Radoslav Panev

SysAdmin and DevOps

Enable PSK Encryption for Zabbix Agent on Linux

04 Dec 2019 » linux, monitoring


By default, agent communication is done in clear text. For encryption we have an option to use PSK-based encryption. PSK means pre shared key. The PSK option consists of two important values, the PSK identity and the PSK Secret. The secret should be minimum a 128-bit (16-byte PSK, entered as 32 hexadecimal digits) up to 2048-bit (256-byte PSK, entered as 512 hexadecimal digits)

You can generate a 256 bit PSK secret with openssl using the command:

openssl rand -hex 32

I will save it directly to the zabbix directory

cd /etc/zabbix

I then run,

openssl rand -hex 32 > secret.psk

I also make sure that only the Zabbix user can read the file.

chown zabbix:zabbix secret.psk && chmod 640 secret.psk

I then edit the Zabbix agent configuration file.

nano /etc/zabbix/zabbix_agentd.conf

and change the options near the bottom,

TLSPSKIdentity=[my secret pass]

I then restart the agent

service zabbix-agent restart

The configuration of the zabbix server is as follows

Configuration > Host > we choose the host for which to put psk and we click on it > Encryption > I select the :

‘Connections to host’ = PSK

‘Connections from host’ = PSK

‘PSK Identity’ = [what ever you used in the Zabbix agent config]

‘PSK’ = [the long hex string generated from the OpenSSL command above]

After a minute or two, the Zabbix Server and Agent will successfully communicate using PSK encryption.