NetBSD/etc/security

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#!/bin/sh -
#
# $NetBSD: security,v 1.54 2001/05/10 14:19:27 atatat Exp $
# from: @(#)security 8.1 (Berkeley) 6/9/93
#
PATH=/sbin:/usr/sbin:/bin:/usr/bin
if [ -f /etc/rc.subr ]; then
. /etc/rc.subr
else
echo "Can't read /etc/rc.subr; aborting."
exit 1;
fi
umask 077
if [ -s /etc/security.conf ]; then
. /etc/security.conf
fi
SECUREDIR=/tmp/_securedir.$$
if ! mkdir $SECUREDIR; then
echo can not create $SECUREDIR.
exit 1
fi
if ! cd $SECUREDIR; then
echo can not chdir to $SECUREDIR.
exit 1
fi
if [ -z "$max_loginlen" ];then
max_loginlen=8
fi
if [ -z "$max_grouplen" ]; then
max_grouplen=8
fi
ERR=secure1.$$
TMP1=secure2.$$
TMP2=secure3.$$
MPBYUID=secure4.$$
MPBYPATH=secure5.$$
LIST=secure6.$$
OUTPUT=secure7.$$
LABELS=secure8.$$
trap '/bin/rm -rf $SECUREDIR ; exit 0' 0 2 3
# Handle backup_dir not being set in .conf file
backup_dir=${backup_dir:-/var/backups}
MP=/etc/master.passwd
# these is used several times.
awk -F: '!/^+/ { print $1 " " $3 }' $MP | sort -k2n > $MPBYUID
awk -F: '{ print $1 " " $9 }' $MP | sort -k2 > $MPBYPATH
# Check the master password file syntax.
#
if checkyesno check_passwd; then
awk -v "len=$max_loginlen" '
BEGIN {
while ( getline < "/etc/shells" > 0 ) {
if ($0 ~ /^\#/ || $0 ~ /^$/ )
continue;
shells[$1]++;
}
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 == "")
printf "Login %s has no password.\n", $1;
if (length($2) != 13 && length($2) != 20 && length($2) != 34 && $2 != "") {
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 && $1 != "root" && $1 != "toor")
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 < $TMP2 | column
fi
fi
# Backup the master password file; a special case, the normal backup
# mechanisms also print out file differences and we don't want to do
# that because this file has encrypted passwords in it.
#
CUR=$backup_dir/${MP##*/}.current
BACK=$backup_dir/${MP##*/}.backup
if [ -s $CUR ] ; then
if cmp -s $CUR $MP; then
:
else
backup_file update $MP $CUR $BACK
fi
else
backup_file add $MP $CUR $BACK
fi
# Check the group file syntax.
#
if checkyesno check_group; then
GRP=/etc/group
awk -F: -v "len=$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
> $OUTPUT
rhome=`csh -fc "echo ~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
# 020 and 002 bits are set.
# we handle this in decimal initially to extract the digits,
# and then extract the `2' bit of each digit.
# this is made especially painful because
# bitwise operations were left out of awk.
egrep '^[ \t]*umask[ \t]+[0-7]+' $i |
awk '{ g= ($2 % 100) - ($2 % 10);
g /= 10;
g = g % 4;
g -= g % 2;
if (g != 2) { print "\tRoot umask is group writeable" }
o = ($2 % 10);
o = o % 4;
o -= o % 2;
if (o != 2) { print "\tRoot umask is other writeable" } }' |
sort -u >> $OUTPUT
SAVE_PATH=$PATH
unset PATH
/bin/csh -f -s << end-of-csh > /dev/null 2>&1
source $i
/bin/ls -ldgT \$path > $TMP1
end-of-csh
PATH=$SAVE_PATH
awk '{
if ($10 ~ /^\.$/) {
print "\tThe root path includes .";
next;
}
}
$1 ~ /^d....w/ \
{ print "\tRoot path directory " $10 " is group writeable." } \
$1 ~ /^d.......w/ \
{ print "\tRoot path directory " $10 " is other writeable." }' \
< $TMP1 >> $OUTPUT
fi
done
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
> $OUTPUT
rhome=/root
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 % 100 < 20 \
{ print "\tRoot umask is group writeable" } \
$2 % 10 < 2 \
{ print "\tRoot umask is other writeable" }' \
>> $OUTPUT
SAVE_PATH=$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 > $TMP1
end-of-sh
PATH=$SAVE_PATH
awk '{
if ($10 ~ /^\.$/) {
print "\tThe root path includes .";
next;
}
}
$1 ~ /^d....w/ \
{ print "\tRoot path directory " $10 " is group writeable." } \
$1 ~ /^d.......w/ \
{ print "\tRoot path directory " $10 " is other writeable." }' \
< $TMP1 >> $OUTPUT
fi
done
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
> $OUTPUT
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" >> $OUTPUT
fi
done
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 writeable.
