I wrote this cool C# web application where you can provide an FTP/SFTP backend, and it creates a new FTP/SFTP/Web server with everything encrypted at rest so it basically proxy + encrypt the backend data source. You interact with it like a regular file server, but in the backend, everything is encrypted via AES including the file names. It uses Stream ciphers so we can support encryption/decryption for files larger than server's available memory.

Check it out. It's all open source.

https://github.com/amir734jj/encrypted-file-server

https://fs.coolify.hesamian.com