Microsoft Azure IoT Hub connection issue using qmqttClient

Arbaj Patel

Hi,

I am trying to connect and send data to Microsoft Azure Iot Hub using

const QString iotHubName = QStringLiteral("<yourIoTHub>");
const QString iotHubHostName = iotHubName + QStringLiteral(".azure-devices.net");
const QString deviceId = QStringLiteral("<yourDeviceName>");

QMqttClient client;
client.setPort(8883);
client.setHostname(iotHubHostName);
client.setClientId(deviceId);
client.setUsername(iotHubHostName + QStringLiteral("/") + deviceId + QStringLiteral("/?api-version=2018-06-30"));
client.setPassword(QLatin1String("SharedAccessSignature sr=<yourIoTHub>.azure-devices.net%2Fdevices…"));

auto caCerts = QSslCertificate::fromData(QByteArray(certificates));
QSslConfiguration sslConf;
sslConf.setCaCertificates(caCerts);

client.connectToHostEncryped(sslConf);

i am getting error while building as

error: ‘certificates’ was not declared in this scope
   auto caCerts = QSslCertificate::fromData(QByteArray(certificates));

error: no matching function for call to ‘QMqttClient::connectToHostEncrypted(QSslConfiguration&)’
   client.connectToHostEncrypted(sslConf);
                                        ^

how to solve this errors.

Thank you!

karlheinzreichel

@Arbaj-Patel said in Microsoft Azure IoT Hub connection issue using qmqttClient:

error: ‘certificates’ was not declared in this scope
auto caCerts = QSslCertificate::fromData(QByteArray(certificates));

I cannot see where the variable certificates is defined/created?

regards
Karl-Heinz

Arbaj Patel

Hi @karlheinzreichel Thank you for reply.

it is not defined anywhere. i am not getting what should be added in place of "certificates". i am referring Cloud providers and telemetry via Qt MQTT this qt documentation to implement.

Thanks.

karlheinzreichel

So how shall your code compile if you done declare a variable?

If you are in doubt how to setup the QSslConfiguration see

QT docs or maybe

https://stackoverflow.com/questions/3683826/qnetworkrequest-and-default-ssl-configuration

helps

regards
karl-heinz

Arbaj Patel

Hi, I resolved the certificates issue by changing 1 line of code

auto caCerts = QSslCertificate::fromPath("<file_path>/verificationCert.pem",QSsl::Pem, QRegExp::Wildcard);

but still there is a error

error: no matching function for call to ‘QMqttClient::connectToHostEncrypted(QSslConfiguration&)’ client.connectToHostEncrypted(sslConf);

and if i use

client.connectToHost();

instead of client.connectToHostEncrypted(sslConf); then there is no Build issue but while connecting to host it throwing client.error 256.
How to fix this? which one is best way to connect? please help me.

Thank you

Pablo J. Rogina

@Arbaj-Patel said in Microsoft Azure IoT Hub connection issue using qmqttClient:

error: no matching function for call to ‘QMqttClient::connectToHostEncrypted(QSslConfiguration&)’ client.connectToHostEncrypted(sslConf);

the problem is that such method expects the name of the server to connect to, not a QSslConfiguration object. Check documentation

Francois W

@Arbaj-Patel said in Microsoft Azure IoT Hub connection issue using qmqttClient:

client.connectToHostEncryped(sslConf);

You forgot the 't' in Encrypted:
Not client.connectToHostEncryped(sslConf);
but client.connectToHostEncrypted(sslConf);

Jeremias.Bosch

Hey,
this is a bit old, but maybe I can still help you, or someone else with a similar issue... We lately released a blog series about how to connect a qt application with Microsoft Azure IoT Hub; from scratch, including working examples in github. Take a look, https://blog.basyskom.com/2020/connect-qt-app-with-azure-iot-hub/

Best

Jeremias