#!/usr/local/bin/bash
#wdns - Script to edit specific zones or the master zones conf file
#Generate random string of characters. This is to ensure we're not directly editing things
#TODO: Make the creation and management of reverse zones easier.
#TODO: Make the 'zones' file easier to manage. Automate creation, editing and removal of entries.
RAND=$(cat /dev/urandom|tr -cd "[:alnum:]"|head -c 8)
FILETOEDIT=""
ORIGDIR="/etc/namedb/"
CHECKBIN="/usr/sbin/named-checkconf"
CHECKRUN="$CHECKBIN /tmp/named.$RAND"
UPDATE_SOA=0
USAGE="wdns - Small bash script for maintaining BIND9 configs.

# wdns [-h]              - Show this help text
# wdns named.conf        - Edit the master named config
# wdns zones             - Edit master zones config
# wdns domain.name       - Edit zonefile for domain.name
# wdns -d domain.name    - Delete zonefile for domain.name
# wdns -l                - list all zones
# wdns -n domain.name    - create new zonefile for domain.name
# wdns -nz domain.name   - recreate blank zonefile for domain.name
# wdns -s domain.name    - secure domain using DNSSEC
# wnds -rs domain.name   - resign DNSSEC-secured zone"
if [ "$1" == "" ]; then
	echo "$USAGE"
	exit 1
elif [ "$1" == "named.conf" ]; then
	#Edit the master config by default
	echo "No zone specified, editing named.conf."
	FILETOEDIT="named.conf"
elif [ "$1" == "-h" ]; then
	echo "$USAGE"
	exit 0
elif [ "$1" == "-d" ]; then
	if [ "$2" == "" ]; then
		echo "$USAGE"
		exit 1
	fi
	echo "Deleting zone for $2."
	if [ ! -f /etc/namedb/master/$2 ]; then
		echo "Error: Zonefile for $2 doesn't exist!"
		exit 1
	fi
	rm /etc/namedb/master/$2
	if [ $? -ne 0 ]; then
		echo "Error: Failed to delete zonefile /etc/namedb/master/$2."
		exit 1
	fi
	exit 0
elif [ "$1" == "-l" ]; then
	echo "The following forward zones exist:"
	ls -l /etc/namedb/master|egrep -v "\.db$|new.domain|\.last|\.arpa|\.signed$|^total "|awk '{print $9}'|sort
	echo
	echo "The following reverse zones exist:"
	ls -l /etc/namedb/master/|egrep "\.arpa$"|egrep -v "\.last|\.signed$"|awk '{print $9}'|sort
	exit 0
elif [ "$1" == "-n" ]; then
	if [ "$2" == "" ]; then
		echo "$USAGE"
		exit 1
	fi
	echo "Creating new zone for $2."
	if [ -f /etc/namedb/master/$2 ]; then
		echo "Error: Zonefile for $2 already exists. Use -nz to overwrite with new zone!"
		exit 1
	fi
	#TODO: Validate input.
	cat /etc/namedb/master/new.domain|sed "s/new\.domain/$2/g">/etc/namedb/master/$2
	if [ $? -ne 0 ]; then
		echo "Error: Failed to copy zone template to /etc/namedb/master/$2"
		exit 1
	fi
	echo "Zone for $2 created. Run the following on all slaves:"
	#TODO: Add zone to slaves
	read -p "Hit exit to open it for editing, or Ctrl-C to exit."
	wdns $2
	exit 0
elif [ "$1" == "-nz" ]; then
	if [ "$2" == "" ]; then
		echo "$USAGE"
		exit 1
	fi
	echo "Recreating zone for $2."
	if [ ! -f /etc/namedb/master/$2 ]; then
		echo "Error: Zonefile for $2 does not exist. Use -n to create a new zone!"
		exit 1
	fi
	#TODO: Validate input.
	cat /etc/namedb/master/new.domain|sed "s/new\.domain/$2/g">/etc/namedb/master/$2
	if [ $? -ne 0 ]; then
		echo "Error: Failed to copy zone template to /etc/namedb/master/$2"
		exit 1
	fi
	read -p "Zone recreated. Hit exit to open it for editing, or Ctrl-C to exit."
	wdns $2
	exit 0
elif [ "$1" == "-s" ]; then
	if [ "$2" == "" ]; then
		echo "$USAGE"
		exit 1
	fi
	if [ ! -f /etc/namedb/master/$2 ]; then
		echo "Error: Zonefile for $2 does not exist. Use -n to create a new zone!"
