#!/usr/bin/env bash
DIR=$HOME/.lehook
configfile=$DIR/config
VALIDMODES="deploy|renew|generate|test"

function doinit() {
	mkdir -p $DIR
	if [[ ! -e $configfile ]]; then
		echo "Creating config in $DIR..."
		cat > $configfile <<EOF
DIR=$HOME/.lehook
NSUPDATE="nsupdate -k /var/named/acme-tsig-key.key"
# DNS server to make updates to
DNSSERVER="127.0.0.1"
# Address to use when talking to DNS server (useful for setups with views)
LOCALADDR="10.99.99.254"
TTL=300
certbase="/etc/letsencrypt/live"
domains="example.net"
email="root@example.net"
# Nameservers to check to see whether the update worked
# (may be different to DNSSERVER above is setups with a silent master)
check_nameservers="ns1.example.net ns2.example.net"

remotes="webserver1 webserver2.example.org webserver3.example.net"
remotecertdir=/etc/ssl
services="nginx httpd ngircd dovecot postfix"
EOF
	else
		echo "$configfile already exists.  Did you mean -I? (install binary)"
	fi
        doinstall
}

function doinstall() {
    local x
    if [[ -z $DIR ]]; then
        echo "Error: no install dir defined"
        exit 1
    elif [[ ! -d $DIR ]]; then
        echo "Error: install dir $DIR doesn't exist"
        exit 1
    fi
    echo "Creating hardlinks in $DIR..."
    cp -f $0 $DIR/lehook.sh
    for x in pre post deploy; do
            ln -f $DIR/lehook.sh $DIR/lehook-${x}.sh
    done
    if [[ $(id -u) == "0" ]]; then
        ln -f $DIR/lehook.sh /usr/local/bin/lehook.sh
    else
        echo "Calling sudo to install to /usr/local/bin, enter password if prompted"
        sudo ln -f $DIR/lehook.sh /usr/local/bin/lehook.sh
    fi
    echo "Init complete.  Files are in $DIR."
    echo "Main binary in /usr/local/bin/lehook.sh."
}

function log() {
    local showtoo txt
    if [[ $1 == "-v" ]]; then
        showtoo=1
        shift 1
    else
        showtoo=0
    fi
    txt="$(date):  $*"

    echo "$txt" >>$LOG
    [[ $showtoo -eq 1 ]] && echo "$txt"
}

function out() {
	local nl
	nl="\n"
	if [[ $1 == "-n" ]]; then
		nl=""
		shift
	fi
	[[ $quiet -ne 1 ]] && printf "%*s%s$nl" $((indent * 2)) '' "$*"
}
function inc() {
	indent=$((indent + 1))
}
function dec() {
	indent=$((indent - 1))
}
function copycert() {
	local err src dst cer
	src=$1
	dst=$2
	cer=$(basename $src)

	inc
	out -n "$cer: "
	err="$(scp "$src" $dst 2>&1 >/dev/null)"
	if [[ -z $err ]]; then
		[[ $quiet -ne 1 ]] && echo "Ok"
	else
		[[ $quiet -ne 1 ]] && echo "$err"
	fi
	dec
}
function dossh() {
	local h desc cmd rv err
	h=$1
	desc="$2"
	cmd="$3"

	inc
	out -n "$desc: "

	rv=0
	err="$(ssh root@$h "$cmd" 2>&1 >/dev/null)"
	if [[ $? -eq 0 ]]; then
		[[ $quiet -ne 1 ]] && echo "Ok"
	else
		[[ $quiet -ne 1 ]] && echo "Error: [$err]"
		rv=1
	fi
	dec
	return $rv
}

