55 lines
1.3 KiB
Bash
Executable File
55 lines
1.3 KiB
Bash
Executable File
#! /bin/sh
|
|
#
|
|
# urandom This script saves the random seed between reboots.
|
|
# It is called from the boot, halt and reboot scripts.
|
|
#
|
|
# Version: @(#)urandom 1.33 22-Jun-1998 miquels@cistron.nl
|
|
#
|
|
|
|
[ -c /dev/urandom ] || exit 0
|
|
#. /etc/default/rcS
|
|
|
|
case "$1" in
|
|
start|"")
|
|
if [ "$VERBOSE" != no ]
|
|
then
|
|
echo -n "Initializing random number generator... "
|
|
fi
|
|
# Load and then save 512 bytes,
|
|
# which is the size of the entropy pool
|
|
if [ -f /etc/random-seed ]
|
|
then
|
|
cat /etc/random-seed >/dev/urandom
|
|
fi
|
|
# check for read only file system
|
|
if ! touch /etc/random-seed 2>/dev/null
|
|
then
|
|
echo "read-only file system detected...done"
|
|
exit
|
|
fi
|
|
rm -f /etc/random-seed
|
|
umask 077
|
|
dd if=/dev/urandom of=/etc/random-seed count=1 \
|
|
>/dev/null 2>&1 || echo "urandom start: failed."
|
|
umask 022
|
|
[ "$VERBOSE" != no ] && echo "done."
|
|
;;
|
|
stop)
|
|
if ! touch /etc/random-seed 2>/dev/null
|
|
then
|
|
exit
|
|
fi
|
|
# Carry a random seed from shut-down to start-up;
|
|
# see documentation in linux/drivers/char/random.c
|
|
[ "$VERBOSE" != no ] && echo -n "Saving random seed... "
|
|
umask 077
|
|
dd if=/dev/urandom of=/etc/random-seed count=1 \
|
|
>/dev/null 2>&1 || echo "urandom stop: failed."
|
|
[ "$VERBOSE" != no ] && echo "done."
|
|
;;
|
|
*)
|
|
echo "Usage: urandom {start|stop}" >&2
|
|
exit 1
|
|
;;
|
|
esac
|