dps-keygen/dps.js

Helper tool to create master and device GroupSAS keys / create connection string

// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license.

'use strict';

var Client = require('node-rest-client').Client;
const crypto = require('crypto');

function computeDrivedSymmetricKey(masterKey, regId) {
  return crypto.createHmac('SHA256', Buffer.from(masterKey, 'base64'))
    .update(regId, 'utf8')
    .digest('base64');
}

var apiVersion = '2018-11-01';

function loopAssign(data, client, args, deviceId, scopeId, deviceKey, callback) {
  var URI = `https://global.azure-devices-provisioning.net/\
${scopeId}/registrations/${deviceId}/operations/${data.operationId}?api-version=${apiVersion}`;
  client.get(URI, args, function (data) {
    if (data.status == 'assigning') {
      setTimeout(function () {
        loopAssign(data, client, args, deviceId, scopeId, deviceKey, callback);
      }, 2500);
    } else if (data.status == 'assigned') {
      var state = data.registrationState;
      var hub = state.assignedHub;
      callback(undefined, 'HostName=' + hub + ';DeviceId=' + deviceId + ';SharedAccessKey=' + deviceKey);
    } else {
      callback(data);
    }
  });
}

exports.EXPIRES = 30; // 30 mins

exports.getConnectionString = function (deviceId, key, scopeId, modelData, isMasterKey, callback) {
  var expires = parseInt((Date.now() + (exports.EXPIRES * 1000)) / 1000);

  var deviceKey = isMasterKey ? computeDrivedSymmetricKey(key, deviceId) : key;
  var sr = `${scopeId}%2fregistrations%2f${deviceId}`;
  var sigNoEncode = computeDrivedSymmetricKey(deviceKey, `${sr}\n${expires}`);
  var sigEncoded = encodeURIComponent(sigNoEncode);

  var args = {
    data: `{"registrationId":"${deviceId}"}`,
    headers: {
      'Accept': 'application/json',
      'Content-Type': 'application/json; charset=utf-8',
      'Connection': 'keep-alive',
      'UserAgent': 'prov_device_client/1.0',
      'Authorization': `SharedAccessSignature sr=${sr}&sig=${sigEncoded}&se=${expires}&skn=registration`
    }
  };
  if (modelData) {
    args.data = JSON.parse(args.data);
    args.data.data = modelData;
    args.data = JSON.stringify(args.data);
    apiVersion = '2019-01-15';
  }

  var client = new Client();
  client.put(`https://global.azure-devices-provisioning.net/${scopeId}/registrations/${deviceId}/register?api-version=${apiVersion}`,
    args, function (data, response) {
      delete args.data;
      if (!response.error && !data.errorCode) {
        setTimeout(function () {
          loopAssign(data, client, args, deviceId, scopeId, deviceKey, callback);
        }, 2500);
      } else {
        callback(response.error ? response.error : data);
      }
    });
};