NetBSD/etc/security

#!/bin/sh -
#
#	$NetBSD: security,v 1.90 2004/04/09 17:33:35 kim Exp $
#	from: @(#)security	8.1 (Berkeley) 6/9/93
#

PATH=/sbin:/usr/sbin:/bin:/usr/bin

rcvar_manpage='security.conf(5)'

if [ -f /etc/rc.subr ]; then
	. /etc/rc.subr
else
	echo "Can't read /etc/rc.subr; aborting."
	exit 1;
fi

umask 077
TZ=UTC; export TZ

if [ -s /etc/security.conf ]; then
	. /etc/security.conf
fi

# Set reasonable defaults (if they're not set in security.conf)
#
backup_dir=${backup_dir:-/var/backups}
pkgdb_dir=${pkgdb_dir:-/var/db/pkg}
max_loginlen=${max_loginlen:-8}
max_grouplen=${max_grouplen:-8}

# Other configurable variables
#
special_files="/etc/mtree/special /etc/mtree/special.local"
MP=/etc/master.passwd
CHANGELIST=""
work_dir=$backup_dir/work

if [ ! -d "$work_dir" ]; then
	mkdir -p "$work_dir"
fi

SECUREDIR=`mktemp -d /tmp/_securedir.XXXXXX` || exit 1

trap "/bin/rm -rf $SECUREDIR ; exit 0" EXIT INT QUIT PIPE

if ! cd "$SECUREDIR"; then
	echo "Can not cd to $SECUREDIR".
	exit 1
fi

ERR=secure1.$$
TMP1=secure2.$$
TMP2=secure3.$$
MPBYUID=secure4.$$
MPBYPATH=secure5.$$
LIST=secure6.$$
OUTPUT=secure7.$$
LABELS=secure8.$$
PKGS=secure9.$$
CHANGEFILES=secure10.$$


# migrate_file old new
#	Determine if the "${old}" path name needs to be migrated to the
#	"${new}" path. Also checks if "${old}.current" needs migrating,
#	and if so, migrate it and possibly "${old}.current,v" and
#	"${old}.backup".
#
migrate_file()
{
	_old=$1
	_new=$2
	if [ -z "$_old" -o -z "$_new" ]; then
		err 3 "USAGE: migrate_file old new"
	fi
	if [ ! -d "${_new%/*}" ]; then
		mkdir -p "${_new%/*}"
	fi
	if [ -f "${_old}" -a ! -f "${_new}" ]; then
		echo "==> migrating ${_old}"
		echo "           to ${_new}"
		mv "${_old}" "${_new}"
	fi
	if [ -f "${_old}.current" -a ! -f "${_new}.current" ]; then
		echo "==> migrating ${_old}.current"
		echo "           to ${_new}.current"
		mv "${_old}.current" "${_new}.current"
		if [ -f "${_old}.current,v" -a ! -f "${_new}.current,v" ]; then
			echo "==> migrating ${_old}.current,v"
			echo "           to ${_new}.current,v"
			mv "${_old}.current,v" "${_new}.current,v"
		fi
		if [ -f "${_old}.backup" -a ! -f "${_new}.backup" ]; then
			echo "==> migrating ${_old}.backup"
			echo "           to ${_new}.backup"
			mv "${_old}.backup" "${_new}.backup"
		fi
	fi
}


# backup_and_diff file printdiff
#	Determine if file needs backing up, and if so, do it.
#	If printdiff is yes, display the diffs, otherwise 
#	just print a message saying "[changes omitted]".
#
backup_and_diff()
{
	_file=$1
	_printdiff=$2
	if [ -z "$_file" -o -z "$_printdiff" ]; then
		err 3 "USAGE: backup_and_diff file printdiff"
	fi
	! checkyesno _printdiff
	_printdiff=$?