function usage() {
	echo "usage:  $0 OPTIONS mode [domain1] ... [domainX]"
	echo "       Pushes wildcard SSL certs for the given domains to hosts [default:  $domains]."
	echo
	echo "       mode is one of:  $VALIDMODES"
	echo
	echo "      -A          In generate/renew modes, Also deploy certs if needed"
	echo "      -c          Cron mode - only output if something is done."
	echo "      -f          Push out certs even if they haven't changed."
	echo "      -i          Iniitalise new config file in $configfile"
	echo "      -I          Install binary symlinks in home dir"
	echo "      -r remotes  Only push certs to the given remotes [default: $remotes]"
	echo "      -s services Only restart the given services [default: $services]"
	echo "      -d domain   Only push cert for given domain [default:  $domains]."
	echo "      -q          Quiet mode - no output except errors"
	echo "      -v          Verbose mode - show certbot output"
	echo "      -h          Show this text."
}

function checkcert() {
	local desc host lsum path rsum rv
	desc="$1"
	host="$2"
	lsum="$3"
	path="$4"
	rv=0
	inc
	out -n "$desc: "
	rsum=$(ssh root@$r "sha256sum $path 2>&1")
	if [[ $? -ne 0 ]]; then
		[[ $quiet -ne 1 ]] && echo "Doesn't exist"
		rv=1
	else
		rsum=$(echo "$rsum" | awk '{ print $1 }')
		if [[ $lsum == $rsum ]]; then
			[[ $quiet -ne 1 ]] && echo "Ok"
		else
			[[ $quiet -ne 1 ]] && echo "Needs updating [$lsum vs $rsum]"
			rv=1
		fi
	fi
	dec
	return $rv
}




indent=0
force=0
quiet=0
verbose=0
cronmode=0
init=0
alsodeploy=0
recurseargs=""

if [[ -e $configfile ]]; then
	. $configfile
fi

ARGS="Acd:fhiIqr:s:v"
while getopts "$ARGS" i; do
	case "$i" in
		A)
                        alsodeploy=1
			;;

		c)
                        cronmode=1
			recurseargs="$recurseargs -c"
			;;
		h)
			usage;
                        exit 1;
			;;
		I)
			doinstall;
                        exit 0;
			;;
		i)
			doinit;
                        exit 0;
			;;
		d)
			domains="$OPTARG"
			;;
		f)
                        force=1
			recurseargs="$recurseargs -$i"
			;;
		q)
                        quiet=1
			recurseargs="$recurseargs -$i"
			;;
		r)
			remotes="$OPTARG"
			recurseargs="$recurseargs -$i $OPTARG"
			;;
		s)
			services="$OPTARG"
			recurseargs="$recurseargs -$i $OPTARG"
			;;
		v)
                        verbose=1
			recurseargs="$recurseargs -$i"
			;;
		*)
			error "invalid argument:  $i";
			usage;
			;;
	esac
done
shift $((OPTIND - 1))

if [[ ! -e $configfile ]]; then
	echo "$0: ERROR: cant find $configfile"
	echo "Use $0 -i to initialise it."
	exit 1
fi

LOG=/var/log/lehook.log

if [[ $0 =~ pre|post|deploy ]]; then
        log -v "lehook running with cmd="$0" args='$*' CERTBOT_DOMAIN='$CERTBOT_DOMAIN' CERTBOT_VALIDATION='$CERTBOT_VALIDATION'"
	set -e
	set -u
	set -o pipefail
	if [[ -z $CERTBOT_DOMAIN ]]; then
		log -v "Error: no \$CERTBOT_DOMAIN env var received from certbot.  vars are:"
		set | grep CERTBOT
		exit 1
	fi
	if [[ -z $CERTBOT_VALIDATION ]]; then
		log -v "Error: no \$CERTBOT_VALIDATION env var received from certbot.  vars are:"
		set | grep CERTBOT
		exit 1
	fi
	DOMAIN="$CERTBOT_DOMAIN"
	DATA="$CERTBOT_VALIDATION"
	rv=0
else
	if [[ $# -lt 1 ]]; then
		echo "Error: no mode specified"
		usage
		exit 1
	fi
	mode=$1
	if [[ ! $mode =~ $VALIDMODES ]]; then
		echo "Error: invalid mode '$mode'.  Valid options: $VALIDMODES"
		exit 1
	fi
	shift

