Quote:
|
So you say that if you have split the code into single instructions, decoded everything so far that each instruction can be placed at any memory location in any random order and know enough about the code to convert it into any code doing the same, it is more than one simple step to write a VM?
|
That is exactly what I say my friend
I would say more: IMHO that is not even a small step for vm development. It's still only a sample of pure code scrambler. Of course it will complicate reversing, especially when you take memory blocks checksum results as descrambling arguments/parameters or opcodes decryption. Complicate, but for whom? Approximately 95% crackers. There is still 5% left of them and they expect much harder protection.
IMHO VM has to operate in own environment (CPU, registers, stack, memory - including structure and communication). Sometimes
virtual machines are misunderstand with
virtualization but the topic we discuss is not close to virtualisation too (VMWare and VirtualPC are).
EDIT: Sorry, I did not notice your question "how vm works then". Well, each one of us can have own definition and imagination but if you want to take a look at vm inside protector then you can take Themida - it contains vm but it resembles x86 (I mean is not very hard to reverse). Question
why is another topic, but you can answer it yourself looking at SPARC/PowerPC open source emulators available on the net.
Next kind of virtual machines are the ones residing in Atari/ZX/C64/Amiga emulators. They are often "perfect" virtual machines, able to serve as real virtual environment. If we are talking about vm in protections then definitely the best vm resides inside StarForce - it is already a legend. The rest is mystic...
Regards.