Slim, the SliTaz Login Manager, asks for a password, when a special command like halt, reboot or shutdown was entered in place of a user name.

The required password is that from user root!

Enter the root password, and the appropriate action for halt, reboot or shutdown as defined in

/etc/slim.conf

with

halt_cmd    /sbin/poweroff

and

reboot_cmd    /sbin/reboot

will be performed, and no login.