path: root/etc/security

#
#	$OpenBSD: security,v 1.84 2009/05/14 21:24:33 schwarze Exp $
#	from: @(#)security	8.1 (Berkeley) 6/9/93
#

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

umask 077

DIR=`mktemp -d /tmp/_secure.XXXXXXXXXX` || exit 1
TMP1=$DIR/_secure2
TMP2=$DIR/_secure3
LIST=$DIR/_secure5

trap 'rm -rf $DIR; exit 1' 0 1 2 3 13 15

# Check the master password file syntax.
MP=/etc/master.passwd
next_part "Checking the ${MP} file:"
awk -F: '{
	if ($0 ~ /^[	 ]*$/) {
		printf("Line %d is a blank line.\n", NR);
		next;
	}
	if (NF != 10)
		printf("Line %d has the wrong number of fields:\n%s\n", NR, $0);
	if ($1 ~ /^[+-]/)
		next;
	if ($1 == "")
		printf("Line %d has an empty login field:\n%s\n", NR, $0);
	else if ($1 !~ /^[A-Za-z0-9_][A-Za-z0-9_\-\.]*\$?$/)
		printf("Login %s has non-alphanumeric characters.\n", $1);
	if (length($1) > 31)
		printf("Login %s has more than 31 characters.\n", $1);
	if ($2 == "")
		printf("Login %s has no password.\n", $1);
	if ($2 != "" && length($2) != 13 && ($10 ~ /.*sh$/ || $10 == "") &&
	   ($2 !~ /^\$[0-9a-f]+\$/) && ($2 != "skey")) {
		if (system("test -s /etc/skey/"$1"") == 0)
			printf("Login %s is off but still has a valid shell and an entry in /etc/skey.\n", $1);
		if (system("test -d "$9" -a ! -r "$9"") == 0)
			printf("Login %s is off but still has valid shell and home directory is unreadable\n\t by root; cannot check for existence of alternate access files.\n", $1);
		else if (system("for file in .ssh .rhosts .shosts .klogin; do if test -e "$9"/$file; then if ((ls -ld "$9"/$file | cut -b 2-10 | grep -q r) && (test ! -O "$9"/$file)) ; then exit 1; fi; fi; done"))
			 printf("Login %s is off but still has a valid shell and alternate access files in\n\t home directory are still readable.\n",$1);
	}
	if ($3 == 0 && $1 != "root")
		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);
	if (int($7) != 0 && system("test "$7" -lt `date +%s`") == 0)
		printf("Login %s has expired.\n", $1);
}' < $MP

next_part "${MP} has duplicate user names."
awk -F: '{ print $1 }' $MP | sort | uniq -d | column

next_part "${MP} has duplicate user IDs."
awk -F: '/^[^\+]/ { print $1 " " $3 }' $MP | sort -n +1 | tee $TMP1 |
uniq -d -f 1 | awk '{ print $2 }' > $TMP2
if [ -s $TMP2 ] ; then
	while read uid; do
		grep -w $uid $TMP1
	done < $TMP2 | column
fi

# Backup the master password file; a special case, the normal backup
# mechanisms also print out file differences and we don't want to do
# that because this file has encrypted passwords in it.
if [ ! -d /var/backups ] ; then
	mkdir /var/backups
	chmod 700 /var/backups
fi
CUR=/var/backups/`basename $MP`.current
BACK=/var/backups/`basename $MP`.backup
if [ -s $CUR ] ; then
	if cmp -s $CUR $MP; then
		:
	else
		cp -p $CUR $BACK
		cp -p $MP $CUR
		chown root:wheel $CUR
	fi
else
	cp -p $MP $CUR
	chown root:wheel $CUR
fi

