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freebsd-dev/libexec/save-entropy/save-entropy.sh

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Add a system to save entropy from /dev/random periodically so that it can be used to reseed at boot time. This will greatly increase the chances that there will be sufficient entropy available at boot time to prevent long delays. For /etc/rc, remove the vmstat and iostat runs from the attempt to provide some cheesy randomness if the files fail, since those programs are dynamically linked, and ldd seems to want some randomness to do its magic. Guidance and parameters for this project were provided by Mark Murray, based on the requirements of the Yarrow algorithm. Some helpful suggestions for implementation (including the tip about iostat and vmstat) were provided by Sheldon Hearn. All blame for problems or mistakes is mine of course.
2001-01-11 13:01:20 +00:00
#!/bin/sh
#
1. Attempt to take one bullet out of the foot-shooting gun by silently ignoring errors when sourcing rc.conf* files. The most common error occurs when users put a command of some sort into those files. (ifconfig is a popular choice) 2. Make the file rotation logic simpler by starting one down from the "top" of the list, rather than at the top. 3. Try to make file rotation more secure by calling unlink(1) on all new file names before rotating an old file to the new name, rather than merely calling 'rm -f' on any files that exceed the number of files to save.
2006-08-28 06:41:50 +00:00
# Copyright (c) 2001-2006 Douglas Barton, DougB@FreeBSD.org
Add a system to save entropy from /dev/random periodically so that it can be used to reseed at boot time. This will greatly increase the chances that there will be sufficient entropy available at boot time to prevent long delays. For /etc/rc, remove the vmstat and iostat runs from the attempt to provide some cheesy randomness if the files fail, since those programs are dynamically linked, and ldd seems to want some randomness to do its magic. Guidance and parameters for this project were provided by Mark Murray, based on the requirements of the Yarrow algorithm. Some helpful suggestions for implementation (including the tip about iostat and vmstat) were provided by Sheldon Hearn. All blame for problems or mistakes is mine of course.
2001-01-11 13:01:20 +00:00
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD$
# This script is called by cron to store bits of randomness which are
# then used to seed /dev/random on boot.
Move the process of storing entropy from /dev/random and reseeding with it at boot time closer to the way we want it to be in the final version. * Move the default directory to /var/db/entropy * Run the entropy saving cron job every 11 minutes. This seems to be a better default, although still bikeshed material. * Feed /dev/random some cheesy "entropy" from various commands and files before the disks are mounted. This gives /dev/random a better chance of running without blocking early. * Move the reseeding with previously stored entropy to the point immediately after the disks are mounted. * Make the harvesting script a little safer in regards to the possibility of accidentally overwriting something other than a regular file.
2001-01-14 07:18:31 +00:00
# Originally developed by Doug Barton, DougB@FreeBSD.org
Add a system to save entropy from /dev/random periodically so that it can be used to reseed at boot time. This will greatly increase the chances that there will be sufficient entropy available at boot time to prevent long delays. For /etc/rc, remove the vmstat and iostat runs from the attempt to provide some cheesy randomness if the files fail, since those programs are dynamically linked, and ldd seems to want some randomness to do its magic. Guidance and parameters for this project were provided by Mark Murray, based on the requirements of the Yarrow algorithm. Some helpful suggestions for implementation (including the tip about iostat and vmstat) were provided by Sheldon Hearn. All blame for problems or mistakes is mine of course.
2001-01-11 13:01:20 +00:00
PATH=/bin:/usr/bin
# If there is a global system configuration file, suck it in.
#
if [ -r /etc/defaults/rc.conf ]; then
. /etc/defaults/rc.conf
1. Attempt to take one bullet out of the foot-shooting gun by silently ignoring errors when sourcing rc.conf* files. The most common error occurs when users put a command of some sort into those files. (ifconfig is a popular choice) 2. Make the file rotation logic simpler by starting one down from the "top" of the list, rather than at the top. 3. Try to make file rotation more secure by calling unlink(1) on all new file names before rotating an old file to the new name, rather than merely calling 'rm -f' on any files that exceed the number of files to save.
2006-08-28 06:41:50 +00:00
source_rc_confs 2>/dev/null
Add a system to save entropy from /dev/random periodically so that it can be used to reseed at boot time. This will greatly increase the chances that there will be sufficient entropy available at boot time to prevent long delays. For /etc/rc, remove the vmstat and iostat runs from the attempt to provide some cheesy randomness if the files fail, since those programs are dynamically linked, and ldd seems to want some randomness to do its magic. Guidance and parameters for this project were provided by Mark Murray, based on the requirements of the Yarrow algorithm. Some helpful suggestions for implementation (including the tip about iostat and vmstat) were provided by Sheldon Hearn. All blame for problems or mistakes is mine of course.
2001-01-11 13:01:20 +00:00
elif [ -r /etc/rc.conf ]; then
1. Attempt to take one bullet out of the foot-shooting gun by silently ignoring errors when sourcing rc.conf* files. The most common error occurs when users put a command of some sort into those files. (ifconfig is a popular choice) 2. Make the file rotation logic simpler by starting one down from the "top" of the list, rather than at the top. 3. Try to make file rotation more secure by calling unlink(1) on all new file names before rotating an old file to the new name, rather than merely calling 'rm -f' on any files that exceed the number of files to save.
