#!/bin/sh
#
#  Copyright (c) 02005 sense.lab <senselab@systemausfall.org>
#
#  License:  This script is distributed under the terms of version 2
#            of the GNU GPL. See the LICENSE file included with the package.
#
# $Id$
#
# this script is part of the building process of the cryptobox
# the "normal" action is necessary for every cryptobox (development & release)
# the "secure" action is mandatory for every release CD
#
# 2008-06-21  Adapted by James Crofts for use with "live-helper"
#

set -eu

#this script runs in chroot, so RUNTIMEDIR is the null string
RUNTIMEDIR=""
TUNDEV=$RUNTIMEDIR/dev/net/tun

REMOVE_PACKAGES="strace
	nvi nano vim vim-common vim-tiny
	unzip zip locate
	ssh elinks curl netkit-inetd telnet
	exim4-daemon-light exim4-config exim4-base
	ppp pppconfig pppoe pppoeconf
	subversion w3m wget lynx less screen
    info man-db manpages
    openssh-server openssh-client"

# Removing these packages would be better for security, but
# breaks the build:
#aptitude tasksel wget iptables
#TODO: evaluate whether to remove other packages under Debian Live

# remove rc symlinks for these services
SERVICES_OFF="ssh setserial nviboot mountnfs ntpdate"

#We run in a chroot environment, so source files accordingly.
. /usr/share/cryptonas-live/etc-scoreboard

function configure_normal()
# the usual stuff - not optimized for security
{
	##### cryptobox settings ######
	# start during bootup
	sed -i 's/^NO_START=.*$/NO_START=0/' /etc/default/cryptobox-server
	# listen to port 80 by default
	sed -i 's/^PORT=.*$/PORT=80/' /etc/default/cryptobox-server
	# use a separate configuration partition
	sed -i 's/^UseConfigPartition.*$/UseConfigPartition = 1/' /etc/cryptobox-server/cryptobox.conf
	# all plugins are enabled (especially: "encrypted_webinterface")
	sed -i 's#^DisabledPlugins.*$#DisabledPlugins = #' /etc/cryptobox-server/cryptobox.conf
	# change the selection of devices, that can be used as the crypto harddisk
	sed -i 's#^AllowedDevices.*$#AllowedDevices = /dev/#' /etc/cryptobox-server/cryptobox.conf

	############ samba ############
	# enable samba startup (disabled before via cbox-build.sh)
	echo 'RUN_MODE="daemons"' >/etc/default/samba
	# install the samba hook script
	cp /usr/share/doc/cryptobox-server/event-scripts/samba /etc/cryptobox-server/events.d/samba 
	chmod +x /etc/cryptobox-server/events.d/samba

	############ dir perms ########
	# For security reasons, many CryptoNAS scripts will refuse
	# to run if their parent directories have unsafe permissions.
	# The files in config/chroot_local-includes are, by default,
	# owned by the user who did the SVN checkout. Therefore
	# reset the important directories there to being owned by root.
	# Debian Policy specifies that local users and package-created
	# users have different uid ranges, so the set of files with
	# unrecognized uid's should be the same as the set of files added
	# by "config/chroot_local-includes/".
	# Note that we are doing this at build time, not run time!
	# Only fix files that are neither setuid nor setgid:
	find / -xdev -nouser ! -perm -4000 ! -perm -2000 -execdir chown root:root '{}' \+

	############ webdav ############
    #TODO: FIXME: configure port; add webdav link in web frontend
	sed -i 's/^NO_START=.*$/NO_START=0/' /etc/default/apache2
	cp /usr/share/doc/cryptobox-server/event-scripts/apache2_dav /etc/cryptobox-server/events.d/apache2_dav
	chmod +x /etc/cryptobox-server/events.d/apache2_dav
	

        ########### boot up ###########
        # turn off creation of "/etc/nologin" (read-only fs)
        sed -i '/^DELAYLOGIN=/s/^DELAYLOGIN=.*$/DELAYLOGIN=no/' /etc/default/rcS
        # turn off modifying /etc/motd (read-only fs)
        sed -i '/^EDITMOTD=/s/^EDITMOTD=.*$/EDITMOTD=no/' /etc/default/rcS