# Check the group file syntax.
GRP=/etc/group
next_part "Checking the ${GRP} file:"
awk -F: '{
	if ($0 ~ /^[	 ]*$/) {
		printf("Line %d is a blank line.\n", NR);
		next;
	}
	if ($1 ~ /^[+-].*$/)
		next;
	if (NF != 4)
		printf("Line %d has the wrong number of fields:\n%s\n", NR, $0);
	if ($1 !~ /^[A-Za-z0-9_][A-Za-z0-9_\-\.]*$/)
		printf("Group %s has non-alphanumeric characters.\n", $1);
	if (length($1) > 31)
		printf("Group %s has more than 31 characters.\n", $1);
	if ($3 !~ /^[0-9]*$/)
		printf("Group %s has an invalid group ID.\n", $1);
}' < $GRP

next_part "${GRP} has duplicate group names."
awk -F: '{ print $1 }' $GRP | sort | uniq -d | column

# 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.
rhome=/root
umaskset=no
list="/etc/csh.cshrc /etc/csh.login ${rhome}/.cshrc ${rhome}/.login"
next_part "Checking root csh paths, umask values:\n${list}"
for i in $list ; do
	if [ -s $i ] ; then
		if egrep -aq '[[:space:]]*umask[[:space:]]' $i ; then
			umaskset=yes
		fi
		awk '{
		    if ($1 == "umask") {
			 if ($2 % 100 / 10 ~ /^[0145]/)
			    print "Root umask is group writable";
			 if ($2 % 10 ~ /^[0145]/)
			    print "Root umask is other writable";
		    }
		}' < $i
		SAVE_PATH=$PATH
		unset PATH
		/bin/csh -f -s << end-of-csh > /dev/null 2>&1
			source $i
			if (\$?path) then
				/bin/ls -ldgT \$path > $TMP1
			else
				cat /dev/null > $TMP1
			endif
end-of-csh
		PATH=$SAVE_PATH
		awk '{
			if ($10 ~ /^\.$/) {
				print "The root path includes .";
				next;
			}
		     }
		     $1 ~ /^d....w/ \
	{ print "Root path directory " $10 " is group writable." } \
		     $1 ~ /^d.......w/ \
	{ print "Root path directory " $10 " is other writable." }' \
		< $TMP1
	fi
done
if [ $umaskset = "no" ] ; then
	echo "\nRoot csh startup files do not set the umask."
fi

> $TMP2
rhome=/root
umaskset=no
list="/etc/profile ${rhome}/.profile"
next_part "Checking root sh paths, umask values:\n${list}"
for i in $list; do
	if [ -s $i ] ; then
		if egrep -a umask $i > /dev/null ; then
			umaskset=yes
		fi
		egrep -a umask $i |
		awk '$2 % 100 < 20 \
			{ print "Root umask is group writable" } \
		     $2 % 10 < 2 \
			{ print "Root umask is other writable" }'
		SAVE_PATH=$PATH
		SAVE_ENV=$ENV
		unset PATH ENV
		/bin/sh << end-of-sh > /dev/null 2>&1
			. $i
			if [ X"\$PATH" != "X" ]; then
				list=\`echo \$PATH | /usr/bin/sed -e 's/:/ /g'\`
				/bin/ls -ldgT \$list > $TMP1
			else
				> $TMP1
			fi
			echo \$ENV >> $TMP2
end-of-sh
		PATH=$SAVE_PATH
		ENV=$SAVE_ENV
		awk '{
			if ($10 ~ /^\.$/) {
				print "The root path includes .";
				next;
			}
		     }
		     $1 ~ /^d....w/ \
	{ print "Root path directory " $10 " is group writable." } \
		     $1 ~ /^d.......w/ \
	{ print "Root path directory " $10 " is other writable." }' \
		< $TMP1

	fi
done
if [ $umaskset = "no" ] ; then
	echo "\nRoot sh startup files do not set the umask."
fi

