how can I un-emcrypt a hex file or bin file guys
if is possible to..


thanks golpemortal
Posted on 2002-12-23 20:34:13 by golpemortal
Hi golpemortal

There's lot of way to encrypt and decrypt "TEXT" or any "CHAR STRING". It depends which one you chose.

Regards
Posted on 2002-12-23 22:05:45 by processingspeed
such as?
Posted on 2002-12-23 22:07:02 by golpemortal
Your question is vague...

What do you want exactly to do ?
Crypt the buffer, encode it ?

Simples solutions are XOR, or binary byte swap table... but that is easily defeatable...

Some encryptions algorithms are much more secure (BlowFish, DES, etc).
Posted on 2002-12-24 01:19:45 by JCP
Heres an example I made a while ago while I was learning asm. You enter a text string and password and it will XOR the text string with the password. Sorry I couldn't find the source code, I just reformatted and its on a backup cd somewhere. I got some help off someone but I can't remember who.

e.g.

invoke GetDlgItemText, hWnd, IDC_PASSWORD, offset PassWord, sizeof PassWord
invoke GetDlgItemText, hWnd, IDC_INPUT, offset buffer, sizeof buffer
or eax, eax
jz finished
xor edx, edx
lea esi, buffer
crypt_loop:
mov dl,
or dl, dl
je fini
.IF PassWord(0)
xor dl, PassWord(1)
.ENDIF
.IF PassWord(1)
xor dl, PassWord(1)
.ENDIF
.IF PassWord(2)
xor dl, PassWord(2)
.ENDIF
.IF PassWord(3)
xor dl, PassWord(3)
.ENDIF
mov , dl
inc esi
jmp crypt_loop
finished:
invoke SetDlgItemText, hWnd, IDC_OUTPUT, offset buffer
xor eax, eax
ret

or something like that was the "macro" I used.
Posted on 2002-12-25 18:22:19 by sMiLeY-jOnEs
thanks ....

that is close enouhgh sMiLeY-jOnEs
Posted on 2002-12-25 19:58:52 by golpemortal
I was just showing you one of many ways to use encryption. The point was that you can't decrypt something unless you know how it was encrypted and what the password was if it used one.
Posted on 2002-12-26 05:05:00 by sMiLeY-jOnEs
golpemortal,

Have a look at some functions in the MASM32 library, there are a few that will encrypt a source with another source. They are there for "one pass padd" style encryption so if you can keep up a supply of truly unique passwords, its a powerful system.

Alternatively look for some of the later block cypher encryption methods.

One thing, please post technical questions in the MAIN forum, this one is for MASM32 specific issues.

Regards,

hutch@movsd.com
Posted on 2002-12-26 18:21:23 by hutch--