MQTT Binding and Azure IoTHub Error

Add-ons Bindings
, ,
1

Hello together,

I am currently trying to send data via the MQTT Binding into Azure IoTHub. Therefore I configured the connection as specified here:

My configuration in OpenHab(under “MQTT Transport”) looks like this (I removed the sensible information):

mqtt:testbroker.url=ssl://domain.azure-devices.net:8883
mqtt:testbroker.clientId=Client
mqtt:testbroker.user=domain.azure-devices.net/Client
mqtt:testbroker.pwd=SharedAccessSignature sr=...&sig=...&se=...
mqtt-eventbus:broker=testbroker
mqtt-eventbus:statePublishTopic=devices/Client/messages/events
mqtt-eventbus:commandPublishTopic=devices/Client/messages/events

What happens is that I get this error right after starting OpenHab.

org.eclipse.paho.client.mqttv3.MqttException: Connection lost
    at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:138) ~[na:na]
    at java.lang.Thread.run(Thread.java:744) ~[na:1.8.0]
Caused by: java.io.EOFException: null
    at java.io.DataInputStream.readByte(DataInputStream.java:267) ~[na:1.8.0]
    at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:56) ~[na:na]
    at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:100) ~[na:na]
    ... 1 common frames omitted

Is it possible that there is a problem with the whitespace in the password field?
If I use another Java based tool, for example MQTT.fx, it runs with the exact same specified fields without any errors.

So my questions are:

  • Can I use whitespaces like shown in the configuration?
  • If not, how can I escape them?
  • Is this indeed an error and should I open an issue on github?

Thanks,
Basti

2

Should not be a problem, as spaces are allows in Java properties files (whitespace is only discarded right after the separator character, which is not the case here). However, you do need to follow these formatting rules:

https://docs.oracle.com/javase/7/docs/api/java/util/Properties.html#load(java.io.Reader)

Do you know for certain that Azure is an MQTT-3.1.1 conforming broker? If it is, it would be a recent development. I know that the MQTT broker that Amazon AWS IoT offers, for example, is not.

You may also be experiencing SSL handshake issues, like not sharing a common certificate authority. I suggest googling compatibility questions between Eclipse Paho and Microsoft Azure IoT MQTT.

3

Thank you for your response!

I’m sure that Azure is using MQTT-3.1.1 as every documentation states this and the working connection via MQTT.fx is configured via MQTT-3.1.1 as well.

I can get the exact same error in MQTT.fx (which uses Eclipse Paho as well) when I disable the needed SSL security. So I guess your hint to SSL handshake issues was correct.

In MQTT.fx I can connect when choosing “CA signed server certificate” and one of the following protocols: SSLv3, TLSv1, TLSv1.1, TLSv1.2. Sadly MQTT.fx is closed source so I couldn’t find any information on how this was done in code.

But I found the code that is used by the Azure IoT Java SDK as well. They use Paho, too:
https://github.com/Azure/azure-iot-sdks/blob/master/java/device/iothub-java-client/src/main/java/com/microsoft/azure/iothub/transport/mqtt/MqttIotHubConnection.java

Do you have any other ideas on how to get this working?

4

If the issue is with SSL negotiation, you would need to know what your local Java installation doesn’t know (like a CA cert in common), and then update your configuration. I don’t know if instructions like these are applicable, because it depends on what your further research finds.

5

Hi Basti,

Did you maybe found a way to connect openHAB and Azure IoT Hub?

Cheers,
Matija

6

same issue in OpenHAB2 :’(

7

Hi Matija,
sadly I didn’t find a solution by now. :confused:
I made my own workaround by using a self implemented MQTT broker which later forwarded the message to IoTHub. I simply ran this broker on the same device that OpenHab was running on.

You can find the code here:

8

Ok, thank You :slight_smile:

Cheers,
Matija

9

I know this is an old thread. I have the beginnings of an Azure Iota Hub binding. it does auto discovery and can send and listen to device events. I will submit the code once its all cleaned up but if anyone wants to help. The devices in azure come up as things…

1 Like
10

David - I would be interested in your progress and perhaps testing it myself between Christmas and New Year if you have anything to share.,

11

I actually moved on from openhab to homeseer. I have the base of the code I
can send over. MS has a great SDK and it was an easy thing to connect up.