Any way to read the scripts?

[Erquint]

I'm getting *.luac files but normal LuaJIT decompilers aren't able to decompile those.

[JustAPotota]

There are 4 main steps to decompile script files (*.luac, *.scriptc, *.gui_scriptc, *.render_scriptc):

1. Decrypt the file using XTEA CTR and this key.
2. Decompress the result using LZ4.
3. Parse the resulting protobuf binary using this definition.
4. Decompile the bytecode stored in the script field.

Unfold can already do steps 2 and 3, but step 1 requires a Lua library that uses the same algorithm. I've got some ideas for that which should be pretty easy to implement. As for step 4, it'd be difficult to integrate a Python project like luajit-decompiler into Unfold, so I'll leave that part to you.

[Erquint]

Thank you for this detailed response.
Do I strictly need Defold installed for step 3?
Would it be possible in the future for you to implement steps 1-3 in Unfold?

[JustAPotota]

Protobufs were made by Google to be independent of programming languages, so you can do step 3 in any language/tool/framework that has a library for it. I do plan to add the first 3 steps to Unfold, but I haven't had a ton of time (or motivation) to work on it.

[Erquint]

Haven't worked with protobufs myself yet but it's good to know. Hopefully Ruby will do.
As for the rest, I see, a slave to whims of motivation myself as well.
It's been delightful to have you clarify all this. Looking forward to applying this knowledge to a datamining/guide-writing project I have for a certain game.
Cheers!

[suphamster]

There are 4 main steps to decompile script files (*.luac, *.scriptc, *.gui_scriptc, *.render_scriptc):

1. Decrypt the file using XTEA CTR and this key.
2. Decompress the result using LZ4.
3. Parse the resulting protobuf binary using this definition.
4. Decompile the bytecode stored in the script field.

Can u plz tell how to decompile attached script after Unfolding the game with latest version build from sources?
Btw most of the scripts decompiled just fine but few of them seems additionally protected (maybe by base64.luac which also encrypted).
check.zip
base64.zip
Both files has "45 91 cc d6 e7 10" in header but I dunno if this means anything...
Error log:
ERROR:SCRIPT: /ddf/ddf.lua:54: attempt to index local 'field' (a nil value)
stack traceback:
/ddf/ddf.lua:54: in function encode
/ddf/ddf.lua:76: in function </ddf/ddf.lua:49>
/unfold.lua:258: in function decode_file
/unfold.lua:271: in function decompile_files
/main/main.gui_script:210: in function on_click
/main/main.gui_script:70: in function button
/main/main.gui_script:151: in function </main/main.gui_script:126>
Update: Also there are a "ERROR:SCRIPT: Lua memory allocation error." at files (game.arcd) bigger 1Gb.

[cweiske]

The .luac files can have both compiled bytecode and lua source code included. You can see that in lua_source_ddf.proto:

message LuaSource
{
    // HTML platforms uses script (vanilla lua), all
    // other platforms uses bytecode instead.
    optional bytes script                               = 1;
...
    optional bytes bytecode                             = 3;
    optional bytes bytecode_64                          = 4;
}

[suphamster]

The .luac files can have both compiled bytecode and lua source code included. You can see that in lua_source_ddf.proto:

message LuaSource
{
    // HTML platforms uses script (vanilla lua), all
    // other platforms uses bytecode instead.
    optional bytes script                               = 1;
...
    optional bytes bytecode                             = 3;
    optional bytes bytecode_64                          = 4;
}

Thanks but sadly this not much help for me since I've tried to decompile it with this tool https://github.com/sztupy/luadec51 and that https://github.com/CallowBlack/genshin-luadec/releases/tag/v1.0.0 but its just throws me error "Luadec51: base64.luac:1: unexpected symbol near 'char(21)'".