Reversing : keygenme

someone has leaked a binary from an activation server.
can you crack the keygen algorithm for me?

using the ELF provided, reverse the keygeneration algorithm.
The server listening at raxcity.com on port 2000 will ask you for 
the passwords of various usernames.  If you can provide 10 passwords, you might get a nice flag :-)

*hint*
Rumor has it that the actual keygen runs in a custom vm. I'd start by decoding the instruction format.