xref: /freebsd/usr.sbin/bsdinstall/scripts/hardening (revision c0e249d32c780ee8240fe8b3b8144078a8eec41f)

#!/bin/sh
#-
# Copyright (c) 2016 Bartek Rutkowski
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#

BSDCFG_SHARE="/usr/share/bsdconfig"
. $BSDCFG_SHARE/common.subr || exit 1

: ${BSDDIALOG_OK=0}

echo -n > $BSDINSTALL_TMPETC/rc.conf.hardening
echo -n > $BSDINSTALL_TMPETC/sysctl.conf.hardening
echo -n > $BSDINSTALL_TMPBOOT/loader.conf.hardening

exec 5>&1
FEATURES=$( bsddialog --backtitle "$OSNAME Installer" \
    --title "System Hardening" --nocancel --separate-output \
    --checklist "Choose system security hardening options:" \
    0 0 0 \
	"0 hide_uids" "Hide processes running as other users" ${hide_uids:-off} \
	"1 hide_gids" "Hide processes running as other groups" ${hide_gids:-off} \
	"2 hide_jail" "Hide processes running in jails" ${hide_jail:-off} \
	"3 read_msgbuf" "Disable reading kernel message buffer for unprivileged users" ${read_msgbuf:-off} \
	"4 proc_debug" "Disable process debugging facilities for unprivileged users" ${proc_debug:-off} \
	"5 random_pid" "Randomize the PID of newly created processes" ${random_pid:-off} \
	"6 clear_tmp" "Clean the /tmp filesystem on system startup" ${clear_tmp:-off} \
	"7 disable_syslogd" "Disable opening Syslogd network socket (disables remote logging)" ${disable_syslogd:-off} \
	"8 secure_console" "Enable console password prompt" ${secure_console:-off} \
	"9 disable_ddtrace" "Disallow DTrace destructive-mode" ${disable_ddtrace:-off} \
2>&1 1>&5 )
retval=$?
exec 5>&-

if [ $retval -ne $BSDDIALOG_OK ]; then
	exit 1
fi

for feature in $FEATURES; do
	case "$feature" in
	hide_uids)
		echo security.bsd.see_other_uids=0 >> $BSDINSTALL_TMPETC/sysctl.conf.hardening
		;;
	hide_gids)
		echo security.bsd.see_other_gids=0 >> $BSDINSTALL_TMPETC/sysctl.conf.hardening
		;;
	hide_jail)
		echo security.bsd.see_jail_proc=0 >> $BSDINSTALL_TMPETC/sysctl.conf.hardening
		;;
	read_msgbuf)
		echo security.bsd.unprivileged_read_msgbuf=0 >> $BSDINSTALL_TMPETC/sysctl.conf.hardening
		;;
	proc_debug)
		echo security.bsd.unprivileged_proc_debug=0 >> $BSDINSTALL_TMPETC/sysctl.conf.hardening
		;;
	random_pid)
		echo kern.randompid=1 >> $BSDINSTALL_TMPETC/sysctl.conf.hardening
		;;
	clear_tmp)
		echo 'clear_tmp_enable="YES"' >> $BSDINSTALL_TMPETC/rc.conf.hardening
		;;
	disable_syslogd)
		echo 'syslogd_flags="-ss"' >> $BSDINSTALL_TMPETC/rc.conf.hardening
		;;
	secure_console)
		sed "s/unknown	off secure/unknown	off insecure/g" $BSDINSTALL_CHROOT/etc/ttys > $BSDINSTALL_TMPETC/ttys.hardening
		;;
	disable_ddtrace)
		echo 'security.bsd.allow_destructive_dtrace=0' >> $BSDINSTALL_TMPBOOT/loader.conf.hardening
		;;
	esac
done