Welcome! This is a collection of java crackmes i made.
| Crackme | Difficulty | Estimated time | Short description | Key format | Solution |
|---|---|---|---|---|---|
| #1 | ★★★☆☆ | 1 hour | Annoying obfuscation | 32-bit int | ✓ |
| #2 | ★★★☆☆ | 1.5 hours | Annoying obfuscation | 32-bit int | ✗ |
| #3 | ★★★★☆ | 6 hours | Dynamic invokation | 64-bit long | ✗ |
| #4 | ★★☆☆☆ | 45 minutes | Easy but tricky | length 16 hex | ✓ |
| #5 | ★★★★★ | 5 hours | Annoying subroutines | hex | ✗ |
| #6 (NEW) | ★★★☆☆ | 2.5 hours | Lockpicking a door | alphanumeric | ✗ |
| #7 (NEW) | ★☆☆☆☆ | 30 minutes | For beginners | hex | ✗ |
Run each file with java -jar <crackme>.jar <key>, if that does not work, use java -cp <crackme>.jar <class with main method> <key>.
The goal is to find a working key to input as argument, without bruteforcing the program, but with writing a keygen (that should not take longer than 30 seconds) or calculating the key by hand. Solutions with only the key are not accepted, you should explain how you solved it and attach the keygen you wrote (if you used one). Every crackme has been tested for a working key. There can be multiple solutions for some crackmes. If you want to, you can submit solutions via issues, and I will add them to the repository.