05-17-2024, 09:55 PM
Hi, I'm interested on getting all the assets of this game called "Windboys" that has announced the termination of its service at May 30th. Researching a little, i was able to find this blog that have some information about reveersing some mobile games, and noticed one talking about "masterdatas" that seems to be databases where all the data of the assets is organized, basically a manifest for the assets i think. My intention is to get all the files names with the masterdata files.
This game have 3 versions for the assets: WebGL, Android, iOS. I guess that the iOS have the best quality for them, but since i don't have an ios device i'm just trying to decrypt the android masterdatas since the webgl picture quality is worst. So I was able to find the server url and the way the download url is made through the web version.
https://play.game.windboys.jp/resources/...1685623358
the link seems to be composed like this
https://play.game.windboys.jp/resources/(asset version)/assets/(hashed name of the asset).Unity3d.(numbers)
I suspect that probably something it's different for the android version. Looking at the files on my phone I can see with the same example that a _ is added to the beginning of the hashed name and the name of the file i just the numbers at the end (not the same numbers as the web version).
i don't really comprehend how to use decompilers, but anyway i decompiled and analyzed the libil2cpp.so in Ghidra to get the functions, and now i'm stucked there. I guess i should find the function that encrypt the databases but i'm not sure how to do that. Since in the blog i mentioned before the encryption method was rijndaelmanaged + rfc2898derivedbytes, i thought that this is maybe using that, but i actually think that's being used for the stories of the game.
i asked this on a discord server and someone tell me that some of the first bytes of the masterdata files are base64 encoded, so maybe that can help with something. the assetbundles have a random byte before the unityfs header, so those aren't a problem.
i would appreciate all type of help, even if it's only some website resource or what's being used for obfuscation. sorry for weird phrasing or typos.
[attachment=16175]
This game have 3 versions for the assets: WebGL, Android, iOS. I guess that the iOS have the best quality for them, but since i don't have an ios device i'm just trying to decrypt the android masterdatas since the webgl picture quality is worst. So I was able to find the server url and the way the download url is made through the web version.
https://play.game.windboys.jp/resources/...1685623358
the link seems to be composed like this
https://play.game.windboys.jp/resources/(asset version)/assets/(hashed name of the asset).Unity3d.(numbers)
I suspect that probably something it's different for the android version. Looking at the files on my phone I can see with the same example that a _ is added to the beginning of the hashed name and the name of the file i just the numbers at the end (not the same numbers as the web version).
i don't really comprehend how to use decompilers, but anyway i decompiled and analyzed the libil2cpp.so in Ghidra to get the functions, and now i'm stucked there. I guess i should find the function that encrypt the databases but i'm not sure how to do that. Since in the blog i mentioned before the encryption method was rijndaelmanaged + rfc2898derivedbytes, i thought that this is maybe using that, but i actually think that's being used for the stories of the game.
i asked this on a discord server and someone tell me that some of the first bytes of the masterdata files are base64 encoded, so maybe that can help with something. the assetbundles have a random byte before the unityfs header, so those aren't a problem.
i would appreciate all type of help, even if it's only some website resource or what's being used for obfuscation. sorry for weird phrasing or typos.
[attachment=16175]