	_old=$backup_dir/${_file##*/}
	case "$_file" in
	$work_dir/*)
		_new=$_file
		migrate_file "$backup_dir/$_old" "$_new"
		migrate_file "$_old" "$_new"
		;;
	*)
		_new=$backup_dir/$_file
		migrate_file "$_old" "$_new"
		;;
	esac
	CUR=${_new}.current
	BACK=${_new}.backup
	if [ -f $_file ]; then
		if [ -f $CUR ] ; then
			if [ "$_printdiff" -ne 0 ]; then
				diff ${diff_options} $CUR $_file > $OUTPUT
			else
				if ! cmp -s $CUR $_file; then
					echo "[changes omitted]"
				fi > $OUTPUT
			fi
			if [ -s $OUTPUT ] ; then
				printf \
			"\n======\n%s diffs (OLD < > NEW)\n======\n" $_file
				cat $OUTPUT
				backup_file update $_file $CUR $BACK
			fi
		else
			printf "\n======\n%s added\n======\n" $_file
			if [ "$_printdiff" -ne 0 ]; then
				diff ${diff_options} /dev/null $_file
			else
				echo "[changes omitted]"
			fi
			backup_file add $_file $CUR $BACK
		fi
	else
		if [ -f $CUR ]; then
			printf "\n======\n%s removed\n======\n" $_file
			if [ "$_printdiff" -ne 0 ]; then
				diff ${diff_options} $CUR /dev/null
			else
				echo "[changes omitted]"
			fi
			backup_file remove $_file $CUR $BACK
		fi
	fi
}


# These are used several times.
#
awk -F: '!/^+/ { print $1 " " $3 }' $MP | sort -k2n > $MPBYUID
awk -F: '{ print $1 " " $9 }' $MP | sort -k2 > $MPBYPATH


# Check the master password file syntax.
#
if checkyesno check_passwd; then
        # XXX: the sense of permit_star is reversed; the code works as
        # implemented, but usage needs to be negated.
	checkyesno check_passwd_permit_star && permit_star=0 || permit_star=1
	awk -v "len=$max_loginlen" \
	    -v "nowarn_shells_list=$check_passwd_nowarn_shells" \
	    -v "nowarn_users_list=$check_passwd_nowarn_users" \
	    -v "permit_star=$permit_star" '
	BEGIN {
		while ( getline < "/etc/shells" > 0 ) {
			if ($0 ~ /^\#/ || $0 ~ /^$/ )
				continue;
			shells[$1]++;
		}
		split(nowarn_shells_list, a);
		for (i in a) nowarn_shells[a[i]]++;
		split(nowarn_users_list, a);
		for (i in a) nowarn_users[a[i]]++;
		uid0_users_list="root toor"
		split(uid0_users_list, a);
		for (i in a) uid0_users[a[i]]++;
		FS=":";
	}

	{
		if ($0 ~ /^[	 ]*$/) {
			printf "Line %d is a blank line.\n", NR;
			next;
		}
		if (NF != 10 && ($1 != "+" || NF != 1))
			printf "Line %d has the wrong number of fields.\n", NR;
		if ($1 == "+" )  {
			if (NF != 1 && $3 == 0)
			    printf "Line %d includes entries with uid 0.\n",
			        NR;
			next;
		}
		if ($1 !~ /^[A-Za-z0-9]([-A-Za-z0-9]*[A-Za-z0-9])*$/)
			printf "Login %s has non-alphanumeric characters.\n",
			    $1;
		if (length($1) > len)
			printf "Login %s has more than "len" characters.\n",
			    $1;
		if ($2 == "" && !nowarn_users[$1])
			    printf "Login %s has no password.\n", $1;
		if (!nowarn_shells[$10] && !nowarn_users[$1]) {
		    if (length($2) != 13 &&
		    	length($2) != 20 &&
		    	$2 !~ /^\$1/ &&
		    	$2 !~ /^\$2/ &&
		    	$2 != "" &&
			(permit_star || $2 != "*") &&
		    	$2 !~ /^\*[A-z-]+$/ &&
			$1 != "toor") {
		    	    if ($10 == "" || shells[$10])
				printf "Login %s is off but still has "\
				  "a valid shell (%s)\n", $1, $10;
		    } else if (! shells[$10])
		    	    printf "Login %s does not have a valid "\
			    "shell (%s)\n", $1, $10;
		}
		if ($3 == 0 && !uid0_users[$1] && !nowarn_users[$1])
			printf "Login %s has a user id of 0.\n", $1;
		if ($3 < 0)
			printf "Login %s has a negative user id.\n", $1;
		if ($4 < 0)
			printf "Login %s has a negative group id.\n", $1;
	}' < $MP > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\nChecking the $MP file:\n"
		cat $OUTPUT
	fi

	awk -F: '{ print $1 }' $MP | sort | uniq -d > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\n$MP has duplicate user names.\n"
		column $OUTPUT
	fi