2006-08-28 06:41:50 +00:00
. /etc/rc.conf 2>/dev/null
Add a system to save entropy from /dev/random periodically so that it can be used to reseed at boot time. This will greatly increase the chances that there will be sufficient entropy available at boot time to prevent long delays. For /etc/rc, remove the vmstat and iostat runs from the attempt to provide some cheesy randomness if the files fail, since those programs are dynamically linked, and ldd seems to want some randomness to do its magic. Guidance and parameters for this project were provided by Mark Murray, based on the requirements of the Yarrow algorithm. Some helpful suggestions for implementation (including the tip about iostat and vmstat) were provided by Sheldon Hearn. All blame for problems or mistakes is mine of course.
2001-01-11 13:01:20 +00:00
fi
case ${entropy_dir} in
[Nn][Oo])
exit 0
;;
*)
Move the process of storing entropy from /dev/random and reseeding with it at boot time closer to the way we want it to be in the final version. * Move the default directory to /var/db/entropy * Run the entropy saving cron job every 11 minutes. This seems to be a better default, although still bikeshed material. * Feed /dev/random some cheesy "entropy" from various commands and files before the disks are mounted. This gives /dev/random a better chance of running without blocking early. * Move the reseeding with previously stored entropy to the point immediately after the disks are mounted. * Make the harvesting script a little safer in regards to the possibility of accidentally overwriting something other than a regular file.
2001-01-14 07:18:31 +00:00
entropy_dir=${entropy_dir:-/var/db/entropy}
Add a system to save entropy from /dev/random periodically so that it can be used to reseed at boot time. This will greatly increase the chances that there will be sufficient entropy available at boot time to prevent long delays. For /etc/rc, remove the vmstat and iostat runs from the attempt to provide some cheesy randomness if the files fail, since those programs are dynamically linked, and ldd seems to want some randomness to do its magic. Guidance and parameters for this project were provided by Mark Murray, based on the requirements of the Yarrow algorithm. Some helpful suggestions for implementation (including the tip about iostat and vmstat) were provided by Sheldon Hearn. All blame for problems or mistakes is mine of course.
2001-01-11 13:01:20 +00:00
;;
esac
entropy_save_sz=${entropy_save_sz:-2048}
entropy_save_num=${entropy_save_num:-8}
if [ ! -d "${entropy_dir}" ]; then
umask 077
mkdir "${entropy_dir}" || {
Move the process of storing entropy from /dev/random and reseeding with it at boot time closer to the way we want it to be in the final version. * Move the default directory to /var/db/entropy * Run the entropy saving cron job every 11 minutes. This seems to be a better default, although still bikeshed material. * Feed /dev/random some cheesy "entropy" from various commands and files before the disks are mounted. This gives /dev/random a better chance of running without blocking early. * Move the reseeding with previously stored entropy to the point immediately after the disks are mounted. * Make the harvesting script a little safer in regards to the possibility of accidentally overwriting something other than a regular file.
2001-01-14 07:18:31 +00:00
logger -is -t "$0" The entropy directory "${entropy_dir}" does not \
Add a system to save entropy from /dev/random periodically so that it can be used to reseed at boot time. This will greatly increase the chances that there will be sufficient entropy available at boot time to prevent long delays. For /etc/rc, remove the vmstat and iostat runs from the attempt to provide some cheesy randomness if the files fail, since those programs are dynamically linked, and ldd seems to want some randomness to do its magic. Guidance and parameters for this project were provided by Mark Murray, based on the requirements of the Yarrow algorithm. Some helpful suggestions for implementation (including the tip about iostat and vmstat) were provided by Sheldon Hearn. All blame for problems or mistakes is mine of course.
2001-01-11 13:01:20 +00:00
exist, and cannot be created. Therefore no entropy can be saved. ;
exit 1;}
/usr/sbin/chown operator:operator "${entropy_dir}"
chmod 0700 "${entropy_dir}"
fi
umask 377
1. Attempt to take one bullet out of the foot-shooting gun by silently ignoring errors when sourcing rc.conf* files. The most common error occurs when users put a command of some sort into those files. (ifconfig is a popular choice) 2. Make the file rotation logic simpler by starting one down from the "top" of the list, rather than at the top. 3. Try to make file rotation more secure by calling unlink(1) on all new file names before rotating an old file to the new name, rather than merely calling 'rm -f' on any files that exceed the number of files to save.
2006-08-28 06:41:50 +00:00
esn_m1=$(( ${entropy_save_num} - 1 ))
for file_num in `jot $esn_m1 $esn_m1 1`; do
Move the process of storing entropy from /dev/random and reseeding with it at boot time closer to the way we want it to be in the final version. * Move the default directory to /var/db/entropy * Run the entropy saving cron job every 11 minutes. This seems to be a better default, although still bikeshed material. * Feed /dev/random some cheesy "entropy" from various commands and files before the disks are mounted. This gives /dev/random a better chance of running without blocking early. * Move the reseeding with previously stored entropy to the point immediately after the disks are mounted. * Make the harvesting script a little safer in regards to the possibility of accidentally overwriting something other than a regular file.
