BoAT SDK

Introduction

BoAT Wallet is an IoT-oriented lightweight Ethereum compatible client SDK written in C. It supports transaction as well as smart contract calling over Ethereum compatible blockchain.

Though Ethereum and its derivatives are very popular, their wallet clients are basicly designed for personal computer and smart phone, and thus typically written in high level languages such as Java, Javascript and Go. However IoT devices are not as powerful as personal computer and smart phone. IoT device typically runs a lightweight linux on its application processor or an RTOS on a processor shared with communication protocol, and high level languages are seldom supported.

BoAT SDK is instead designed for IoT devices running linux or RTOS. It's written in C and easy to integrate into traditional lightweight IoT application. It depends on very few third-party libraries. It doesn't require any third-party package being imported on-line at runtime. It's important for cellular IoT devices because cellular operator usually charges by traffic volume.

Dependencies

Current BoAT SDK is only available for linux. An RTOS version is in plan.

1. gcc is required. On Windows Cygwin is required. For cross-compiling, an appropriate gcc tool chain meeting the target is required.

2. OpenSSL libraries are required for random number generation and AES ciphering. If a TRNG (True Random Number Generator) is available on the target, it's recommended to use TRNG to generate seed for CSPRNG. For cross-compiling, if appropriate target libraries are not available in the cross-compiling tool chain, you must manually cross-compile it from source.

3. CURL libraries are required for HTTP connection to blockchain node. For cross- compiling, if appropriate target libraries are not available in the cross- compiling tool chain, you must manually cross-compile it from source.

Code Structure

boatwallet
|
+---3rd             | Open source code from third-party
|   +---cJSON       | cJSON source code
|   +---curl        | Head files for libcurl (Only use when libcurl is not available in tool chain)
|   \---ecdsa       | Crypto and hash algorithm
|
+---build           | Directory to store object files and executable
|       
+---demo            | Demonstrate how to use BoAT SDK
|
+---docs            | Documents generated from comments by Doxygen
|
+---hwdep           | Hardware dependent source (pure software by default)
|
+---lib             | Directory to store compiled libraries
|
\---src             | Source of BoAT SDK
    +---rpc         | Remote Procedure Call wrapper
    +---utilities   | Utilities such as string manipulation
    +---wallet      | Client protocol
    \---web3        | Web3 interface

How to build

To build BoAT SDK libraries with demo application

$make

The built demo application locates at: boatwallet/build/boatwallet_demo

The built libraries locate at: boatwallet/lib/libboatwallet.a boatwallet/lib/libcJSON.a boatwallet/lib/libecdsa.a boatwallet/lib/libhwdep.a

To build BoAT SDK libraries only

$make boatwalletlib
$make hwdeplib
$make thirdlibs

To clean everything

$make distclean

To clean everything except third-party libraries

$make clean

Run the demo application

Run the demo

To run the demo application, either an Ethereum simulator (e.g. Ganache) or a real node of an Ethereum compatible blockchain network must be available.

$./build/boatdemo http://IPAddress:Port
or
$./build/boatdemo https://IPAddress:Port

The parameter following the application executable name is the URL to the blockchain node's RPC interface. The exact Protocol (http or https), IP address or site name and Port depend on how the blockchain node is deployed.

For early phase of development it's recommended to run a local Ethereum simulator instead of deploying a real blockchain network.

Truffle Suite (https://www.truffleframework.com) is a well-known tool to simulate an Ethereum network and deploy smart contract onto simulated or real Ethereum compatible network. Ganache is part of the suite and could simulate an Ethereum network. Ganache is available in both graphics version and command line version.

To connect a local Ganache Ethereum Simulator, it typically looks like:

$./build/boatdemo http://127.0.0.1:7545

If you're connecting to a real Ethereum compatible blockchain node, please make sure you know the appropriate parameters (such as gasLimit) of the network and you have enough token to pay for gas.

Before run the demo

The private key and account address generated by Ethereum simulator are surely different from the ones in the demo. You must modify the demo code with appropriate private key and account address.

Before run a case calling a smart contract, you must deploy the smart contract onto the blockchain network. The deployed contract address is surely different from the one in the demo. You must modify the demo code with appropriate contract address.

How to integrate BoAT SDK with your own application

• Step 1 Build BoAT SDK libraries

• Step 2 Add following include file search path to you project:

boatwallet/src
boatwalelt/3rd/cJSON
boatwalelt/3rd/ecdsa

• Step 3 Your application calls APIs declared in boatwallet/src/wallet/boatwallet.h. See documents in boatwallet/docs for APIs' details.

• Step 4 Compile your application and link with following libraries in sequence:

boatwallet/lib/libboatwallet.a
boatwallet/lib/libecdsa.a
boatwallet/lib/libcJSON.a
boatwallet/lib/libhwdep.a
-lcurl
-lcrypto

Documents

Documents locate in docs directory. They are generated by Doxygen from code comments in both HTML and RTF formats:

• HTML Documents Entry: boatwallet/docs/html/index.html
• RTF Document: boatwallet/docs/rtf/refman.rtf

Note that documents in github may be somewhat older than the code. You can use Doxygen to manually generate fresh new documents with configuration file boatwallet/docs/boatwallet.doxy.