#!/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
#
# called by:
#	- cbox-build.sh after copying custom files and before creating the iso image
#

set -eu

RUNTIMEDIR=/opt/dfsruntime/runtimerd
TUNDEV=$RUNTIMEDIR/dev/net/tun
ADD_GROUPS="floppy cdrom tape video plugdev"

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

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

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
	# add the cryptobox user to some more groups
	for new_group in $ADD_GROUPS
	  do	adduser cryptobox "$new_group"
	 done

	############ 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


	############ webdav ############
    #TODO: add apache2 packages; configure port; add webdav link in web frontend

#This breaks the build until apache2 is integrated into the package list
#	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
	# default runlevel (out of some strange reason, runlevel 2 is not working)
	sed -i 's/^id:.*$/id:3:initdefault:/' /etc/inittab
	# add tmpfs entry for mount parent
	# remove old line, if fstab exists
	test -e /etc/fstab && sed -i '#/var/cache/cryptobox-server/mnt#d' /etc/fstab
	# add new line
	echo "tmpfs	/var/cache/cryptobox-server/mnt	tmpfs	defaults	0	0" >>/etc/fstab
	
	######### 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?
	rm -rf /opt/packages /var/cache/bootstrap /var/cache/apt/ /var/cache/locate 
	rm -rf /usr/share/man /usr/share/vim /var/lib/apt /var/cache/debconf /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 660 /var/cache/cryptobox-server/settings/

	return 0
}


################ main ####################


ACTION=help
[ $# -gt 0 ] && ACTION=$1

case "$ACTION" in
	normal )
		configure_normal
		;;
	secure )
		configure_secure
		;;
	* )
		echo "Syntax: `basename $0` { normal | secure }"
		echo
		;;
  esac