mat-tls.py

#!/usr/bin/env python

import mosquitto
import ssl

def on_connect(mosq, userdata, rc):
    print("Connect: rc: "+str(rc))

def on_message(mosq, userdata, msg):
    print "%s (qos=%s, r=%s) %s" % (msg.topic, str(msg.qos), msg.retain, str(msg.payload))

def on_publish(mosq, userdata, mid):
    print("mid: "+str(mid))

def on_subscribe(mosq, userdata, mid, granted_qos):
    print("Subscribed: "+str(mid)+" "+str(granted_qos))

def on_disconnect(mosq, userdata, rc):
    print "OOOOPS! disconnect"

mqttc = mosquitto.Mosquitto('py-jp1', clean_session=True)
mqttc.on_message = on_message
mqttc.on_connect = on_connect
mqttc.on_disconnect = on_disconnect
mqttc.on_publish = on_publish
mqttc.on_subscribe = on_subscribe

mqttc.tls_insecure_set(True)    # optional: avoid check certificate name if true
mqttc.tls_set('root.ca',
    cert_reqs=ssl.CERT_REQUIRED,
    tls_version=1
    )

mqttc.connect("localhost", 8883, 60)

mqttc.publish("p1", "Hi", 0)
mqttc.loop()

Thx for that, publish it on your website, hard to find this info for novice like me to python and mosquitto.

In the end I I did have had tls_version=1 part, but was missing the cert_required part.

But after a bit of playing around with your code and still not working I found that I had to remove the tls_version=1 part from the python code because I kept getting this error;

Server log :
OpenSSL Error: error:1408A10B:SSL routines:SSL3_GET_CLIENT_HELLO:wrong version number

Python error :
ssl.SSLError: [Errno 1] _ssl.c:504: error:14094410:SSL routines:SSL3_READ_BYTES:sslv3 alert handshake failure

Even though I have the following settings in my mosquitto.conf file;

listener 8883
tls_version tlsv1
cafile /etc/mosquitto/ca.crt
certfile /etc/mosquitto/server.crt
keyfile /etc/mosquitto/server.key
require_certificate false

@matbor What version of Python are you running, on which platform? (python -V)

@jpmens This was done on windows7 python 2.7.5. Didn't try it on my linux box.