Blockchain Services

Blockchain services connecting your institutional users and lab access control system to the blockchain

Comprehensive Spring Boot service for the DecentraLabs ecosystem that combines authentication, authorization, and institutional treasury management with full Ethereum wallet capabilities. While it is designed so that it can be deployed as an independent container, it is recommended to use it with the Lab Gateway.

This service provides two main components:

1. Authentication & Authorization Service: Web3-based JWT authentication with wallet challenges and SAML2 SSO integration

2. Institutional Wallet & Treasury: Complete Ethereum wallet management and treasury operations for institutional lab providers and consumers

Together, they offer a bridge between institutional access control systems (like the Lab Gateway in the figure above) and blockchain-based smart contracts.

📚 Documentation Structure

This documentation is organized into specialized sections:

• Authentication Service - Wallet challenges, SAML2 SSO, JWT generation and validation

• Institutional Wallet & Treasury - Ethereum wallet management, treasury operations, and smart contract interactions

🏗️ Architecture Overview

+------------------+     +------------------------+     +--------------------+
| Marketplace dApp | <-->| Auth Service           | <-->| Smart Contracts    |
| (User Frontend)  |     | - Wallet challenges    |     | - Diamond proxy    |
|                  |     | - SAML2 SSO            |     | - LAB token        |
|                  |     | - JWT generation       |     | - Reservations     |
+------------------+     +------------------------+     +--------------------+
         ^                         |                             ^
         |                         |                             |
    End Users                      v                             |
                        +------------------------+               |
                        | Wallet & Treasury      |---------------+
                        | - Wallet management    |
                        | - Treasury operations  |
                        | - Contract queries     |
                        | - Auto-approval engine |
                        +------------------------+
                                   |
                                   v
                        +------------------------+
                        | Lab Gateway            |
                        | (Provider Access)      |
                        +------------------------+

🛠️ Technology Stack

Core Framework

• Spring Boot - Application framework with embedded Tomcat

• Java - LTS version with modern language features

• Maven - Build automation and dependency management

Security & Authentication

• Spring Security - Authentication and authorization

• JJWT - JWT generation and validation

• Bouncy Castle - Cryptographic operations (AES-256-GCM, PBKDF2)

Blockchain Integration

• Web3j - Ethereum client library for smart contract interactions

• Netty - Async I/O for RPC communication

• OkHttp - HTTP client with connection pooling

Data Processing

• Jackson - JSON serialization/deserialization

• Lombok - Boilerplate code reduction

• Bucket4j - Rate limiting for API endpoints

Deployment & Operations

• Docker - Containerized deployment with multi-stage builds

• Tomcat Embedded - Servlet container (via Spring Boot)

• GitHub Actions - CI/CD for build, test, security scanning, and releases

🚀 Key Features

Authentication & Authorization Service

• Wallet Challenges: Web3 signature-based authentication with blockchain verification

• SAML2 Integration: Dual-path SSO (auth-only and booking-aware flows)

• JWT Management: JWKS discovery, dynamic key rotation, and claim-based authorization

• Smart Contract Validation: Direct on-chain reservation and booking queries

Institutional Wallet & Treasury

• Wallet Management: Create/import encrypted institutional wallets (AES-256-GCM + PBKDF2)

• Multi-Network Support: Mainnet/Sepolia/Goerli with automatic RPC failover

• Treasury Operations: Deposits, withdrawals, spending limits, and user financial stats

• Reservation Engine: Metadata-driven auto-approval/denial based on lab availability

• Event Monitoring: Real-time blockchain event listening and status reporting

🔧 API Overview

Authentication Endpoints (/auth)

Endpoint	Method	Description
/auth/.well-known/openid-configuration	GET	OIDC discovery metadata
/auth/jwks	GET	JSON Web Keys for token validation
/auth/message	GET	Get wallet challenge message
/auth/wallet-auth	POST	Wallet authentication (no booking)
/auth/wallet-auth2	POST	Wallet authentication + authorization
/auth/saml-auth	POST	SAML2 authentication
/auth/saml-auth2	POST	SAML2 authentication + authorization

Wallet Endpoints (/wallet) 🔒 localhost only

Endpoint	Method	Description
/wallet/create	POST	Create new encrypted wallet
/wallet/import	POST	Import existing wallet
/wallet/{address}/balance	GET	Get ETH and LAB token balance
/wallet/{address}/transactions	GET	Get transaction history
/wallet/listen-events	GET	Event listener status
/wallet/networks	GET	List available networks
/wallet/switch-network	POST	Switch active network
/wallet/reveal	POST	Reveal institutional private key (localhost + password)

