native-bip39 (with java bindings)

Bip39 mnemonic C++ implementation. Contains java bindings.

Description

Logic almost completely taken from bitcoin-js library for generating mnemonic phrases. Site and github

Features

Generate random mnemonic (PCG generator)
Create root and extended bip* standard keys using some derivation path

Build native JNI libs

Install cmake (if not installed yet)
Install Oracle JDK or OpenJDK (not tested yet)
Set environment variable: JAVA_HOME=/path/to/jdk
Build

mkdir build && cd build
cmake ../ -DCMAKE_BUILD_TYPE=Release -DENABLE_SHARED=On -DENABLE_BIP39_JNI=On -DENABLE_BIP39_C=Off -DENABLE_TEST=Off

make

Pickup lib files:
- libbip39.[a | so | dylib]
- libbip39_jni.[so | dylib]

Cross-compile for Windows under mingw64

Setup mingw64 for linux or macOS
Setup Windows JDK (or just copy from windows machine to somewhere path)
Build

mkdir build && cd build
cmake ../ -DCMAKE_BUILD_TYPE=Release \
-DCMAKE_TOOLCHAIN_FILE=../cmake/mingw-w64.cmake \
-DCMAKE_SYSROOT=/path/to/mingw \
-DCROSS_ARCH=[choose i686 or x86_64] \
-DJAVA_HOME=/path/to/extracted/windows/jdk

make

Pickup lib files:
- libbip39.dll
- libbip39.dll.a
- libbip39_jni.dll
- libbip39_jni.dll.a

Build under the Windows

Requirements

CMake for Windows
Visual Studio (at least community edition), tested only version 2019
Visual Studio C++ compiler
To build tests, you could install Conan OR just set configure-time flag -DENABLE_CONAN=Off and resolve submodules: git submodule update --init --recursive

Step-by-step:

cmake .. -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX="D:\path\you\want\to\install\libs"
cmake --build .
cmake --build . --target install

Then pick-up lib files and headers from D:\path\you\want\to\install\libs

Examples

C++

#include <bip3x/utils.h>
#include <bip3x/Bip39Mnemonic.h>
#include <bip3x/HDKeyEncoder.h>
#include <iostream>

using namespace bip3x;

int main(int argc, char** argv) {
    // create random words
    Bip39Mnemonic::MnemonicResult encodedMnemonic = Bip39Mnemonic::generate();
    std::cout << encodedMnemonic.words << std::endl;
    
    // create mnemonic seed
    bytes_64 seed = HDKeyEncoder::makeBip39Seed(encodedMnemonic.words);
    
    // create root key from mnemonic seed
    HDKey bip32RootKey = HDKeyEncoder::makeBip32RootKey(seed);
    
    // and, finally derive keys
    HDKey ethereumKey = HDKeyEncoder::makeExtendedKey(bip32RootKey, "m/44'/60'/0'/0");

    // extended private key
    std::cout << ethereumKey.extPrivateKey.toString() << std::endl;
    
    // private key
    std::cout << ethereumKey.privateKey.toString() << std::endl;
    
    // extended public key
    std::cout << ethereumKey.extPublicKey.toString() << std::endl;
    
    // public key
    std::cout << ethereumKey.publicKey.toString() << std::endl;
    
    // et cetera..

    // the end.
    return 0;
}

Java

tbd

Android and java bindings

Add this project as submodule (or just copy as sources) to your android module:

cd /path/to/project/app/src/main
mkdir cpp && cd cpp
git submodule add https://github.com/edwardstock/bip3x.git bip39

Create root cmake project in /path/to/project/[moduleName]/src/main/cpp

project(moduleName-bindings)
cmake_minimum_required(VERSION 3.4)
    
# include bip39
include_directories(bip39)
    
# add library
add_subdirectory(bip39)

Configure gradle

android {
    ...
    sourceSets {
        main {
            jni.srcDirs = ['src/main/cpp/bip39/src/java']
            java.srcDirs = ['src/main/cpp/bip39/src/java']
        }
    }
    
    externalNativeBuild {
        cmake {
            path 'src/main/cpp/CMakeLists.txt'
        }
    }
    ...
}

Initialize it

import com.edwardstock.bip3x.NativeBip39

class Main {
    public static int main(String[] args) {
        NativeBip39.init();
        
        if(!NativeBip39.isEnabled()) {
            throw new RuntimeException(NativeBip39.getError());
        }
    }
}

Done!

Add to CMake project

Just add it

# include bip39
include_directories(bip39)
    
# add library
add_subdirectory(bip39)

and

target_link_libraries(bip39)

Done!

Documentation

TBD (see src/main.cpp for simple examples)

masterjedy/bip3x