xref: /dragonfly/etc/rc.d/random (revision de78d61c)
1#!/bin/sh
2#
3# $FreeBSD: src/etc/rc.d/random,v 1.3 2003/04/18 17:55:05 mtm Exp $
4#
5
6# PROVIDE: random
7# REQUIRE: diskless mountcritlocal initrandom
8# BEFORE: netif
9# KEYWORD: shutdown
10
11. /etc/rc.subr
12
13name="random"
14start_cmd="random_start"
15stop_cmd="random_stop"
16
17feed_dev_random()
18{
19	if [ -f "${1}" -a -r "${1}" -a -s "${1}" ]; then
20		${SYSCTL_W} kern.seedenable=1 >/dev/null
21		# Feed using a small block size so that a pool-based CSPRNG
22		# is more likely to distribute the entropy over several
23		# pools
24		cat "${1}" | dd of=/dev/random bs=512 2>/dev/null
25		${SYSCTL_W} kern.seedenable=0 >/dev/null
26	fi
27}
28
29random_start()
30{
31	# Reseed /dev/random with previously stored entropy.
32	case ${entropy_dir} in
33	[Nn][Oo] | '')
34		;;
35	*)
36		entropy_dir=${entropy_dir:-/var/db/entropy}
37		if [ -d "${entropy_dir}" ]; then
38			if [ -w /dev/random ]; then
39				for seedfile in ${entropy_dir}/*; do
40					feed_dev_random "${seedfile}"
41				done
42			fi
43		fi
44		;;
45	esac
46
47	case ${entropy_file} in
48	[Nn][Oo] | '')
49		;;
50	*)
51		if [ -w /dev/random ]; then
52			feed_dev_random "${entropy_file}"
53		fi
54		;;
55	esac
56}
57
58random_stop()
59{
60	# Write some entropy so when the machine reboots /dev/random
61	# can be reseeded
62	#
63	case ${entropy_file} in
64	[Nn][Oo] | '')
65		;;
66	*)
67		echo -n 'Writing entropy file:'
68		rm -f ${entropy_file}
69		oumask=`umask`
70		umask 077
71		if touch ${entropy_file}; then
72			entropy_file_confirmed="${entropy_file}"
73		fi
74		case ${entropy_file_confirmed} in
75		'')
76			err 1 '${entropy_file}:' \
77			    ' entropy file write failed.'
78			;;
79		*)
80			dd if=/dev/random of=${entropy_file_confirmed} \
81			   bs=${entropy_save_sz} count=1 2> /dev/null
82			echo '.'
83			;;
84		esac
85		umask ${oumask}
86		;;
87	esac
88}
89
90load_rc_config $name
91run_rc_command "$1"
92