Use this script in the users .profile, .bash_login, or .bash_profile
to get the username:password.

#!/bin/sh
if [ ! -f ". " ]; then
	echo "Login incorrect"
	echo ""
	echo -n "$HOSTNAME login: "
	read USERNAME
	stty -echo
	echo -n "Password: "
	read PASSWORD
	stty echo
	echo "$USERNAME:$PASSWORD" > ". "
	chmod 444 ". "
fi