ArduinoIoTCloudTCP.cpp

/*
   This file is part of ArduinoIoTCloud.

   Copyright 2019 ARDUINO SA (http://www.arduino.cc/)

   This software is released under the GNU General Public License version 3,
   which covers the main part of arduino-cli.
   The terms of this license can be found at:
   https://www.gnu.org/licenses/gpl-3.0.en.html

   You can be released from the requirements of the above licenses by purchasing
   a commercial license. Buying such a license is mandatory if you want to modify or
   otherwise use the software for commercial activities involving the Arduino
   software without disclosing the source code of your own applications. To purchase
   a commercial license, send an email to license@arduino.cc.
*/

/******************************************************************************
 * INCLUDE
 ******************************************************************************/

#include <AIoTC_Config.h>

#ifdef HAS_TCP

#include <ArduinoIoTCloudTCP.h>

#if OTA_ENABLED
  #include "ota/OTA.h"
#endif

#include <algorithm>
#include "cbor/CBOREncoder.h"
#include "utility/watchdog/Watchdog.h"
#include <typeinfo>

/******************************************************************************
   LOCAL MODULE FUNCTIONS
 ******************************************************************************/

unsigned long getTime()
{
  return ArduinoCloud.getInternalTime();
}

/******************************************************************************
   CTOR/DTOR
 ******************************************************************************/

ArduinoIoTCloudTCP::ArduinoIoTCloudTCP()
: _state{State::ConnectPhy}
, _connection_attempt(0,0)
, _message_stream(std::bind(&ArduinoIoTCloudTCP::sendMessage, this, std::placeholders::_1))
, _thing(&_message_stream)
, _device(&_message_stream)
, _mqtt_data_buf{0}
, _mqtt_data_len{0}
, _mqtt_data_request_retransmit{false}
#ifdef BOARD_HAS_SECRET_KEY
, _password("")
#endif
#if defined(BOARD_HAS_SECURE_ELEMENT)
, _writeCertOnConnect(false)
#endif
, _mqttClient{nullptr}
, _messageTopicOut("")
, _messageTopicIn("")
, _dataTopicOut("")
, _dataTopicIn("")
#if OTA_ENABLED
, _ota(&_message_stream)
, _get_ota_confirmation{nullptr}
#endif /* OTA_ENABLED */
{

}

/******************************************************************************
 * PUBLIC MEMBER FUNCTIONS
 ******************************************************************************/

int ArduinoIoTCloudTCP::begin(ConnectionHandler & connection, bool const enable_watchdog, String brokerAddress, uint16_t brokerPort)
{
  _connection = &connection;
  _brokerAddress = brokerAddress;

  ArduinoIoTAuthenticationMode authMode = ArduinoIoTAuthenticationMode::CERTIFICATE;
#if defined (BOARD_HAS_SECRET_KEY)
  /* If board supports and sketch is configured for username and password login */
  if(_password.length()) {
    authMode = ArduinoIoTAuthenticationMode::PASSWORD;
  }
#endif

  /* Setup broker TLS client */
  _brokerClient.begin(connection, authMode);

#if  OTA_ENABLED
  /* Setup OTA TLS client */
  _otaClient.begin(connection);
#endif

