⟦7dc2f2825⟧

TextFile

#!/bin/sh
#
# paths to some important programs
#

#
# This is the language used to parse the .rhosts file.  If you rewrite the
# parser in a different language, you should change this.  If it doesn't
# exist, that's "ok".  chkacct will notice that.
#
PERL=perlpath()

#
# This is the program used to parse the .rhosts file.  If you rewrite it, you
# should change PERL1 to be the location of your new program.  You should also
# send me a copy because I'm a packrat for stuff like this.
#
PERL1=installpath()lib/chkacct/rhosts.pl

#
# This directory contains the info and effect files that chkacct(1L) references.
#
DOCPATH=installpath()lib/chkacct

# default variable values prevent nasty surprises
# (its good style, too)
#

# The title of the guru to send customers to  (maybe your name if you work at a 
#  small company..)
GURU=gurudude()

#
# The name of the security article
#
ARTICLE=Article

#
# The name of the pager you want to use to display info files.  This is 
# probably "more" or "less" at most sites, but never cat, because things
# scroll off the screen too quickly.
# 
PAGER=pagerpath()

#
# miscellaneous stuff
#
CAT=catpath()
THISSHELL=$$
EXITCOND=0
UNIQUE=1
trap 'echo "Exiting."; %eval^ $stop_dots; exit;' 0;
trap 'echo "Exiting."; %eval^ $stop_dots; exit;' 1;
trap 'echo "Exiting."; %eval^ $stop_dots; exit;' 2;
trap 'echo "Exiting."; %eval^ $stop_dots; exit;' 3;

# an example shell command line parser that conforms to the getopt	(ksb)
# standard, Kevin Braunsdorf, ksb@cc.purdue.edu

# our program name and usage message
progname=`basename $0`
usage="$progname: usage [-ehinqrv] [-f <startdir>] [-m <homedir>] [-s <username]"

# how to slide a single letter option off the beginning of a bundle
# -barf -> -arf
slide='P=$1; %shift^; set _ -`expr "$P" : '\''-.\(.*\)'\''` ${1+"$@"}; %shift^'
param='if [ $# -lt 2 ]; then echo "$progname: missing value for $1" 1>&2 ; exit 1; fi'

# default values for all the flags, or leave unset for a ${flag-value) form

# verbose by default
VERBOSE=1
# interactive by default
INTERACTIVE=1
# cavalier by default
HARMLESS=0
# check .rhosts file by default
RHOSTS=1

# read an environment variable as well as the command line options:
# protect this script from leading -x's with a bogus underbar, then remove it
set _ $ZZZ ${1+"$@"}
%shift^

# get the options from the command line (+ any variables)
while [ $# -gt 0 ]
do
	case "$1" in
	-e)
		INTERACTIVE=0
		%shift^
		;;
	-e*)
		INTERACTIVE=0
		%eval^ "$slide"
		;;
	-f)
		%eval^ "$param"
                START_DIR=$2
                %shift^ ; %shift^
		;;
	-f*)
		START_DIR=`expr "$1" : '-.\(.*\)'`
                %shift^
		;;
	-i)
		INTERACTIVE=1
		%shift^
		;;
	-i*)
		INTERACTIVE=1
		%eval^ "$slide"
		;;
	-m)
		%eval^ "$param"
                HOME=$2
                %shift^ ; %shift^
		;;
	-m*)
		HOME=`expr "$1" : '-.\(.*\)'`
                %shift^
		;;
	-n)
		HARMLESS=1
		%shift^
		;;
	-n*)
		HARMLESS=1
		%eval^ "$slide"
		;;
	-q)
		VERBOSE=0
		%shift^
		;;
	-q*)
		VERBOSE=0
		%eval^ "$slide"
		;;
	-r)
		RHOSTS=0
		%shift^
		;;
	-r*)
		RHOSTS=0
		%eval^ "$slide"
		;;
	-s)
		%eval^ "$param"
		ME=$2
		HOME=`echo "echo ~${ME}" | cshpath() `;
		%shift^ ; %shift^
		;;
	-s*)
		ME=`expr "$1" : '-.\(.*\)'`
		HOME=`echo "echo ~${ME}" | cshpath() `;
		%shift^
		;;
	-v)
		VERBOSE=1
		%shift^
		;;
	-v*)
		VERBOSE=1
		%eval^ "$slide"
		;;
	--)
		%shift^
		break
		;;
	-h|-h*)
		cat <<HERE
$usage
e		expert (non-interactive) do not ask the user any questions
f <startdir>	specify the directory in which to begin the general file check
			(\${HOME} is the default)
h		print this help message
i		interactive mode - ask the user about every file (default)
m <home dir>	specify a home directory (\${HOME} is the default)
n		do not actually alter any file permissions or files
q		perform actions quietly
r		do not check of \${HOME}/.rhosts file
s <username>	run chkacct as if my userid were <username> (also sets \${HOME} to ~username)
v		perform actions verbosely (this is the default)
HERE
		exit 0
		;;
	-*)
		echo "$usage" 1>&2 
		exit 1
		;;
	*)
		# process and continue for intermixed options & args
		break
		;;
	esac
done

