This is a bugfix and security release.

Version 1.5.5 changes

Security

If per_listener_settings is set to true, then the acl_file setting was ignored for the "default listener" only. This has been fixed. This does not affect any listeners defined with the listener option. Closes #1073. This is now tracked as CVE-2018-20145.

Broker

Add socket_domain option to allow listeners to disable IPv6 support. This is required to work around a problem in libwebsockets that means sockets only listen on IPv6 by default if IPv6 support is compiled in. Closes #1004.
When using ADNS, don't ask for all network protocols when connecting, because this can lead to confusing "Protocol not supported" errors if the network is down. Closes #1062.
Fix outgoing retained messages not being sent by bridges on initial connection. Closes #1040.
Don't reload auth_opt_ options on reload, to match the behaviour of the other plugin options. Closes #1068.
Print message on error when installing/uninstalling as a Windows service.
All non-error connect/disconnect messages are controlled by the connection_messages option. Closes #772. Closes #613. Closes #537.

Library

Fix reconnect delay backoff behaviour. Closes #1027.
Don't call on_disconnect() twice if keepalive tests fail. Closes #1067.

Client

Always print leading zeros in mosquitto_sub when output format is hex. Closes #1066.

Build

Fix building where TLS-PSK is not available. Closes #68.