downloadbrowseDrPepUr's DrPepUr #3 [KeyGenMe]

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DrPepUr#3 KeyGenMe

1. No Patching
2. No Self-Keygens (Refer to rule #1)
3. No Fishing - Valid Name & Serial Not Valid Solution
4. Write A Tutorial If You Feel Like It

Valid Solution

1. Working Keygen
By: Dustyh1981 / DrPepUr

Difficulty: 1 - Very easy, for newbies
Platform: Windows
Language: Assembler

Published: 10. Mar, 2008
Downloads: 801


Votes: 5
Crackme is quite nice.

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Solution by kilobyte.asm, published 27. dec, 2009; download (15 kb), password: or browse.

kilobyte.asm has rated this crackme as quite nice.

Solution by ORacLE_nJ, published 27. dec, 2009; download (45 kb), password: or browse.

ORacLE_nJ has rated this crackme as quite nice.

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Discussion and comments

14. Mar 2008
I can re-write its algrithm,but the program cheat my ollyDbg.I hope some one would like to improve it,and mail me if him(or she) like.Thanks.
14. Mar 2008
I do not understand what you are trying to say.
14. Mar 2008
oh,i am sorry.I had uploaded my solution and left that comment. But I do not know why the solution has not shown by now.And I also sent a mail to you.
That,my keygen only fits your program running under ollyDbg.
14. Mar 2008
in fact,the program didn't clear the right serial string in the memory,so,i changed the original file to make in display the right serial string other then wrong message when i typed a wrong serial string but had a right format.

to write a keygen,i re-wrote its algrithm.but found that the serial strings are different between running alone and running in ollyDbg. So I do not know to to resolve it.
14. Mar 2008
I think the admins look over the solutions before they put them up, however if your keygen does not work outside of ollydbg, you need to go back in and find out why. This is not a bug in the program it is intentional.....if you still can't figure it out drop me another email and I will give you a hint.
14. Mar 2008
my keygen work well now.but i could not update my uploaded solution now. someones needed will be welcom to mail me to gain a solution:
I also is a newbie,this is my first practice.
thnx DrPepUr
15. Mar 2008
Yes, we check every keygen with a list of names outside the debugger.
It would be a bad idea for people to learn from faulty solutions.
Also if the keygen is not compiled, the solution is rejected automatically.
16. Mar 2008
OK.I will update a new one with executable file again.
19. Dec 2009
Can you please give a hint...

I found a serial for my name, but it doesnt work outside the debugger..
I saw your post & decided to ask you for a hint..

This is the key i found to be working in the debugger..

Name: Administrator
S/N: B753B5-9267AD9EB161818F9

I keygenned it too.. But it doesnt work outside the debugger...

And one more question,

PUSH 004040D8 ; /String = "Thank You For Taking The Time To CrackMe ! ; - )"
CALL <JMP.&kernel32.OutputDebugString>; \OutputDebugStringA

What is the role of these lines in the keygenme??

Pls help me.. I'm a newbie..
20. Dec 2009
google OutputDebugStringA to find out what it does,
search for API references in code to find out where it is called then check the return values and see what it is stored as and then follow that value through out the program.

hope that helps a little.
21. Dec 2009
Thanx kilobyte.asm.. :-)

This is what i found from Win32Api Reference

The OutputDebugString function sends a string to the debugger for the current application.

Return Values
This function does not return a value.

If the application has no debugger, the system debugger displays the string. If the application has no debugger and the system debugger is not active, OutputDebugString does nothing.

But in this keygenme i didnt understand how it affects the serial generation.... Hope i'm being clear..
21. Dec 2009
step through the subroutine at 401000, after execution of OutputDebugString, something is definately returned in eax, then stored in 40445C, find references to this address constant in olly and follow the value about. Anyways outputdebugstring should return a 1 in eax in normal conditions(when not being ran under a debugger) according to the PDF I have on anti-debugging techniques.
23. Dec 2009
Thank you kilobyte.asm..

I have successfully keygened it...

I'll definitely post my solution soon.. :-)
23. Dec 2009
no problem, i'll post mine too when it's done.

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