sh at one point in time. My solution was to not only have a time limit but a download limit as well. I'd guess most people transferring files from the command line want to transfer something from one machine to another, or maybe to a few other machines. I was going to allow a transfer limit of 10 transfers before the file/link went dead, which would hopefully deter most nefarious people using it to widely spread files around..
Unless you are storing hashes, what would prevent someone from writing a script that simply reuploads the file to your service after downloading? That would increase the share limit.
Let's say you generate the identifier for the upload based on the file hash. If you add a timestamp or random nonce then they'll have to redistribute the link to the file every time they re-upload as it will change every time.
Exactly. Nothing would stop someone from re-uploading it, but they'd end up with a different url which would go dead pretty quick if used to share something publicly.
