view debian/dropbear.init @ 1930:299f4f19ba19

Add /usr/sbin and /sbin to default root PATH When dropbear is used in a very restricted environment (such as in a initrd), the default user shell is often also very restricted and doesn't take care of setting the PATH so the user ends up with the PATH set by dropbear. Unfortunately, dropbear always sets "/usr/bin:/bin" as default PATH even for the root user which should have /usr/sbin and /sbin too. For a concrete instance of this problem, see the "Remote Unlocking" section in this tutorial: https://paxswill.com/blog/2013/11/04/encrypted-raspberry-pi/ It speaks of a bug in the initramfs script because it's written "blkid" instead of "/sbin/blkid"... this is just because the scripts from the initramfs do not expect to have a PATH without the sbin directories and because dropbear is not setting the PATH appropriately for the root user. I'm thus suggesting to use the attached patch to fix this misbehaviour (I did not test it, but it's easy enough). It might seem anecdotic but multiple Kali users have been bitten by this. From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403
author Raphael Hertzog <hertzog@debian.org>
date Mon, 09 Jul 2018 16:27:53 +0200
parents 4ca2872c7d9e
children
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#!/bin/sh
### BEGIN INIT INFO
# Provides:          dropbear
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Dropbear SSH server
### END INIT INFO
#
# Do not configure this file. Edit /etc/default/dropbear instead!
#

PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
DAEMON=/usr/sbin/dropbear
NAME=dropbear
DESC="Dropbear SSH server"

DROPBEAR_PORT=22
DROPBEAR_EXTRA_ARGS=
NO_START=0

set -e

cancel() { echo "$1" >&2; exit 0; };
test ! -r /etc/default/dropbear || . /etc/default/dropbear
test -x "$DAEMON" || cancel "$DAEMON does not exist or is not executable."
test ! -x /usr/sbin/update-service || ! update-service --check dropbear ||
  cancel 'The dropbear service is controlled through runit, use the sv(8) program'

test -z "$DROPBEAR_BANNER" || \
  DROPBEAR_EXTRA_ARGS="$DROPBEAR_EXTRA_ARGS -b $DROPBEAR_BANNER"
test -n "$DROPBEAR_RSAKEY" || \
  DROPBEAR_RSAKEY="/etc/dropbear/dropbear_rsa_host_key"
test -n "$DROPBEAR_DSSKEY" || \
  DROPBEAR_DSSKEY="/etc/dropbear/dropbear_dss_host_key"
test -n "$DROPBEAR_RECEIVE_WINDOW" || \
  DROPBEAR_RECEIVE_WINDOW="65536"

case "$1" in
  start)
	test "$NO_START" = "0" || cancel 'NO_START is not set to zero.'
	echo -n "Starting $DESC: "
	start-stop-daemon --start --quiet --pidfile /var/run/"$NAME".pid \
	  --exec "$DAEMON" -- -d "$DROPBEAR_DSSKEY" -r "$DROPBEAR_RSAKEY" \
	    -p "$DROPBEAR_PORT" -W "$DROPBEAR_RECEIVE_WINDOW" $DROPBEAR_EXTRA_ARGS
	echo "$NAME."
	;;
  stop)
	echo -n "Stopping $DESC: "
	start-stop-daemon --stop --quiet --oknodo --pidfile /var/run/"$NAME".pid
	echo "$NAME."
	;;
  restart|force-reload)
	test "$NO_START" = "0" || cancel 'NO_START is not set to zero.'
	echo -n "Restarting $DESC: "
	start-stop-daemon --stop --quiet --oknodo --pidfile /var/run/"$NAME".pid
	sleep 1
	start-stop-daemon --start --quiet --pidfile /var/run/"$NAME".pid \
	  --exec "$DAEMON" -- -d "$DROPBEAR_DSSKEY" -r "$DROPBEAR_RSAKEY" \
	    -p "$DROPBEAR_PORT" -W "$DROPBEAR_RECEIVE_WINDOW" $DROPBEAR_EXTRA_ARGS
	echo "$NAME."
	;;
  *)
	N=/etc/init.d/$NAME
	echo "Usage: $N {start|stop|restart|force-reload}" >&2
	exit 1
	;;
esac

exit 0