part of this can be done with openSSH by setting the banner option in sshd_config.
"Banner The contents of the specified file are sent to the remote user before authentication is allowed. If the argument is ``none'' then no banner is displayed. By default, no banner is displayed."
"Banner The contents of the specified file are sent to the remote user before authentication is allowed. If the argument is ``none'' then no banner is displayed. By default, no banner is displayed."