	if [[ $# -gt 0 ]]; then
		domains="$*"
	fi
fi

function dodeploy() {
    local certdirs d rv
    local r newcerta  ip domain dest_cert dest_priv
    local local_cert_sum local_priv_sum needupate
    local isrh checkcmd reloadcmd enabled
    local nok nfail okservs failservs s
	certdirs=""
	for d in $domains; do
		thisone=$certbase/$d
		if [[ -d $thisone ]]; then
			certdirs="$certdirs $thisone"
		else
			echo "Error:  $thisone not found, skipping." >/dev/stderr
			rv=$((rv + 1))
		fi
	done

	if [[ -z $certdirs ]]; then
		echo "Error:  No certificates found.  Aborting."
		exit 2
	fi


	for r in $remotes; do
		out "Processing $r..."
		inc

		newcerts=""
		ip=$(getent hosts $r 2>/dev/null)
		if [[ -z $ip ]]; then
			out "* No DNS entry for '$r'.  Skipping."
			rv=$((rv + 1))
		else
			for d in $certdirs; do
				domain=$(basename $d)
				dest_cert=$remotecertdir/certs/$domain
				dest_priv=$remotecertdir/private/$domain

				local_cert_sum=$(sha256 -q $d/fullchain.pem 2>&1)
				local_priv_sum=$(sha256 -q $d/privkey.pem 2>&1)

				if [[ $force -eq 1 ]]; then
					needupdate=1
				else
					out "* Checking existing certs"
					needupdate=0
					checkcert "Certificate" $r $local_cert_sum $dest_cert/fullchain.pem || needupdate=1
					if [[ $needupdate -eq 0 ]]; then
						checkcert "Private key" $r $local_priv_sum $dest_priv/privkey.pem || needupdate=1
					fi
				fi

				if [[ $needupdate -eq 1 ]]; then
					out "* Creating cert dirs in $remotecertdir"
					ssh root@$r "[ -d $dest_cert ] || mkdir -p $dest_cert && chmod 755 $dest_cert; [ -d $dest_priv ] || mkdir -p $dest_priv && chmod 700 $dest_priv; grep -qi ubuntu /etc/os-release 2>/dev/null && chown -R root:ssl-cert $dest_cert $dest_priv"
					out "* Uploading certs"
					copycert $d/fullchain.pem root@$r:$dest_cert
					copycert $d/privkey.pem root@$r:$dest_priv
					newcerts="$newcerts $domain"

					out "* Restarting services"
					inc
					isrh=$(ssh root@$r "test -f /etc/redhat-release && echo yes || echo no")
					if [[ $isrh == "no" ]]; then
						checkcmd="service --status-all"
						reloadcmd="service XX restart && echo Ok || echo failed"
					else
						checkcmd="systemctl list-unit-files --state=enabled"
						reloadcmd="systemctl restart XX"
					fi

					enabled=$(ssh root@$r "$checkcmd 2>&1" | awk '/:on|nabled/ { print $1 } ($2 == "+") { print $4 }')
					nok=0
					nfail=0
					okservs=""
					failservs=""
					for s in $services; do
						if [[ $enabled == *$s* ]]; then
							reloadcmd=$(echo "$reloadcmd" | sed -e "s/XX/$s/")
							dossh $r $s "$reloadcmd"
							thisrv=$?
							rv=$((rv + $thisrv))
							if [[ $thisrv -eq 0 ]]; then
								nok=$((nok + 1))
								okservs="$okservs $s"
							else
								nfail=$((nfail + 1))
								failservs="$failservs $s"
							fi
						else
							inc
							out "$s: Not enabled"
							dec
						fi
					done
					dec
				else
					out "* No update needed"
				fi

