openrc/init.d/urandom.in

#!@SBINDIR@/openrc-run
# Copyright (c) 2007-2015 The OpenRC Authors.
# See the Authors file at the top-level directory of this distribution and
# https://github.com/OpenRC/openrc/blob/master/AUTHORS
#
# This file is part of OpenRC. It is subject to the license terms in
# the LICENSE file found in the top-level directory of this
# distribution and at https://github.com/OpenRC/openrc/blob/master/LICENSE
# This file may not be copied, modified, propagated, or distributed
# except according to the terms contained in the LICENSE file.

: ${urandom_seed:=${URANDOM_SEED:-/var/lib/misc/random-seed}}
description="Initializes the random number generator."

depend()
{
	after clock
	need localmount
	keyword -docker -jail -lxc -openvz -prefix -systemd-nspawn
}

save_seed()
{
	local psz=1

	if [ -e /proc/sys/kernel/random/poolsize ]; then
		: $(( psz = $(cat /proc/sys/kernel/random/poolsize) / 4096 ))
	fi

	(	# sub shell to prevent umask pollution
		umask 077
		dd if=/dev/urandom of="$urandom_seed" count=${psz} 2>/dev/null
	)
}

start()
{
	[ -c /dev/urandom ] || return
	if [ -f "$urandom_seed" ]; then
		ebegin "Initializing random number generator"
		cat "$urandom_seed" > /dev/urandom
		eend $? "Error initializing random number generator"
	fi
	rm -f "$urandom_seed" && save_seed
	return 0
}

stop()
{
	ebegin "Saving random seed"
	save_seed
	eend $? "Failed to save random seed"
}