Cheat Engine

oib111 · Posted: Sun Aug 19, 2007 2:23 pm Post subject: Encrypting programs?

Plain and simple. How do I encrypt certain things in programs. Like passwords, id's, stuff like that?

Symbol · Posted: Sun Aug 19, 2007 2:30 pm Post subject:

make another check? and a check to that?
u said "how can i check if the check was changed"
so... u can change the check of the check of the check of the check etc...
i guess u can make a value that always changes and checks the check? O_o

UnLmtD · Posted: Sun Aug 19, 2007 2:31 pm Post subject:

Well if you want to do it they way you described, you could check the opcodes at the address.

oib111 · Posted: Sun Aug 19, 2007 2:31 pm Post subject:

I mean the check in the program that checks for the password and id. I want to make a check to see if they changed that check ^^

Ex.

Someone changed JE to JNE

Someone changed JNE to JE

Edit:

I figured it out. I was thinking. Well, why not go into olly and change a program and see what it was. But before I even did that I remembered godmode(good 'ol godmode). Which struck when I first learned direct byte. When godmode was at JE its bytes started with 74, and when it was JNE it was 75. So I just check for that change on the first byte. And I realized that nop was equivalent to DB 90 90 90, so just check for 90 instead of 0...

UnLmtD · Posted: Sun Aug 19, 2007 2:41 pm Post subject:

I don't know if you got me, what I meant is check the opcode at your address if it is what you want. If I'm not wrong, JE = 0x74 JNE = 0x75

oib111 · Posted: Sun Aug 19, 2007 2:46 pm Post subject:

I was going for that too, but since I'm reading bytes I can't do that. And I just said JE = 74 and JNE = 75.

Ok, this thread is now going to be about encrypting programs!

hcavolsdsadgadsg · Posted: Sun Aug 19, 2007 2:46 pm Post subject:

Symbol · Posted: Sun Aug 19, 2007 2:49 pm Post subject:

actully nop is 0x90 not 90 90 90... thats nop nop nop
but u can nop that check... O_O
well why would we want to do that..?
and if u want to make the check work u gotta check bytes 0x90 if thats what u've done :O
what if u change it to db dd? xD

edit:
now that u edited ur post...
there are few ways... i know only 1 O_o
it sux... so.. :O
i use 2 variables (or more...) and then make like

var
var1:=Integer, String;
var2:=Integer, String;
begin
var1:=z0mg
var2:=lolz
if Edit1.Text = Var1+var2+'1337' then

so if password is z0mglolz1337 then...

oib111 · Posted: Sun Aug 19, 2007 2:58 pm Post subject:

Um, I was talking about assembly. In assembly nop is equivalent to db 90 90 90...and I edited the post because I solved the problem and I have a new one...

sponge · Posted: Sun Aug 19, 2007 3:03 pm Post subject:

CRC...

kittonkicker · Posted: Sun Aug 19, 2007 3:06 pm Post subject:

Make your program generate an MD5 hash of the .code section, and then create a thread to watch it.

If at any point the MD5 != the MD5 you stored, crash the process!

Symbol · Posted: Sun Aug 19, 2007 3:11 pm Post subject:

what..? english?
i understand the last part but if MD5 = lets say 1337 then MD5 = 1337 which = MD5 so therfore MD5 = MD5?

kittonkicker · Posted: Sun Aug 19, 2007 3:13 pm Post subject:

I'm not gonna teach this guy how to code...

TheSorc3r3r · Posted: Sun Aug 19, 2007 4:45 pm Post subject:

Search the crackme section for Uligor's second crackme, good example of encryption.

DeletedUser14087 · Posted: Sun Aug 19, 2007 5:51 pm Post subject:

The best crackme source ever