http://www.rune-server.org/runescape...bling-rsa.html
Use Nikki's class for RSA Key gen if you don't have one already.
Your keys will be in your user home directory, in 2 .txt files:
rsapriv.txt (Your private keys, these are stored locally in your Login class)
rsapub.txt (Public keys, these are stored in the client in RSBuffer class)
Just replace the existing keys with those and you'll be fine