Treasury Endpoints (/treasury) 🔒 localhost only

Endpoint	Method	Description
/treasury/reservations	POST	Create reservation (auto-approved/denied)
/treasury/admin/execute	POST	Execute treasury admin operations

🔒 Wallet and Treasury endpoints are protected by LocalhostOnlyFilter and only accept requests from 127.0.0.1 / ::1

🛠️ Quick Start

Prerequisites

• Java 21+

• Maven 3.6+

• Docker (optional, for containerized deployment)

Local Development

1. Build the project:

   mvn clean package -DskipTests

2. Run locally:

   java -jar target/auth-1.0-SNAPSHOT.war

3. Access the service:

   • Health check: http://localhost:8080/health

   • OIDC discovery: http://localhost:8080/auth/.well-known/openid-configuration

   • JWKS endpoint: http://localhost:8080/auth/jwks

Docker Deployment (Development)

⚠️ IMPORTANT: Docker deployment requires RSA keys and wallet configuration that are NOT included in the repository.

1. Generate RSA keys for JWT signing:

   mkdir -p keys
   openssl genrsa -out keys/private_key.pem 2048
   openssl rsa -in keys/private_key.pem -pubout -out keys/public_key.pem
   chmod 400 keys/*.pem

2. Start services (local dev uses the bundled docker-compose.override.yml to expose port 8080):

   docker-compose up -d

3. Configure institutional wallet:

   Open http://localhost:8080/wallet-dashboard in your browser

   • Create new wallet: Click "Create Wallet" → Set password → Save credentials

   • Import existing: Click "Import Wallet" → Provide private key + password

   • The backend automatically encrypts the private key into /app/data/wallets.json, stores the address and an AES-GCM–encrypted password in /app/data/wallet-config.properties (institutional.wallet.password.encrypted), and hot-reloads the institutional wallet.

   💡 Nothing else to configure unless you want to override the wallet via environment variables (see below).

💡 Testing APIs: For manual testing, use test-wallet-local.sh / test-wallet-local.ps1

💡 Reverse Proxy: When this project is consumed as a submodule behind OpenResty, reference only docker-compose.yml (omit docker-compose.override.yml) so the container stays on the internal network without publishing 8080.

📦 CI/CD & Production Deployment

This project uses a security-first deployment approach:

GitHub Actions Workflows

Pipeline	Purpose	Output	Trigger
Build & Test	Validates code quality	Test results	Every PR/push
Security Scan	Detects vulnerabilities	Security alerts	Weekly + PR
Release	Creates versioned artifacts	WAR + checksums	Git tag v*.*.*
Docker Image	Builds container	Docker image	Manual dispatch

Secrets Management

• ✅ .env.example tracked (public template). Copy it to .env locally (gitignored) before running anything.

• 🔐 keys/*.pem gitignored (generate per environment)

• 🔐 Wallet address/password captured through /wallet-dashboard → private key encrypted into /app/data/wallets.json, password stored as institutional.wallet.password.encrypted inside wallet-config.properties. Persist wallet.config.encryption-key separately (env/secrets manager) or let the service auto-generate it into /app/data/.wallet-encryption-key (configurable via wallet.config.encryption-key-file). Just ensure that /app/data is a persistent volume so restarts can decrypt the password; provide env overrides only if you need full external secret management.

Production Deployment Steps

1. Download release artifacts:

   # Get latest release WAR
   wget https://github.com/DecentraLabsCom/blockchain-services/releases/latest/download/blockchain-services-X.Y.Z.war
   
   # Verify integrity
   sha256sum -c blockchain-services-X.Y.Z.war.sha256

2. Prepare environment:

   # Generate RSA keys
   mkdir -p keys
   openssl genrsa -out keys/private_key.pem 2048
   openssl rsa -in keys/private_key.pem -pubout -out keys/public_key.pem
   chmod 400 keys/*.pem
   
   # Copy .env file and edit it in case you need it
   cp .env.example .env
   
   # For improved security, configure production secrets in AWS/Azure secret manager
   # INSTITUTIONAL_WALLET_PASSWORD
   # RPC URLs with API keys

3. Deploy:

   docker-compose up -d

4. Configure institutional wallet:

   Access http://your-domain/wallet-dashboard and create/import the wallet.

⚠️ CRITICAL: Never commit secrets. Use AWS Secrets Manager / Azure Key Vault for production.