# set my identity if it hasn't been done yet
if [ -z "${ME}" ]; then

	ME=`whoami`;
	if [ \( -z "${ME}" \) -o \( $? -ne 0 \) ]; then
		echo "Cannot determine your identity - exiting, nothing checked.";
		EXITCOND=1;
		exit ${EXITCOND};
	fi;
fi;

# set my home directory if it hasn't been set yet
if [ -z "${HOME}" ]; then

	HOME=`echo "echo ~${ME}" | cshpath() `;
	if [ -z "${HOME}" ]; then
		echo "Cannot determine your home directory - exiting, nothing checked.";
		EXITCOND=1;
		exit ${EXITCOND};
	fi;
fi;

# search only in the home dir by default
if [ -z "${START_DIR}" ]; then

	START_DIR=${HOME};
fi

#
# For debugging, silly.
#
# echo "Performing account check with username = ${ME}, home dir = ${HOME}, and";
# echo "starting directory ${START_DIR}";

#
# Ok, this is actually checkacct.
#

#
# Define a routine which will display files.  If sites have their own favorite
# pager or display method, it can be specified here.  If you just wanted
# to use a simple pager, you would define PAGER to be equal to it, and then
# you would change the line below that display it to be:
#   ${PAGER} ${DOCPATH}/${DISPLAY};
# 
# REMEMBER!  Before you call this routine, you must set DISPLAYFILE to be
# the file you want displayed
#
display_file='
if [ -f ${DOCPATH}/${DISPLAYFILE} ]; then

	${PAGER} ${DOCPATH}/${DISPLAYFILE};
fi;'

#
# Its crucial that we don't leave shell variables like $* set 
# when we're not expecting it.  For that reason, here's a small routine
# to clear the contents of $* by shift'ing.  For some reason, each set
# successively lengthens $*.
#
clear_args='
for i
do
	%shift^;
done;'

#
#  Before each situation where the user might be queried as to the action,
#  one needs to remember to set the following shell variables:
#
#  FIX - the shell command to fix it with \$TARGET to be the file to
#	 be operated upon
#  MANPAGES - a list of man pages it will tell you to look at
#  INFO - The name of the info file in which more info is to be found (if any)
#  EFFECT - The name of the file which describes the effect of the fix
#  PROBLEM - This is the problem string -- it may be printed several times.
#
# define the prompt/decision routine which will make the fix if necessary, print
# out specific info, refer someone to a manual page.
prompt='
FIXED=0;
while [ ${FIXED} -eq 0 ]; do
	echo "";
	echo "${PROBLEM}";
	echo "The output of the command \"ls -lsopt()ld ${PROBLEMFILE}\" is:";
	/bin/ls -lsopt()ld ${PROBLEMFILE};
	echo "";
	echo "The suggested fix for this is to execute the command:";
	echo "	${FIX}";

	if [ ${VERBOSE} -eq 1 ]; then
		if [ \( -f ${DOCPATH}/${EFFECT} \) -a \( ! -d  ${DOCPATH}/${EFFECT} \) ]; then
			${CAT} ${DOCPATH}/${EFFECT};
		fi;
	fi;

	if [ ${INTERACTIVE} -eq 1 ]; then
		echo ""; 
		echo "Press a letter (a) to enter automatic mode (no more questions), (f)ix problem,";
		echo "(h)elp me out with this menu, (i)gnore problem, (m)ore info";
		echownl(%Press RETURN/NEWLINE to fix the problem and go on> ^);
		read input;
	else
		input="f";
	fi;

