Hacking the Xbox

Chapter 11 - Developing Software for the Xbox 169
out the Project B Prize Rules web page at
http://xbox-linux.sourceforge.net/
articles.php?aid=20030023081956.)
Recently, a buffer overrun exploit was discovered in the way saved games
are handled by Electronic Arts’ “007: Agent Under Fire” game. The
exploit was first divulged by a hacker known simply as “habibi_xbox” on
March 29, 2003 through a posting on the XboxHacker.net BBS. Significantly,
the exploit was identified in an undisclosed number of games, but
“007: Agent Under Fire” was the only game explicitly named in the
posting. The exploit leverages an unchecked string to run a short segment
(a few hundred bytes) of code that inserts a series of kernel patches.
Various measures were included in the design of the hack to make it very
difficult to modify the hack to do anything other than run the intended
Xbox-Linux target. For example, the hack patches the original Xbox
RSA public key, used for verifying digital signatures, with a new public
key, while leaving the digital signature check algorithm unpatched. Only
the Xbox-Linux bootloader, provided as part of the hack, is appropriately
signed with the corresponding new private key. Other hackers
would have to factor the new public key in order to use this hack to run
other executables. Also, the “007: Agent Under Fire” game itself
performs an independent digital signature check on all saved games, so
modifying the exploit code in the hacked savegame file is not trivial. The
inclusion of such security measures in the hack is a laudable decision on
Why do you hack?
After getting more experienced in programming I started to
discover that the beautiful and bright entity of the computer
world is in fact a fragile patchwork.
In the beginning hacking was like a game for me. You could
walk around inside your computer system discovering worlds
of new code and possibilities every single day. Occasionally
one could challenge the application authors to a duel
by trying to analyze and circumvent their copy protections.
Sometimes it was like playing chess; other times it was
like a deathmatch.
On one hand I was excited to see my knowledge growing
and on the other hand it was naturally a great ego boost
for a 14 year old child to circumvent security systems of
overpaid godlike hardcore programmers. During my time
as a senior high school, I revised this view — while programming
tools and applications for some local companies during
school vacations I met some genuine programmers —
and was disappointed: they were neither gods, nor godlike.
After some time i realized that writing a cool demo, hacking
application X, or finding a nifty hack for Y doesn’t change
the world more than a sack of rice toppling down somewhere
in China. So I started choosing my realms more wisely
— technologies of everyday life like telephones, computers,
(continued)