cert-blockchain-poc

A Proof-of-Concept blockchain network for managing civil registry certificates using Hyperledger Fabric. This repository includes the full infrastructure (Docker-based test network), chaincode, deployment scripts, and examples for interaction and testing.

📌 Prerequisites

Before starting, ensure you have:

• Docker (recommended: version 28.x or earlier due to networking changes)
• Docker Compose
• Fabric binaries installed (peer, configtxgen, etc.)
• Linux or WSL2 environment

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🏁 1. Starting the Network

The project uses a custom network.sh script to create and manage the Fabric test network.

Start the network from scratch creating a channel

# Create a new channel and join peers  
./network.sh up createChannel -c certchannel -ca

Then, to restart it with the channel already created:

./network.sh down
./network.sh up

🧱 2. Deploying the Smart Contract (Chaincode)

The chaincode deployment script packages, installs, approves, and commits a new chaincode version.

Deploy chaincode version 1.0

bash ./deployCC.sh certcc ../../chaincode 1.0 2 certchannel

Arguments:

1. Chaincode name → certcc
2. Chaincode path → ../../chaincode
3. Version → 1.1
4. Sequence → 2
5. Channel → certchannel

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🧪 3. Interacting With the Network (CLI)

You can create a temporary CLI container to interact with the peers manually.

Atention: The CLI container is already being created in the compose-test-net.yaml file as cli service, so you can also use it with docker exec -it cli bash.

Start a CLI container inside the network

docker run -it --rm \
  --network fabric_test \
  -v $(pwd)/organizations:/opt/organizations \
  -v $(pwd)/deployCC.sh:/opt/deployCC.sh \
  -e CORE_PEER_TLS_ENABLED=true \
  -e CORE_PEER_LOCALMSPID=Org1MSP \
  -e CORE_PEER_ADDRESS=peer0.org1.example.com:7051 \
  -e CORE_PEER_MSPCONFIGPATH=/opt/organizations/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp \
  -e CORE_PEER_TLS_ROOTCERT_FILE=/opt/organizations/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt \
  hyperledger/fabric-tools:2.5 bash

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📄 4. Smart Contract Usage (Chaincode Functions)

Below are examples of invoking and querying the chaincode.

🍼 Register a Birth Certificate

peer chaincode invoke \
  -o orderer.example.com:7050 \
  -C certchannel \
  --ordererTLSHostnameOverride orderer.example.com \
  --tls --cafile $ORDERER_CA \
  -n certcc \
  --peerAddresses peer0.org1.example.com:7051 --tlsRootCertFiles $PEER0_ORG1_CA \
  --peerAddresses peer0.org2.example.com:9051 --tlsRootCertFiles $PEER0_ORG2_CA \
  -c '{"Args":["RegisterCert","CERT001","João Silva","2000-05-10","13:30","Hospital Municipal","Carlos Silva","Maria Silva","Cartorio A","Cartorio A","{\"docType\":\"birth\",\"notes\":\"registro inicial\"}"]}' \
  --waitForEvent

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✏️ Update a Certificate Field

peer chaincode invoke \
  -o orderer.example.com:7050 \
  --ordererTLSHostnameOverride orderer.example.com \
  --tls --cafile $ORDERER_CA \
  -C certchannel -n certcc \
  --peerAddresses peer0.org1.example.com:7051 --tlsRootCertFiles $PEER0_ORG1_CA \
  --peerAddresses peer0.org2.example.com:9051 --tlsRootCertFiles $PEER0_ORG2_CA \
  -c '{"Args":["UpdateCert","CERT001","name","João M. Silva"]}' \
  --waitForEvent

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🔍 Verify Certificate Integrity

peer chaincode query -C certchannel -n certcc -c '{"Args":["VerifyCert","CERT001"]}'

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🕓 Check Modification History

peer chaincode query \
  -C certchannel \
  -n certcc \
  -c '{"Args":["GetHistory","CERT001"]}'

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📦 5. Container Monitoring

List containers in a clean layout:

docker ps --format "table {{.Names}}\t{{.Status}}\t{{.Ports}}"

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6. Running the streamlit frontend

To run the Streamlit frontend for interacting with the blockchain network, follow these steps:

1. Navigate to the frontend directory:

   cd frontend

2. Install the required dependencies using pip:

    pip install -r requirements.txt

3. Configure the .env file following the example in .env.example.

4. Start the Streamlit application:

   streamlit run main.py

📘 License

This project is published under the Apache 2 license.