			done
		fi
		if [[ $quiet -eq 0 || $cronmode -eq 1 ]]; then
			if [[ ! -z $newcerts ]]; then
				echo -n "Refreshed these SSL certs on '$r':  $newcerts (restarted $okservs"
				if [[ $nfail -ge 1 ]]; then
					echo ", FAILED to restart $failservs)"
				else
					echo ")"
				fi
			fi
		fi
		dec
	done
}

function wait_for_dns_update() { # wait_for_dns_update [-v for inverse match] domain value
	local ns record  secs grv wantgrv verb
        if [[ $1 == "-v" ]]; then
            # want grep NOT to match
            verb="does NOT contain"
            wantgrv=1
            shift 1
        else
            # want grep to match
            verb="contains"
            wantgrv=0
        fi
	record="_acme-challenge.$1"
	value="$2"
        secs=5

        log -v "Delaying until dns is done with:"
        log -v "      servers:    $check_nameservers"
        log -v "       record:    $record"
        log -v "desired value:    $verb $value"
        log -v "        delay:    $secs"
	for ns in $check_nameservers; do
		[[ $verbose -eq 1 || $quiet -eq 0 || $cronmode -eq 1 ]] && echo -n "Waiting for challenge record to update on $ns..."
		res=$(dig +short @${ns} $record IN TXT | tr -d '"' 2>&1)
                (echo "$res" | grep -q "$value") && grv=0 || grv=1
		while [[ $grv -ne $wantgrv ]]; do
			sleep $secs
                        [[ $verbose -eq 1 || $quiet -eq 0 || $cronmode -eq 1 ]] && echo -n "."
			res=$(dig +short @${ns} $record IN TXT | tr -d '"' 2>&1)
                        (echo "$res" | grep -q "$value") && grv=0 || grv=1
		done
                [[ $verbose -eq 1 || $quiet -eq 0 || $cronmode -eq 1 ]] && echo "done"
	done
        log -v "All DNS updates done."
        return 0
}

if [[ $0 == *pre* ]]; then
	DOMAIN="$CERTBOT_DOMAIN"
	DATA="$CERTBOT_VALIDATION"
	cmd=$(printf "server %s\nlocal $LOCALADDR\n update add _acme-challenge.%s. %d in TXT \"%s\"\nsend\n" "${DNSSERVER}" "${DOMAIN}" "${TTL}" "${DATA}")
	log -v "PREHOOK - Adding challenge key '$DATA' for domain "$DOMAIN" via:"
	log -v "$cmd" | sed -e 's/^/   /'
	echo "$cmd" | $NSUPDATE
	rv=$?
	log -v "PREHOOK - Done, now waiting for dns update."
	wait_for_dns_update "$DOMAIN" "$DATA"
	log -v "PREHOOK - Waiting for any children"
        wait
	log -v "PREHOOK - About to exit with code $rv"
	exit $rv
elif [[ $0 == *post* ]]; then
	DOMAIN="$CERTBOT_DOMAIN"
	DATA="$CERTBOT_VALIDATION"
	cmd=$(printf "server %s\nlocal $LOCALADDR\n update delete _acme-challenge.%s. %d in TXT \"%s\"\nsend\n" "${DNSSERVER}" "${DOMAIN}" "${TTL}" "${DATA}")
	#echo "POSTHOOK - ABOUT TO RUN"
	#echo "$cmd" | sed -e 's/^/   /'
	log -v "POSTHOOK - Removing challenge key '$DATA' via:"
	log -v "$cmd" | sed -e 's/^/   /'
	echo "$cmd" | $NSUPDATE
	rv=$?
	log -v "POSTHOOK - Done, now waiting for dns update."
	wait_for_dns_update -v "$DOMAIN" "$DATA"
	log -v "POSTHOOK - Waiting for any children"
        wait
	log -v "POSTHOOK - About to exit with code $rv"
	exit $rv
elif [[ $0 == *deploy* ]]; then
	DOMAIN="$CERTBOT_DOMAIN"
	/usr/local/bin/lehook.sh deploy -d $DOMAIN $recurseargs
	exit 1
fi



