ObfuscatorNDK

Android Obfuscator NDK 23 for Windows

Fully tested

• Origin NDK : 23c (23.2.8568313)
• Clang : 12.0.9
• LLVM : 12.0.9

1. Usage

Add CMAKE_C_FLAGS in CmakeLists.txt file

This will apply the obfuscation, module by module.

set(CMAKE_C_FLAGS "-mllvm -fla -mllvm -bcf -mllvm -sub -mllvm -sobf")

Or, in case of using Android.mk :

LOCAL_CFLAGS := -Wall -D__MODULE__=\"$(LOCAL_MODULE)\" -fcommon -mllvm -fla -mllvm -bcf -mllvm -sub -mllvm -sobf

Currently available options

Option	Description
-mllvm -sub	substitution
-mllvm -fla	flattening
-mllvm -bcf	bogus
-mllvm -sobf	string obf

2. How to build this NDK?

Env	Desc
Built on	Ubuntu 16.04 (VM)
Host	windows

Avoid using ubuntu 20.04 -> might have sym-link problem

1. Check for exact NDK version and branch

Check AndroidVersion.txt from{NDK_PATH}}\toolchains\llvm\prebuilt\windows-x86_64

12.0.9
based on r416183c2

2. Download repo bin for clone from google source repository

curl https://storage.googleapis.com/git-repo-downloads/repo > /usr/bin/repo
chmod a+x /usr/bin/repo

Upgrade to python 3.9 if lower

##### Download required packages
sudo apt-get install build-essential checkinstall
sudo apt-get install libreadline-gplv2-dev libncursesw5-dev libssl-dev \
    libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev libffi-dev zlib1g-dev

##### Download 
cd /opt
sudo wget https://www.python.org/ftp/python/3.9.1/Python-3.9.1.tgz
sudo tar xzf Python-3.9.1.tgz
cd Python-3.9.1
sudo ./configure --enable-optimizations
sudo make altinstall
sudo update-alternatives --install /usr/bin/python python /usr/local/bin/python3.9 1

3. Download essential packages to build ndk toolchain

##### CMAKE and bison for toolchain build
apt install cmake bison

4. Check for manifest file in original ndk

##### Search for "manifest" in original ndk directory
-> Result : manifest_8481493.xml

5. Clone the repo

mkdir llvm-toolchain && cd llvm-toolchain
repo init -u https://android.googlesource.com/platform/manifest -b llvm-toolchain

## >>> [COPY {NDK_PATH}/~~/manifest_8181493.xml to llvm-toolchain/.repo/manifests]

repo init -m manifest_8481493.xml
repo sync -c

6. Build with --no-build linux option

python toolchain/llvm_android/build.py --no-build linux

7. Cherry pick the source from ollvm 12.x

# Changing Targets :
cp -r {TARGET}/llvm/lib/Transforms/Obfuscation {SOURCE}/llvm/lib/Transforms/Obfuscation
cp -r {TARGET}/llvm/include/Transforms/Obfuscation {SOURCE}/llvm/include/Transforms/Obfuscation

# add Obfuscation to 
-> lib/Transforms/IPO/CMakeList.txt
-> lib/Transforms/CMakeList.txt

#Cherry pick the sources from lib/Transforms/IPO/PassManagerBuilder.cpp

8. Build again

python toolchain/llvm_android/build.py --no-build linux

3. Handle the built output

out/install/windows-x86/clang-dev from result corresponds to toolchains/llvm/prebuilt/windows-x86-64

so, copy and paste the output(clang-dev) to original ndk directory

don't forget to manually substitute symbolic-linked binaries in bin/

(usually 1KB files in output are symbolic linked, except lldb.cmd)

4. Known issues when apply

NONE

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Android NDK

Documentation

NDK documentation, guides, and API reference are available on our website.

NDK code samples are available on GitHub.

Information about Android Studio can be found on the Android Studio website.

Filing Bugs

NDK bugs should be filed on GitHub.

Android Studio and Gradle bugs should be filed in the Android Studio Bug Tracker. For the fastest response, make sure you follow their guide on Filing Bugs.