		exit 1
	fi
	ZONE=$2
	DNSSEC_DIR="/etc/namedb/dnssec"
	DSKEYG_MSG="$(dnssec-keygen -f KSK -a RSASHA256 -b 2048 -K $DNSSEC_DIR -n ZONE $ZONE. 2>&1)"
	if [ $? -ne 0 ]; then
		echo "DNSSEC signing key generation failed! Error: $DSKEYG_MSG"
		exit 1
	fi
	mv $DNSSEC_DIR/K$ZONE.+*.key $DNSSEC_DIR/K$ZONE.KSK.key
	mv $DNSSEC_DIR/K$ZONE.+*.private $DNSSEC_DIR/K$ZONE.KSK.private
	DSKEYG_MSG="$(dnssec-keygen -a RSASHA256 -b 2048 -K $DNSSEC_DIR -n ZONE $ZONE. 2>&1)"
	if [ $? -ne 0 ]; then
		echo "DNSSEC zone signing key generation failed! Error: $DSKEYG_MSG"
		exit 1
	fi
	mv $DNSSEC_DIR/K$ZONE.+*.key $DNSSEC_DIR/K$ZONE.ZSK.key
	mv $DNSSEC_DIR/K$ZONE.+*.private $DNSSEC_DIR/K$ZONE.ZSK.private
	echo "The following lines must now be added to the zone file for $ZONE, right after the nameserver records:
	\$include $DNSSEC_DIR/K$ZONE.KSK.key
	\$include $DNSSEC_DIR/K$ZONE.ZSK.key

	After this has been done, please remember to edit the zone definition in your bind config to change the zone file to '/etc/namedb/master/$ZONE.signed'" && echo
	read -p "Press enter to open the zone for editing, or Ctrl-C to exit and add these later."
	wdns $ZONE
	exit 0
elif [ "$1" == "-rs" ]; then
	if [ "$2" == "" ]; then
		echo "$USAGE"
		exit 1
	fi
	if [ ! -f /etc/namedb/master/$2 ]; then
		echo "Error: Zonefile for $2 does not exist. Use -n to create a new zone!"
		exit 1
	fi
	ZONE=$2
	DNSSEC_DIR="/etc/namedb/dnssec"
	if [ ! -f /etc/namedb/master/$ZONE.signed ]; then
		echo "Zone $ZONE doesn't appear to be DNSSEC-enabled! Use -s to sign an unsigned zone!"
		exit 1
	fi
	if [ ! -f $DNSSEC_DIR/K$ZONE.KSK.key -o ! -f $DNSSEC_DIR/K$ZONE.ZSK.key ]; then
		echo "Signing keys for $ZONE don't exist! Use -s to sign an unsigned zone!"
		exit 1
	fi
	#sorry
	ORIGDIR="/etc/namedb/master/"
	SOA="$(cat "$ORIGDIR$ZONE"|grep "; Serial"|sed -E 's/;.*//g;s/[[:space:]]*//g')"
	SOA_VERSION="$(echo $SOA|tail -c2)"
	SOA_DATE="$(echo $SOA|head -c8)"
	SOA_NEW_DATE="$(date "+%Y%m%d")"
	if [[ "$SOA_DATE" == "$SOA_NEW_DATE" ]]; then
		SOA_VERSION="$(echo "$SOA_VERSION+1"|bc)"
		if [ "$(echo "$(echo "$SOA_VERSION"|wc -c|tr -cd '[:alnum:]')-1"|bc)" == "1" ]; then
			SOA_VERSION="0$SOA_VERSION"
		fi
	else
		SOA_VERSION="00"
		SOA_DATE="$SOA_NEW_DATE"
	fi
	cat "$ORIGDIR$ZONE"|sed "s/$SOA/$SOA_DATE$SOA_VERSION/">/tmp/soatmp$ZONE
	mv /tmp/soatmp$ZONE $ORIGDIR$ZONE
	DNSSEC_OUT="$(dnssec-signzone -o $ZONE -e +31536000 -d /etc/namedb/dnssec -K /etc/namedb/dnssec -k /etc/namedb/dnssec/K$ZONE.KSK.key /etc/namedb/master/$ZONE /etc/namedb/dnssec/K$ZONE.ZSK.key 2>&1)"
	if [ $? -ne 0 ]; then
		echo "DNSSEC signing failed! Error: $DNSSEC_OUT"
		exit 1
	fi
	echo "Zone $ZONE resigned."
