I'm in this company's network and I've MITM'd this weird protocol between a dev client and server, but I can't figure out how it works. Connect to reversing.chal.csaw.io:9002 and I'll send the client traffic to you. Forward it on to the dev server at reversing.chal.csaw.io:9001 to figure out what's going on. Once you're ready, hit up the prod server at reversing.chal.csaw.io:9000 which should have a flag for you.

hint 1: "the servers have functionality that the official client never uses" Hint1 released Sat: 10:40 PM

hint 2: "each message has a packet type" Hint 2 released Sat: 11:53 PM

hint 3: "for the final stage, the server's prompt is just trying to confirm that the client has the data that an official client would have. It is referring to what the client sends." Hint 3 released Sun 3:00 AM