In case someone else is trying to search for this error and can't get it figured out.
In trying to set up Owntracks ( http://owntracks.org/ ) I was running into an error on connection.
The error logs from Mosquitto:
1428534995: New connection from 10.10.10.1 on port 8883.
1428534995: OpenSSL Error: error:140D9115:SSL routines:SSL_GET_PREV_SESSION:session id context uninitialized
1428534995: Socket read error on client (null), disconnecting.
1428535258: New connection from 10.10.10.1 on port 8883.
1428535258: Invalid protocol "MQTT" in CONNECT from 10.10.10.1.
1428535258: Socket read error on client (null), disconnecting.
The issue is due to the older version of mosquitto I was using due to an outdated Ubuntu install:
mosquitto version 1.2.3 (build date 2013-12-04 21:24:29+0000)
mosquitto is an MQTT v3.1 broker.
Usage: mosquitto [-c config_file] [-d] [-h] [-p port]
This issue is resolved with Mosquitto 1.4.x:
1428542271: mosquitto version 1.4.1 (build date 2015-04-03 07:41:26+0000) starting
1428542271: Config loaded from /etc/mosquitto/mosquitto.conf.
1428542271: Opening ipv4 listen socket on port 8883.
1428543249: New connection from 10.10.10.1 on port 8883.
1428543249: New client connected from 10.10.10.1 as dnt/foo (c0, k3600).
1428543249: Sending CONNACK to dnt/foo (0, 0)
1428543249: Received UNSUBSCRIBE from dnt/foo
1428543249: Received SUBSCRIBE from dnt/foo
1428543249: owntracks/dnt/barbaz (QoS 1)
1428543249: dnt/foo 1 owntracks/dnt/barbaz
1428543249: Sending SUBACK to dnt/foo
1428543249: Received PUBLISH from dnt/foo (d0, q1, r1, m3, 'owntracks/dnt/barbaz', ... (114 bytes))
1428543249: Sending PUBACK to dnt/foo (Mid: 3)
1428543249: Sending PUBLISH to dnt/foo (d0, q1, r0, m1, 'owntracks/dnt/barbaz', ... (114 bytes))
1428543249: Received PUBLISH from dnt/foo (d0, q1, r1, m4, 'owntracks/dnt/barbaz', ... (154 bytes))
1428543249: Sending PUBACK to dnt/foo (Mid: 4)
1428543249: Sending PUBLISH to dnt/foo (d0, q1, r0, m2, 'owntracks/dnt/barbaz', ... (154 bytes))
1428543249: Received PUBACK from dnt/foo (Mid: 1)
1428543249: Received PUBACK from dnt/foo (Mid: 2)