not() {
	case "${1}" in
	"false") echo "true" ;;
	"true") echo "false" ;;
	*) ;;
	esac
}

read_passphrase() {
	read_secret "PassPhrase: "
}

read_secret() {
	local prompt="${1}"
	local secret
	printf "%s" "${prompt}" 1>&2
	read -r -s secret
	echo >&2
	echo "${secret}"
	unset secret
}