jledger

Ledger hardware cryptocurrency wallet key library for Java.

Usage

Use hid4java to find your device, then LedgerDevice ledger = new HidLedgerDevice(hidDevice);.

Then you can do ledger.open();, and define your protocol using for example (Ergo) ErgoProtocol protocol = new ErgoProtocol(ledger);.

Finally, you can call any method you want for example protocol.getVersion().

Artifacts

Note: No artifacts are published yet. You need to build them yourself.

For desktop programs

Use com.satergo.jledger:core:VERSION and com.satergo.jledger:transport-hid4java:VERSION (class HidLedgerDevice). Hid4java is used.

For testing with the Speculos emulator, use com.satergo.jledger:transport-speculos:VERSION (class SpeculosLedgerDevice).

Implementing a custom transport or protocol

If you only want the core library, use com.satergo.jledger:core:VERSION. Use this if your project is an app protocol or if you are developing for another platform.

App Protocols

An app protocol is the lowest-level access to an app on the Ledger device. Everything in the protocol is implemented 1:1.

• ergo (com.satergo.jledger:protocol-ergo:VERSION)

Library Integrations

Integrations with various cryptocurrency Java libraries. These would be artifacts that use the jledger app protocols and work with classes provided by the crypto library. They are not meant to be integrated into this repository.

Example

public class Example {
	public static void main(String[] args) {
		HidServicesSpecification hidSpec = new HidServicesSpecification();
		hidSpec.setAutoStart(false);

		// Scan for devices
		HidServices hidServices = HidManager.getHidServices(hidSpec);
		hidServices.start();

		for (HidDevice hidDevice : hidServices.getAttachedHidDevices()) {
			if (LedgerDevice.isLedgerDevice(hidDevice.getVendorId(), hidDevice.getProductId())) {
				handleLedgerDevice(hidDevice);
			}
			System.out.println(hidDevice);
		}

		hidServices.stop();
	}
	
	private static void handleLedgerDevice(HidDevice hidDevice) {
		HidLedgerDevice device = new HidLedgerDevice(hidDevice);
		device.open();
		ErgoProtocol protocol = new ErgoProtocol(device);
		
		System.out.println("Ergo app version: " + protocol.getVersion());
		device.close();
	}
}