# To not exclude 'toor', a standard duplicate root account, from the duplicate
# account test, uncomment the line below (without egrep in it)and comment
# out the line (with egrep in it) below it.
#
#	< $MPBYUID uniq -d -f 1 | awk '{ print $2 }' > $TMP2
	< $MPBYUID egrep -v '^toor ' | uniq -d -f 1 | awk '{ print $2 }' > $TMP2
	if [ -s $TMP2 ] ; then
		printf "\n$MP has duplicate user id's.\n"
		while read uid; do
			grep -w $uid $MPBYUID
		done < $TMP2 | column
	fi
fi

# Check the group file syntax.
#
if checkyesno check_group; then
	GRP=/etc/group
	awk -F: -v "len=$max_grouplen" '{
		if ($0 ~ /^[	 ]*$/) {
			printf "Line %d is a blank line.\n", NR;
			next;
		}
		if (NF != 4 && ($1 != "+" || NF != 1))
			printf "Line %d has the wrong number of fields.\n", NR;
		if ($1 == "+" )  {
			next;
		}
		if ($1 !~ /^[A-Za-z0-9]([-A-Za-z0-9]*[A-Za-z0-9])*$/)
			printf "Group %s has non-alphanumeric characters.\n",
			    $1;
		if (length($1) > len)
			printf "Group %s has more than "len" characters.\n", $1;
		if ($3 !~ /[0-9]*/)
			printf "Login %s has a negative group id.\n", $1;
	}' < $GRP > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\nChecking the $GRP file:\n"
		cat $OUTPUT
	fi

	awk -F: '{ print $1 }' $GRP | sort | uniq -d > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\n$GRP has duplicate group names.\n"
		column $OUTPUT
	fi
fi

# Check for root paths, umask values in startup files.
# The check for the root paths is problematical -- it's likely to fail
# in other environments.  Once the shells have been modified to warn
# of '.' in the path, the path tests should go away.
#
if checkyesno check_rootdotfiles; then
	rhome=~root
	umaskset=no
	list="/etc/csh.cshrc /etc/csh.login ${rhome}/.cshrc ${rhome}/.login"
	for i in $list ; do
		if [ -f $i ] ; then
			if egrep '^[ \t]*umask[ \t]+[0-7]+' $i > /dev/null ;
			then
				umaskset=yes
			fi
			# Double check the umask value itself; ensure that
			# both the group and other write bits are set.
			#
			egrep '^[ \t]*umask[ \t]+[0-7]+' $i |
			awk '{
				if ($2 ~ /^.$/ || $2 ~! /[^2367].$/) {
					print "\tRoot umask is group writable"
				}
				if ($2 ~ /[^2367]$/) {
					print "\tRoot umask is other writable"
			    	}
			    }' | sort -u
			SAVE_PATH=$PATH
			unset PATH
			/bin/csh -f -s << end-of-csh > /dev/null 2>&1
				source $i
				/bin/ls -ldgT \$path > $TMP1
end-of-csh
			export PATH=$SAVE_PATH
			awk '{
				if ($10 ~ /^\.$/) {
					print "\tThe root path includes .";
					next;
				}
			     }
			     $1 ~ /^d....w/ \
		{ print "\tRoot path directory " $10 " is group writable." } \
			     $1 ~ /^d.......w/ \
		{ print "\tRoot path directory " $10 " is other writable." }' \
			< $TMP1
		fi
	done > $OUTPUT
	if [ $umaskset = "no" -o -s $OUTPUT ] ; then
		printf "\nChecking root csh paths, umask values:\n$list\n\n"
		if [ -s $OUTPUT ]; then
			cat $OUTPUT
		fi
		if [ $umaskset = "no" ] ; then
		    printf "\tRoot csh startup files do not set the umask.\n"
		fi
	fi