	case $input in
		a*)
			echo "";
			echo "This will put you into automatic mode.  No more questions will be asked,";
			echo "and all problems will be automatically fixed unless you specified the";
			echo "\"harmless(-n)\" option on startup.";
			echo "";
			echownl(%Press \"yes\" to enter automatic mode> ^);
			read confirm;
			if [ \( ! -z "$confirm" \) -a \( "$confirm" = "yes" \) ]; then
				echo "Beginning automatic mode.";
				INTERACTIVE=0;
				echo "";
			fi;
			;;
		h*)
			DISPLAYFILE="prompt.help";
			%eval^ $display_file;
			;;
		m*)
			DISPLAYFILE=${INFO};
			%eval^ $display_file;
			if [ -n "$MANPAGES" -a ${VERBOSE} -eq 1 ]; then
				echo "";
				echo "For additional information, read the manual page for the following";
				echo "program(s): ${MANPAGES}";
				echo "The command man <name of program> will show you the manual page.";
				echo "";
			fi;
			;;
		i*)
			echo "Ignoring problem -- taking no action.";
			FIXED=1;
			;;
		*|f*) 
			if [ ${HARMLESS} -eq 0 ]; then
				echownl(%Fixing problem...^);
				%eval^ ${FIX};
				echo "Done.";
			else
				echo "In \"harmless\" (-n) mode, ignoring problem.";
			fi;
			FIXED=1;
			;;
	   esac;
done;'

#
# define the waiting routine that prints those neat dots
#
make_dots='
if [ ${VERBOSE} -eq 1 ]; then
	(touch /tmp/makedots${THISSHELL};while [ -f /tmp/makedots${THISSHELL} ]; do echownl(%.^); sleep 1; done)& 2>&1 >/dev/null;
fi;'

stop_dots='sleep 1; /bin/rm -rf /tmp/makedots${THISSHELL};'

if [ 1 -eq $VERBOSE ]; then

	DISPLAYFILE="Intro";
	%eval^ $display_file;

fi

if [ ${INTERACTIVE} -eq 1 ]; then
	echownl(%Press RETURN/NEWLINE to begin> ^); read input;
fi;

NO_WRITE="rhosts profile login logout cshrc bashrc bash_profile inputrc";
NO_WRITE="$NO_WRITE screenrc kshrc tcshrc netrc forward dbxinit distfile";
NO_WRITE="$NO_WRITE exrc emacsrc remote mh_profile xinitrc xsession Xdefaults";
NO_WRITE="$NO_WRITE Xresources rninit mwmrc twmrc emacs rhosts";
NO_READ="badpass netrc"

#
# First, are any of the dot files writable & does the user own every dot file?
#
PERMLINE="FindPermWrite()";

if [ ${VERBOSE} -eq 1 ]; then
	echo ""
	echo "Step one (three total) - Evaluating your account's dot files."
fi

%eval^ $make_dots;
for i in ${NO_WRITE}
do
	TARGET=${HOME}/.$i;
	if [ -f ${TARGET} -o -d ${TARGET} ]; then
		while [ -f ${HOME}/dangerous.${i}.${UNIQUE} ];
		do
			UNIQUE=`echo "${UNIQUE} + 1" | bc -l`;
		done;
		FIX="/bin/mv -i ${TARGET} ${HOME}/dangerous.${i}.${UNIQUE}";
		MANPAGES="chmod"
		EFFECT="effect.owners"
		INFO="owners"
		RESULT=`/bin/ls -ld ${TARGET}`;
		%eval^ $clear_args;
		set $*=${RESULT};
		if [ $3 != ${ME} ]; then
			PROBLEM="File '${TARGET}' is owned by user $3.";
			PROBLEMFILE=${TARGET};
			EXITCOND=1;
			%eval^ $stop_dots;
			%eval^ $prompt;
			%eval^ $make_dots;
			continue;
		fi
		TEMP="`find ${TARGET} ! -type l \( ${PERMLINE} \) -print`"
		EFFECT="dotwrite";
		INFO="effect.dotwrit";
		FIX="/bin/chmod ChmodPermSymbol()-w ${TARGET};"
		if [ -n "${TEMP}" ]; then
			PROBLEM="File '${TARGET}' is world or group writable.";
			PROBLEMFILE=${TARGET};
			EXITCOND=1;
			%eval^ $stop_dots;
			%eval^ $prompt;
			%eval^ $make_dots;
		fi
	fi
done

PERMLINE="FindPermRead()";
EFFECT="effect.read";
INFO="readable";

for i in ${NO_READ}
do
	TARGET=${HOME}/.${i};
	if [ -f ${TARGET} ]; then
		FIX="/bin/chmod ChmodPermSymbol()-r ${TARGET};"
		if [ -n "`find ${TARGET} \( ${PERMLINE} \) -exec /bin/ls {} \;`" ]; then
			PROBLEM="File '${TARGET}' is world or group readable.";
			PROBLEMFILE=${TARGET};
			EXITCOND=1;
			%eval^ $stop_dots;
			%eval^ $prompt;
			%eval^ $make_dots;
		fi
	fi
done
%eval^ $stop_dots;

if [ ${VERBOSE} -eq 1 ]; then
	echo "Step one complete."
	echo ""
	echo "Step two (three total) - Evaluating the file permissions in your account."
fi

