Author:
prague

Language:
Java

Upload:
7:25 PM 04/29/2024

Download

Platform
Multiplatform

Difficulty:
5.0

Quality:
4.0

Arch:
java

Description

I believe a lot of crackmes nowadays focus too much on key gens and not the actual protection of the crackme, you also at some point need to learn how software protection techniques are employed, how they work, and most importantly how to break them, because at some point you may not have the luxury of being able to actually understand what the code is doing. This crackme attempts to teach you exactly that, it is not easy, you are encouraged to patch your way through it, it attempts to show off the most modern software protection techniques at the moment and how much they can really do even when the actual licensing system at the core of the software is easy to reverse. Techniques in this crackme include: multi-layered bytecode obfuscation, virtualization and packing. There may be more but you will have to find them yourself. Any solutions for the crackme are always appreciated. P.S. "@.bin" needs to be in the same location as "crackme.jar". Good luck, god bless.

• Comments
• Solutions

cnathansmith on 11:27 AM 05/08/2024: Are we supposed to just make it not crash? $ java -jar crackme.jar Picked up _JAVA_OPTIONS: -Dawt.useSystemAAFontSettings=on -Dswing.aatext=true Exception in thread "main" java.lang.ExceptionInInitializerError at org.prague.o.main(o.java) Caused by: java.lang.ArrayIndexOutOfBoundsException: Index 13 out of bounds for length 13 at org.prague.k.(k.java) ... 1 more

jvmka on 10:03 AM 05/09/2024: As I understand it, we must enter the correct key, we need to try to decompile the class because selecting the key may take too much time.

prague on 10:37 AM 05/09/2024: forgot to say, use OpenJDK or one of its derivatives, i personally suggest Zulu 17.

prague on 5:16 AM 05/13/2024: nvm, this crackme is somehow broken, i am completely lost in the sauce. =(

cnathansmith on 11:38 PM 05/16/2024: I'm interested in seeing a version of this that does work correctly. I don't know anything at all about Java bytecode. If there's a new version of this challenge that just requires me to learn a bunch of things then that would be interesting.

You must me logged to submit a solution