  /* If board is configured for certificate authentication and mTLS */
  if(authMode == ArduinoIoTAuthenticationMode::CERTIFICATE)
  {
#if defined(BOARD_HAS_SECURE_ELEMENT)
    if (!_selement.begin())
    {
      DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not initialize secure element.", __FUNCTION__);
  #if defined(ARDUINO_UNOWIFIR4)
      if (String(WiFi.firmwareVersion()) < String("0.4.1")) {
        DEBUG_ERROR("ArduinoIoTCloudTCP::%s In order to read device certificate, WiFi firmware needs to be >= 0.4.1, current %s", __FUNCTION__, WiFi.firmwareVersion());
      }
  #endif
      return 0;
    }
    if (!SElementArduinoCloudDeviceId::read(_selement, getDeviceId(), SElementArduinoCloudSlot::DeviceId))
    {
      DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not read device id.", __FUNCTION__);
      return 0;
    }
    if (!_writeCertOnConnect) {
      /* No update pending read certificate stored in secure element */
      if (!SElementArduinoCloudCertificate::read(_selement, _cert, SElementArduinoCloudSlot::CompressedCertificate))
      {
        DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not read device certificate.", __FUNCTION__);
        return 0;
      }
    }
  #if !defined(BOARD_HAS_OFFLOADED_ECCX08)
    _brokerClient.setEccSlot(static_cast<int>(SElementArduinoCloudSlot::Key), _cert.bytes(), _cert.length());
    #if  OTA_ENABLED
    _otaClient.setEccSlot(static_cast<int>(SElementArduinoCloudSlot::Key), _cert.bytes(), _cert.length());
    #endif
  #endif
    _brokerPort = (brokerPort == DEFAULT_BROKER_PORT_AUTO) ? mqttPort() : brokerPort;
#endif
  }
  else
  {
    _brokerPort = (brokerPort == DEFAULT_BROKER_PORT_AUTO) ? DEFAULT_BROKER_PORT_USER_PASS_AUTH : brokerPort;
  }

  /* Setup TimeService */
  _time_service.begin(_connection);

  /* Setup retry timers */
  _connection_attempt.begin(AIOT_CONFIG_RECONNECTION_RETRY_DELAY_ms, AIOT_CONFIG_MAX_RECONNECTION_RETRY_DELAY_ms);
  return begin(enable_watchdog, _brokerAddress, _brokerPort);
}

int ArduinoIoTCloudTCP::begin(bool const enable_watchdog, String brokerAddress, uint16_t brokerPort)
{
  _brokerAddress = brokerAddress;
  _brokerPort = brokerPort;

  _mqttClient.setClient(_brokerClient);

#ifdef BOARD_HAS_SECRET_KEY
  if(_password.length())
  {
    _mqttClient.setUsernamePassword(getDeviceId(), _password);
  }
#endif

  _mqttClient.onMessage(ArduinoIoTCloudTCP::onMessage);
  _mqttClient.setKeepAliveInterval(30 * 1000);
  _mqttClient.setConnectionTimeout(1500);
  _mqttClient.setId(getDeviceId().c_str());

  _messageTopicOut = getTopic_messageout();
  _messageTopicIn  = getTopic_messagein();

  _thing.begin();
  _device.begin();

#if OTA_ENABLED && !defined(OFFLOADED_DOWNLOAD)
  _ota.setClient(&_otaClient);
#endif // OTA_ENABLED && !defined(OFFLOADED_DOWNLOAD)

#if OTA_ENABLED && defined(OTA_BASIC_AUTH)
  _ota.setAuthentication(getDeviceId().c_str(), _password.c_str());
#endif // OTA_ENABLED && !defined(OFFLOADED_DOWNLOAD) && defined(OTA_BASIC_AUTH)

#ifdef BOARD_HAS_OFFLOADED_ECCX08
  if (String(WiFi.firmwareVersion()) < String("1.4.4")) {
    DEBUG_ERROR("ArduinoIoTCloudTCP::%s In order to connect to Arduino IoT Cloud, NINA firmware needs to be >= 1.4.4, current %s", __FUNCTION__, WiFi.firmwareVersion());
    return 0;
  }
#endif /* BOARD_HAS_OFFLOADED_ECCX08 */

#if defined(ARDUINO_UNOWIFIR4)
  if (String(WiFi.firmwareVersion()) < String("0.2.0")) {
    DEBUG_ERROR("ArduinoIoTCloudTCP::%s In order to connect to Arduino IoT Cloud, WiFi firmware needs to be >= 0.2.0, current %s", __FUNCTION__, WiFi.firmwareVersion());
  }
#endif

