[Essays]

Here you will find essays on various things, mostly reversing oriented. I will try only to pick interesting targets, and to not cover the entire protection scheme. I do not wish to provide keygens or "code giveaways", as I believe software authors should be given a chance. Call me a white hat if you wish.

Dualcore musings
After upgrading to a dualcore system, I ran into some problems and performance tweaks. This is a short text with some of my musings and solutions, and stray thoughts. Enjoy :)

 

Playing with MSRs: AMD -> Pentium4
Many AMD CPUs allow you to change the information returned from CPUID by programming Machine Specific Registers. This little essay discusses this further, and provides code to make an AMD box report itself as a Pentium4.

 

Synchronize It! (WinSin)
An interesting protection with encrypted code and CRC32 checking. Unless you have a valid name/serial combination, you will need to do bruteforcing to complete this target. I focus on how to reduce the keyspace search to make it possible to find the key in a reasoable amount of time.

 

[yAtEs] crackme1
Bruteforcing a reduced TEA encryption, and removing the decryption (and keyfile checking) wrapper. Brew a cup of coffee and enjoy.

 

XCOM Pitch-Patching
Fixing a bug without having the source. Good old "XCOM: Ufo Defense" (with the much cooler european title: "UFO: Enemy Unknown"). Following DirectDraw method calls, creatin a loader to fix the bug.

 

DesrevereDD0f