#
# Second, do we have any writable files or directories?
#
%eval^ $make_dots
PERMLINE="FindPermWrite()";
RESULT=`(cd ${HOME}; find . -user ${ME} ! -type l \( ${PERMLINE} \) -print)`;
EFFECT="effect.write";
INFO="write";
%eval^ $stop_dots

for i in ${RESULT}
do
	FIX="/bin/chmod ChmodPermSymbol()-w ${i};"
	if [ -d $i ]; then
		PROBLEM="Your directory $i is world or group writable.";
		PROBLEMFILE=$i;
		EXITCOND=1;
		%eval^ $prompt;
	else
		PROBLEM="Your file $i is world or group writable.";
		PROBLEMFILE=$i;
		EXITCOND=1;
		%eval^ $prompt;
	fi
done

%eval^ $make_dots
PERMLINE="FindPermSuid()";
RESULT=`(cd ${HOME} ; find . -user ${ME} ! \( -type l -o -type d \) \( ${PERMLINE} \) -print)`;
EFFECT="effect.setuid";
INFO="setuid";

for i in ${RESULT}
do
	FIX="/bin/chmod ChmodPermSuidSymbol()-s ${i};"
	PROBLEM="Your file $i is user or group setuid.";
	PROBLEMFILE=$i;
	EXITCOND=1;
	%eval^ $stop_dots
	%eval^ $prompt;
	%eval^ $make_dots
done

sleep 1
%eval^ $stop_dots

if [ ${VERBOSE} -eq 1 ]; then
	echo "Step two complete."
	echo ""
	echo "Step three (three total) - Checking the contents of your rhosts file."
fi

FIX="/bin/mv -i ${HOME}/.rhosts ${HOME}/rhosts.$$;"
EFFECT="effect.rhosts";
INFO="rhosts";
MANPAGES="hosts.equiv rlogin";
#
# Third, does our rhost file contain any glaring dangers?
# see "man hosts.equiv"
#
if [ ${RHOSTS} -eq 0 ]; then

	echo "The file ${HOME}/.rhosts will not be checked (as requested).";

elif [ -f ${HOME}/.rhosts ]; then
	if [ ! -x ${PERL} ]; then
		echo "${PERL} does not exist on your system -- skipping .rhosts check.";
		echo "If you are unfamiliar with the uses of a .rhosts file, you should";
		echo "definately have a ${GURU} take a look at it.";
	else
		${PERL1} ${HOME}/.rhosts;
		if [ $? -ne 0 ]; then
			PROBLEM="Your .rhosts file is unsafe.";
			PROBLEMFILE=${HOME}/.rhosts;
			EXITCOND=1;
			%eval^ $prompt;
		else
			if [ ${VERBOSE} -eq 1 ]; then
				echo "Your .rhosts file doesn't appear to be a security hole.";
			fi;
		fi;
	fi;
else
	if [ ${VERBOSE} -eq 1 ]; then
		echo "Congratulations!  You don't have a .rhosts file!";
		echo "(If I had a cookie, I would give you one.)";
	fi;
fi;

%eval^ $stop_dots

if [ ${VERBOSE} -eq 1 ]; then
	echo "Step 3 complete."
	echo "";
	echo "Checkacct is complete.  If you still have questions about this program,";
	echo "please see a ${GURU}." ;
	echo "";
	if [ ${INTERACTIVE} -eq 1 ]; then
		echo "If you are interested in reading an article on Unix";
		echo "security, type \"yes\" and hit RETURN/NEWLINE now.";
		echownl(%If not, simply hit RETURN/NEWLINE and checkacct will exit.> ^);
		read input;
		if [ \( ! -z "$input" \) -a \( "$input" = "yes" \) ]; then
			DISPLAYFILE=${ARTICLE};
			%eval^ $display_file;
		fi;
	fi;
fi;
if [ \( ${EXITCOND} -eq 0 \) -a \( ${VERBOSE} -eq 1 \) ]; then
	echo "There were no obvious problems with your Unix account.";
	echo "(I owe you a cookie.)";
fi;
exit ${EXITCOND};
DataMuseum.dk

DKUUG/EUUG Conference tapes

⟦7dc2f2825⟧ TextFile

Derivation

TextFile