⚙️ Configuration

Critical Environment Variables

Variable	Required	Description	Default
CONTRACT_ADDRESS	🔴 Yes	DecentraLabs contract address	-
WALLET_ADDRESS	🔴 Yes	Institutional wallet address	-
BLOCKCHAIN_NETWORK_ACTIVE	🟡 Recommended	Initial network (mainnet/sepolia)	sepolia
ETHEREUM_MAINNET_RPC_URL	🟡 Recommended	Mainnet RPC endpoints (comma-separated)	Public RPCs
ETHEREUM_SEPOLIA_RPC_URL	🟡 Recommended	Sepolia RPC endpoints (comma-separated)	Public RPCs

Optional Environment Variables

Variable	Description	Default
SPRING_PROFILES_ACTIVE	Active Spring profile	default
JAVA_OPTS	JVM options	-
ALLOWED_ORIGINS	CORS allowed origins	-
PRIVATE_KEY_PATH	Path to JWT private key	config/keys/private_key.pem
PUBLIC_KEY_PATH	Path to JWT public key	config/keys/public_key.pem
ADMIN_DASHBOARD_LOCAL_ONLY	true blocks /treasury/admin/** to localhost, false keeps it open (dev default)	true

Configuration Files

Repository structure:

.env.example                  # Environment template (tracked in git)
.env                          # Local config (gitignored)
data/
└── wallet-config.properties  # Auto-generated wallet address + encrypted password (gitignored)
keys/                         # RSA keys (gitignored)
├── private_key.pem           # JWT signing key
└── public_key.pem            # JWT verification key
src/main/resources/
└── application.properties    # Compiled into WAR

Docker container structure:

/app/
├── blockchain-services.war   # Application
├── config/
│   └── keys/                 # Mounted from ./keys
│       ├── private_key.pem
│       └── public_key.pem
├── data/                     # Persistent volume
│   └── wallets.json          # Encrypted wallets
└── logs/                     # Mounted from ./logs

💡 Configuration priority: Environment variables > .env (local file) > application.properties. For the institutional wallet specifically: env vars / secrets manager > wallet-config.properties (auto-generated institutional.wallet.address + encrypted password) > persisted wallet metadata.

Example Docker Run

docker run -p 8080:8080 \
  -e CONTRACT_ADDRESS=0xYourContractAddress \
  -e WALLET_ADDRESS=0xYourWalletAddress \
  -e ETHEREUM_SEPOLIA_RPC_URL=https://your-rpc-endpoint \
  -v /secure/keys:/app/config/keys:ro \
  blockchain-services:latest

🔐 Security

CRITICAL: This service handles sensitive cryptographic keys and blockchain transactions.

Security Checklist

• ✅ Private keys provided via environment variables (never hardcoded)

• ✅ RSA keys mounted with proper permissions (chmod 400)

• ✅ RPC URLs configured with authenticated endpoints

• ✅ Localhost-only filters enabled for sensitive operations

• ✅ CORS origins restricted to trusted domains

Reservation Notifications (email + ICS)

• Enable with NOTIFICATIONS_MAIL_ENABLED=true and choose driver NOTIFICATIONS_MAIL_DRIVER=smtp|graph|noop (default: noop).

• Common settings: NOTIFICATIONS_MAIL_FROM, NOTIFICATIONS_MAIL_DEFAULT_TO (comma-separated), and NOTIFICATIONS_MAIL_TIMEZONE (IANA zone, e.g., Europe/Madrid).

• SMTP driver: configure NOTIFICATIONS_MAIL_SMTP_HOST, PORT, USERNAME, PASSWORD, plus NOTIFICATIONS_MAIL_SMTP_STARTTLS when required.

• Microsoft Graph driver: NOTIFICATIONS_MAIL_GRAPH_TENANT_ID, CLIENT_ID, CLIENT_SECRET, GRAPH_FROM (UPN/mailbox with Mail.Send app permission).

• ICS invite attached when start/end are available; subject Reserva aprobada: <lab> and body includes lab, window, renter, payer, and tx hash.

• Runtime config (localhost): GET/POST /treasury/admin/notifications to view/update settings; persisted at ./data/notifications-config.json.

📊 Monitoring & Health Checks

Health endpoint available at /health:

{
  "status": "UP",
  "timestamp": "2025-11-09T12:00:00Z",
  "service": "blockchain-services",
  "version": "1.0.0",
  "marketplace_key_cached": true,
  "jwt_validation": "ready",
  "endpoints": {
    "wallet-auth": "available",
    "wallet-auth2": "available",
    "saml-auth": "available",
    "saml-auth2": "available",
    "jwks": "available",
    "message": "available",
    "wallet-create": "available (localhost only)",
    "wallet-balance": "available (localhost only)",
    "treasury-reservations": "available (localhost only)",
    "health": "available"
  }
}

🤝 Contributing

1. Fork the project

2. Create feature branch (git checkout -b feature/AmazingFeature)

3. Commit changes (git commit -m 'Add AmazingFeature')

4. Push to branch (git push origin feature/AmazingFeature)

5. Open Pull Request

📄 License

See LICENSE file for details.