How to deobfuscate AS3 source code? - actionscript-3

Is there a way to de-obfuscate AS3? With de-obfuscation I mean making it compilable again. At this moment I lost some source code and only have the Flash file left. The problem I now face is that the compiler is not able to compile it as the class names contain illegal characters.
I could start manually naming all classes again however I'm not even certain if the de-compiler worked.
To compile the SWF again I use flash develop and the FlashSDK.
Regards.

This depends on how the code was obfuscated to begin with. If it was simply obfuscated by changing class/variable/function names, then you could use an IDE such as FlashDevelop which allows you to Refactor->Rename by right clicking the instance name which would rename it across the entire project. Or just do a simple find/replace using a text editor.
Knowing how the code was obfuscated is the most important thing though. Whichever program you used to obfuscate is probably going to provide you with the most information.
I would suggest, however, doing the bare minimum by removing all illegal characters first to see if it will compile.

Related

Trace Flash Builder compiling commands

is there a way to trace the compiler command for flash builder? I mean, I want to know the parameters and files that is compiling internally when I click "build" on FB.
Basically I moved a project to Flash Builder, and everything works fine but I have some runtime issues, and looks like the compiler is doing something wrong with some files (like using old files instead of using the one im changing, this occur only for a particular file, the rest works fine or I think that works fine). Also is different the way to embed some file, that's another reason to check what's doing internally.
I ran the game with mxmlc before, and probably I can compare what's the difference if I get the command executed by FB.
Also, I want to know how to do it if I need to research something in future.
Thanks for any help,
Regards
Flash Builder only recompiles if there has been a change to the code. So if you are changing an asset (image), for example, you won't recompile unless you also make a change to the project.
There are a few ways around this:
Easiest way is to just go into a file and press the space bar at the end of a line. It will add an extra byte to your file, but not to the project (compiler is "smart" and gets rid of unused files, classes, and characters). Since this is not a common thing, it shouldn't be an issue
Project->Clean.... That will force your workspace to rebuild and, in most cases, will also recompile your project
If #2 is failing, first delete bin-debug or whatever you are using as your debug folder, then run Project->Clean...
It's a tad bit annoying (especially when editing external libraries), but it allows for quicker re-launches of the debugger, which is the ultimate goal of that behavior.

Is Code On The Timeline Easier Or Harder For Hackers To Steal/Decompile?

Can anyone tell me whether code on the timeline is harder or easier to steal/decompile?
Or is it all just the same?
There's no real difference. A dedicated programmer can always get to and reverse engineer your ActionScript. Bear in mind it's not just 3rd party apps like Sothink that can be used. Even Adobe have a tool for 'inspecting' a swf: http://labs.adobe.com/technologies/swfinvestigator/.
If your code is genuinely special enough to warrant stealing, then you would want to use a platform other than Flash (or put your sensitive code into an external C/C++ assembly and run that using something like Alchemy).
Are you really doing something so unique that people are going to try to steal it, though? Is it so special they couldn't just figure out what you've done and copy it?
The difference is essentially nil. In AS3, timeline code will end up inside classes anyway. The code for the main timeline will appear in *filename*_fla.MainTimeline. The code for Symbol1 will appear in *filename*_fla.Symbol1, and so on.
Timeline code can be slightly easily to understand, since variables not explicitly declared as local variables will become class variables. The names of class variables are preserved in a SWF, whereas local variables are not.
Check out my online ActionScript dissembler if you're curious about how your code is stored inside a SWF.

Unify the size of swf

When I compile the same project with ant many times it gives a different sizes for each compilation
I added the rsl and more option to mxml it works fine ,but the size is still changed
Please any idea to unify the size
This is not really possible, unless you do some, quite involved post-processing. Below is the list of things I know to change the size between compiles, but it may not be exhaustive:
When you compile pure AS3 project or a project that uses framework:
Resources you embed on variables have their class names generated using the current date in the name.
Flex compiler generates a tag of obscure purpose (can be removed manually, but persists in release builds), which seem to contain a GUID and a compilation time or something similar. It is usually found at the very beginning of the SWF file, somewhere after the rectangle of the SWF dimensions.
In a project that uses framework:
All code generation is suspect to generating inconsistent names, particularly, all bindings will certainly produce different assembly upon each compile. Styles and some other rarely used metadata will cause this too.
Specifically for spark skins, which come as sources rather then compiled libraries - some of them embed resources in a bad way, so you would probably need to compile them into a library and plug it into a project, removing the sources from the source path.
All in all, if you are using pure AS3 project, your task is difficult, but doable (will require following certain conventions and some post-build script that unzips the SWF, purges the compiler-added extra tag and zips the SWF back. But if it is a SWF based on the framework - I'd say the effort isn't worth it, just accept it cannot be done.