# A good .kshrc will not have a umask or path, that being set in .profile
# check anyway.
rhome=/root
list="/etc/ksh.kshrc `cat $TMP2`"
next_part "Checking root ksh paths, umask values:\n${list}"
(cd $rhome
 for i in $list; do
	if [ -s $i ] ; then
		egrep -a umask $i |
		awk '$2 % 100 < 20 \
			{ print "Root umask is group writable" } \
		     $2 % 10 < 2 \
			{ print "Root umask is other writable" }'
		if egrep -a PATH= $i > /dev/null ; then
			SAVE_PATH=$PATH
			unset PATH
			/bin/ksh << end-of-sh > /dev/null 2>&1
				. $i
				if [ X"\$PATH" != "X" ]; then
					list=\`echo \$PATH | /usr/bin/sed -e 's/:/ /g'\`
					/bin/ls -ldgT \$list > $TMP1
				else
					> $TMP1
				fi
end-of-sh
			PATH=$SAVE_PATH
			awk '{
				if ($10 ~ /^\.$/) {
					print "The root path includes .";
					next;
				}
			    }
			    $1 ~ /^d....w/ \
		{ print "Root path directory " $10 " is group writable." } \
			    $1 ~ /^d.......w/ \
		{ print "Root path directory " $10 " is other writable." }' \
			< $TMP1
		fi

	fi
 done
)

next_part "Checking configuration files:"
# Root and uucp should both be in /etc/ftpusers.
if egrep root /etc/ftpusers > /dev/null ; then
	:
else
	echo "Root not listed in /etc/ftpusers file."
fi
if egrep uucp /etc/ftpusers > /dev/null ; then
	:
else
	echo "Uucp not listed in /etc/ftpusers file."
fi

# Uudecode should not be in the /etc/mail/aliases file.
if egrep 'uudecode|decode' /etc/mail/aliases; then
	echo "There is an entry for uudecode in the /etc/mail/aliases file."
fi

# hostname.if files may contain secrets and should not be
# world-readable.

for f in /etc/hostname.* ; do
	if [ ! -e $f ]; then
		continue
	fi
	if [ "$(stat -Lf "%SLp" $f)" != "---" ]; then
		echo "$f is world readable."
	fi
done

# Files that should not have + signs.
list="/etc/hosts.equiv /etc/shosts.equiv /etc/hosts.lpd"
for f in $list ; do
	if [ -s $f ] ; then
		awk '{
			if ($0 ~ /^\+@.*$/)
				next;
			if ($0 ~ /^\+.*$/)
				printf("Plus sign in %s file.\n", FILENAME);
		}' $f
	fi
done

# Check for special users with .rhosts/.shosts files.  Only root
# should have .rhosts/.shosts files.  Also, .rhosts/.shosts
# files should not have plus signs.
next_part "Checking for special users with .rhosts/.shosts files."
awk -F: '$1 != "root" && $1 !~ /^[+-]/ && \
	($3 < 100 || $1 == "ftp" || $1 == "uucp") \
		{ print $1 " " $6 }' /etc/passwd |
while read uid homedir; do
	for j in .rhosts .shosts; do
		# Root owned .rhosts/.shosts files are ok.
		if [ -s ${homedir}/$j -a ! -O ${homedir}/$j ] ; then
			rhost=`ls -ldgT ${homedir}/$j`
			echo "${uid}: ${rhost}"
		fi
	done
done

next_part "Checking .rhosts/.shosts files syntax."
awk -F: '/^[^+-]/ { print $1 " " $6 }' /etc/passwd | \
while read uid homedir; do
	for j in .rhosts .shosts; do
		if [ -s ${homedir}/$j ] ; then
			awk '{
				if ($0 ~ /^+@.*$/ )
					next;
				if ($0 ~ /^\+[ 	]*$/ )
					printf("%s has + sign in it.\n",
						FILENAME);
			}' ${homedir}/$j
		fi
	done
done

# Check home directories.  Directories should not be owned by someone else
# or writeable.
next_part "Checking home directories."
awk -F: '/^[^+-]/ { print $1 " " $6 }' /etc/passwd | \
while read uid homedir; do
	if [ -d ${homedir}/ ] ; then
		file=`ls -ldgT ${homedir}`
		echo "${uid} ${file}"
	fi
done |
awk '$1 != $4 && $4 != "root" \
	{ print "user " $1 " home directory is owned by " $4 }
     $2 ~ /^-....w/ \
	{ print "user " $1 " home directory is group writable" }
     $2 ~ /^-.......w/ \
	{ print "user " $1 " home directory is other writable" }'