	######### shutdown #########
	# Remove the prompt to eject CD
	rm -r /etc/rc0.d/*casper
	rm -r /etc/rc6.d/*casper

	######### devices ##########
	# create tun device for running under qemu
	if [ ! -e "$TUNDEV" ]
		then	mkdir -p `dirname "$TUNDEV"`
			mknod "$TUNDEV" c 10 200
	  fi

	########## sshd ############
	if [ -e "/etc/ssh" ]; then
	    # allow empty passwords for ssh
	    #  the daemon is NOT started automatically, so you have to start it
	    #  manually in case of need - as the root pw is empty and passwd is ro, you
	    #  have to allow empty passwords for this rare case
	    sed -i 's/^PermitEmptyPass.*$/PermitEmptyPasswords yes/' /etc/ssh/sshd_config
	    # turn off PAM for ssh, as it prevents the use of empty passwords (stange behaviour)
	    sed -i 's/^UsePAM.*$/UsePAM no/' /etc/ssh/sshd_config
	    # allow input of password
	    sed -i 's/^PasswordAuthentication.*$/PasswordAuthentication yes/' /etc/ssh/sshd_config
	  fi

	# remove symlinks for unwanted services
	for a in $SERVICES_OFF; do
	  # echo "Turning off service $a ..."
	  find /etc/rc?.d/ -type l -name "[SK][0-9][0-9]$a" | while read b
	    do	rm "$b"
	   done
	 done

	return 0
}


function configure_secure()
# remove everything that could weaken security
# configure_normal should be called too!
{
	# disable keyboard login
	sed -i '/getty/d' /etc/inittab

	# remove unnecessary packages
	dpkg --force-all -P $REMOVE_PACKAGES 2>&1 | grep -v "which isn't installed." || true

	# maybe an authorized_keys file was created - but it is not dangerous,
	# as the openssh package was removed anyway
	[ -d /root/.ssh ] && rm -rf /root/.ssh

	# disable root account
	passwd -l root

	############## clean up ################
	# remove deb-files, that were left by dfsbuild
	# remove packages and package lists
	# remove locale files
	# remove doc files
	# remove man pages
	# some vim files stay behind?

	# Need to keep these files for live-helper to complete successfully
	# rm -rf /var/cache/apt /var/lib/apt /var/cache/debconf /opt/packages

	rm -rf /var/cache/bootstrap /var/cache/locate
	rm -rf /usr/share/man /usr/share/vim /var/cache/man
	# remove docs except for the cryptobox's
	ls /usr/share/doc | while read dname
	  do	test "$dname" == "cryptobox-server" || rm -rf "/usr/share/doc/$dname"
	 done
	# remove all locale files and symlinks except for the cryptobox's
	(find /usr/share/locale -type f; find /usr/share/locale -type l) | grep -v "cryptobox-server" | while read fname
	  do	rm "$fname"
	 done
	# remove all empty locale directories
	find /usr/share/locale -type d | while read dname
	  do	test -d "$dname" && rmdir --ignore-fail-on-non-empty --parents "$dname"
	 done

	# change some dir permissions
	chmod 770 /var/cache/cryptobox-server/settings/

	# remove developer-specific script(s)
	rm -f /usr/share/cryptonas-live/devel-features.sh
	rm -f /etc/init.d/*devel-features
	rm -f /etc/rcS.d/*devel-features
	rm -f /etc/rc3.d/*devel-features

	return 0
}


################ main ####################
# Allow this script to be run either manually by the
# developer using live-helper's "interactive chroot"
# mode or automatically by "lh_build".
ACTION="$CNAS_HARDNESS"
[ $# -gt 0 ] && ACTION=$1

case "$ACTION" in
	normal|devel)
		configure_normal
		;;
	secure|hard)
                configure_normal
		configure_secure
		;;
	* )
        echo "`basename $0`:warning: CryptoNAS security level\
 not specified; defaulting to \"secure\""
        configure_normal
        configure_secure
		;;
  esac

#FIXME: Not ideal to unconditionally return "SUCCESS"
exit 0