Always importing too many classes... I think

I have a basic problem with knowing which classes to import for a given application, renderer, AS package, mxml component, etc. There seems to be hundreds of classes (both mx and flash) and I'm never sure which one(s) to import... so I just keep adding import statements until the errors go away. Is there a reference somewhere that I don't know about? Or does this just come with experience? Also... does importing a load of classes actually make the file size larger or does Flex only import the classes used nregardless of what I specify? If it only uses what is needed, why wouldn't everyone just do: import mx.*;
I would suggest that if you find yourself bringing in tons of imports, you should ask yourself: Does this class do to much?
It is less of a technical issue, and more of problem of object-oriented design -- maintainability, testability and stability.
I do my best to limit my external dependencies. I try to conform to SOLID principles that tell me that classes should exist for one reason. If a class does too much, it is a "code smell" and an indication that you should split it up.
How much is too much? It is tough to have a specific litmus test or limit... I just ask myself "What does this class do"? If my answer contains an "and" in it, then I consider splitting it up.
I think your problem is a not a real problem if you use any half decent IDE. If you're not using one, you probably should (even if it's not stricly necessary and you can write and compile with notepad and the command line).
If you are using Flex/Flash Builder, it will add the imports automatically (and remove the unneeded ones as well). Also, you can use Ctrl + SPACE to prompt autocomplete, which should add the necessary imports.
Flash Develop also manages this for you (the shortcut was Ctrl + Shift + 1 if I recall correctly, but I haven't used FD for a while).
There are other IDEs out there that I haven't personally used but also have this very basic feature.
If you're using the Flash IDE, well, it really sucks for writting code, so you should probably consider writting your code in some other less brain-dead editor if you plan to do anything more than a couple of lines of code here and there (again, you can write code in the Flash IDE but why not taking advantage of better tools when they're available?).
When you get an error, look at the API Reference for the class, and then either import the whole package or just the class you want. Highlighting the class and hitting F1 should also work (but I never search help this way).
As for file size, see my answer on Is it possible to dynamically create an instance of user-defined Class in Action Script 3?
As Juan pointed out, use FlashDevelop, it is a great (and free) IDE.
If you're using FlashDevelop with the Flex Compiler, you can compile straight from FlashDevelop, and use the refactoring tools they offer to slim down your imports.
Aside from that though, if you're not referencing them, they don't get compiled, so it's not like your compiled swf is any bigger.

How to compile the generated AS

hope you can help me with this question.
So, I've been working for a while with Flex, and had the crazy idea to create pure AS project.
If I compile a Flex app with the -keep flag, the generated actionscript gets generated.
Do you guys know of a way to make it compile, without going trough the code and gluing it all together?
Thanks.
Generated ActionScript is really only provided for reference; it's not really intended to be repurposed in that sense. Indeed, if you even have any, you've most likely compiled your project already anyway (unless you got it from somewhere else), so one might ask why you'd want to compile the generated stuff rather than your own source -- but nonetheless, although I haven't actually tried it, you should be able to point the Flex compiler mxmlc at your generated source to compile it, provided you're able to get all your dependencies to line up (which may be what you mean by "gluing it all together").
Just a thought, although again, I haven't actually tried it, so your results may vary. What is it you're trying to do, though? Just curious. :)
Like Christian mentioned, the generated AS code is pretty much there to serve as a reference. Just for fun, I tried compiling it from the command line using mxmlc, but part of the problem with doing that is that the class files generated don't match the classes they represent. So, you'd need to start renaming a bunch of your class files so that compiling those could even work. Many of the other classes in Flex won't be compiled in either, for the same reason.
As an example, the project I tested this with, had only one mxml file of source code in it. The generated output was 45 files. I'm sure that if you really wanted to do this, and were willing to invest the time in cleaning things up you could. But I'm curious too - why would you want to do this?
Actually it was just mere curiosity. I wanted to understand how the framework works and see how it merges it all together to make the final application, as I thought that the generated actionscript files were just a step in between the final SWF file, so I tought there should be a way for it to grab those files and generate the final application.
Eventually I would have tried to create a pure actionscript project just for the heck of it to see how complicated it was and what errors could happen when developing other stuff.
I know it sounds crazy, but I had some spare time, ha ha ha.