dexdump is a lightweight toolchain for dumping in-memory DEX files from Android apps with root access.
It consists of 3 components: a minimal AOSP patch, a command line utility to trigger dumps, and a Python script to repair dumped DEX files.

• 🔧 AOSP Patch: Modifies DexFile::Init() to dump in-memory DEX when triggered.
• ⚙️ dexdump: Triggers the dump process by placing a flag file with correct ownership.
• 🛠️ fix_dex.py: Repairs broken DEX files by recalculating SHA-1 and Adler32 checksums.

This patch injects logic into the ART runtime (DexFile::Init) to dump the in-memory DEX when a trigger file is found:

• Trigger path: /data/data/<package_name>/files/dump.flag
• Output: /data/data/<package_name>/files/dump_<pid>_<ptr>_<timestamp>.dex

How to apply:

# Navigate to the ART module
cd ~/aosp/android-15.0.0_r36/art

# Apply the patch
git apply /path/to/dexdump.patch

Then rebuild AOSP as usual.

A Go-based command-line utility that creates the trigger file with correct UID/GID ownership based on the target app.

Usage

adb push dexdump /data/local/tmp/
adb shell su -c "/data/local/tmp/dexdump com.example.targetapp"

This will:

• Create /data/data/com.example.targetapp/files/ if missing
• Touch dump.flag
• Set UID/GID ownership to match the target app

Build

GOOS=android GOARCH=arm64 go build -o dexdump dexdump.go

A Python script to repair DEX files dumped from memory (which often have invalid checksums).

Usage

python fix_dex.py -f path/to/dump_*.dex

• By default, the original file will be deleted and replaced with the fixed one.
• Use -k to keep the original file.

• Rooted Android device or emulator
• AOSP build environment
• Go for building the binary
• Python 3.0+ for fix_dex.py