downloadbrowseT.0.R.N.A.D.0.'s CrackMe #1

Download T.0.R.N.A.D.0.__s_CrackMe_#1.zip, 9 kb (password: crackmes.de)
Browse contents of T.0.R.N.A.D.0.__s_CrackMe_#1.zip

>>>> READ-ME FOR T.0.R.N.A.D.0.'s CrackMe #1
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

PLATFORM :: WINDOWS
LANGUAGE :: ANSI C++
DIFFICULTY :: 1 [ Very Easy, for newbies ]

The Rules:
==========---
** Universal ** : (*) NO BRUTE-FORCING
(*) NO PATCHING

The Tasks:
==========---
1. Simply enter a secret code that would pass ALL the tests.
2. Reverse the complete algorithm for checking the code.
3. Write a descent tutorial.

IMPORTANT :: Explain in your solution, how you found "the" secret code that would
pass Test #3. Tests #1, #2 are easy enough. NO BRUTE-FORCING.
Pure Mathematics :)
The secret code is interesting enough, although very small.

~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~

printf("T.0.R.N.A.D.0. - born 2 %X\n",49374);

_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_

Difficulty: 1 - Very easy, for newbies
Platform: Windows
Language: C/C++

Published: 16. Apr, 2009
Downloads: 1181

Rating

Waiting for at least 3 votes
(we have only 1).

Rate this crackme:

Send a message to T.0.R.N.A.D.0. »

View profile of T.0.R.N.A.D.0. »

Solutions

Solution by DoomsDay, published 20. apr, 2009; download (4 kb), password: crackmes.de or browse.

DoomsDay has not rated this crackme yet.

Submit your solution »

Discussion and comments

T.0.R.N.A.D.0.
Author
16. Apr 2009		Very easy, for newbies ! :)
T.0.R.N.A.D.0.
Author
19. Apr 2009		IMPORTANT :::

I forgot 2 mention : THERE ARE '2' VALID SECRET CODES. FIND BOTH OF THEM AND THEN POST YOUR SOLUTION.

YOUR SOLUTION SHOULD EXPLAIN HOW YOU FOUND THOSE CODES *WITHOUT* BRUTE-FORCE.
T.0.R.N.A.D.0.
Author
20. Apr 2009		@ DoomsDay :

INCORRECT ANALYSIS !!!!

Test #2 does NOT ONLY accept integers which are made of "8"s.

Please think again.

Try to enter 8118 and see that it passes Test #2.


FURTHER, -8 cannot be accepted. There exist ONLY ONE MORE acceptable POSITIVE SOLUTION except 8.

Try to find it :)
T.0.R.N.A.D.0.
Author
20. Apr 2009		Even 6119 passes Test #2, it has NO "8"s AT ALL !!!!

Please update your solution DoomsDay and thanx for trying. :)
andrewl.us
Moderator
20. Apr 2009		I tested 8 and -8 and they were (and are) both accepted by the crackme.

The original requirement was "Simply enter a secret code that would pass ALL the tests." which DoomsDay found: 8.

Your comment at a later date indicated the existence of a second number that would pass all test. DoomsDay's tutorial named a second number: -8.

While his analysis may not be perfect, the results of the analysis do indeed satisfy the crackme requirement. It is my opinion that the cracker can and should try any shortcut/exploit/attack allowed. If the crackme author wishes to constrain the cracker's behavior to his expectations, this should be reflected in precise crackme code and description.
T.0.R.N.A.D.0.
Author
20. Apr 2009		OK. Gonna upload Ver.2.0 :)

"While his analysis may not be perfect, the results of the analysis do indeed satisfy the crackme requirement."

What's important is the ANALYSIS i guess, and NOT the result.

You may leave your comment, thoughts and discuss this crackme with other reversers here.
Acting childish will not be tolerated.
HTML and such will be left as-is, so don't try.