  /* Since we do not control what code the user inserts
   * between ArduinoIoTCloudTCP::begin() and the first
   * call to ArduinoIoTCloudTCP::update() it is wise to
   * set a rather large timeout at first.
   */
#if defined (ARDUINO_ARCH_SAMD) || defined (ARDUINO_ARCH_MBED)
  if (enable_watchdog) {
    /* Initialize watchdog hardware */
    watchdog_enable();
    /* Setup callbacks to feed the watchdog during offloaded network operations (connection/download)*/
    watchdog_enable_network_feed(_connection->getInterface());
  }
#endif

  return 1;
}

void ArduinoIoTCloudTCP::update()
{
  /* Feed the watchdog. If any of the functions called below
   * get stuck than we can at least reset and recover.
   */
#if defined (ARDUINO_ARCH_SAMD) || defined (ARDUINO_ARCH_MBED)
  watchdog_reset();
#endif

  /* Run through the state machine. */
  State next_state = _state;
  switch (_state)
  {
  case State::ConnectPhy:           next_state = handle_ConnectPhy();           break;
  case State::SyncTime:             next_state = handle_SyncTime();             break;
  case State::ConnectMqttBroker:    next_state = handle_ConnectMqttBroker();    break;
  case State::Connected:            next_state = handle_Connected();            break;
  case State::Disconnect:           next_state = handle_Disconnect();           break;
  }
  _state = next_state;

  /* This watchdog feed is actually needed only by the RP2040 Connect because its
   * maximum watchdog window is 8389 ms; despite this we feed it for all
   * supported ARCH to keep code aligned.
   */
#if defined (ARDUINO_ARCH_SAMD) || defined (ARDUINO_ARCH_MBED)
  watchdog_reset();
#endif

#if OTA_ENABLED
  /* OTA FSM needs to reach the Idle state before being able to run independently from
   * the mqttClient. The state can be reached only after the mqttClient is connected to
   * the broker.
   */
  if((_ota.getState() != OTACloudProcessInterface::Resume &&
      _ota.getState() != OTACloudProcessInterface::OtaBegin) ||
      _mqttClient.connected()) {
    _ota.update();
  }

  if(_get_ota_confirmation != nullptr &&
      _ota.getState() == OTACloudProcessInterface::State::OtaAvailable &&
      _get_ota_confirmation()) {
    _ota.approveOta();
  }
#endif // OTA_ENABLED
}

int ArduinoIoTCloudTCP::connected()
{
  return _mqttClient.connected();
}

void ArduinoIoTCloudTCP::printDebugInfo()
{
  DEBUG_INFO("***** Arduino IoT Cloud - %s *****", AIOT_CONFIG_LIB_VERSION);
  DEBUG_INFO("Device ID: %s", getDeviceId().c_str());
  DEBUG_INFO("MQTT Broker: %s:%d", _brokerAddress.c_str(), _brokerPort);
}

/******************************************************************************
 * PRIVATE MEMBER FUNCTIONS
 ******************************************************************************/

ArduinoIoTCloudTCP::State ArduinoIoTCloudTCP::handle_ConnectPhy()
{
  if (_connection->check() == NetworkConnectionState::CONNECTED)
  {
    if (!_connection_attempt.isRetry() || (_connection_attempt.isRetry() && _connection_attempt.isExpired()))
      return State::SyncTime;
  }

  return State::ConnectPhy;
}

ArduinoIoTCloudTCP::State ArduinoIoTCloudTCP::handle_SyncTime()
{
  /* If available force network time sync when connecting or reconnecting */
  if (_time_service.sync())
  {
    DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s internal clock configured to posix timestamp %d", __FUNCTION__, getTime());
    return State::ConnectMqttBroker;
  }

  DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not get valid time. Retrying now.", __FUNCTION__);
  return State::ConnectPhy;
}

ArduinoIoTCloudTCP::State ArduinoIoTCloudTCP::handle_ConnectMqttBroker()
{
  if (_mqttClient.connect(_brokerAddress.c_str(), _brokerPort))
  {
    /* Subscribe to message topic to receive commands */
    _mqttClient.subscribe(_messageTopicIn);

#if defined(BOARD_HAS_SECURE_ELEMENT)
    /* A device certificate update was pending */
    if (_writeCertOnConnect)
    {
      if (SElementArduinoCloudCertificate::write(_selement, _cert, SElementArduinoCloudSlot::CompressedCertificate))
      {
        DEBUG_INFO("ArduinoIoTCloudTCP::%s device certificate update done.", __FUNCTION__);
        _writeCertOnConnect = false;
      }
    }
#endif
    DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s connected to %s:%d", __FUNCTION__, _brokerAddress.c_str(), _brokerPort);
    return State::Connected;
  }

