xref: /dragonfly/etc/rc.d/random (revision bb8c85ff) 
1#!/bin/sh
2#
3# $FreeBSD: src/etc/rc.d/random,v 1.3 2003/04/18 17:55:05 mtm Exp $
4# $DragonFly: src/etc/rc.d/random,v 1.4 2006/07/10 22:19:14 dillon Exp $
5#
6
7# PROVIDE: random
8# REQUIRE: diskless mountcritlocal initrandom
9# BEFORE: netif
10# KEYWORD: shutdown
11
12. /etc/rc.subr
13
14name="random"
15start_cmd="random_start"
16stop_cmd="random_stop"
17
18feed_dev_random()
19{
20	if [ -f "${1}" -a -r "${1}" -a -s "${1}" ]; then
21		sysctl kern.seedenable=1 >/dev/null
22		# Feed using a small block size so that a pool-based CSPRNG
23		# is more likely to distribute the entropy over several
24		# pools
25		cat "${1}" | dd of=/dev/random bs=512 2>/dev/null
26		sysctl kern.seedenable=0 >/dev/null
27	fi
28}
29
30random_start()
31{
32	# Reseed /dev/random with previously stored entropy.
33	case ${entropy_dir} in
34	[Nn][Oo] | '')
35		;;
36	*)
37		entropy_dir=${entropy_dir:-/var/db/entropy}
38		if [ -d "${entropy_dir}" ]; then
39			if [ -w /dev/random ]; then
40				for seedfile in ${entropy_dir}/*; do
41					feed_dev_random "${seedfile}"
42				done
43			fi
44		fi
45		;;
46	esac
47
48	case ${entropy_file} in
49	[Nn][Oo] | '')
50		;;
51	*)
52		if [ -w /dev/random ]; then
53			feed_dev_random "${entropy_file}"
54		fi
55		;;
56	esac
57}
58
59random_stop()
60{
61	# Write some entropy so when the machine reboots /dev/random
62	# can be reseeded
63	#
64	case ${entropy_file} in
65	[Nn][Oo] | '')
66		;;
67	*)
68		echo -n 'Writing entropy file:'
69		rm -f ${entropy_file}
70		oumask=`umask`
71		umask 077
72		if touch ${entropy_file}; then
73			entropy_file_confirmed="${entropy_file}"
74		fi
75		case ${entropy_file_confirmed} in
76		'')
77			err 1 '${entropy_file}:' \
78			    ' entropy file write failed.'
79			;;
80		*)
81			dd if=/dev/random of=${entropy_file_confirmed} \
82			   bs=${entropy_save_sz} count=1 2> /dev/null
83			echo '.'
84			;;
85		esac
86		umask ${oumask}
87		;;
88	esac
89}
90
91load_rc_config $name
92run_rc_command "$1"
93