HDSLedger

Introduction

HDSLedger is a simplified permissioned (closed membership) blockchain system with high dependability guarantees. It uses the Istanbul BFT consensus algorithm to ensure that all nodes run commands in the same order, achieving State Machine Replication (SMR) and guarantees that all nodes have the same state.

Requirements

• Java 17 - Programming language;

• Maven 3.8 - Build and dependency management tool;

• Python 3 - Programming language;

Public Key Infrastructure

Both the nodes and the clients of the blockchain should use self-generated public/private keys which are pre-distributed before the start of the system.

The steps to generate the keys are the following:

Compile generator

cd PKI/
javac *.java

Generate keys

java RSAKeyGenerator w ./<IDENTIFIER>.priv ./<IDENTIFIER>.pub

Configuration Files

Client configuration

Can be found inside the resources/ folder of the Client module.

{
    "id": <CLIENT_ID>,
    "hostname": "localhost",
    "port": <CLIENT_PORT>,
    "publicKeyPath": "../PKI/client<CLIENT_ID>.pub",
    "privateKeyPath": "../PKI/client<CLIENT_ID>.priv",
    "byzantineBehavior": <BYZANTINE_BEHAVIOR>,
}

Node configuration

Can be found inside the resources/ folder of the Service module.

{
    "id": <NODE_ID>,
    "isLeader": <IS_LEADER>,
    "hostname": "localhost",
    "port": <NODE_PORT>,
    "clientPort": <CLIENT_PORT>,
    "publicKeyPath": "../PKI/node<CLIENT_ID>.pub",
    "privateKeyPath": "../PKI/node<CLIENT_ID>.priv",
    "byzantineBehavior": <BYZANTINE_BEHAVIOR>,
}

Note: clientPort is the port where the client will connect to the node.

Dependencies

To install the necessary dependencies run the following command:

./install_deps.sh

This should install the following dependencies:

• Google's Gson - A Java library that can be used to convert Java Objects into their JSON representation.

Puppet Master

The puppet master is a python script puppet-master.py which is responsible for starting the nodes and clients of the blockchain. The script runs with kitty terminal emulator by default since it's installed on the RNL labs.

To run the script you need to have python3 installed. The script has arguments which can be modified:

• terminal - the terminal emulator used by the script
• debug - if set to "True" the client process will print logs about the perfect link and library operations
• server_config - a string from the array server_configs which contains the possible configurations for the blockchain nodes

Run the script with the following command:

python3 puppet-master.py

Maven

It's also possible to run the project manually by using Maven.

Instalation

Compile and install all modules using:

mvn clean install

Execution

Run without arguments

cd <module>/
mvn compile exec:java

Run with arguments

cd <module>/
mvn compile exec:java -Dexec.args="..."

Authors

Name	Github
David Belchior	https://github.com/DavidAkaFunky
Diogo Santos	https://github.com/DiogoSantoss
Vasco Correia	https://github.com/Vaascoo