NetBSD/etc/security

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#!/bin/sh -
#
# from: @(#)security 8.1 (Berkeley) 6/9/93
# $Id: security,v 1.9 1994/06/15 04:28:20 cgd Exp $
#
PATH=/sbin:/usr/sbin:/bin:/usr/bin
umask 077
ERR=/tmp/_secure1.$$
TMP1=/tmp/_secure2.$$
TMP2=/tmp/_secure3.$$
TMP3=/tmp/_secure4.$$
LIST=/tmp/_secure5.$$
OUTPUT=/tmp/_secure6.$$
trap 'rm -f $ERR $TMP1 $TMP2 $TMP3 $LIST $OUTPUT' 0
# Check the master password file syntax.
MP=/etc/master.passwd
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", NR);
if ($1 !~ /^[A-Za-z0-9]*$/)
printf("Login %s has non-alphanumeric characters.\n", $1);
if (length($1) > 8)
printf("Login %s has more than 8 characters.\n", $1);
if ($2 == "")
printf("Login %s has no password.\n", $1);
if (length($2) != 13 && ($10 ~ /.*sh$/ || $10 == ""))
printf("Login %s is off but still has a valid shell.\n", $1);
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
awk -F: '{ print $1 " " $3 }' $MP | sort -n +1 | tee $TMP1 |
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 $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.
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
awk -F: '{
if ($0 ~ /^[ ]*$/) {
printf("Line %d is a blank line.\n", NR);
next;
}
if (NF != 4)
printf("Line %d has the wrong number of fields.\n", NR);
if ($1 !~ /^[A-za-z0-9]*$/)
printf("Group %s has non-alphanumeric characters.\n", $1);
if (length($1) > 8)
printf("Group %s has more than 8 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
# 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.
> $OUTPUT
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 umask $i > /dev/null ; then
umaskset=yes
fi
egrep umask $i |
awk '$2 % 100 < 20 \
{ print "Root umask is group writeable" }
$2 % 10 < 2 \
{ print "Root umask is other writeable" }' >> $OUTPUT
/bin/csh -f -s << end-of-csh > /dev/null 2>&1
unset path
source $i
/bin/ls -ldgT \$path > $TMP1
end-of-csh
awk '{
if ($10 ~ /^\.$/) {
print "The root path includes .";
next;
}
}
$1 ~ /^d....w/ \
{ print "Root path directory " $10 " is group writeable." } \
$1 ~ /^d.......w/ \
{ print "Root 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"
if [ -s $OUTPUT ]; then
cat $OUTPUT
fi
if [ $umaskset = "no" ] ; then
printf "\nRoot csh startup files do not set the umask.\n"
fi
fi
> $OUTPUT
rhome=/root
umaskset=no
list="${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 "Root umask is group writeable" } \
$2 % 10 < 2 \
{ print "Root umask is other writeable" }' >> $OUTPUT
/bin/sh << end-of-sh > /dev/null 2>&1
PATH=
. $i
list=\`echo \$PATH | /usr/bin/sed -e 's/:/ /g'\`
/bin/ls -ldgT \$list > $TMP1
end-of-sh
awk '{
if ($10 ~ /^\.$/) {
print "The root path includes .";
next;
}
}
$1 ~ /^d....w/ \
{ print "Root path directory " $10 " is group writeable." } \
$1 ~ /^d.......w/ \
{ print "Root 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 "\nRoot sh startup files do not set the umask.\n"
fi
fi
# Root and uucp should both be in /etc/ftpusers.
if egrep root /etc/ftpusers > /dev/null ; then
:
else
printf "\nRoot not listed in /etc/ftpusers file.\n"
fi
if egrep uucp /etc/ftpusers > /dev/null ; then
:
else
printf "\nUucp not listed in /etc/ftpusers file.\n"
fi
# Uudecode should not be in the /etc/aliases file.
if egrep 'uudecode|decode' /etc/aliases; then
printf "\nThere is an entry for uudecode in the /etc/aliases file.\n"
fi
# Files that should not have + signs.
list="/etc/hosts.equiv /etc/hosts.lpd"
for f in $list ; do
if 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 a .rhosts files. Also, .rhosts files should not plus signs.
