Flow Ctrl Tech Engineering

Securing Eclipse Mosquitto MQTT: Mutual TLS (mTLS), ACLs & Production Hardening

Field guide to locking down an on-premises Mosquitto MQTT broker: generating private CA certificates, enforcing client-side mutual TLS (mTLS), topic ACLs, and rate limiting.

  • Never allow unauthenticated anonymous connections on port 1883 in an industrial plant.
  • Mutual TLS (mTLS) validates both the server identity and the client edge device using cryptographic certificates.
  • Access Control Lists (ACLs) prevent a compromised sensor node from publishing malicious commands to machine actuator topics.

Flow Ctrl Tech Engineering: Turnkey industrial automation, PLC programming, SCADA development, HMI, fieldbuses, and IIoT architectures. Contact our engineering center at [email protected] or phone +91 91110 91005.