# My simple ACL breaks my Mosquitto broker
**URL:** https://forum.cedalo.com/t/my-simple-acl-breaks-my-mosquitto-broker/1047
**Category:** Security
**Created:** [September 29, 2024, 6:37pm UTC](https://forum.cedalo.com/t/my-simple-acl-breaks-my-mosquitto-broker/1047 "2024-09-29T18:37:21Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@HerrimanCoder](https://forum.cedalo.com/u/HerrimanCoder)
#### Post date: [September 29, 2024, 6:37pm UTC](https://forum.cedalo.com/t/my-simple-acl-breaks-my-mosquitto-broker/1047/1 "2024-09-29T18:37:21Z")
My Mosquitto MQTT broker has been working fine in production (Ubuntu) for 2 months. I didn’t have any ACL restrictions yet, so I tried to implement some yesterday. After saving the 2 files (more details below) and restarting the broker, it immediately blew up with the following error messages:
> × mosquitto.service - Mosquitto MQTT Broker
> Loaded: loaded (/lib/systemd/system/mosquitto.service; enabled; vendor preset: enabled)
> Active: failed (Result: exit-code) since Sat 2024-09-28 14:31:51 MDT; 29s ago
> Docs: man:mosquitto.conf(5)
> man:mosquitto(8)
> Process: 2804595 ExecStartPre=/bin/mkdir -m 740 -p /var/log/mosquitto (code=exited, status=0/SUCCESS)
> Process: 2804596 ExecStartPre=/bin/chown mosquitto /var/log/mosquitto (code=exited, status=0/SUCCESS)
> Process: 2804597 ExecStartPre=/bin/mkdir -m 740 -p /run/mosquitto (code=exited, status=0/SUCCESS)
> Process: 2804598 ExecStartPre=/bin/chown mosquitto /run/mosquitto (code=exited, status=0/SUCCESS)
> Process: 2804599 ExecStart=/usr/sbin/mosquitto -c /etc/mosquitto/mosquitto.conf (code=exited, status=3)
> Main PID: 2804599 (code=exited, status=3)
> CPU: 11ms
Here is the only ACL line in my mosquitto.conf file:
`acl_file /etc/mosquitto/ezsalt.acl`
And here are the full contents of ezsalt.acl:
```auto
user ezsaltsensor
topic tele/+/SENSOR
topic cmnd/EZsalt_+/teleperiod
```
The user **ezsaltsensor** is the username by which all our devices interact with the broker. There is also a password. These credentialed interactions have been working great; it’s only when I tried to implement this ACL file that everything broke.
Because I created the _ezsalt.acl_ file with the root user, I (at first) thought that the mosquitto process didn’t have permissions to interact with that file. So I changed ownership of that file to the mosquitto user. Tried again, still fails, same errors.
I ran this:
`ls -l ezsalt.acl`
…and got this:
`-rw-rw-r-- 1 mosquitto mosquitto 69 Sep 28 15:03 ezsalt.acl`
What am I doing wrong?
Mosquitto version info:
```auto
mosquitto version 2.0.11
mosquitto is an MQTT v5.0/v3.1.1/v3.1 broker.
```
---
### Author:  [@ckrey](https://forum.cedalo.com/u/ckrey)
#### Post date: [October 1, 2024, 12:20pm UTC](https://forum.cedalo.com/t/my-simple-acl-breaks-my-mosquitto-broker/1047/2 "2024-10-01T12:20:50Z")
Your topic `cmnd/EZsale_+/teleperiod` is not a valid topic filter.
Simply speaking, a `+` sign cannot be used together with other characters on a level.
[https://docs.oasis-open.org/mqtt/mqtt/v5.0/mqtt-v5.0.pdf](https://docs.oasis-open.org/mqtt/mqtt/v5.0/mqtt-v5.0.pdf) ,
section 4.7.1.3 Single-level wildcard
---
### Author:  [@HerrimanCoder](https://forum.cedalo.com/u/HerrimanCoder)
#### Post date: [October 1, 2024, 2:00pm UTC](https://forum.cedalo.com/t/my-simple-acl-breaks-my-mosquitto-broker/1047/3 "2024-10-01T14:00:48Z")
ckrey - How should that line be modified so it’s valid?
---
### Author:  [@ckrey](https://forum.cedalo.com/u/ckrey)
#### Post date: [October 1, 2024, 3:21pm UTC](https://forum.cedalo.com/t/my-simple-acl-breaks-my-mosquitto-broker/1047/4 "2024-10-01T15:21:28Z")
It depends on what you are trying to achieve, I don’t know the topics/messages of EZsalt…
Maybe
topic `cmnd/+/teleperiod` ?
---
### Author:  [@HerrimanCoder](https://forum.cedalo.com/u/HerrimanCoder)
#### Post date: [November 17, 2024, 8:13pm UTC](https://forum.cedalo.com/t/my-simple-acl-breaks-my-mosquitto-broker/1047/5 "2024-11-17T20:13:55Z")
Thank you!