dart_web3_ledger #

Professional Ledger hardware wallet support for Dart. Connect via USB or Bluetooth to perform secure, on-device signing for Ethereum and other supported blockchains.

🚀 Features #

• Multi-Transport: Native support for Ledger HID (USB) on Desktop/Mobile and Bluetooth (BLE) on iOS/Android.
• Secure Signing: Fully compatible with the Ledger Ethereum App (including Clear Signing for EIP-712).
• Device Management: List, connect, and monitor device status (Locked, App Not Open).
• Path Derivation: Access any BIP-44 account directly from the hardware's secure element.

Usage Flow #

sequenceDiagram
    participant A as App
    participant T as Transport (USB/BLE)
    participant L as Ledger Device
    A->>T: open()
    T->>L: handshake
    A->>T: send APDU (SignTx)
    T->>L: process data
    L-->>L: user confirms on screen
    L->>T: signature response
    T-->>A: EthSignature

🏗️ Architecture #

graph TD
    App[Flutter/Dart App] --> Transport[Transport HID/BLE]
    Transport --> LedgerCLI[Ledger Client]
    
    subgraph Device [Ledger Hardware]
        SEC[Secure Element]
        Apps[Eth / BTC Apps]
    end
    
    LedgerCLI <--> Apps

📚 Technical Reference #

Core Classes #

🛡️ Security Considerations #

• Bluetooth Bonding: When using BLE, ensure your application handles bonding correctly to prevent man-in-the-middle pairing attempts.
• Firmware Versions: The SDK target specific APDU versions. Warn users if their device firmware is outdated to avoid signing failures.
• Physical Verification: The "Golden Rule" of hardware wallets: Never trust the computer; only trust what is on the device screen.

💻 Usage #

Fetching Address (USB) #

import 'package:dart_web3_ledger/dart_web3_ledger.dart';

void main() async {
  final ledger = LedgerConnection.usb();
  await ledger.open();

  final ethApp = LedgerAppEth(ledger);
  
  // Shows 'Verify Address' prompt on device
  final address = await ethApp.getAddress("m/44'/60'/0'/0/0", display: true);
  print('Connected: $address');
}

📦 Installation #

dependencies:
  dart_web3_ledger: ^0.1.0