Error closing inbound of SSL/TLS connection

Chariot MQTT Server
1

Hello and apologies if this is the wrong place for this question.

I am having an issue with a (Python) paho-mqtt client connection receiving a [SSL: TLSV1_ALERT_INTERNAL_ERROR] tlsv1 alert internal error from Chariot (and crashing) when the “Stop server” button is clicked (or the service is stopped) on the Chariot broker.
On the Chariot side I see the error:
“Error closing inbound of SSL/TLS connection with ID ######: closing inbound before receiving peer’s close_notify”

Normally, my Python client will “walk” to the next available server if the server it is connected to goes down. This is tested to be working on:

  • Chariot without SSL
  • Mosquitto broker with/without SSL
  • Chariot with SSL *** ONLY if the docker container containing Chariot is restarted, or if access to port 8883 is blocked via firewall ****

There seems to be something in the Chariot shutdown process that is causing this error. Preliminary Googling seems to suggest either a bug in JVM 11, or a mix-up in the order of closing the request and the reader.

Any suggestions?

Tested using:

  • Both Linux and Windows Chariot v2.2.3
  • Python client is using Open SSL 1.1.1q and connected via TLSv1.2
2

We were able to reproduce this behavior. This is due to the Chariot server forcefully closing the connection with the client on server shutdown and not first attempting a “cleaner” disconnect/closure. The next release of Chariot will have this behavior addressed and the (Python) Paho-MQTT client should experience a cleaner disconnect without errors.
For now, you should be able to catch the TLSV1_ALERT_INTERNAL_ERROR and attempt any logic (like walking to the next server) without having the application crash.

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