Repository

The repository can be found here

Intro

PokeMMO Packet Editor (ppe) is a tool to intercept and modify network packets of the PokeMMO game. It is the follow-up project to the, rather simple, PokeMMO Packet Snooper. This Project is is a bit more advanced and does not hook into the game directly but instead creates a proxy server which the game connects to. This allows us to intercept and modify packets with nearly zero modifications to the game itself. The Implementation is close to the actual implementation of the game and does not use frameworks like Netty.

Because of the nature of the PokeMMO Packet protocol there is still some patching involved. The game uses a custom TLS implementation which compares the signed public key from the server with a hardcoded certificate. This is a problem because we cannot sign our own certificate with the same key. To bypass this we need to patch the game to accept our certificate. This is simply done by patching the base64 encoded certificate in the game via a agent.

How it works

The user overwrites the login domain in its hosts file to point to the proxy server. The domains and port for the login server can be found here. PPE creates a TCP server running on the specified port. The game then connects to the proxy server and the proxy server connects to the actual login server. The proxy server intercepts the packets, decrypts them and encrypts them again with the correct key.

After a successful login the game receives the game server IP and port. This data is intercepted by the proxy server and modified to point to the proxy server. The game then connects to the proxy server and the proxy server connects to the real game server. The proxy server then intercepts the packets, decrypts them and encrypts them again with the correct key.