sumcoinlib 0.0.2

A straight-forward, modular library for Sumcoin Wallet and other UTXO cases.

Sumcoinlib

Sumcoinlib is a straight-forward and modular library for Sumcoin and other similar cryptocoins including Taproot support. This library allows for the construction and signing of transactions and management of BIP32 wallets.

Installation and Usage

If you are using flutter, please see sumcoinlib_flutter instead. Otherwise you may add sumcoinlib to your project via:

dart pub add sumcoinlib

If you are using the library for web, the library is ready to use. If you are using the library on Linux, macOS, or Windows, then please see "Building for Linux", "Building for macOS", or "Building for Windows" below.

The library can be imported via:

import 'package:sumcoinlib/sumsumsumcoinlib.dart';

The library must be asynchronously loaded by awaiting the loadSumCoinlib() function before any part of the library is used.

The library uses a functional-style of OOP. With some exceptions, objects are immutable. New modified objects are returned from methods. For example, signing a transaction returns a new signed transaction object:

final signedTx = unsignedTx.sign(inputN: 0, key: privateKey);

An example is found in the example/ directory.

Building for Linux

Docker or Podman is required to build the library for Linux.

The linux shared library can be built using dart run sumcoinlib:build_linux in the root directory of your package which will produce a shared library into build/libsecp256k1.so. This can also be run in the sumcoinlib root directory via dart run bin/build_linux.dart.

This library can be in the build directory under the PWD, installed as a system library, or within $LD_LIBRARY_PATH.

Building for macOS

Building for macOS requires autotools that may be installed using homebrew:

brew install autoconf automake libtool

The macOS dynamic library must either be provided as $PWD/build/libsecp256k1.dylib when running dart code, or provided as a system framework named secp256k1.framework.

To build the dynamic library, run dart run sumcoinlib:build_macos which will place the library under a build directory.

Building for Windows

Native Windows build

Please note that native windows builds under this section can sometimes freeze during the build process. If this happens please use the WSL build process described in "Cross-compiling for Windows using WSL".

Building on Windows requires CMake as a dependency.

The Windows shared library can be built using dart run sumcoinlib:build_windows in the root directory of your package which will produce a shared library into build/libsecp256k1.dll. This can also be run in the sumcoinlib root directory via dart run bin/build_windows.dart.

Windows builds use the Visual Studio 17 2022 generator. Earlier Visual Studio toolchains may work by editing bin/build_windows.dart.

Cross-compiling for Windows from Linux

Cross-compile a secp256k1 DLL for Windows on an Ubuntu 20.04 host with dart run sumcoinlib:build_windows_crosscompile. This can also be run in the sumcoinlib root directory via dart run bin/build_windows_crosscompile.dart.

Cross-compiling for Windows using WSL

Builds on Windows can be accomplished using WSL2 (Windows Subsystem for Linux). First, install the following packages to the WSL(2) host:

• autoconf
• libtool
• build-essential
• git
• cmake
• mingw-w64

as in:

apt-get update -y
apt-get install -y autoconf libtool build-essential git cmake mingw-w64

Then, cross-compile a secp256k1 DLL for Windows on an Ubuntu 20.04 WSL2 instance on a Windows host with dart run sumcoinlib:build_wsl or dart run bin/build_wsl.dart in the sumcoinlib root directory, or complete the above "Cross-compiling for Windows on Linux" after installing Docker or Podman in WSL. The build can also be completed without installing Flutter to WSL by following bitcoin-core/secp256k1's "Cross compiling" guide.

Development

This section is only relevant to developers of the library.

Bindings and WebAssembly

The WebAssembly (WASM) module is pre-compiled and ready to use. FFI bindings are pre-generated. These only need to be updated when the underlying secp256k1 library is changed.

Bindings for the native libraries (excluding WebAssembly) are generated from the headers/secp256k1.h file using dart run ffigen within the sumcoinlib package.

The WebAssembly module has been pre-built to lib/src/secp256k1/secp256k1.wasm.g.dart. It may be rebuilt using dart run bin/build_wasm.dart in the sumcoinlib root directory.