rv=0
if [[ $mode == "generate" ]]; then
	rv=0
	for this in $domains; do
		res=$(certbot certonly -n --manual --preferred-challenges=dns --email $email --agree-tos --manual-auth-hook $DIR/lehook-pre.sh --manual-cleanup-hook $DIR/lehook-post.sh --deploy-hook $DIR/lehook-deploy.sh --expand -d "${this},*.${this}" 2>&1)
		rv=$((rv + $?))
		[[ $verbose -eq 1 ]] && echo "$res"
	done
        if [[ $rv -eq 0 && $alsodeploy -eq 1 ]]; then
            dodeploy
            rv=$?
        fi
elif [[ $mode == "renew" ]]; then
	rv=0
	extraargs=""
        renewed=0
	[[ $force -eq 1 ]] && extraargs="$extraargs --force-renewal"
        cp -f /dev/null /tmp/lh-renew
	for this in $domains; do
		[[ $verbose -eq 1 ]] && echo "Will run:    certbot renew -n --manual --preferred-challenges=dns --email $email --agree-tos --manual-auth-hook $DIR/lehook-pre.sh --manual-cleanup-hook $DIR/lehook-post.sh --deploy-hook $DIR/lehook-deploy.sh $extraargs --cert-name ${this} 2>&1" | tee -a /tmp/lh-renew
		res=$(certbot renew -n --manual --preferred-challenges=dns --email $email --agree-tos --manual-auth-hook $DIR/lehook-pre.sh --manual-cleanup-hook $DIR/lehook-post.sh --deploy-hook $DIR/lehook-deploy.sh $extraargs --cert-name ${this} 2>&1 | tee -a /tmp/lh-renew)
		rv=$((rv + $?))
		[[ $verbose -eq 1 ]] && echo "$res"
		if [[ "$res" =~ "not due for" ]]; then
			if [[ $quiet -eq 0 && $cronmode -eq 0 ]]; then
				exp=$(certbot certificates --cert-name $this 2>&1 | grep Expiry | sed -e 's/^.*Date: //')
				echo "$this not due for renewal yet.  Expiry: $exp"
			fi
		elif [[ "$res" =~ "renewals succeeded" ]]; then
                        renewed=$((renewed + 1))
			if [[ $quiet -eq 0 || $cronmode -eq 1 ]]; then
				exp=$(certbot certificates --cert-name $this 2>&1 | grep Expiry | sed -e 's/^.*Date: //')
				echo "$this has been renewed.  New expiry: $exp"
			fi
		else
			echo "Error renewing $this. Certbot output:"
			echo "$res"
		fi
	done
        if [[ $rv -eq 0 && $alsodeploy -eq 1 && $renewed -gt 0 ]]; then
            dodeploy
            rv=$?
        fi
elif [[ $mode == "test" ]]; then
	nowdate="$(date +%s)"
	echo "== Test mode."
	echo "== About to run pre-hook"
	export CERTBOT_DOMAIN="${domains%% *}" # just use the first one
	export CERTBOT_VALIDATION="test-${nowdate}"
	$DIR/lehook-pre.sh
	echo "== Pre-hook done.  Checking DNS record:"
	dig -b $LOCALADDR @${DNSSERVER} _acme-challenge.${domains%% *}. IN txt
	echo -n "The above should show a TXT record saying '$nowdate'.... hit ENTER:  "
	read dummy
	echo "== About to run post-hook"
	export CERTBOT_DOMAIN="${domains%% *}"
	export CERTBOT_VALIDATION="test-${nowdate}"
	echo "== Post-hook done.  Checking DNS record:"
	$DIR/lehook-post.sh
	dig -b $LOCALADDR @${DNSSERVER} _acme-challenge.${domains%% *}. IN txt
	echo -n "The above should NOT show a TXT record any more.   Hit ENTER:  "
	read dummy
	exit 1
elif [[ $mode == "deploy" ]]; then
    dodeploy
    rv=$?
fi
exit $rv