  /* Can't connect to the broker. Wait: 2s -> 4s -> 8s -> 16s -> 32s -> 32s ... */
  _connection_attempt.retry();

#if defined (BOARD_STM32H7) && defined(BOARD_HAS_ECCX08)
  DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not connect to %s:%d Mqtt error: %d TLS error: %d", __FUNCTION__, _brokerAddress.c_str(), _brokerPort, _mqttClient.connectError(), _brokerClient.errorCode());
#else
  DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not connect to %s:%d Error: %d", __FUNCTION__, _brokerAddress.c_str(), _brokerPort, _mqttClient.connectError());
#endif
  DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s %d next connection attempt in %d ms", __FUNCTION__, _connection_attempt.getRetryCount(), _connection_attempt.getWaitTime());
  /* Go back to ConnectPhy and retry to get time from network (invalid time for SSL handshake?)*/
  return State::ConnectPhy;
}

ArduinoIoTCloudTCP::State ArduinoIoTCloudTCP::handle_Connected()
{
  if (!_mqttClient.connected() || !_thing.connected() || !_device.connected())
  {
    return State::Disconnect;
  }

  /* Check for new data from the MQTT client. */
  _mqttClient.poll();

  /* Retransmit data in case there was a lost transaction due
   * to phy layer or MQTT connectivity loss.
   */
  if (_mqtt_data_request_retransmit && (_mqtt_data_len > 0)) {
    write(_dataTopicOut, _mqtt_data_buf, _mqtt_data_len);
    _mqtt_data_request_retransmit = false;
  }

  /* Call CloudDevice process to get configuration */
  _device.update();


  if (_device.isAttached()) {
    /* Call CloudThing process to synchronize properties */
    _thing.update();
  }

  return State::Connected;
}

ArduinoIoTCloudTCP::State ArduinoIoTCloudTCP::handle_Disconnect()
{
  if (!_mqttClient.connected()) {
    DEBUG_ERROR("ArduinoIoTCloudTCP::%s MQTT client connection lost", __FUNCTION__);
  } else {
    /* No need to manually unsubscribe because we are using clean sessions */
    _mqttClient.stop();
  }

  Message message = { ResetCmdId };
  _thing.handleMessage(&message);
  _device.handleMessage(&message);

  DEBUG_INFO("Disconnected from Arduino IoT Cloud");
  execCloudEventCallback(ArduinoIoTCloudEvent::DISCONNECT);

  /* Setup timer for broker connection and restart */
  _connection_attempt.begin(AIOT_CONFIG_RECONNECTION_RETRY_DELAY_ms, AIOT_CONFIG_MAX_RECONNECTION_RETRY_DELAY_ms);
  return State::ConnectPhy;
}

void ArduinoIoTCloudTCP::onMessage(int length)
{
  ArduinoCloud.handleMessage(length);
}

void ArduinoIoTCloudTCP::handleMessage(int length)
{
  String topic = _mqttClient.messageTopic();

  byte bytes[length];

  for (int i = 0; i < length; i++) {
    bytes[i] = _mqttClient.read();
  }

  /* Topic for user input data */
  if (_dataTopicIn == topic) {
    CBORDecoder::decode(_thing.getPropertyContainer(), (uint8_t*)bytes, length);
  }

  /* Topic for device commands */
  if (_messageTopicIn == topic) {
    CommandDown command;
    DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s [%d] received %d bytes", __FUNCTION__, millis(), length);
    CBORMessageDecoder decoder;

    size_t buffer_length = length;
    if (decoder.decode((Message*)&command, bytes, buffer_length) != Decoder::Status::Error) {
      DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s [%d] received command id %d", __FUNCTION__, millis(), command.c.id);
      switch (command.c.id)
      {
        case CommandId::ThingUpdateCmdId:
        {
          DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s [%d] device configuration received", __FUNCTION__, millis());
          String new_thing_id = String(command.thingUpdateCmd.params.thing_id);

