@abandonware/bleno/lib/hci-socket/mgmt.js

A Node.js module for implementing BLE (Bluetooth Low Energy) peripherals

const debug = require('debug')('mgmt');

const BluetoothHciSocket = require('@abandonware/bluetooth-hci-socket');

const LTK_INFO_SIZE = 36;

const MGMT_OP_LOAD_LONG_TERM_KEYS = 0x0013;

class Mgmt {
  constructor() {
    this._socket = new BluetoothHciSocket();
    this._ltkInfos = [];

    this._socket.on('data', this.onSocketData.bind(this));
    this._socket.on('error', this.onSocketError.bind(this));

    this._socket.bindControl();
    this._socket.start();
  }

  onSocketData(data) {
    debug('on data ->' + data.toString('hex'));
  }

  onSocketError(error) {
    debug('on error ->' + error.message);
  }

  addLongTermKey(address, addressType, authenticated, master, ediv, rand, key) {
    const ltkInfo = Buffer.alloc(LTK_INFO_SIZE);

    address.copy(ltkInfo, 0);
    ltkInfo.writeUInt8(addressType.readUInt8(0) + 1, 6); // BDADDR_LE_PUBLIC = 0x01, BDADDR_LE_RANDOM 0x02, so add one

    ltkInfo.writeUInt8(authenticated, 7);
    ltkInfo.writeUInt8(master, 8);
    ltkInfo.writeUInt8(key.length, 9);

    ediv.copy(ltkInfo, 10);
    rand.copy(ltkInfo, 12);
    key.copy(ltkInfo, 20);

    this._ltkInfos.push(ltkInfo);

    this.loadLongTermKeys();
  }

  clearLongTermKeys() {
    this._ltkInfos = [];

    this.loadLongTermKeys();
  }

  loadLongTermKeys() {
    const numLongTermKeys = this._ltkInfos.length;
    const op = Buffer.alloc(2 + numLongTermKeys * LTK_INFO_SIZE);

    op.writeUInt16LE(numLongTermKeys, 0);

    for (let i = 0; i < numLongTermKeys; i++) {
      this._ltkInfos[i].copy(op, 2 + i * LTK_INFO_SIZE);
    }

    this.write(MGMT_OP_LOAD_LONG_TERM_KEYS, 0, op);
  }

  write(opcode, index, data) {
    let length = 0;

    if (data) {
      length = data.length;
    }

    const pkt = Buffer.alloc(6 + length);

    pkt.writeUInt16LE(opcode, 0);
    pkt.writeUInt16LE(index, 2);
    pkt.writeUInt16LE(length, 4);

    if (length) {
      data.copy(pkt, 6);
    }

    debug('writing -> ' + pkt.toString('hex'));
    this._socket.write(pkt);
  }
}

module.exports = new Mgmt();