awk -F: '$1 != "root" && $1 != "toor" && \
($3 < 100 || $1 == "ftp" || $1 == "uucp") \
{ print $1 " " $6 }' /etc/passwd |
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
awk -F: '{ print $1 " " $6 }' /etc/passwd | \
while read uid homedir; do
if [ -f ${homedir}/.rhosts ] && \
egrep '\+' ${homedir}/.rhosts > /dev/null ; then
printf "$uid: + in .rhosts file.\n"
fi
done > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\nChecking .rhosts files syntax.\n"
cat $OUTPUT
fi
# Check home directories. Directories should not be owned by someone else
# or writeable.
awk -F: '{ print $1 " " $6 }' /etc/passwd | \
while read uid homedir; do
if [ -d ${homedir}/ ] ; then
file=`ls -ldgT ${homedir}`
printf "$uid $file\n"
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 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=".netrc .rhosts"
awk -F: '{ print $1 " " $6 }' /etc/passwd | \
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 |
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=".bashrc .cshrc .emacsrc .exrc .forward .klogin .login .logout \
.profile .tcshrc"
awk -F: '{ print $1 " " $6 }' /etc/passwd | \
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 |
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
# Mailboxes should be owned by user and unreadable.
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 $OUTPUT
fi
# File systems should not be globally exported.
awk '{
readonly = 0;
for (i = 2; i <= NF; ++i) {
if ($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
# Display any changes in setuid files and devices.
printf "\nChecking setuid files and devices:\n"
(find / ! -fstype local -a -prune -o \
\( -perm -u+s -o -perm -g+s -o ! -type d -a ! -type f -a ! -type l -a \
! -type s \) | \
sort | sed -e 's/^/ls -ldgT /' | sh > $LIST) 2> $OUTPUT
# Display any errors that occurred during system file walk.
if [ -s $OUTPUT ] ; then
printf "Setuid/device find errors:\n"
cat $OUTPUT
printf "\n"
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"
fi
CUR=/var/backups/setuid.current
BACK=/var/backups/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"
tee -a $TMP2 < $OUTPUT
printf "\n"
fi
join -110 -210 -v1 $CUR $TMP1 > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Setuid deletions:\n"
tee -a $TMP2 < $OUTPUT
printf "\n"
fi
sort +9 $TMP2 $CUR $TMP1 | \
sed -e 's/[ ][ ]*/ /g' | uniq -u > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Setuid changes:\n"
column -t $OUTPUT
printf "\n"
fi
cp $CUR $BACK
cp $TMP1 $CUR
fi
else
printf "Setuid additions:\n"
column -t $TMP1
printf "\n"
cp $TMP1 $CUR
fi
fi
# Check for block and character disk devices that are readable or writeable
# or not owned by root.operator.
>$TMP1
DISKLIST="dk fd hd hk hp jb kra ra rb rd rl rx rz sd up wd"
for i in $DISKLIST; do
egrep "^b.*/${i}[0-9][0-9]*[a-h]$" $LIST >> $TMP1
egrep "^c.*/r${i}[0-9][0-9]*[a-h]$" $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"
cat $OUTPUT
printf "\n"
fi
# Display any changes in the device file list.
egrep '^[bc]' $LIST | sort +10 > $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
> $TMP2
join -111 -211 -v2 $CUR $TMP1 > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Device additions:\n"
tee -a $TMP2 < $OUTPUT
printf "\n"
fi
join -111 -211 -v1 $CUR $TMP1 > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Device deletions:\n"
tee -a $TMP2 < $OUTPUT
printf "\n"
fi
# Report any block device change. Ignore character
# devices, only the name is significant.
cat $TMP2 $CUR $TMP1 | \
sed -e '/^c/d' | \
sort +10 | \
sed -e 's/[ ][ ]*/ /g' | \
uniq -u > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "Block device changes:\n"
column -t $OUTPUT
printf "\n"
fi
cp $CUR $BACK
cp $TMP1 $CUR
fi
else
printf "Device additions:\n"
column -t $TMP1
printf "\n"
cp $TMP1 $CUR
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 cd /etc/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 *.secure; do
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
# 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.
if [ -s /etc/changelist ] ; then
for file in `cat /etc/changelist`; do
CUR=/var/backups/`basename $file`.current
BACK=/var/backups/`basename $file`.backup
if [ -s $file ]; then
if [ -s $CUR ] ; then
diff $CUR $file > $OUTPUT
if [ -s $OUTPUT ] ; then
printf "\n======\n%s diffs (OLD < > NEW)\n======\n" $file
cat $OUTPUT
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
done
fi