protected-file-delivery

To secure private file downloads in a Next.js SaaS application, implement server-side API routes for session validation and access checks, generating short-lived presigned URLs to prevent unauthorized access and direct storage key exposure.

Presigned URLs prevent unauthorized access by providing short-lived links to Cloudflare R2 files. This approach generates 60-second presigned URLs via a 302 redirect, ensuring expired links cannot be reused and original storage keys remain hidden from clients.

Yes, you can gate file downloads based on user purchases and subscriptions in Next.js. This approach performs server-side database lookups using a resourceId to verify active subscriptions or purchases before issuing a short-lived presigned download URL.

The best way to hide storage keys when serving private files is to eliminate direct client exposure entirely. Perform server-side resource lookups using a generic resourceId, validate user access, then return a 302 redirect to a short-lived presigned URL.

A 60-second presigned URL for private file delivery ensures links expire almost immediately, preventing users from sharing long-lived access. Combined with server-side session validation, it strictly controls downloads to authenticated users with valid access rights.

To audit a Next.js download flow for security vulnerabilities, verify that session checks are enforced, database lookups map generic resourceIds to file keys safely, and presigned URL expiry is set to a short duration to prevent link sharing.