Mario Kart Disassembly

In this lab you learn how code and data are represented in memory and how to make low-level changes to a program in an assembly language. You will create modifications (mods) to a game.

Use the following commands to connect to your remote home directory:

• mkdir tardis-home/
• sshfs <yournethzlogin>@login.ee.ethz.ch: tardis-home/

Store all your files during this lab in a folder below tardis-home, so it is stored remotely in case your machine crashes.

• 0) Download and unpack the ZIP file with the the material for this lab from http://www.disco.ethz.ch/lectures/ti2fp/exercises/disassembly.zip. It contains the necessary files for exercises 1&2.

• 1) Execute the program bomb. It tells your to find a correct input to defuse its 'bomb'. Find the correct input by disassembling the program or looking at the HEX-representation.

• 2) When you run this program (TuxRaR), a pop-up will appear that asks you to pay for a license. Disable this pop-up (or postpone it for a long time).

• 3) Now, you are ready to hack into SuperTuxKart! The game is installed on your machines. Show us your abilities by modifying the game in cool ways. For instance, make your kart faster, get better items, etc. Before you start modifying the binary, we recommend you to save a backup copy of it so when you break the game, you always have a clean copy. If you prefer, you can also modify a different game.
  Hint: Have a look at the --demangle option of objdump.

• Text editor: Geany
• Hex editors: wxHexEditor, ghex
• Disassembler: objdump
• Web assembler/disassembler: https://defuse.ca/online-x86-assembler.htm (Attention: Uses Intel syntax, which has arguments in different order than objdump.)

• IA-32 cheat sheet (GNU format): http://www.cs.utsa.edu/~clark/cs3843/IA32cheatSheet.pdf
• Intel IA-32 instruction set reference: http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-instruction-set-reference-manual-325383.pdf

• Some items and events slow karts down, that is, their maximum speed is reduced. Disable the function which sets this slowdown.
• Karts' maximum speed can be increased by some events. Prevent the maximum speed from being reset to its original value.
• Karts are slowed down when being off the track.
• Infinite nitro: When nitro is burned, the nitro reservers shrink…