# Files that should not be owned by someone else or readable.
list=".netrc .rhosts .gnupg/secring.gpg .gnupg/random_seed \
	.pgp/secring.pgp .shosts .ssh/identity .ssh/id_dsa .ssh/id_rsa"
next_part "Checking dot files."
awk -F: '/^[^+-]/ { print $1 " " $6 }' /etc/passwd | \
while read uid homedir; do
	for f in $list ; do
		file=${homedir}/${f}
		if [ -f $file ] ; then
			echo "${uid} ${f} `ls -ldgT ${file}`"
		fi
	done
done |
awk '$1 != $5 && $5 != "root" \
	{ print "user " $1 " " $2 " file is owned by " $5 }
     $3 ~ /^-...r/ \
	{ print "user " $1 " " $2 " file is group readable" }
     $3 ~ /^-......r/ \
	{ print "user " $1 " " $2 " file is other readable" }
     $3 ~ /^-....w/ \
	{ print "user " $1 " " $2 " file is group writable" }
     $3 ~ /^-.......w/ \
	{ print "user " $1 " " $2 " file is other writable" }'

# Files that should not be owned by someone else or writeable.
list=".bashrc .bash_profile .bash_login .bash_logout .cshrc \
      .emacs .exrc .forward .fvwmrc .inputrc .klogin .kshrc .login \
      .logout .nexrc .profile .screenrc .ssh .ssh/config \
      .ssh/authorized_keys .ssh/authorized_keys2 .ssh/environment \
      .ssh/known_hosts .ssh/rc .tcshrc .twmrc .xsession .xinitrc \
      .Xdefaults .Xauthority"
awk -F: '/^[^+-]/ { print $1 " " $6 }' /etc/passwd | \
while read uid homedir; do
	for f in $list ; do
		file=${homedir}/${f}
		if [ -f $file ] ; then
			echo "${uid} ${f} `ls -ldgT ${file}`"
		fi
	done
done |
awk '$1 != $5 && $5 != "root" \
	{ print "user " $1 " " $2 " file is owned by " $5 }
     $3 ~ /^-....w/ \
	{ print "user " $1 " " $2 " file is group writable" }
     $3 ~ /^-.......w/ \
	{ print "user " $1 " " $2 " file is other writable" }'

# Mailboxes should be owned by user and unreadable.
next_part "Checking mailbox ownership."
ls -l /var/mail | sed 1d | \
awk '$3 != $9 \
	{ print "user " $9 " mailbox is owned by " $3 }
     $1 != "-rw-------" \
	{ print "user " $9 " mailbox is " $1 ", group " $4 }'

# File systems should not be globally exported.
next_part "Checking for globally exported file systems."
if [ -s /etc/exports ] ; then
	awk '{
		if (($1 ~ /^#/) || ($1 ~ /^$/))
			next;
		readonly = 0;
		for (i = 2; i <= NF; ++i) {
			if ($i ~ /^-ro$/)
				readonly = 1;
			else if ($i !~ /^-/ || $i ~ /^-network/)
				next;
		}
		if (readonly)
			print "File system " $1 " globally exported, read-only."
		else
			print "File system " $1 " globally exported, read-write."
	}' < /etc/exports
fi

# Display any changes in setuid/setgid files and devices.
next_part "Setuid/device find errors:"
find / \( ! -fstype local \
	-o -fstype procfs -o -fstype afs -o -fstype xfs \) -a -prune -o \
	-type f -a \( -perm -u+s -o -perm -g+s \) -print0 -o \
	! -type d -a ! -type f -a ! -type l -a ! -type s -a ! -type p \
	-print0 | xargs -0 ls -ldgT | sort +9 > $LIST