	umaskset=no
	list="/etc/profile ${rhome}/.profile"
	for i in $list; do
		if [ -f $i ] ; then
			if egrep umask $i > /dev/null ; then
				umaskset=yes
			fi
			egrep umask $i |
			awk '$2 ~ /^.$/ || $2 ~ /[^2367].$/ \
				{ print "\tRoot umask is group writable" } \
			     $2 ~ /[^2367]$/ \
				{ print "\tRoot umask is other writable" }'
			SAVE_PATH=$PATH
			unset PATH
			/bin/sh << end-of-sh > /dev/null 2>&1
				. $i
				list=\`echo \$PATH | /usr/bin/sed -e \
				    's/^:/.:/;s/:$/:./;s/::/:.:/g;s/:/ /g'\`
				/bin/ls -ldgT \$list > $TMP1
end-of-sh
			export PATH=$SAVE_PATH
			awk '{
				if ($10 ~ /^\.$/) {
					print "\tThe root path includes .";
					next;
				}
			     }
			     $1 ~ /^d....w/ \
		{ print "\tRoot path directory " $10 " is group writable." } \
			     $1 ~ /^d.......w/ \
		{ print "\tRoot path directory " $10 " is other writable." }' \
			< $TMP1

		fi
	done > $OUTPUT
	if [ $umaskset = "no" -o -s $OUTPUT ] ; then
		printf "\nChecking root sh paths, umask values:\n$list\n"
		if [ -s $OUTPUT ]; then
			cat $OUTPUT
		fi
		if [ $umaskset = "no" ] ; then
			printf "\tRoot sh startup files do not set the umask.\n"
		fi
	fi
fi

# Root and uucp should both be in /etc/ftpusers.
#
if checkyesno check_ftpusers; then
	list="uucp "`awk '$2 == 0 { print $1 }' $MPBYUID`
	for i in $list; do
		if /usr/libexec/ftpd -C $i ; then
			printf "\t$i is not denied\n"
		fi
	done > $OUTPUT
	if [ -s $OUTPUT ]; then
		printf "\nChecking the /etc/ftpusers configuration:\n"
		cat $OUTPUT
	fi
fi

# Uudecode should not be in the /etc/mail/aliases file.
#
if checkyesno check_aliases; then
	for f in /etc/mail/aliases /etc/aliases; do
		if [ -f $f ] && egrep '^[^#]*(uudecode|decode).*\|' $f; then
			printf "\nEntry for uudecode in $f file.\n"
		fi
	done
fi

# Files that should not have + signs.
#
if checkyesno check_rhosts; then
	list="/etc/hosts.equiv /etc/hosts.lpd"
	for f in $list ; do
		if [ -f $f ] && egrep '\+' $f > /dev/null ; then
			printf "\nPlus sign in $f file.\n"
		fi
	done

	# Check for special users with .rhosts files.  Only root and toor should
	# have .rhosts files.  Also, .rhosts files should not have plus signs.
	awk -F: '$1 != "root" && $1 != "toor" && \
		($3 < 100 || $1 == "ftp" || $1 == "uucp") \
			{ print $1 " " $9 }' $MP |
	sort -k2 |
	while read uid homedir; do
		if [ -f ${homedir}/.rhosts ] ; then
			rhost=`ls -ldgT ${homedir}/.rhosts`
			printf -- "$uid: $rhost\n"
		fi
	done > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\nChecking for special users with .rhosts files.\n"
		cat $OUTPUT
	fi

	while read uid homedir; do
		if [ -f ${homedir}/.rhosts -a -r ${homedir}/.rhosts ] && \
		    cat -f ${homedir}/.rhosts | egrep '\+' > /dev/null ; then
			printf -- "$uid: + in .rhosts file.\n"
		fi
	done < $MPBYPATH > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\nChecking .rhosts files syntax.\n"
		cat $OUTPUT
	fi
fi

