#!/bin/sh -e

ETC_DEFAULT_SSH=@ETC_DEFAULT_SSH@

ETC_INIT_D_SSH=@ETC_INIT_D_SSH@

ETC_PAM_D_SSH=@ETC_PAM_D_SSH@

action=$1
version=$2

prepare_transfer_conffile () {
	CONFFILE="$1"
	TEXT="$2"
	MODE="$3"
	[ "$CONFFILES" ] || return 0
	[ -e "$CONFFILE" ] || return 0

	md5sum="$(md5sum "$CONFFILE" |sed -e 's/ .*//')"
	old_md5sum="$(echo "$CONFFILES" | awk '$1 == "'"$CONFFILE"'" { print $2 }')"
	if [ "$md5sum" = "$old_md5sum" ]; then
		echo >&2 "Transferring ownership of conffile $CONFFILE ..."
		# We have to write out the desired new text of the conffile,
		# which is tricky in the preinst, hence the nasty way we
		# have to hardcode the text here. Fortunately, this is only
		# necessary with sarge's dpkg and older.
		if echo "$TEXT" | head -n1 | grep -q '^@.*@$'; then
			echo >&2 'Unsubstituted conffile text! Please report this bug.'
			exit 1
		fi
		printf '%s' "$TEXT" >"$CONFFILE.dpkg-new"
		chmod "$MODE" "$CONFFILE.dpkg-new"
		mv -f "$CONFFILE" "$CONFFILE.moved-by-preinst"
		mv -f "$CONFFILE.dpkg-new" "$CONFFILE"
		return 0
	fi
}

prepare_mv_conffile () {
	CONFFILE="$1"
	[ -e "$CONFFILE" ] || return 0

	md5sum="$(md5sum "$CONFFILE" | sed -e 's/ .*//')"
	old_md5sum="$(dpkg-query -W -f '${Conffiles}\n' openssh-server 2>/dev/null | sed 's/^ *//' | awk '$1 == "'"$CONFFILE"'" { print $2 }')"
	if [ "$md5sum" = "$old_md5sum" ]; then
		mv -f "$CONFFILE" "$CONFFILE.dpkg-old"
	else
		mv -f "$CONFFILE" "$CONFFILE.moving"
	fi
}

if [ -d /etc/ssh-nonfree ] && [ ! -d /etc/ssh ]; then
  version=1.2.27
fi

if [ "$action" = upgrade ] || [ "$action" = install ]
then
  # check if debconf is missing
  if ! test -f /usr/share/debconf/confmodule
  then
    cat <<EOF

WARNING: ssh's pre-configuration script relies on debconf to tell you
about some problems that might prevent you from logging in if you are
upgrading from the old, Non-free version of ssh.

If this is a new installation, you don't need to worry about this.
Just go ahead and install ssh (make sure to read .../ssh/README.Debian).

If you are upgrading, but you have alternative ways of logging into
the machine (i.e. you're sitting in front of it, or you have telnetd
running), then you also don't need to worry too much, because you can
fix it up afterwards if there's a problem.

If you're upgrading from an older (non-free) version of ssh, and ssh
is the only way you have to access this machine, then you should
probably abort the installation of ssh, install debconf, and then
retry the installation of ssh.

EOF
    echo -n "Do you want to install SSH anyway [yN]: "
    read input
    expr "$input" : '[Yy]' >/dev/null || exit 1

    # work around for missing debconf
    db_get() { : ; }
    RET=true
    if [ -d /etc/ssh-nonfree ] && [ ! -d /etc/ssh ]; then
      cp -a /etc/ssh-nonfree /etc/ssh
    fi
  else
    # Source debconf library.
    . /usr/share/debconf/confmodule
    db_version 2.0
  fi

  db_get ssh/use_old_init_script
  if [ "$RET" = "false" ]; then
    echo "ssh config: Aborting because ssh/use_old_init_script = false" >&2
    exit 1
  fi

  # deal with upgrading from pre-OpenSSH versions
  key=/etc/ssh/ssh_host_key
  export key
  if [ -n "$version" ] && [ -x /usr/bin/ssh-keygen ] && [ -f $key ] &&
     dpkg --compare-versions "$version" lt 1.2.28
  then
    # make sure that keys get updated to get rid of IDEA
    #
    # N.B. this only works because we've still got the old
    # nonfree ssh-keygen at this point
    #
    # First, check if we need to bother
    printf '\0\0' | 3<&0 sh -c \
        'dd if=$key bs=1 skip=32 count=2 2>/dev/null | cmp -s - /dev/fd/3' || {
      # this means that bytes 32&33 of the key were not both zero, in which
      # case the key is encrypted, which we need to fix
      chmod 600 $key
      ssh-keygen -u -f $key >/dev/null
      if which restorecon >/dev/null 2>&1; then
        restorecon "$key.pub"
      fi
    }
  fi

  if dpkg --compare-versions "$version" lt 0; then
    CONFFILES="$(dpkg-query -W -f '${Conffiles}\n' ssh 2>/dev/null | sed 's/^ *//')"
    prepare_transfer_conffile /etc/default/ssh "$ETC_DEFAULT_SSH" 0644
    prepare_transfer_conffile /etc/init.d/ssh "$ETC_INIT_D_SSH" 0755
    prepare_transfer_conffile /etc/pam.d/ssh "$ETC_PAM_D_SSH" 0644
  fi

  if dpkg --compare-versions "$version" lt 1:4.7p1-4; then
    prepare_mv_conffile /etc/pam.d/ssh
  fi

  if dpkg --compare-versions "$version" lt 1:5.5p1-6 && \
     [ -d /var/run/sshd ]; then
    # make sure /var/run/sshd is not removed on upgrades
    touch /var/run/sshd/.placeholder
  fi
fi

#DEBHELPER#