# Display any changes in the setuid/setgid file list.
next_part "Checking setuid/setgid files and devices:"
FIELDS1=1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,0
FIELDS2=2.1,2.2,2.3,2.4,2.5,2.6,2.7,2.8,2.9,0
egrep -av '^[bc]' $LIST | join -o $FIELDS2 -110 -210 -v2 /dev/null - > $TMP1
if [ -s $TMP1 ] ; then
	# Check to make sure uudecode isn't setuid.
	if grep -aw uudecode $TMP1 > /dev/null ; then
		echo "Uudecode is setuid."
	fi

	CUR=/var/backups/setuid.current
	BACK=/var/backups/setuid.backup

	if [ -s $CUR ] ; then
		if cmp -s $CUR $TMP1 ; then
			:
		else
			next_part "Setuid additions:"
			join -o $FIELDS2 -110 -210 -v2 $CUR $TMP1 | \
				tee $TMP2 | column -t

			next_part "Setuid deletions:"
			join -o $FIELDS1 -110 -210 -v1 $CUR $TMP1 | \
				tee -a $TMP2 | column -t

			next_part "Setuid changes:"
			sort +9 $TMP2 $CUR $TMP1 | \
			    sed -e 's/[	 ][	 ]*/ /g' | uniq -u | column -t

			cp $CUR $BACK
			cp $TMP1 $CUR
		fi
	else
		echo "Setuid additions:"
		column -t $TMP1
		cp $TMP1 $CUR
	fi
fi

# Check for block and character disk devices that are readable or writeable
# or not owned by root.operator.
next_part "Checking disk ownership and permissions."
>$TMP1
DISKLIST="ccd dk fd hd hk hp jb kra ra rb rd rl rx rz sd up vnd wd xd"
for i in $DISKLIST; do
	egrep "^b.*/${i}[0-9][0-9]*[B-H]?[a-p]$"  $LIST >> $TMP1
	egrep "^c.*/r${i}[0-9][0-9]*[B-H]?[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

FIELDS1=1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,1.10,0
FIELDS2=2.1,2.2,2.3,2.4,2.5,2.6,2.7,2.8,2.9,2.10,0
# Display any changes in the device file list.
egrep -a '^[bc]' $LIST | sort +10 | \
    join -o $FIELDS2 -111 -211 -v2 /dev/null - > $TMP1
if [ -s $TMP1 ] ; then
	CUR=/var/backups/device.current
	BACK=/var/backups/device.backup

	if [ -s $CUR ] ; then
		if cmp -s $CUR $TMP1 ; then
			:
		else
			next_part "Device additions:"
			join -o $FIELDS2 -111 -211 -v2 $CUR $TMP1 | \
				tee $TMP2 | column -t

			next_part "Device deletions:"
			join -o $FIELDS1 -111 -211 -v1 $CUR $TMP1 | \
				tee -a $TMP2 | column -t

			# Report any block device change.  Ignore character
			# devices, only the name is significant.
			next_part "Block device changes:"
			cat $TMP2 $CUR $TMP1 | \
			sed -e '/^c/d' | \
			sort +10 | \
			sed -e 's/[	 ][	 ]*/ /g' | \
			uniq -u | \
			column -t

			cp $CUR $BACK
			cp $TMP1 $CUR
		fi
	else
		echo "Device additions:"
		column -t $TMP1
		echo ""
		cp $TMP1 $CUR
	fi
fi

# Check special files.
# Check system binaries.
#
# Create the mtree tree specifications using:
#
#	mtree -cx -p DIR -K md5digest,type >/etc/mtree/DIR.secure
#	chown root:wheel /etc/mtree/DIR.secure
#	chmod 600 /etc/mtree/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.
next_part "Checking special files and directories.
Output format is:\n\tfilename:\n\t\tcriteria (shouldbe, reallyis)"
if [ -d /etc/mtree ] ; then
	cd /etc/mtree
	mtree -e -l -p / -f /etc/mtree/special
	for file in *.secure; do
		[ $file = '*.secure' ] && continue
		tree=`sed -n -e '3s/.* //p' -e 3q $file`
		next_part "Checking system binaries in ${tree}:"
		mtree -f $file -p $tree
	done
else
	echo /etc/mtree is missing
fi