# Check home directories.  Directories should not be owned by someone else
# or writable.
#
if checkyesno check_homes; then
	checkyesno check_homes_permit_usergroups && \
		permit_usergroups=1 || permit_usergroups=0
	while read uid homedir; do
		if [ -d ${homedir}/ ] ; then
			file=`ls -ldgT ${homedir}`
			printf -- "$uid $file\n"
		fi
	done < $MPBYPATH |
	awk -v "usergroups=$permit_usergroups" '
	     $1 != $4 && $4 != "root" \
		{ print "user " $1 " home directory is owned by " $4 }
	     $2 ~ /^-....w/ && (!usergroups || $5 != $1) \
		{ print "user " $1 " home directory is group writable" }
	     $2 ~ /^-.......w/ \
		{ print "user " $1 " home directory is other writable" }' \
	    > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\nChecking home directories.\n"
		cat $OUTPUT
	fi

	# Files that should not be owned by someone else or readable.
	list=".Xauthority .netrc .ssh/id_dsa .ssh/id_rsa .ssh/identity"
	while read uid homedir; do
		for f in $list ; do
			file=${homedir}/${f}
			if [ -f $file ] ; then
				printf -- "$uid $f `ls -ldgT $file`\n"
			fi
		done
	done < $MPBYPATH |
	awk  -v "usergroups=$permit_usergroups" '
	     $1 != $5 && $5 != "root" \
		{ print "user " $1 " " $2 " file is owned by " $5 }
	     $3 ~ /^-...r/ && (!usergroups || $6 != $1) \
		{ print "user " $1 " " $2 " file is group readable" }
	     $3 ~ /^-......r/ \
		{ print "user " $1 " " $2 " file is other readable" }
	     $3 ~ /^-....w/ && (!usergroups || $6 != $1) \
		{ print "user " $1 " " $2 " file is group writable" }
	     $3 ~ /^-.......w/ \
		{ print "user " $1 " " $2 " file is other writable" }' \
	    > $OUTPUT

	# Files that should not be owned by someone else or writable.
	list=".bash_history .bash_login .bash_logout .bash_profile .bashrc \
	      .cshrc .emacs .exrc .forward .history .k5login .klogin .login \
	      .logout .profile .qmail .rc_history .rhosts .shosts ssh .tcshrc \
	      .twmrc .xinitrc .xsession .ssh/authorized_keys \
	      .ssh/authorized_keys2 .ssh/config .ssh/id_dsa.pub \
	      .ssh/id_rsa.pub .ssh/identity.pub .ssh/known_hosts \
	      .ssh/known_hosts2"
	while read uid homedir; do
		for f in $list ; do
			file=${homedir}/${f}
			if [ -f $file ] ; then
				printf -- "$uid $f `ls -ldgT $file`\n"
			fi
		done
	done < $MPBYPATH |
	awk -v "usergroups=$permit_usergroups" '
	     $1 != $5 && $5 != "root" \
		{ print "user " $1 " " $2 " file is owned by " $5 }
	     $3 ~ /^-....w/ && (!usergroups || $6 != $1) \
		{ print "user " $1 " " $2 " file is group writable" }
	     $3 ~ /^-.......w/ \
		{ print "user " $1 " " $2 " file is other writable" }' \
	    >> $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\nChecking dot files.\n"
		cat $OUTPUT
	fi
fi

# Mailboxes should be owned by user and unreadable.
#
if checkyesno check_varmail; then
	ls -lA /var/mail | \
	awk '	NR == 1 { next; }
		$9 ~ /^\./ {next; }
	    	$3 != $9 {
			print "user " $9 " mailbox is owned by " $3
		}
		$1 != "-rw-------" {
			print "user " $9 " mailbox is " $1 ", group " $4
		}' > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\nChecking mailbox ownership.\n"
		cat $OUTPUT
	fi
fi

