Hello,
Here is the source code of a program that xors a file (from which we type the location/name, xored file is copied to file "output.fle").
I guess there are many flaws in it:
-the xor process is a bit trivial, this encryption is very easy to crack.
-the file size must not exceed 2GB, the file title must not exceed 64 bytes.
-Im pretty sure there are other concerns, in matter of security as in term of efficiency.
Thanks in advance for your advices.
Olivier
PS:
(build.bat file):
ml64 madXor.asm /link /subsystem:console /entry:main
(Visual Studio 2022 Developer Command Prompt v17.6.4)
First of all: why 64-bit? This would be so much easier in 32-bit. And 64-bit is total overkill for the trivial task you're doing here.
Hi OlivierS,
You would like to use the Masm64 SDK making easier coding.
Hi and thank you for your replies.
Why 64 bits? My computer OS is a windows 64 machine and the book i have is about 64 bit masm programming. Those are the reasons why i did not choose 32 bits. As you probably noticed, im a beginner(lol). I didnot know i could compile in x32 bit on a win64 machine. I will take a look at the documentation on the forum.
@Vortex, i will take a look at the masm64 sdk for easier coding.
Thank you all :smiley:
It is really so much easier (Win32) and it still works like a charm even on fancy-schmancy 64-bit systems.
BTW, 32-bit is referred to as "X86" (after the Intel line of processors), while 64-bit is "X64".
Quote from: OlivierS on April 08, 2024, 02:39:00 AMHello,
Here is the source code of a program that xors a file (from which we type the location/name, xored file is copied to file "output.fle").
I guess there are many flaws in it:
-the xor process is a bit trivial, this encryption is very easy to crack.
-the file size must not exceed 2GB, the file title must not exceed 64 bytes.
-Im pretty sure there are other concerns, in matter of security as in term of efficiency.
Thanks in advance for your advices.
Olivier
PS:
(build.bat file):
ml64 madXor.asm /link /subsystem:console /entry:main
(Visual Studio 2022 Developer Command Prompt v17.6.4)
2 byte password resets at FF+1 (range: 0, FF) if you're implementing byte per byte XORing but visualize the extra routines that you can use at full, say, rax register..
and wait, there are more registers...