Add server section to your Maven settings

This is the preferred way. Firstly, add a server section to your Maven settings like this (see https://maven.apache.org/settings.html#Servers for further information):

<settings>
	<servers>
		<server>
			<id>my-server</id>
			<privateKey>/path/to/your/private_key</privateKey>
			<passphrase>optional_passphrase</passphrase>
		</server>
	</servers>
</settings>

If your key is password protected, specify the password within element passphrase. Tip: do not confuse this with element password.

Secondly, specify the serverId in the plugin configuration

<plugin>
	...
	<configuration>
		<serverId>my-server</serverId>
	</configuration>
</plugin>

Specify private key and optional passphrase in your POM

This is the insecure way to specify your custom private key. Add following properties to your plugin configuration:

<plugin>
	...
	<configuration>
		<privateKey>/path/to/your/private_key</privateKey>
		<passphrase>optional_passphrase</passphrase> <!-- This is optional -->
	</configuration>
</plugin>

Note: POM configuration has precedence over Maven settings.

Custom known_hosts

Per default, the plugin uses ~/.ssh/known_hosts. You can override this with following property in your plugin configuration:

<plugin>
	...
	<configuration>
		<knownHosts>/path/to/your/known_hosts</knownHosts>
	</configuration>
</plugin>

Note: Maven settings related to known_hosts will not be considered by the plugin.