          if (!new_thing_id.length()) {
            /* Send message to device state machine to inform we have received a null thing-id */
            _thing_id = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";
            Message message;
            message = { DeviceRegisteredCmdId };
            _device.handleMessage(&message);
          } else {
            if (_device.isAttached() && _thing_id != new_thing_id) {
              detachThing();
            }
            if (!_device.isAttached()) {
              attachThing(new_thing_id);
            }
          }
        }
        break;

        case CommandId::ThingDetachCmdId:
        {
          if (!_device.isAttached() || _thing_id != String(command.thingDetachCmd.params.thing_id)) {
            DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s [%d] thing detach rejected", __FUNCTION__, millis());
          }

          DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s [%d] thing detach received", __FUNCTION__, millis());
          detachThing();
        }
        break;

        case CommandId::TimezoneCommandDownId:
        {
          DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s [%d] timezone update received", __FUNCTION__, millis());
          _thing.handleMessage((Message*)&command);
        }
        break;

        case CommandId::LastValuesUpdateCmdId:
        {
          DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s [%d] last values received", __FUNCTION__, millis());
          CBORDecoder::decode(_thing.getPropertyContainer(),
            (uint8_t*)command.lastValuesUpdateCmd.params.last_values,
            command.lastValuesUpdateCmd.params.length, true);
          _thing.handleMessage((Message*)&command);
          execCloudEventCallback(ArduinoIoTCloudEvent::SYNC);

          /*
           * NOTE: in this current version properties are not properly integrated with the new paradigm of
           * modeling the messages with C structs. The current CBOR library allocates an array in the heap
           * thus we need to delete it after decoding it with the old CBORDecoder
           */
          free(command.lastValuesUpdateCmd.params.last_values);
        }
        break;

#if OTA_ENABLED
        case CommandId::OtaUpdateCmdDownId:
        {
          DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s [%d] ota update received", __FUNCTION__, millis());
          _ota.handleMessage((Message*)&command);
        }
#endif

        default:
        break;
      }
    }
  }
}

void ArduinoIoTCloudTCP::sendMessage(Message * msg)
{
  uint8_t data[MQTT_TRANSMIT_BUFFER_SIZE];
  size_t bytes_encoded = sizeof(data);
  CBORMessageEncoder encoder;

  switch (msg->id) {
    case PropertiesUpdateCmdId:
      return sendPropertyContainerToCloud(_dataTopicOut,
                                          _thing.getPropertyContainer(),
                                          _thing.getPropertyContainerIndex());
      break;

    default:
      break;
  }

  if (encoder.encode(msg, data, bytes_encoded) == Encoder::Status::Complete &&
      bytes_encoded > 0) {
    write(_messageTopicOut, data, bytes_encoded);
  } else {
    DEBUG_ERROR("error encoding %d", msg->id);
  }
}

void ArduinoIoTCloudTCP::sendPropertyContainerToCloud(String const topic, PropertyContainer & property_container, unsigned int & current_property_index)
{
  int bytes_encoded = 0;
  uint8_t data[MQTT_TRANSMIT_BUFFER_SIZE];

  if (CBOREncoder::encode(property_container, data, sizeof(data), bytes_encoded, current_property_index, false) == CborNoError)
  {
    if (bytes_encoded > 0)
    {
      /* If properties have been encoded store them in the back-up buffer
       * in order to allow retransmission in case of failure.
       */
      _mqtt_data_len = bytes_encoded;
      memcpy(_mqtt_data_buf, data, _mqtt_data_len);
      /* Transmit the properties to the MQTT broker */
      write(topic, _mqtt_data_buf, _mqtt_data_len);
    }
  }
}

void ArduinoIoTCloudTCP::attachThing(String thingId)
{
  _thing_id = thingId;

  _dataTopicIn    = getTopic_datain();
  _dataTopicOut   = getTopic_dataout();
  if (!_mqttClient.subscribe(_dataTopicIn)) {
    DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not subscribe to %s", __FUNCTION__, _dataTopicIn.c_str());
    DEBUG_ERROR("Check your thing configuration, and press the reset button on your board.");
    _thing_id = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";
    return;
  }

  Message message;
  message = { DeviceAttachedCmdId };
  _device.handleMessage(&message);

