#!/bin/sh

#(@)generate-CA.sh - Create CA key-pair and server key-pair signed by CA

# Copyright (c) 2013 Jan-Piet Mens <jpmens()gmail.com>

# All rights reserved.

#

# Redistribution and use in source and binary forms, with or without

# modification, are permitted provided that the following conditions are met:

#

# 1. Redistributions of source code must retain the above copyright notice,

#    this list of conditions and the following disclaimer.

# 2. Redistributions in binary form must reproduce the above copyright

#    notice, this list of conditions and the following disclaimer in the

#    documentation and/or other materials provided with the distribution.

# 3. Neither the name of mosquitto nor the names of its

#    contributors may be used to endorse or promote products derived from

#    this software without specific prior written permission.

#

# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

# POSSIBILITY OF SUCH DAMAGE.

set -e

DIR=${TARGET:='.'}

# A space-separated list of alternate hostnames (subjAltName)

# may be empty ""

ALTHOSTNAMES="broker.example.com foo.example.de"

CA_ORG='/O=MQTTitude.org/emailAddress=nobody@example.net'

CA_DN="/CN=An MQTT broker${CA_ORG}"

CACERT=${DIR}/ca

SERVER=${DIR}/server

SERVER_DN="/CN=$(hostname -f)$CA_ORG"

keybits=2048

openssl=$(which openssl)

function maxdays() {

	nowyear=$(date +%Y)

	years=$(expr 2032 - $nowyear)

	days=$(expr $years '*' 365)

	echo $days

}

function getipaddresses() {

	/sbin/ifconfig |

		sed -En '/inet6? /p' |

		sed -Ee 's/inet6? (addr:)?//' |

		awk '{print $1;}' |

		sed -e 's/[%/].*//' |

		egrep -v '(::1|127\.0\.0\.1)'	# omit loopback to add it later

}

function addresslist() {

	ALIST=""

	for a in $(getipaddresses); do

		ALIST="${ALIST}IP:$a,"

	done

	ALIST="${ALIST}IP:127.0.0.1,IP:::1,"

	for h in $(echo ${ALTHOSTNAMES}); do

		ALIST="${ALIST}DNS:$h,"

	done

	ALIST="${ALIST}DNS:localhost"

	echo $ALIST

}

days=$(maxdays)

if [ -n "$CAKILLFILES" ]; then

	rm -f $CACERT.??? $SERVER.??? $CACERT.srl

fi

if [ ! -f $CACERT.crt ]; then

	# Create un-encrypted (!) key

	$openssl req -newkey rsa:${keybits} -x509 -nodes -days $days -extensions v3_ca -keyout $CACERT.key -out $CACERT.crt -subj "${CA_DN}"

	echo "Created CA certificate in $CACERT.crt"

	$openssl x509 -in $CACERT.crt -nameopt multiline -subject -noout

	chmod 400 $CACERT.key

	chmod 444 $CACERT.crt

fi

if [ ! -f $SERVER.key ]; then

	echo "--- Creating server key and signing request"

	$openssl genrsa -out $SERVER.key $keybits

	$openssl req -new \

		-out $SERVER.csr \

		-key $SERVER.key \

		-subj "${SERVER_DN}"

	chmod 400 $SERVER.key

fi

if [ -f $SERVER.csr -a ! -f $SERVER.crt ]; then

	# There's no way to pass subjAltName on the CLI so

	# create a cnf file and use that.

	CNF=`mktemp /tmp/cacnf.XXXXXXXX` || { echo "$0: can't create temp file" >&2; exit 1; }

	sed -e 's/^.*%%% //' > $CNF <<\!ENDconfig

	%%% [ JPMextensions ]

	%%% basicConstraints        = critical,CA:false

	%%% nsCertType              = server

	%%% keyUsage                = nonRepudiation, digitalSignature, keyEncipherment

	%%% nsComment               = "Broker Certificate"

	%%% subjectKeyIdentifier    = hash

	%%% authorityKeyIdentifier  = keyid,issuer:always

	%%% subjectAltName          = $ENV::SUBJALTNAME

	%%% # issuerAltName           = issuer:copy

	%%% nsCaRevocationUrl       = http://mqttitude.org/carev/

	%%% nsRevocationUrl         = http://mqttitude.org/carev/

!ENDconfig

	SUBJALTNAME="$(addresslist)"

	export SUBJALTNAME		# Use environment. Because I can. ;-)

	echo "--- Creating and signing server certificate"

	$openssl x509 -req \

		-in $SERVER.csr \

		-CA $CACERT.crt \

		-CAkey $CACERT.key \

		-CAcreateserial \

		-CAserial "${DIR}/ca.srl" \

		-out $SERVER.crt \

		-days $days \

		-extfile ${CNF} \

		-extensions JPMextensions

	rm -f $CNF

	chmod 444 $SERVER.crt

fi

$ wget https://github.com/iandl/mqttitude/blob/master/tools/TLS/generate-CA.sh .

$ bash ./generate-CA.sh