• No root password on a server. Privileges of operators are elevated with sudo.
• Locally installed software should not need root privileges in order to be installed.
• Only private/public key access to the server
  • Of course, private keys for humans have a passphrase.
  • Of course, public keys for services are locked down to the minimal required functionality, see only.
• SSH login only for specific user/group combinations.
• Privilege separation wherever possible: all services run with different users/groups.
• Wherever possible use runit and ?svlogd for running a service and logging its diagnostics.
• Use socklog instead of syslog
• Avoid software which needs root privileges, or does not drop them after acquiring the needed resources (e.g. IP ports below 1024).
• Always keep Time in sync.
• Have a working resolution.