#
if checkyesno check_homes; then
while read uid homedir; do
if [ -d ${homedir}/ ] ; then
file=`ls -ldgT ${homedir}`
printf -- "$uid $file\n"
fi
done < $MPBYPATH |
awk '$1 != $4 && $4 != "root" \
{ print "user " $1 " home directory is owned by " $4 }
$2 ~ /^-....w/ \
{ print "user " $1 " home directory is group writeable" }
$2 ~ /^-.......w/ \
{ print "user " $1 " home directory is other writeable" }' \
> $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"
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 '$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 writeable" }
$3 ~ /^-.......w/ \
{ print "user " $1 " " $2 " file is other writeable" }' \
> $OUTPUT
# Files that should not be owned by someone else or writeable.
list=".bash_history .bash_login .bash_logout .bash_profile .bashrc \
.cshrc .emacs .exrc .forward .history .klogin .login .logout \
.profile .qmail .rc_history .rhosts .tcshrc .twmrc .xinitrc \
.xsession"
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 '$1 != $5 && $5 != "root" \
{ print "user " $1 " " $2 " file is owned by " $5 }
$3 ~ /^-....w/ \
{ print "user " $1 " " $2 " file is group writeable" }
$3 ~ /^-.......w/ \
{ print "user " $1 " " $2 " file is other writeable" }' \
>> $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 -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 }' > $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 / \( ! -fstype local -o -fstype fdesc -o -fstype kernfs \
-o -fstype procfs \) -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" >> $ERR
fi
CUR=$backup_dir/setuid.current
BACK=$backup_dir/setuid.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 $BACK
fi
fi
# Check for block and character disk devices that are readable or
# writeable or not owned by root.operator.
>$TMP1
DISKLIST="acd ccd cd ch fd hk hp mcd md ra rb rd rl rx rz \
sd se ss tz 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 $TMP1 ] ; then
CUR=$backup_dir/device.current
BACK=$backup_dir/device.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 -kcksum,gid,mode,nlink,size,link,time,uid > DIR.secure
# chown root:wheel DIR.secure
# chmod 600 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
mtree -e -p / -f /etc/mtree/special > $OUTPUT
if [ -s $OUTPUT ]; then
printf "\nChecking special files and directories.\n"
cat $OUTPUT
fi
> $OUTPUT
for file in /etc/mtree/*.secure; do
[ $file = '/etc/mtree/*.secure' ] && continue
tree=`sed -n -e '3s/.* //p' -e 3q $file`
mtree -f $file -p $tree > $TMP1
if [ -s $TMP1 ]; then
printf "\nChecking $tree:\n" >> $OUTPUT
cat $TMP1 >> $OUTPUT
fi
done
if [ -s $OUTPUT ]; then
printf "\nChecking system binaries:\n"
cat $OUTPUT
fi
fi
CHANGELIST=""
# Backup disklabels of available disks
#
if checkyesno check_disklabels; then
# generate list of old disklabels and remove them
ls -1d $backup_dir/disklabel.* 2>/dev/null |
egrep -v '\.(backup|current)(,v)?$' > $LABELS
xargs rm < $LABELS
disks=`iostat -x | sed 1d | awk '$1 !~ /^[cfm]d/ { print $1; }'`
for i in $disks; do
dlf="$backup_dir/disklabel.$i"
disklabel $i > $dlf 2>/dev/null
done
# append list of new disklabels, sort list
ls -1d $backup_dir/disklabel.* 2>/dev/null |
egrep -v '\.(backup|current)(,v)?$' >> $LABELS
sort -u -o $LABELS $LABELS
CHANGELIST=$LABELS
fi
# List of files that get backed up and checked for any modifications. Each
# file is expected to have two backups, $backup_dir/file.{current,backup}.
# Any changes cause the files to rotate.
#
if checkyesno check_changelist && [ -s /etc/changelist ] ; then
CHANGELIST="/etc/changelist $CHANGELIST"
fi
if [ -n "$CHANGELIST" ]; then
for file in `egrep -hv "^#|$MP" $CHANGELIST`; do
# old changelist backup names
OCUR=$backup_dir/${file##*/}.current
OBACK=$backup_dir/${file##*/}.backup
# new changelist backup names
CUR=$backup_dir$file.current
BACK=$backup_dir$file.backup
# roll over old backups
if [ ! -d ${CUR%/*} ]; then
mkdir -p ${CUR%/*}
fi
if [ -f $OCUR -a ! -f $CUR ]; then
mv $OCUR $CUR
fi
if [ -f $OCUR,v -a ! -f $CUR,v ]; then
mv $OCUR,v $CUR,v
fi
if [ -f $OBACK -a ! -f $BACK ]; then
mv $OBACK $BACK
fi
# and down to work
if [ -f $file ]; then
if [ -f $CUR ] ; then
diff $CUR $file > $OUTPUT
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
diff /dev/null $file
backup_file add $file $CUR $BACK
fi
else
if [ -f $CUR ]; then
printf "\n======\n%s removed\n======\n" $file
diff $CUR /dev/null
backup_file remove $file $CUR $BACK
fi
fi
done
fi
if [ -f /etc/security.local ]; then
echo ""
echo "Running /etc/security.local:"
. /etc/security.local
fi