Sunday, March 16, 2014

Magic Numbers crackme solution

I've decided to solve some crackme and randomly selected a crackme named magic. I've downloaded this one from a good crackmes collection here. This is my first solution write up for crackme, so don't judge strictly :)
In this crackme needed to find a correct combination of 16 "magic numbers" (serial). So firstly it's needed to understand checking algorithm.
Checking algorithm is the next:
1) The serial must contain all numbers in the range [0..F] and these numbers must be unique.
2) Numbers must satisfy the following conditions:
x1 + x2 + x3 + x4 = x5 + x6 + x7 + x8 = x9 + x10 + x11 + x12 = x13 + x14 + x15 + x16 =
x1 + x5 + x9 + x13 = x2 + x6 + x10 + x14 = x3 + x7 + x11 + x15 = x4 + x8 + x12 + x16 =
x1 + x6 + x11 + x16 =
x4 + x7 + x10 + x13
After understanding the magic numbers checking algorithm, I've coded a program to find some appropriate combinations.
Success!
By the way "About" button doing nothing until you have created a file "Info.txt" with the some about data.
Here is about dialog with my info:
That's all.