Too Long; Didn't Read
I’ve been looking for months for a solution to add Basic HTTP Authentication to S3 buckets on Amazon. There are options involving <a href="http://docs.aws.amazon.com/cli/latest/reference/s3/presign.html" target="_blank">pre-signed URLs</a> (single object only), using a 3rd-party <a href="http://www.s3auth.com/" target="_blank">free</a> or <a href="https://storagemadeeasy.com/" target="_blank">commercial</a> service (privacy concerns), spinning up an EC2/Heroku/etc. with <a href="https://www.npmjs.com/package/s3-basic-auth" target="_blank">middleware</a> to proxy requests (complicated and not serverless), using <a href="http://xingdig.com/blog/password-protecting-an-s3-website/" target="_blank">page redirects and bucket policies</a> (not secure). They all have one issue in common — all are workarounds.