# NFS exports shouldn't be globally exported
#
if checkyesno check_nfs && [ -f /etc/exports ]; then
	awk '{
		# ignore comments and blank lines
		if ($0 ~ /^\#/ || $0 ~ /^$/ )
			next;

		readonly = 0;
		for (i = 2; i <= NF; ++i) {
			if ($i ~ /-ro/)
				readonly = 1;
			else if ($i !~ /^-/)
				next;
		}
		if (readonly)
			print "File system " $1 " globally exported, read-only."
		else
			print "File system " $1 " globally exported, read-write."
	}' < /etc/exports > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\nChecking for globally exported file systems.\n"
		cat $OUTPUT
	fi
fi

# Display any changes in setuid files and devices.
#
if checkyesno check_devices; then
	> $ERR
	(find / \( ! -fstype local -o -fstype fdesc -o -fstype kernfs \
			-o -fstype null \
			-o -fstype procfs \) -a -prune -o \
	    \( \( -perm -u+s -a ! -type d \) -o \
	       \( -perm -g+s -a ! -type d \) -o \
	       -type b -o -type c \) -print0 | \
	xargs -0 ls -ldgTq | sort +9 > $LIST) 2> $OUTPUT

	# Display any errors that occurred during system file walk.
	if [ -s $OUTPUT ] ; then
		printf "Setuid/device find errors:\n" >> $ERR
		cat $OUTPUT >> $ERR
		printf "\n" >> $ERR
	fi

	# Display any changes in the setuid file list.
	egrep -v '^[bc]' $LIST > $TMP1
	if [ -s $TMP1 ] ; then
		# Check to make sure uudecode isn't setuid.
		if grep -w uudecode $TMP1 > /dev/null ; then
			printf "\nUudecode is setuid.\n" >> $ERR
		fi

		file=$work_dir/setuid
		migrate_file "$backup_dir/setuid" "$file"
		CUR=${file}.current
		BACK=${file}.backup
		if [ -s $CUR ] ; then
			if cmp -s $CUR $TMP1 ; then
				:
			else
				> $TMP2
				join -110 -210 -v2 $CUR $TMP1 > $OUTPUT
				if [ -s $OUTPUT ] ; then
					printf "Setuid additions:\n" >> $ERR
					tee -a $TMP2 < $OUTPUT >> $ERR
					printf "\n" >> $ERR
				fi

				join -110 -210 -v1 $CUR $TMP1 > $OUTPUT
				if [ -s $OUTPUT ] ; then
					printf "Setuid deletions:\n" >> $ERR
					tee -a $TMP2 < $OUTPUT >> $ERR
					printf "\n" >> $ERR
				fi

				sort -k10 $TMP2 $CUR $TMP1 | \
				    sed -e 's/[	 ][	 ]*/ /g' | \
				    uniq -u > $OUTPUT
				if [ -s $OUTPUT ] ; then
					printf "Setuid changes:\n" >> $ERR
					column -t $OUTPUT >> $ERR
					printf "\n" >> $ERR
				fi

				backup_file update $TMP1 $CUR $BACK
			fi
		else
			printf "Setuid additions:\n" >> $ERR
			column -t $TMP1 >> $ERR
			printf "\n" >> $ERR
			backup_file add $TMP1 $CUR $BACK
		fi
	fi

	# Check for block and character disk devices that are readable or
	# writable or not owned by root.operator.
	>$TMP1
	DISKLIST="ccd ch hk hp ld md ra raid rb rd rl rx \
	    sd se ss uk up vnd wd xd xy"
#	DISKLIST="$DISKLIST ct mt st wt"
	for i in $DISKLIST; do
		egrep "^b.*/${i}[0-9][0-9]*[a-p]$"  $LIST >> $TMP1
		egrep "^c.*/r${i}[0-9][0-9]*[a-p]$"  $LIST >> $TMP1
	done

	awk '$3 != "root" || $4 != "operator" || $1 !~ /.rw-r-----/ \
		{ printf "Disk %s is user %s, group %s, permissions %s.\n", \
		    $11, $3, $4, $1; }' < $TMP1 > $OUTPUT
	if [ -s $OUTPUT ] ; then
		printf "\nChecking disk ownership and permissions.\n" >> $ERR
		cat $OUTPUT >> $ERR
		printf "\n" >> $ERR
	fi

