Cheat Engine

Game Hacking Dojo · Posted: Sun Oct 15, 2023 10:22 am Post subject: Script for random allocation

I don't know how to explain this correctly.
I'm dealing with a game that allocates memory as it goes and in many cases out of its modules. So, there's no way to get a module base address and offset to make a script. Well of course using AOB is always the best to eliminate all that. But when there are no caves it becomes more challenging. There are no empty sections close by, so it requires a 14-byte jump to reach the cave. In this case, I have to rewrite more addresses than needed. Within those addresses, I may get calls like 7FF9D9CE1B90 jumps like 7FF9D9F6EE78. After writing the script and jumping far to the cave, those calls and jumps bytes will have to change because it's no longer relevant.
is there a way I could write the script where it gets the original code as opcodes and rewrites it as opcodes?

Example:

ParkourPenguin · Posted: Sun Oct 15, 2023 12:24 pm Post subject:

Use `reassemble` if needed

Can't you just inject at 7FF9D9F8E374 instead?

Game Hacking Dojo · Posted: Sun Oct 15, 2023 1:21 pm Post subject:

What is reassemble?

Yes, I could inject a bit further from the jumps. But this script is only for demonstration purposes. I want a way to solve this issue completely without trying to solve it accordingly.
Worse case, I could inject a 5-byte jump to another address-free assembly code to inject my 14-byte jump there. But this is so inconvenient. There are always ways but I want something easy, secure and efficient.

Dark Byte · Posted: Sun Oct 15, 2023 2:13 pm Post subject:

use jmp1

ParkourPenguin · Posted: Sun Oct 15, 2023 3:00 pm Post subject:

`reassemble` disassembles an instruction at a given address and assembles it in place

e.g.

Game Hacking Dojo · Posted: Sun Oct 15, 2023 4:37 pm Post subject:

I tried the reassemble method (it's the best in my opinion for such a problem)
But it didn't work. The script didn't run <<84:Failure assembling ?? at 1B41E63009F>>
What did I do wrong?
I searched for documentation on the function but only found Cheat Engine Wiki.

This code is used in the script above without it, it runs but with it, I get the error <<84:Failure assembling ?? at 1B41E63009F>>

ParkourPenguin · Posted: Sun Oct 15, 2023 4:52 pm Post subject:

Reassemble runs before instructions get written to memory

Read from the original injection point. In your first example, it would be `aob_CharacterSelect+8` and `aob_CharacterSelect+A` (pretty sure it uses hex)

Game Hacking Dojo · Posted: Sun Oct 15, 2023 5:18 pm Post subject:

Yes, it worked this way. Thank you both
And yes it is in hex

The moral of the story the reassemble function copies a single line of assembly opcodes and writes the line back at the preferred location.