Unfold - WIP Defold Modding Tool

#1

Hey, all! I’m proud to release a little something I’ve been working on for a while now. It’s a currently unfinished tool for modding Defold games, made in Defold. Right now, it can only extract files from a game’s archive. It’s possible to decompile most of these files into their original form, though implementing that requires a native extension port of lua-lz4, which I can’t make myself. Adding in the ability to re-import assets (actually modding a game) also requires that extension, so I’m at a bit of a stand-still with development at the moment. The README has more details about the technical side of things, so go read it if you’re interested.

Installation

You can download a build from the releases page or download the source code from the GitHub page and build it with Defold. Only Windows and macOS builds are available, since def-diags doesn’t support Linux yet. Until that gets fixed, you can easily run the Windows build on Linux through Wine.

Screenshots

UI:
38%20AM

Output from @pawel.jarosz21’s Witchcrafter:
10%20AM

9 Likes

#2

This is cool, and inevitable (devs have to assume anything they put into their games will inevitably be extracted / data mined), but by making it easy and accessible it lowers the technical barrier required to do other unfair things to the work of creators. Some of us had working exporting to see how possible it was years ago but did not publish it on purpose because a tool like this existing is a disincentive to use Defold. Besides being unfair to devs, it will encourage custom private forks of Defold that add more obstacles to the extraction process but also private forks of projects tend to not push their improvements back to main once they happen which hurts the entire ecosystem. Is easy modding worth it? Maybe. If you didn’t do it, someone else would have eventually but it’s still bittersweet when it happens.

Pros

  • Modding
  • Learning
  • Preservation

Cons

  • It can be illegal to do, unethical, immoral, opens people (who use this) up to liability
  • Piracy (any Lua authentication is easily defeated)
  • Cheating (multiplayer games get hacked clients even easier and faster to make)
  • Stealing (ripping assets, rehosting domain locked html5 games, taking all code and simply reskinning)
  • Malware (injecting bad code into your game and putting it on pirate sites)
  • More private forks of Defold to make the obfuscation process more complicated / everything else positive made on private forks less likely to be contributed back
  • Discourages devs to not publicize they made their games with Defold (why put a target on it, people will just search how to decompile Defold games)
  • Discourages devs from using Defold (not having an easy public decompile tool was one less momentary advantage it had)

In response to this, to make potential devs looking at Defold feel better, there needs to be a way to use custom encryption keys that can be obfuscated in ways which are not easily extracted (though I doubt this will happen in the official releases). It’s still a cat and mouse game but at least it can be distributed instead of having an all in one method. Decompiling should not be easy, not be easy to be human readable.

Other tools like Unity and Unreal have decompilers too, but they also make it less human readable and editable, and have options for custom encryption keys, so if people want a higher bar to decompiling it’s one more reason to use them.

5 Likes

#3

+, I have the same questions.
I am far from packing Defold files, so I would like to hear from more experienced ones: how much is the source code protected?
I quickly tried several decompilers and was unable to decompile the luac file. I don’t know much about this, but I hope there is some kind of protection.
P.S. This project is really cool

1 Like

#4

This tool is for now not yet complete. Even with custom obfuscation you have to assume that someone motivated enough will eventually decompile it, but making it easy for anyone who can press buttons is a real pity.

You can always beat people to punch by releasing most of your project’s code as public and open modules as many of us do. :innocent:

1 Like

#5

If completed, it will be amazing! Writing mods for Defold games :thinking:. That sounds nice!
It would be just cool to know such things to take them into account when writing code (for example, multiplayer, verification or some special things)

1 Like

#6

Yes, though unauthorized mods. There were already ways to mod Defold based games that could be done in official ways without decompiling the entire project. I’ve thought about it a lot but to me it seems dangerous because it’s hard to sandbox Lua code to protect users from dangerous mods that are actually malware. With the full project approach, there is no way to protect / sandbox users from malicious modifications. Once it happens we will all have to deal with many false positives from AV vendors in the future for all of our games.

1 Like

#7

If you really want to open up to modding of a game there’s other ways to go about it.

  • Lua code can easily be loaded from external files and executed in a running Defold game.
    • If you want to create a moddable game this is definitely the first and most obvious step.
    • If you add the ability to load external Lua files to your game you can open up your game to a lot of modding:
      • Modders could move UI elements, change their size and color.
      • Modders can create bots or tweak enemies, items and anything else imaginable
  • Being able to load and replace the contents of an entire texture is possible using resource.set() and soemthing like the Image Loader extension.
    • This would allow a modder to change the graphics in your game as well.
  • Switching out sounds should also be quite easy to do.

