[Unit]
Description=Dropbear DSS Keygeneration.
After=syslog.target
Before=dropbear.service
ConditionPathExists=!/etc/dropbear/dropbear_dss_host_key

[Service]
Type=oneshot
ExecStart=/usr/bin/dropbearkey -t dss -f /etc/dropbear/dropbear_dss_host_key
RemainAfterExit=yes