DroidFS relies on modified versions of the original encrypted filesystems programs to open volumes. CryFS is written in C++ while gocryptfs is written in Go. Thus, building DroidFS requires the compilation of native code. However, for the sake of simplicity, the application has been designed in a modular way: you can build a version of DroidFS that supports both Gocryptfs and CryFS, or only one of the two.
Moreover, DroidFS aims to be accessible to as many people as possible. If you encounter any problems or need help with the build, feel free to open an issue, a discussion, or contact me (currently the main developer) by email or on Matrix: @hardcoresushi:matrix.underworld.fr
The following two steps assume you're using a Debian-based Linux distribution. Package names might be similar for other distributions. Don't hesitate to ask if you're having trouble with this.
Install required packages:
$ sudo apt-get install openjdk-17-jdk-headless build-essential pkg-config git gnupg2 wget apksigner npm
You also need to manually install the Android SDK and the Android Native Development Kit (NDK) version 25.2.9519653 (r25c). libcryfs cannot be built with newer NDK versions at the moment due to compatibility issues with boost. If you succeed in building it with a more recent version of NDK, please report it.
If you want a support for Gocryptfs volumes, you need to install Go:
$ sudo apt-get install golang-go
The code should be authenticated before being built. To verify the signatures, you will need my PGP key:
$ gpg --keyserver hkps://keyserver.ubuntu.com --recv-keys AFE384344A45E13A
Fingerprint: B64E FE86 CEE1 D054 F082 1711 AFE3 8434 4A45 E13A
Email: Hardcore Sushi <hardcore.sushi@disroot.org>
Download DroidFS source code:
$ git clone --depth=1 https://forge.chapril.org/hardcoresushi/DroidFS.git
Verify sources:
$ cd DroidFS
$ git verify-commit HEAD
Don't continue if the verification fails!
Initialize submodules:
$ git submodule update --depth=1 --init
FFmpeg is needed to record encrypted video:
$ cd app/ffmpeg
$ git clone --depth=1 https://git.ffmpeg.org/ffmpeg.git
If you want Gocryptfs support, you need to download OpenSSL:
$ cd ../libgocryptfs
$ wget https://openssl.org/source/openssl-3.3.1.tar.gz
Verify OpenSSL signature:
$ wget https://openssl.org/source/openssl-3.3.1.tar.gz.asc
$ gpg --verify openssl-3.3.1.tar.gz.asc openssl-3.3.1.tar.gz
Continue ONLY if the signature is VALID.
$ tar -xzf openssl-3.3.1.tar.gz
If you want CryFS support, initialize libcryfs:
$ cd app/libcryfs
$ git submodule update --depth=1 --init
Retrieve your Android NDK installation path, usually something like /home/\<user\>/Android/SDK/ndk/\<NDK version\>. Then, make it available in your shell:
$ export ANDROID_NDK_HOME="<your ndk path>"
Start by compiling FFmpeg:
$ cd app/ffmpeg
$ ./build.sh ffmpeg
This step is only required if you want Gocryptfs support.
$ cd app/libgocryptfs
$ ANDROID_NDK_ROOT="$ANDROID_NDK_HOME" OPENSSL_PATH="./openssl-3.3.1" ./build.sh
Gradle build libgocryptfs and libcryfs by default.
To build DroidFS without Gocryptfs support, run:
$ ./gradlew assembleRelease -PdisableGocryptfs=true
To build DroidFS without CryFS support, run:
$ ./gradlew assembleRelease -PdisableCryFS=true
If you want to build DroidFS with support for both Gocryptfs and CryFS, just run:
$ ./gradlew assembleRelease
If the build succeeds, you will find the unsigned APKs in app/build/outputs/apk/release/. These APKs need to be signed in order to be installed on an Android device.
If you don't already have a keystore, you can create a new one by running:
$ keytool -genkey -keystore <output file> -alias <key alias> -keyalg EC -validity 10000
Then, sign the APK with:
$ apksigner sign --out droidfs.apk -v --ks <keystore> app/build/outputs/apk/release/<unsigned apk file>
Now you can install droidfs.apk on your device.