50 lines
1.4 KiB
Bash
Executable File
50 lines
1.4 KiB
Bash
Executable File
#!/bin/sh
|
|
### BEGIN INIT INFO
|
|
# Provides: urandom
|
|
# Required-Start: $local_fs mountvirtfs
|
|
# Required-Stop: $local_fs
|
|
# Default-Start: S
|
|
# Default-Stop: 0 6
|
|
# Short-Description: Save and restore the random seed
|
|
# Description: Save the random seed on shutdown and restore it on boot,
|
|
# to ensure that the seed isn't predicable on startup
|
|
# (because the boot process is predictable)
|
|
### END INIT INFO
|
|
|
|
test -c /dev/urandom || exit 0
|
|
|
|
RANDOM_SEED_FILE=/var/lib/urandom/random-seed
|
|
|
|
. /etc/default/rcS
|
|
[ -f /etc/default/urandom ] && . /etc/default/urandom
|
|
|
|
case "$1" in
|
|
start|"")
|
|
test "$VERBOSE" != no && echo "Initializing random number generator..."
|
|
# Load and then save 512 bytes, which is the size of the entropy
|
|
# pool. Also load the current date, in case the seed file is
|
|
# empty.
|
|
( date +%s.%N; [ -f "$RANDOM_SEED_FILE" ] && cat "$RANDOM_SEED_FILE" ) \
|
|
>/dev/urandom
|
|
rm -f "$RANDOM_SEED_FILE"
|
|
umask 077
|
|
dd if=/dev/urandom of=$RANDOM_SEED_FILE count=1 \
|
|
>/dev/null 2>&1 || echo "urandom start: failed."
|
|
umask 022
|
|
;;
|
|
stop)
|
|
# Carry a random seed from shut-down to start-up;
|
|
# see documentation in linux/drivers/char/random.c
|
|
test "$VERBOSE" != no && echo "Saving random seed..."
|
|
umask 077
|
|
dd if=/dev/urandom of=$RANDOM_SEED_FILE count=1 \
|
|
>/dev/null 2>&1 || echo "urandom stop: failed."
|
|
;;
|
|
*)
|
|
echo "Usage: urandom {start|stop}" >&2
|
|
exit 1
|
|
;;
|
|
esac
|
|
|
|
exit 0
|