	# Display any changes in the device file list.
	egrep '^[bc]' $LIST | sort -k11 > $TMP1
	if [ -s $TMP1 ] ; then
		file=$work_dir/device
		migrate_file "$backup_dir/device" "$file"
		CUR=${file}.current
		BACK=${file}.backup

		if [ -s $CUR ] ; then
			if cmp -s $CUR $TMP1 ; then
				:
			else
				> $TMP2
				join -111 -211 -v2 $CUR $TMP1 > $OUTPUT
				if [ -s $OUTPUT ] ; then
					printf "Device additions:\n" >> $ERR
					tee -a $TMP2 < $OUTPUT >> $ERR
					printf "\n" >> $ERR
				fi

				join -111 -211 -v1 $CUR $TMP1 > $OUTPUT
				if [ -s $OUTPUT ] ; then
					printf "Device deletions:\n" >> $ERR
					tee -a $TMP2 < $OUTPUT >> $ERR
					printf "\n" >> $ERR
				fi

				# Report any block device change. Ignore
				# character devices, only the name is
				# significant.
				cat $TMP2 $CUR $TMP1 | \
				    sed -e '/^c/d' | \
				    sort -k11 | \
				    sed -e 's/[	 ][	 ]*/ /g' | \
				    uniq -u > $OUTPUT
				if [ -s $OUTPUT ] ; then
					printf "Block device changes:\n" >> $ERR
					column -t $OUTPUT >> $ERR
					printf "\n" >> $ERR
				fi

				backup_file update $TMP1 $CUR $BACK
			fi
		else
			printf "Device additions:\n" >> $ERR
			column -t $TMP1 >> $ERR
			printf "\n" >> $ERR
			backup_file add $TMP1 $CUR $BACK >> $ERR
		fi
	fi
	if [ -s $ERR ] ; then
		printf "\nChecking setuid files and devices:\n"
		cat $ERR
		printf "\n"
	fi
fi

# Check special files.
# Check system binaries.
#
# Create the mtree tree specifications using:
#	mtree -cx -pDIR -kmd5,uid,gid,mode,nlink,size,link,time > DIR.secure
#	chown root:wheel DIR.secure
#	chmod u+r,go= DIR.secure
#
# Note, this is not complete protection against Trojan horsed binaries, as
# the hacker can modify the tree specification to match the replaced binary.
# For details on really protecting yourself against modified binaries, see
# the mtree(8) manual page.
#
if checkyesno check_mtree; then
	if checkyesno check_mtree_follow_symlinks; then
		check_mtree_flags="-L"
	else
		check_mtree_flags=""
	fi
	for file in $special_files; do
		[ ! -s $file ] && continue
		mtree -e -l -p / $check_mtree_flags -f $file
	done 3>&1 >$OUTPUT 2>&3 |
		grep -v '^mtree: dev/tty: Device not configured$' >&2
	if [ -s $OUTPUT ]; then
		printf "\nChecking special files and directories.\n"
		cat $OUTPUT
	fi

	for file in /etc/mtree/*.secure; do
		[ $file = '/etc/mtree/*.secure' ] && continue
		tree=`sed -n -e '3s/.* //p' -e 3q $file`
		mtree $check_mtree_flags -f $file -p $tree > $TMP1
		if [ -s $TMP1 ]; then
			printf "\nChecking $tree:\n"
			cat $TMP1
		fi
	done > $OUTPUT
	if [ -s $OUTPUT ]; then
		printf "\nChecking system binaries:\n"
		cat $OUTPUT
	fi
fi

# Backup disklabels of available disks
#
if checkyesno check_disklabels; then
		# migrate old disklabels
	for file in `ls -1d $backup_dir/$backup_dir/disklabel.* \
	    $backup_dir/disklabel.* 2>/dev/null`; do
		migrate_file "$file" "$work_dir/${file##*/}"
	done

		# generate list of old disklabels & fdisks and remove them
	ls -1d $work_dir/disklabel.* $work_dir/fdisk.* 2>/dev/null |
	    egrep -v '\.(backup|current)(,v)?$' > $LABELS
	xargs rm < $LABELS