I agree. You can never ever protect your game from someone with enough dedication and time on their hands. But with accessible tools the bar is lowered.

Also, since the code of Defold now is available it makes it that much easier for someone intent on decompiling and ripping apart your game.

6 Likes

#8

Random thought from someone who doesn’t know anything about decompiling or modding games. This project makes me feel two things: :astonished: and :pensive:.

I think it’s sad that things like this exist because suddenly I feel like my privacy as a developer is gone. If people can easily dissect exactly how I made the game, I feel like everything I do with the project files (comments in the code, naming conventions, consistency, etc) are all being “watched” and judged by a bunch of random people. Although that may be irrational, it’s only an initial impression.

Additionally, if I want to open my game to modding, I’d rather offer an “official” process for it like @britzl mentioned rather than dealing with people ripping and changing the source files without restriction.

The :astonished: of course refers to how this project looks like pure wizardry to me. Really impressive.

4 Likes

#9

There are currently two layers of protection in place against decompiling source code:

  1. The code is encrypted using a static key and algorithm that are both available in plain text in the Defold repo
  2. Even after decrypting it, decompiling code is very difficult, and there aren’t any tools online that can completely decompile LuaJIT (though some do come quite close)

If Defold adds the option to change the encryption key and obfuscates it well in the game binary, source code will be practically impossible to decompile.

4 Likes

#10

I agree with most of the things said in this thread. I’m usually a fan of tinkering and breaking things, but when such tools are so easy to use that they can be used by somebody who doesn’t have enough background about our field to realise the moral implications of their tinkering, that’s a problem. I’ll always appreciate a good unauthorised mod to my games, but if the existence of this tool creates more problems and bad experiences for me/my players than it solves, then maybe no.

Having said that, I’d like to add something for @klaytonkowalski: Don’t ever be ashamed with your work. Focus on writing code that works. I probably have tens of thousands of lines of “dirty” code publicly on GitHub and I’m 100% fine with that. Moreso, I’m proud of it. I’m proud that it sometimes works, I’m proud that writing it was a learning experience and I’m also proud that I had fun doing it. And I still sometimes write “bad” code to get a job done fast and I’m still not ashamed of it, because I can say “Hey! I made a thing and that thing solved a problem I was having!”. Most people outside of yourself and your team don’t really give a damn about your code. And when there are others that do for whatever reason, the kind of people that would judge you when they see “a hack” in your work are exactly the kind of people you don’t need validation from. :slight_smile:

5 Likes

#11

Oo :hushed:

While modding is totally cool and definitely unevitable (if it would be, I guess we won’t be able to mod Witcher or RDR and so on) I must admit I feel really strange (not ashamed, but rather… appreciated, I guess, but kind of uncanny too :sweat_smile:) and I agree with others, that making it accessible for anyone could easily imply in having a lot of problems with people with bad intensions, @Pkeod pointed out almost all the cons :pensive:

There is one topic on the forum about modding, afaik @topbraj started it - how is it going now Alex?

BTW @JustAPotota, are you on my Discord with the same nick? :grin:

2 Likes

#12

That’s me!

1 Like

#13

I want to point out that the encryption of scripts exists only to make it moderately more difficult for a “hacker” to access your source code. We don’t want scripts to exist in plain text in the archive (which is the case for HTML5 where we can’t use LuaJIT). What we can do as an additional step, although it won’t matter much in the long run, is to move the key outside of the repo and inject it at build time.

As a developer I wouldn’t worry much about the source code. It the game as a whole I’d be more concerned about or your game idea. @Pkeod has done a great job with HTML5 games to advocate for domain locking your games so that they can’t be copied as is. And when it comes to protecting your game idea it’s an uphill battle. There are companies that are super skilled at cloning existing games and releasing with deceptively similar names and with similar graphics.

6 Likes

#14

The negative response here seems a bit out-of-proportion to me. Your 4000-line hobby project is not going to radically alter the Defold ecosystem. If someone wants to steal/hack a game, they’re going to do it. They’re probably already way better at it than you and have their own tools.

I wouldn’t expect your tool to see a lot of use, since any developer who wants modding will just build it into their project, but if it’s fun for you anyway, go for it. Maybe in the future it’ll help someone save a broken Defold project.

Dark Souls would have been unplayable on PC (with Keyboard/Mouse) if not for some hero who hacked the game to fix it.

4 Likes