Add entropy caching. With this, some entropy is cached at shutdown

time, and this is used to reseed the random number generator at
boot time.

NOTE - this has no hope of working if you halt(); you need to
execute rc.shutdown to get the entropy stash.

1 files changed, 15 insertions, 0 deletions

diff --git a/etc/rc.shutdown b/etc/rc.shutdown
index 0d93bcf..7014c70 100644
--- a/etc/rc.shutdown
+++ b/etc/rc.shutdown
@@ -26,6 +26,21 @@ elif [ -r /etc/rc.conf ]; then
 	. /etc/rc.conf
 fi
 
+# Write some entropy so the rebooting /dev/random can reseed
+#
+case ${entropy_file} in
+[Nn][Oo] | '')
+	;;
+*)
+	if [ -f ${entropy_file} -a -r ${entropy_file} ] ; then
+		echo -n "Writing entropy file"
+		touch ${entropy_file} && \
+			chmod 600 ${entropy_file} && \
+			dd if=/dev/random of=${entropy_file} bs=4096 count=1
+	fi
+	;;
+esac
+
 # Check if /var/db/mounttab is clean.
 case $1 in
 reboot)