Lars

About

Lars is a collection of libraries that provide a programmatic way to manipulate Lua 5.1 bytecode in Luau.

Lars targets Roblox, but the code could be easily modified to work in another Luau environment.

Use cases

Re-implementing arbitrary code execution in an environment without loadstring or similar (bytecode compiler not included)
Sandboxing
Analyzing obfuscation with a custom deserializer implementation
Modifying existing bytecode to optimize or change instructions

Features

This project is still a work-in-progress, so not all features have been implemented yet. Planned and implemented features are listed below.

Installation

WIP, not published on Wally yet

Documentation

WIP

Credits

FiOne by Rerumu was used as the base for most of the virtual machine.

FiOne
Copyright (C) 2021  Rerumu

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

A No-Frills Introduction to Lua 5.1 VM Instructions by Kein-Hong Man, esq. provided a great deal of insight into Lua's internals, and is the foundation of my own knowledge of the bytecode format.

chreen/Lars