S20urandom
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#! /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 "$1" in
start|"")
# check for read only file system
if ! touch /etc/random-seed 2>/dev/null
then
echo "read-only file system detected...done"
exit
fi
if [ "$VERBOSE" != no ]
then
printf "Initializing random number generator... "
fi
# Load and then save 512 bytes,
# which is the size of the entropy pool
cat /etc/random-seed >/dev/urandom
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 ] && printf "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