ottonta's keygenme

Author:
ottonta

Language:
C/C++

Upload:
2023-04-15 15:46

Download

Platform:
Windows

Difficulty:
3.6

Quality:
4.5

Arch:
x86-64

Downloads:
12

Size:
56.00 KB

Writeups:
0

Comments:
6

Description

my first try to create crackme. No patching only keygen ( or just find key but it easy ). Use custom code mutation

Comments (6)
Writeups (0)

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janbabie on 2023-04-18 17:10: When I try to drag any of the Crackme challenges file's to x64dbg it says "invalid PE file", how can I fix this.

nnxstnt on 2023-05-09 10:39: Great crackme had a lot of fun

f1ref1st on 2023-06-09 07:45: do i need just to get the key for my input or understand the keygen process itself !!

jeffli6789 on 2023-07-05 14:12: @f1ref1st, the intention is to understand the algorithm and write a keygen, otherwise the challenge would be trivial

timotei_ on 2023-07-07 17:43: This crackme welcomes us with code obfuscation, to be more precise with control-flow transformation that removes the structured flow (tigress obfuscator?). Basically it cyphers the username and extend it. Afterwards the cyphered username string gets hashed word-wise. The main challenge seems to keep track on the flow since the code is overbloated with useless instructions and uses unconventional arithmetics for simple tasks.

HateTeamsAndHatePPL on 2024-02-08 12:30: I decrypted every strings using the static key, found the algo using dynamic analysis, wrote an algo. My algo didn't work for all usernames, then i tried to understand why ! I tried the username "bb" and everytime the corresponding password is different. I'm pretty sure that algo used in this application have some flaws and make it harder to do it properly. The example with "bb" is just a weird case, i didn't talk about other evidences. The word "username" triggered : 22 B3 96 01 7F F6 23 24 also did for the word "florentt" : 22 B3 96 01 7F F6 1C 15 but the second part is still different (which i have properly computed)

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ottonta's keygenme