Google Cloud Storage getting download link

Question

I'm working in an Asp.Net Core 2 web api for files hosted at Google Cloud Storage. The files hosted there are not public, so I can't use the MediaLink property of the object. I tried to make a download endpoint using MemoryStream but when there are many users downloading large files at once I run into memory issues.

My question is: is there a way to create something link a one-time download link for a file or something similar?

I'm also trying to implement what's described in this link but I'd need to give the bearer token to the user. I can't do that.

Any tips?

Answer 1

Yes. Google Cloud Storage offers a feature called "signed URLs" that is what you described: a URL that is only good for a short while to download a single file. The idea is that you craft a download URL, then use the private key of a service account to "sign" the URL. Anyone holding that final URL can use it to act as that service account for the purpose of downloading that one object.

Take a look: https://cloud.google.com/storage/docs/access-control/#Signed-URLs

Writing code to generate the signed URL is a bit tricky, but the client libraries provide helper methods in several languages to do it for you. You can also generate one with the gsutil command: gsutil signurl -d 10m privatekey.p12 gs://bucket/foo

There is a code sample for generating he signed URLs programatically on their GitHub project: Signed URLs