46413cedf7
Before this commit, the save-entropy script rotates entropy files like logs. This involves creating a new file that holds the entropy and renaming of all existing entropy files. However, the entropy data do not really need to be kept in a particular order, and replacing the oldest file is sufficient. This commit replaces the rotation with a scan in the [1..entropy_save_num] space that finds the first empty slot, or the slot of the oldest file, and writes entropy into that slot. This also fixes an issue that prevents save-entropy from saving any entropy when there is one non-regular file in any slot as a side effect. Based on an earlier patch from peterj@. PR: 134225 Reported by: peterj Reviewed by: csprng (cem, markm) MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D22612
134 lines
4.2 KiB
Bash
Executable File
134 lines
4.2 KiB
Bash
Executable File
#!/bin/sh
|
|
#
|
|
# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
|
|
#
|
|
# Copyright (c) 2001-2006,2012 Douglas Barton, dougb@FreeBSD.org
|
|
# 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.
|
|
|
|
# Originally developed by Doug Barton, dougb@FreeBSD.org
|
|
|
|
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
|
|
source_rc_confs 2>/dev/null
|
|
elif [ -r /etc/rc.conf ]; then
|
|
. /etc/rc.conf 2>/dev/null
|
|
fi
|
|
|
|
[ $(/sbin/sysctl -n security.jail.jailed) = 0 ] || exit 0
|
|
|
|
case ${entropy_dir} in
|
|
[Nn][Oo])
|
|
exit 0
|
|
;;
|
|
*)
|
|
entropy_dir=${entropy_dir:-/var/db/entropy}
|
|
;;
|
|
esac
|
|
|
|
entropy_save_sz=${entropy_save_sz:-4096}
|
|
entropy_save_num=${entropy_save_num:-8}
|
|
|
|
if [ ! -d "${entropy_dir}" ]; then
|
|
install -d -o operator -g operator -m 0700 "${entropy_dir}" || {
|
|
logger -is -t "$0" The entropy directory "${entropy_dir}" does \
|
|
not exist, and cannot be created. Therefore no entropy can \
|
|
be saved.; exit 1; }
|
|
fi
|
|
|
|
cd "${entropy_dir}" || {
|
|
logger -is -t "$0" Cannot cd to the entropy directory: "${entropy_dir}". \
|
|
Entropy file rotation is aborted.; exit 1; }
|
|
|
|
for f in saved-entropy.*; do
|
|
case "${f}" in saved-entropy.\*) continue ;; esac # No files match
|
|
[ ${f#saved-entropy\.} -gt ${entropy_save_num} ] && unlink ${f}
|
|
done
|
|
|
|
umask 177
|
|
|
|
# Scan slots [1..$entropy_save_num), picking an empty slot or the oldest
|
|
# existing file if no empty slot was available.
|
|
#
|
|
# 1. Find out the first regular file or empty slot (and its serial number)
|
|
#
|
|
n=1
|
|
while [ ${n} -le ${entropy_save_num} ]; do
|
|
save_file="saved-entropy.${n}"
|
|
if [ ! -e "${save_file}" -o -f "${save_file}" ]; then
|
|
break
|
|
else
|
|
logger -is -t "$0" \
|
|
"${save_file}" is not a regular file, skipped.
|
|
fi
|
|
n=$(( ${n} + 1 ))
|
|
done
|
|
#
|
|
# 2. Start from (serial number + 1), and check if the slot is empty
|
|
# or is an older regular file, update save_file pointer in either
|
|
# case, and break early if we found an empty slot.
|
|
#
|
|
if [ -f ${save_file} ]; then
|
|
n=$(( ${n} + 1 ))
|
|
while [ ${n} -le ${entropy_save_num} ]; do
|
|
next_file=saved-entropy.${n}
|
|
if [ -f "${next_file}" ]; then
|
|
[ "${next_file}" -ot "${save_file}" ] && \
|
|
save_file="${next_file}"
|
|
elif [ ! -e "${next_file}" ]; then
|
|
save_file="${next_file}"
|
|
break
|
|
else
|
|
logger -is -t "$0" \
|
|
"${next_file}" is not a regular file, skipped.
|
|
fi
|
|
n=$(( ${n} + 1 ))
|
|
done
|
|
fi
|
|
#
|
|
# 3. Check if the pointer we have in hand is really a regular file or
|
|
# an empty slot, and bail out as that means there is no available slot.
|
|
#
|
|
if [ -e "${save_file}" -a ! -f "${save_file}" ]; then
|
|
logger -is -t "$0" \
|
|
No available slot in "${entropy_dir}", save entropy is aborted.
|
|
exit 1
|
|
fi
|
|
|
|
# Save entropy to the selected slot.
|
|
chmod 600 "${save_file}" 2>/dev/null || :
|
|
dd if=/dev/random of="${save_file}" bs=${entropy_save_sz} count=1 2>/dev/null
|
|
chflags nodump "${save_file}" 2>/dev/null || :
|
|
fsync "${save_file}" "."
|
|
|
|
exit 0
|