Facing Error while running mosquitto broker using TLS with mosquitto

问题

I am trying to use TLS for communicating over mqtt. I have ubuntu installed in my system. For using TLS, I have created certificates using the below link:

http://www.embedded101.com/Blogs/PaoloPatierno/entryid/366/mqtt-over-ssl-tls-with-the-m2mqtt-library-and-the-mosquitto-broker

I am able to create certificates. I have removed bind_address from config file. I am starting mosquitto with the new config file with mosquitto -c mosquitto_m2mqtt.conf -v. Mosquitto starts, but when I run mosquitto_sub command, I am getting error as below:

mosquitto -c mosquitto_m2mqtt.conf -v
1551172930: mosquitto version 1.4.8 (build date 2016-09-21 11:21:45+0530) starting
1551172930: Config loaded from mosquitto_m2mqtt.conf.
1551172930: Opening ipv4 listen socket on port 8883.
1551172930: Opening ipv6 listen socket on port 8883.
Enter PEM pass phrase:
1551172960: New connection from 127.0.0.1 on port 8883.
1551172960: OpenSSL Error: error:14094416:SSL routines:ssl3_read_bytes:sslv3 alert certificate unknown
1551172960: OpenSSL Error: error:140940E5:SSL routines:ssl3_read_bytes:ssl handshake failure
1551172960: Socket error on client <unknown>, disconnecting.

In the window that I am subscribing, I am getting error as below:

mosquitto_sub -p 8883 -q 1 -t sensor/temp --cafile /etc/mosquitto/m2mqtt_srv.crt --tls-version tlsv1 -d
Unable to connect (A TLS error occurred.).

Below are the parameters added in config file.

port 8883
cafile /etc/mosquitto/m2mqtt_ca.crt
certfile /etc/mosquitto/m2mqtt_srv.crt
keyfile /etc/mosquitto/m2mqtt_srv.key
tls_version tlsv1

回答1:

mosquitto_sub and pub needs a host address or ip. For example i use test.mosquitto.org in my local, download the pem formatted certificate file from this site and added to the conf file just this certificate as "cafile". And here is my command:

mosquitto_sub -h test.mosquitto.org -t "test" -p 8883 --cafile "<pem formatted crt file path (downloaded from test.mosquitto.org)>"

来源：https://stackoverflow.com/questions/54899215/facing-error-while-running-mosquitto-broker-using-tls-with-mosquitto