rc.d/init.d/random

   1 #!/bin/sh
   2 #
   3 # random        Script to snapshot random state and reload it at boot time.
   4 #
   5 # chkconfig:    12345 20 80
   6 #
   7 # description:  Saves and restores system entropy pool for higher quality \
   8 #               random number generation.
   9 #
  10
  11 # Source function library.
  12 . /etc/rc.d/init.d/functions
  13
  14 random_seed=/var/run/random-seed
  15
  16 poolfile=/proc/sys/kernel/random/poolsize
  17 [ -r $poolfile ] && bytes="$(cat $poolfile)" || bytes=512
  18
  19 start() {
  20         # Check if the service is already running?
  21         if [ -f /var/lock/subsys/random ]; then
  22                 return
  23         fi
  24
  25         show "Initializing random number generator"
  26         busy
  27         # Carry a random seed from start-up to start-up
  28         if [ -f $random_seed ]; then
  29                 cat $random_seed >/dev/urandom
  30         else
  31                 touch $random_seed
  32         fi
  33         chmod 600 $random_seed
  34         dd if=/dev/urandom of=$random_seed count=1 bs=$bytes 2>/dev/null
  35         touch /var/lock/subsys/random
  36         deltext
  37         ok
  38 }
  39
  40 stop() {
  41         if [ ! -f /var/lock/subsys/random ]; then
  42                 return
  43         fi
  44
  45         # Carry a random seed from shut-down to start-up
  46         show "Saving random seed"
  47         busy
  48         touch $random_seed
  49         chmod 600 $random_seed
  50         dd if=/dev/urandom of=$random_seed count=1 bs=$bytes 2>/dev/null
  51
  52         rm -f /var/lock/subsys/random >/dev/null 2>&1
  53         deltext
  54         ok
  55 }
  56
  57 status() {
  58         entropy_avail="$(cat /proc/sys/kernel/random/entropy_avail)"
  59         if [ "$entropy_avail" -eq 0 -o ! -c /dev/random ] ; then
  60                 nls "The random data source is missing"
  61                 RETVAL=1
  62         else
  63                 nls "%d bytes of entropy available" $entropy_avail
  64         fi
  65 }
  66
  67 # See how we were called.
  68 case "$1" in
  69   start)
  70         start
  71         ;;
  72   stop)
  73         stop
  74         ;;
  75   status)
  76         status
  77         ;;
  78   *)
  79         msg_usage "$0 {start|stop|status}"
  80         exit 3
  81 esac
  82
  83 exit 0