# List of files that get backed up and checked for any modifications.  Each
# file is expected to have two backups, /var/backups/file.{current,backup}.
# Any changes cause the files to rotate.
_fnchg() {
	echo "$1" | sed 's/^\///;s/\//_/g'
}
if [ -s /etc/changelist ] ; then
	for file in `egrep -v "^(#|\+|$MP)" /etc/changelist`; do
		CUR=/var/backups/$(_fnchg  "$file").current
		BACK=/var/backups/$(_fnchg "$file").backup
		next_part "======\n${file} diffs (-OLD  +NEW)\n======"
		if [ -s $file -a ! -d $file ] ; then
			if [ -s $CUR ] ; then
				diff -ua $CUR $file
				if [ -s $PARTOUT ] ; then
					cp -p $CUR $BACK
					cp -p $file $CUR
					chown root:wheel $CUR $BACK
				fi
			else
				diff -u /dev/null $file
				cp -p $file $CUR
				chown root:wheel $CUR
			fi
		fi
		if [ ! -s $file -a -s $CUR ]; then
			diff -u $CUR /dev/null
			cp -p $CUR $BACK
			rm -f $CUR
			chown root:wheel $BACK
		fi
	done
	for file in `egrep "^\+" /etc/changelist`; do
		file="${file#+}"
		CUR=/var/backups/$(_fnchg  "$file").current.md5
		BACK=/var/backups/$(_fnchg "$file").backup.md5
		if [ -s $file -a ! -d $file ] ; then
			MD5_NEW=`md5 $file | sed 's/^.* //'`
			if [ -s $CUR ] ; then
				MD5_OLD="`cat $CUR`"
				if [ "$MD5_NEW" != "$MD5_OLD" ]; then
		echo "\n======\n${file} MD5 checksums\n======"
					echo "OLD: $MD5_OLD"
					echo "NEW: $MD5_NEW"
					cp -p $CUR $BACK
					echo $MD5_NEW > $CUR
					chown root:wheel $CUR $BACK
					chmod 600 $CUR
				fi
			else
			echo "\n======\n${file} new MD5 checksum\n======"
				echo "NEW: $MD5_NEW"
				echo $MD5_NEW > $CUR
				chown root:wheel $CUR
				chmod 600 $CUR
			fi
		fi
		if [ ! -s $file -a -s $CUR ]; then
			MD5_OLD="`cat $CUR`"
		echo "\n======\n${file} removed MD5 checksum\n======"
			echo "OLD: $MD5_OLD"
			cp -p $CUR $BACK
			rm $CUR
			chown root:wheel $BACK
		fi
	done
fi

# Make backups of the labels for any mounted disks and produce diffs
# when they change.
for d in `df -ln | sed -n 's:^/dev/\([a-z]*[0-9]*\)[a-p].*$:\1:p' | sort -u`; do
	file=/var/backups/disklabel.$d
	CUR=$file.current
	BACK=$file.backup
	next_part "======\n${d} diffs (-OLD  +NEW)\n======"
	if disklabel $d > $file 2>&1 ; then
		if [ -s $CUR ] ; then
			diff -u $CUR $file
			if [ -s $PARTOUT ] ; then
				cp -p $CUR $BACK
				cp -p $file $CUR
				chown root:wheel $CUR $BACK
			fi
		else
			cp -p $file $CUR
			chown root:wheel $CUR
		fi
	fi
	rm -f $file
done

# Backup the list of installed packages and produce diffs when it changes.
next_part "======\nPackage list changes (-OLD  +NEW)\n======"
file=/var/backups/pkglist
CUR=$file.current
BACK=$file.backup
if pkg_info > $file 2>&1 ; then
	if [ -s $CUR ] ; then
		diff -u $CUR $file
		if [ -s $PARTOUT ] ; then
			cp -p $CUR $BACK
			cp -p $file $CUR
			chown root:wheel $CUR $BACK
		fi
	else
		cp -p $file $CUR
		chown root:wheel $CUR
	fi
fi
rm -f $file