2001-01-14 07:18:31 +00:00
if [ -e "${entropy_dir}/saved-entropy.${file_num}" ]; then
if [ -f "${entropy_dir}/saved-entropy.${file_num}" ]; then
1. Attempt to take one bullet out of the foot-shooting gun by silently ignoring errors when sourcing rc.conf* files. The most common error occurs when users put a command of some sort into those files. (ifconfig is a popular choice) 2. Make the file rotation logic simpler by starting one down from the "top" of the list, rather than at the top. 3. Try to make file rotation more secure by calling unlink(1) on all new file names before rotating an old file to the new name, rather than merely calling 'rm -f' on any files that exceed the number of files to save.
2006-08-28 06:41:50 +00:00
new_file=saved-entropy.$(( $file_num + 1 ))
if [ -e "${entropy_dir}/${new_file}" ]; then
unlink ${entropy_dir}/${new_file}
Move the process of storing entropy from /dev/random and reseeding with it at boot time closer to the way we want it to be in the final version. * Move the default directory to /var/db/entropy * Run the entropy saving cron job every 11 minutes. This seems to be a better default, although still bikeshed material. * Feed /dev/random some cheesy "entropy" from various commands and files before the disks are mounted. This gives /dev/random a better chance of running without blocking early. * Move the reseeding with previously stored entropy to the point immediately after the disks are mounted. * Make the harvesting script a little safer in regards to the possibility of accidentally overwriting something other than a regular file.
2001-01-14 07:18:31 +00:00
fi
1. Attempt to take one bullet out of the foot-shooting gun by silently ignoring errors when sourcing rc.conf* files. The most common error occurs when users put a command of some sort into those files. (ifconfig is a popular choice) 2. Make the file rotation logic simpler by starting one down from the "top" of the list, rather than at the top. 3. Try to make file rotation more secure by calling unlink(1) on all new file names before rotating an old file to the new name, rather than merely calling 'rm -f' on any files that exceed the number of files to save.
2006-08-28 06:41:50 +00:00
mv "${entropy_dir}/saved-entropy.${file_num}" \
"${entropy_dir}/${new_file}"
Move the process of storing entropy from /dev/random and reseeding with it at boot time closer to the way we want it to be in the final version. * Move the default directory to /var/db/entropy * Run the entropy saving cron job every 11 minutes. This seems to be a better default, although still bikeshed material. * Feed /dev/random some cheesy "entropy" from various commands and files before the disks are mounted. This gives /dev/random a better chance of running without blocking early. * Move the reseeding with previously stored entropy to the point immediately after the disks are mounted. * Make the harvesting script a little safer in regards to the possibility of accidentally overwriting something other than a regular file.
2001-01-14 07:18:31 +00:00
else
logger -is -t "$0" \
"${entropy_dir}/saved-entropy.${file_num} is not a regular file, and therefore \
it will not be rotated. Entropy file harvesting is aborted."
exit 1
fi
Add a system to save entropy from /dev/random periodically so that it can be used to reseed at boot time. This will greatly increase the chances that there will be sufficient entropy available at boot time to prevent long delays. For /etc/rc, remove the vmstat and iostat runs from the attempt to provide some cheesy randomness if the files fail, since those programs are dynamically linked, and ldd seems to want some randomness to do its magic. Guidance and parameters for this project were provided by Mark Murray, based on the requirements of the Yarrow algorithm. Some helpful suggestions for implementation (including the tip about iostat and vmstat) were provided by Sheldon Hearn. All blame for problems or mistakes is mine of course.
2001-01-11 13:01:20 +00:00
fi
done
dd if=/dev/random of="${entropy_dir}/saved-entropy.1" \
The script mistakenly ignores the entropy_save_sz variable from rc.conf[.local]. Fix this, and leave the default as 2048. Update the copyright year to include the present. Update the assignment of the copyright to be me personally, instead of "The FreeBSD Project" which is not a legal entity, and therefore not a proper assignee. My intention remains the same however, that this code continue to be BSD licensed, and freely available to anyone that wants it under those terms. PR: conf/75722 Submitted by: Nicolas Rachinsky <list@rachinsky.de>
2005-04-11 02:07:33 +00:00
bs="$entropy_save_sz" count=1 2> /dev/null
Add a system to save entropy from /dev/random periodically so that it can be used to reseed at boot time. This will greatly increase the chances that there will be sufficient entropy available at boot time to prevent long delays. For /etc/rc, remove the vmstat and iostat runs from the attempt to provide some cheesy randomness if the files fail, since those programs are dynamically linked, and ldd seems to want some randomness to do its magic. Guidance and parameters for this project were provided by Mark Murray, based on the requirements of the Yarrow algorithm. Some helpful suggestions for implementation (including the tip about iostat and vmstat) were provided by Sheldon Hearn. All blame for problems or mistakes is mine of course.
2001-01-11 13:01:20 +00:00
exit 0
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