I implemented a 3 parts file transfer/storage with custom encryption per storage communication and custom protocol. The initialization handshake is done over UDP, agreeing if the storage encryption is trusted, and the file transfer is done over TCP.

There’s 3 programs/parts:

A client program in python to manage servers and send files to the file transfer program
A multi-threaded file transfer server in C which manages the encryption and sessions between it and the file storage
A file storage in python which decrypts and stores the files.

This was challenging and fun to do.