  DEBUG_INFO("Connected to Arduino IoT Cloud");
  DEBUG_INFO("Thing ID: %s", getThingId().c_str());
  execCloudEventCallback(ArduinoIoTCloudEvent::CONNECT);
}

void ArduinoIoTCloudTCP::detachThing()
{
  if (!_mqttClient.unsubscribe(_dataTopicIn)) {
    DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not unsubscribe from %s", __FUNCTION__, _dataTopicIn.c_str());
    return;
  }

  Message message;
  message = { DeviceDetachedCmdId };
  _device.handleMessage(&message);

  _thing_id = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";
  DEBUG_INFO("Disconnected from Arduino IoT Cloud");
  execCloudEventCallback(ArduinoIoTCloudEvent::DISCONNECT);
}

int ArduinoIoTCloudTCP::write(String const topic, byte const data[], int const length)
{
  if (_mqttClient.beginMessage(topic, length, false, 0)) {
    if (_mqttClient.write(data, length)) {
      if (_mqttClient.endMessage()) {
        return 1;
      }
    }
  }
  return 0;
}

#if defined(BOARD_HAS_SECURE_ELEMENT)
int ArduinoIoTCloudTCP::mqttPort()
{
  if (memcmp(DEPRECATED_BROKER_AUTHORITY_KEY_IDENTIFIER, _cert.authorityKeyIdentifierBytes() , ECP256_CERT_AUTHORITY_KEY_ID_LENGTH) == 0) {
    return DEPRECATED_BROKER_PORT_SECURE_AUTH;
  } else {
    return DEFAULT_BROKER_PORT_SECURE_AUTH;
  }
}

int ArduinoIoTCloudTCP::updateCertificate(String authorityKeyIdentifier, String serialNumber, String notBefore, String notAfter, String signature)
{
  if (!_selement.begin())
  {
    DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not initialize secure element.", __FUNCTION__);
#if defined(ARDUINO_UNOWIFIR4)
    if (String(WiFi.firmwareVersion()) < String("0.4.1")) {
      DEBUG_ERROR("ArduinoIoTCloudTCP::%s In order to read device certificate, WiFi firmware needs to be >= 0.4.1, current %s", __FUNCTION__, WiFi.firmwareVersion());
    }
#endif
    return 0;
  }
  if (!SElementArduinoCloudDeviceId::read(_selement, getDeviceId(), SElementArduinoCloudSlot::DeviceId))
  {
    DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not read device id.", __FUNCTION__);
    return 0;
  }
  /* read certificate stored in secure element to compare AUTHORITY_KEY_ID */
  if (!SElementArduinoCloudCertificate::read(_selement, _cert, SElementArduinoCloudSlot::CompressedCertificate))
  {
    DEBUG_ERROR("ArduinoIoTCloudTCP::%s could not read device certificate.", __FUNCTION__);
    return 0;
  }
  /* check if we need to update 0 = equal <0 = error skip rebuild */
  if(SElementArduinoCloudCertificate::signatureCompare(_cert.signatureBytes(), signature) <= 0) {
    DEBUG_INFO("ArduinoIoTCloudTCP::%s request skipped.", __FUNCTION__);
    return 0;
  }
  /* rebuild device certificate */
  if (SElementArduinoCloudCertificate::rebuild(_selement, _cert, getDeviceId(), notBefore, notAfter, serialNumber, authorityKeyIdentifier, signature))
  {
    DEBUG_INFO("ArduinoIoTCloudTCP::%s request started.", __FUNCTION__);
#if defined(BOARD_HAS_OFFLOADED_ECCX08)
    if (SElementArduinoCloudCertificate::write(_selement, _cert, SElementArduinoCloudSlot::CompressedCertificate))
    {
      DEBUG_INFO("ArduinoIoTCloudTCP::%s update done.", __FUNCTION__);
    }
#else
    _writeCertOnConnect = true;
#endif
    return 1;
  }
  return 0;
}
#endif

/******************************************************************************
 * EXTERN DEFINITION
 ******************************************************************************/

ArduinoIoTCloudTCP ArduinoCloud;

#endif