GTA.Android.ASILoader

Proof of concept shared library (.so) loader for GTA III/VC/SA/LCS

Quick info

Android provides two locations for apps to store files into:

1. internal storage: no permissions needed, only the owning app can access the files (not even the user!)
2. external storage: permissions needed, any app can access the files (including the user)

For security reasons, Android apps can load shared libraries from these locations only:

1. APK (hard/time consuming to patch)
2. system directories (not writable by the user/app)
3. internal storage (readable/writable by the app only)

Usually, mods circumvent this loader restriction by packing the .so files directly into the APK. However, this approach comes with a big downside: you have to rebuild and reinstall the APK every time you make a change to the mod.

Solution

A master mod (ASI Loader) is packed into the APK like a normal mod. Everytime the app starts, the ASI Loader scans Android/data/<appid>/files/ASI/ directory for .asi files, copies them to internal storage then loads them into the process.

This way libs can be updated with a simple adb push to the app external directory.

Requirements

• GTA .apk file (preferably the latest version, otherwise the .patch file might fail)
• Android NDK
• apktool
• uber-apk-signer

Installation

1. Unpack the APK (apktool)
2. Apply: (patch)
   • src/patches/WarMedia.patch for GTA III/VC/SA
   • src/patches/GTAActivityBase.patch for GTA LCS
3. Build the ASI Loader (ndk-build)
4. Copy libASILoader.so to <unpack>/lib/armeabi-v7a/
5. Rebuild the APK (apktool)
6. Sign the APK (uber-apk-signer)
7. Copy and install the signed APK

If everything went good, you should see a message in logcat from the ASI Loader at game startup. You can also build and load the example mod.