lutio's Keygenme1 by Lutio
| Download Keygenm1_By_Lutio.zip, 27 kb (password: crackmes.de) Browse contents of Keygenm1_By_Lutio.zip This is my first KeygenMe.
Difficulty: 2 - Needs a little brain (or luck) | RatingWaiting for at least 3 votes View profile of lutio » |
Solutions
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Discussion and comments
| DataBus 01. Jan 2014 | I believe this is impossible to keygen for the following reasons. Please correct me if I am wrong. (Not sure where to post this). I may be incorrect, but this is what I have found: 1. User computes a hash of a value and then compares it to the key. This is impossible to keygen without brute forcing. (But brute forcing isn't allowed). This algorithm is dependent on the value discussed in pointer number 2, however; it is always the same (no matter the inputted serial) therefore it is impossible to write a keygen for at this moment (or so I have found) 2. Most importantly, the user computes some values based on the inputted 8 length serial. However, he throws out the unique value and then saves the value that is the same for them all. This value is the same for any serial you input, I believe OP made a mistake here and possibly saved the wrong value MOV ECX,DWORD PTR SS:[EBP-4] SHL ECX, 3 MOV DWORD PTR SS:[EBP-4], ECX the value of EBP-4 is set earlier to 1 Therefore, as we can see, no matter what serial is entered the unique value will always be 0x01000000. And this will always fail the users verification check. |
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| DataBus 01. Jan 2014 | Also, I did not state this in my prior post. But the aforementioned code happens while OP enumerates the users serial. Therefore, the value eventually reaches 0x01000000 after the users enumeration of the inputted serial (The entered name seems to have no impact on the output of the key) |
| acruel 28. Nov 2015 | Still solvable, though. C:\Users\acruel\Desktop>c:\Python27\python.exe -c "print 'alice\n' + 'A' * 32 + '\xe4\x12\x34\x01'" | Keygenme1.exe Name: Serial: Invalid serial! Wrong serial! Congratulations, you've solved it! C:\Users\acruel\Desktop> |
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