		# generate disklabels of all disks excluding:	cd fd md
	disks=`iostat -x | awk 'NR > 1 && $1 !~ /^[cfm]d/ { print $1; }'`
	for i in $disks; do
		disklabel $i > "$work_dir/disklabel.$i" 2>/dev/null
	done

		# if fdisk is available, generate fdisks for:	ed ld sd wd
	if [ -x /sbin/fdisk ]; then
		disks=`iostat -x| awk 'NR > 1 && $1 ~ /^[elsw]d/ { print $1; }'`
		for i in $disks; do
			/sbin/fdisk $i > "$work_dir/fdisk.$i" 2>/dev/null
		done
	fi

		# append list of new disklabels and fdisks
	ls -1d $work_dir/disklabel.* $work_dir/fdisk.* 2>/dev/null |
	    egrep -v '\.(backup|current)(,v)?$' >> $LABELS
	CHANGELIST="$LABELS $CHANGELIST"
fi

# Check for changes in the list of installed pkgs
#
if checkyesno check_pkgs && [ -d $pkgdb_dir ]; then
	pkgs=$work_dir/pkgs
	migrate_file "$backup_dir/pkgs" "$pkgs"
	(	cd $pkgdb_dir
		pkg_info | sort
		echo ""
		find . \( -name +REQUIRED_BY -o -name +CONTENTS \) -print0 |
			xargs -0 ls -ldgTq | sort -t. +1 | sed -e 's, \./, ,'
	 ) > $pkgs
	echo "$pkgs" > $PKGS
	CHANGELIST="$PKGS $CHANGELIST"
fi

# List of files that get backed up and checked for any modifications.
# Any changes cause the files to rotate.
#
if checkyesno check_changelist ; then
	for file in $special_files; do
		[ ! -s $file ] && continue
		mtree -D -k type -f $file -E exclude |
		    sed '/^type=file/!d ; s/type=file \.//'
	done > $CHANGEFILES

	(
		# Add other files which might dynamically exist:
		#	/etc/ifconfig.*
		#	/etc/raid*.conf
		#	/etc/rc.d/*
		#	/etc/rc.conf.d/*
		#
		echo "/etc/ifconfig.*"
		echo "/etc/raid*.conf"
		echo "/etc/rc.d/*"
		echo "/etc/rc.conf.d/*"

		# Add /etc/changelist
		#
		if [ -s /etc/changelist ]; then
			grep -v '^#' /etc/changelist
		fi
	) | while read file; do
		case "$file" in
		*[\*\?\[]*)	# If changelist line is a glob ...
				# ... expand possible backup files
				#
			ls -1d $(echo $backup_dir/${file}.current) 2>/dev/null \
			    | sed "s,^$backup_dir/,, ; s,\.current$,,"
				
				# ... expand possible files
				#
			ls -1d $(echo $file) 2>/dev/null
			;;
		*)
				# Otherwise, just print the filename
			echo $file
			;;
		esac
	done >> $CHANGEFILES
	CHANGELIST="$CHANGEFILES $CHANGELIST"
fi

# Special case backups, including the master password file and
# ssh private host keys. The normal backup mechanisms for
# $check_changelist (see below) also print out the actual file
# differences and we don't want to do that for these files
#
echo $MP > $TMP1			# always add /etc/master.passwd
for file in $special_files; do
	[ ! -s $file ] && continue
	mtree -D -k type -f $file -I nodiff |
	    sed '/^type=file/!d ; s/type=file \.//'
done >> $TMP1
grep -v '^$' $TMP1 | sort -u > $TMP2

while read file; do
	backup_and_diff "$file" no
done < $TMP2


if [ -n "$CHANGELIST" ]; then
	grep -h -v '^$' $CHANGELIST | sort -u > $TMP1
	comm -23 $TMP1 $TMP2 | while read file; do
		backup_and_diff "$file" yes
	done
fi

if [ -f /etc/security.local ]; then
	. /etc/security.local > $OUTPUT 2>&1
	if [ -s $OUTPUT ] ; then
		printf "\nRunning /etc/security.local:\n"
		cat $OUTPUT
	fi
fi