hash-wallet/cw_monero/lib/ledger.dart

import 'dart:async';
import 'dart:ffi';
import 'dart:typed_data';

import 'package:cw_core/hardware/hardware_wallet_service.dart';
import 'package:cw_core/utils/print_verbose.dart';
import 'package:ffi/ffi.dart';
import 'package:flutter/foundation.dart';
import 'package:ledger_flutter_plus/ledger_flutter_plus.dart';
import 'package:ledger_flutter_plus/ledger_flutter_plus_dart.dart';
import 'package:monero/src/monero.dart' as api;

LedgerConnection? gLedger;
String? latestLedgerCommand;

typedef LedgerCallback = Void Function(Pointer<UnsignedChar>, UnsignedInt);
NativeCallable<LedgerCallback>? callable;

Future<void> enableLedgerExchange(LedgerConnection connection) async {
  callable?.close();

  void callback(Pointer<UnsignedChar> request, int requestLength) async {
    final ledgerRequest = request.cast<Uint8>().asTypedList(requestLength);

    _logLedgerCommand(ledgerRequest, false);
    final response = await exchange(connection, ledgerRequest);
    _logLedgerCommand(response, true);

    final Pointer<Uint8> result = malloc<Uint8>(response.length);
    for (var i = 0; i < response.length; i++) {
      result.asTypedList(response.length)[i] = response[i];
    }

    latestLedgerCommand = _ledgerMoneroCommands[ledgerRequest[1]];

    api.MoneroWallet.setDeviceReceivedData(
         result.cast<UnsignedChar>(), response.length);
    malloc.free(result);
    // api.MoneroFree().free(result.cast());
  }

  callable = NativeCallable<LedgerCallback>.listener(callback);
  api.MoneroWallet.setLedgerCallback(callable!.nativeFunction);
}

void disableLedgerExchange() {
  callable?.close();
  gLedger?.disconnect();
  gLedger = null;
  latestLedgerCommand = null;
}

Future<Uint8List> exchange(LedgerConnection connection, Uint8List data) async =>
    connection.sendOperation<Uint8List>(ExchangeOperation(data));

class ExchangeOperation extends LedgerRawOperation<Uint8List> {
  final Uint8List inputData;

  ExchangeOperation(this.inputData);

  @override
  Future<Uint8List> read(ByteDataReader reader) async =>
      reader.read(reader.remainingLength);

  @override
  Future<List<Uint8List>> write(ByteDataWriter writer) async => [inputData];
}

const _ledgerMoneroCommands = {
  0x00: "INS_NONE",
  0x02: "INS_RESET",
  0x20: "INS_GET_KEY",
  0x21: "INS_DISPLAY_ADDRESS",
  0x22: "INS_PUT_KEY",
  0x24: "INS_GET_CHACHA8_PREKEY",
  0x26: "INS_VERIFY_KEY",
  0x28: "INS_MANAGE_SEEDWORDS",
  0x30: "INS_SECRET_KEY_TO_PUBLIC_KEY",
  0x32: "INS_GEN_KEY_DERIVATION",
  0x34: "INS_DERIVATION_TO_SCALAR",
  0x36: "INS_DERIVE_PUBLIC_KEY",
  0x38: "INS_DERIVE_SECRET_KEY",
  0x3A: "INS_GEN_KEY_IMAGE",
  0x3B: "INS_DERIVE_VIEW_TAG",
  0x3C: "INS_SECRET_KEY_ADD",
  0x3E: "INS_SECRET_KEY_SUB",
  0x40: "INS_GENERATE_KEYPAIR",
  0x42: "INS_SECRET_SCAL_MUL_KEY",
  0x44: "INS_SECRET_SCAL_MUL_BASE",
  0x46: "INS_DERIVE_SUBADDRESS_PUBLIC_KEY",
  0x48: "INS_GET_SUBADDRESS",
  0x4A: "INS_GET_SUBADDRESS_SPEND_PUBLIC_KEY",
  0x4C: "INS_GET_SUBADDRESS_SECRET_KEY",
  0x70: "INS_OPEN_TX",
  0x72: "INS_SET_SIGNATURE_MODE",
  0x74: "INS_GET_ADDITIONAL_KEY",
  0x76: "INS_STEALTH",
  0x77: "INS_GEN_COMMITMENT_MASK",
  0x78: "INS_BLIND",
  0x7A: "INS_UNBLIND",
  0x7B: "INS_GEN_TXOUT_KEYS",
  0x7D: "INS_PREFIX_HASH",
  0x7C: "INS_VALIDATE",
  0x7E: "INS_MLSAG",
  0x7F: "INS_CLSAG",
  0x80: "INS_CLOSE_TX",
  0xA0: "INS_GET_TX_PROOF",
  0xC0: "INS_GET_RESPONSE"
};

void _logLedgerCommand(Uint8List command, [bool isResponse = true]) {
  String toHexString(Uint8List data) =>
      data.map((e) => e.toRadixString(16).padLeft(2, '0')).join();

  if (isResponse) {
    printV("< ${toHexString(command)}");
  } else {
    printV(
        "> ${_ledgerMoneroCommands[command[1]]} ${toHexString(command.sublist(2))}");
  }
}

class MoneroLedgerService extends HardwareWalletService {
  final LedgerConnection connection;

  MoneroLedgerService(this.connection);
}