	#Reload zones
	echo "Reloading named"
	/etc/rc.d/named reload
	if [ $? -ne 0 ]; then
		echo "Error while reloading named!"
		exit 1
	fi
	exit 0
else
	#Check if we want to edit the master zones config
	if [ "$1" == "zones" ]; then
		echo "Editing zones.conf."
		FILETOEDIT="zones.conf"
	else
		#Edit a specific zonefile
		if [ ! -f /etc/namedb/master/$1 ]; then
			#Error out if the zone doesn't exist. Zones should be created using the newzone function
			echo "Zone for $1 doesn't exist!"
			exit 1
		fi
		echo "Editing zonefile for $1."
		FILETOEDIT="$1"
		ORIGDIR="/etc/namedb/master/"
		CHECKBIN="/usr/sbin/named-checkzone"
		CHECKRUN="$CHECKBIN $1 /tmp/named.$RAND"
		UPDATE_SOA=1
	fi
fi
if [ $UPDATE_SOA -eq 1 ]; then
	#Update SOA
	SOA="$(cat "$ORIGDIR$FILETOEDIT"|grep "; Serial"|sed -E 's/;.*//g;s/[[:space:]]*//g')"
	SOA_VERSION="$(echo $SOA|tail -c2)"
	SOA_DATE="$(echo $SOA|head -c8)"
	SOA_NEW_DATE="$(date "+%Y%m%d")"
	if [[ "$SOA_DATE" == "$SOA_NEW_DATE" ]]; then
		SOA_VERSION="$(echo "$SOA_VERSION+1"|bc)"
		if [ "$(echo "$(echo "$SOA_VERSION"|wc -c|tr -cd '[:alnum:]')-1"|bc)" == "1" ]; then
			SOA_VERSION="0$SOA_VERSION"
		fi
	else
		SOA_VERSION="00"
		SOA_DATE="$SOA_NEW_DATE"
	fi
	cat "$ORIGDIR$FILETOEDIT"|sed "s/$SOA/$SOA_DATE$SOA_VERSION/">/tmp/named.$RAND
else
	cp "$ORIGDIR$FILETOEDIT" /tmp/named.$RAND
fi
#Generate MD5 sum of the original file
ORIGHASH=$(md5 -q /tmp/named.$RAND)
for (( ; ; )); do
	#Edit zone
	vim /tmp/named.$RAND
	NEWHASH=$(md5 -q /tmp/named.$RAND)
	if [ "$ORIGHASH" == "$NEWHASH" ]; then
		echo "No changes made to $FILETOEDIT."
		exit 0
	fi
	echo -n "Checking $FILETOEDIT for errors... "
	CHECK_OUT=$($CHECKRUN)
	if [ $? -eq 0 ]; then
		#Changes cleared named-checkzone
		echo "No errors."
		#Make a backup of the previous known-good zone, just in case
		cp "$ORIGDIR$FILETOEDIT" "$ORIGDIR$FILETOEDIT.last"
		#Move the new zone in over the old one
		mv /tmp/named.$RAND "$ORIGDIR$FILETOEDIT"
		#DNSSEC
		if [ -f /etc/namedb/dnssec/K$1.KSK.key ]; then
			echo "Signing zone"
			DNSSEC_OUT="$(dnssec-signzone -o $1 -e +31536000 -d /etc/namedb/dnssec -K /etc/namedb/dnssec -k /etc/namedb/dnssec/K$1.KSK.key /etc/namedb/master/$1 /etc/namedb/dnssec/K$1.ZSK.key 2>&1)"
			if [ $? -ne 0 ]; then
				echo "Failed to sign zone!\n$DNSSEC_OUT"
			fi
		fi
		#Reload zones
		echo "Reloading named"
		/etc/rc.d/named reload
		if [ $? -eq 0 ]; then
			break
		else
			echo "Error while reloading named!"
			exit 1
		fi
	else
		#Changes didn't clear named-checkzone
		echo "Errors found."
		#Output the errors, wait for the user to hit enter, then the loop starts all over.
		echo "$CHECKRUN_OUT"
		read -p "Press enter to reopen $FILETOEDIT for editing"
	fi
done
if [ -f /tmp/named.$RAND ]; then
	rm /tmp/named.$RAND
fi