| View previous topic :: View next topic |
| Author |
Message |
False Prophet
Expert Cheater
 Reputation: -1
Joined: 28 May 2006
Posts: 121
|
 Posted: Tue Oct 27, 2009 6:36 am Post subject: [CrackMe] zxcEncryptor -- Attempt 2 |
 |
|
Alright, my very first attempt at making a CrackMe failed 2 or 3 hours later.
Here is my second attempt.
There is no predetermined key.
I've added dummy code, and used a little bit of Assembly.
If you figure it out, please post how you did it.
My last attempt had direct comparison. This shouldn't have that(I hope).
Download: here.
_________________
Last edited by False Prophet on Tue Oct 27, 2009 6:58 am; edited 1 time in total |
|
| Back to top |
|
 |
Bswap
Newbie cheater
 Reputation: 0
Joined: 18 Aug 2009
Posts: 21
|
| Posted: Tue Oct 27, 2009 6:53 am Post subject: re: |
|
|
Breakpoint @0040758F;
| Code: | 00407583 |. 030D F8C04000 |ADD ECX,DWORD PTR DS:[40C0F8]
00407589 |. 0315 F8C04000 |ADD EDX,DWORD PTR DS:[40C0F8]
0040758F |. E8 5C2D0000 |CALL zxcEncyp.0040A2F0 |
| Code: | ECX 003F07E0 ASCII "1234567890" (what I entered)
EDX 003F07EB ASCII "tf08n5vnyofajzucf3cs" (valid computed serial) |
Modify the ECX (003F07E0) register so that it's contents are the same as EDX (003F07EB).
| Code: | ECX 003F07EB ASCII "tf08n5vnyofajzucf3cs"
EDX 003F07EB ASCII "tf08n5vnyofajzucf3cs" |
F9 to continue execution.
"Unlocked!"
|
|
| Back to top |
|
|
False Prophet
Expert Cheater
Reputation: -1
Joined: 28 May 2006
Posts: 121
|
| Posted: Tue Oct 27, 2009 6:59 am Post subject: |
|
|
Damn, I suck. 
Nice job. + rep for you!
[Edit] I was going to add an encryption rotate code, but decided against it. Maybe I should do that?
_________________
|
|
| Back to top |
|
|
Bswap
Newbie cheater
Reputation: 0
Joined: 18 Aug 2009
Posts: 21
|
| Posted: Tue Oct 27, 2009 7:10 am Post subject: re: |
|
|
Parts of the program are nice.
|
|
| Back to top |
|
|
False Prophet
Expert Cheater
Reputation: -1
Joined: 28 May 2006
Posts: 121
|
| Posted: Tue Oct 27, 2009 7:16 am Post subject: Re: re: |
|
|
| Bswap wrote: | Parts of the program are nice.
|
Thank you 
I think I am slowly strengthening my program.
I hope that I'll be able to make something much more secure with a little bit more practice.
_________________
|
|
| Back to top |
|
|
DoomsDay
Grandmaster Cheater
 Reputation: 0
Joined: 06 Jan 2007
Posts: 768
Location: %HomePath%
|
| Posted: Tue Oct 27, 2009 9:50 am Post subject: |
|
|
You should modify the entered password and then compare it against a constant, or, in case of a keygenme, a different item generated from the user-name\id\etc.
An axample would be:
if (rotate1(name) == rotate2(password))...
when the rotate algorithms differ.
|
|
| Back to top |
|
|
False Prophet
Expert Cheater
Reputation: -1
Joined: 28 May 2006
Posts: 121
|
| Posted: Tue Oct 27, 2009 8:59 pm Post subject: |
|
|
What would the best method be at creating an "uncrackable" crackme?
CRC's?
_________________
|
|
| Back to top |
|
|
&Vage
Grandmaster Cheater Supreme
![]() Reputation: 0
Joined: 25 Jul 2008
Posts: 1053
|
| Posted: Wed Oct 28, 2009 4:31 pm Post subject: |
|
|
| Nothing is uncrackable, what I do is use the custom hash of my string and compare it to a hashed user inputted string.
|
|
| Back to top |
|
|
mingyuan
How do I cheat?
![]() Reputation: 0
Joined: 16 Aug 2011
Posts: 1
|
| Posted: Mon Sep 12, 2011 2:35 am Post subject: |
|
|
| &Vage wrote: | | Nothing is uncrackable, what I do is use the custom hash of my string and compare it to a hashed user inputted string. |
then other people can crack the compare ,such as jnz --> jz ,
|
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
