#!/bin/sh

##############################################
# release.sh                                 #
# Automate rolling new trust store releases. #
##############################################

# Environment variables used by this script (note that sensible defaults
# will be used where applicable).
# - EXPIRATION_WINDOW: the minimum time certificates must be valid for
#   in order to be included in the new release. The default is 0h, which
#   includes all currently validate certificates. This must be parsable by
#   Go's time package.
# - NOPUSH: do not push the release branch upstream.
# - ALLOW_SKIP_PR: allows the script to complete successfully without
#   creating a release if there are no changes to the bundles.  The
#   intended use for this is the scheduled cronjob, we only want to
#   create a release and PR if there are changes
# - TRUST_CONFIG_PATH: the path to a cfssl-trust configuration file. The
#   default is to not specify a configuration file; the cfssl-trust program
#   will check for one in the standard places.
# - TRUST_DATABASE_PATH: the path to the cfssl-trust cert database. This
#   must either be specified here or in a configuration file.

# Fail on errors and undefined expansions; print what is being executed
# at every step.
set -eux

die () {
    echo "$@" > /dev/stderr
    exit 1
}

##########################
# PROLOGUE: release prep #
##########################

# Make sure we're in the git toplevel.

# If the path to a config file or certificate database are present as
# environment variables, then use those as flags to the cfssl-trust
# program.

CONFIG_PATH="${TRUST_CONFIG_PATH:-}"
if [ -n "${CONFIG_PATH}" ]
then
	CONFIG_PATH="-f ${CONFIG_PATH}"
fi

DATABASE_PATH="${TRUST_DATABASE_PATH:-./cert.db}"
if [ -n "${DATABASE_PATH}" ]
then
	DATABASE_PATH="-d ${DATABASE_PATH}"
fi

# The expiration window defaults to including all currently
# valid certificates.
EXPIRATION_WINDOW="${EXPIRATION_WINDOW:-0h}"

# We need to verify that we have the right tooling in place:
# cfssl-trust to perform the release, and certdump to produce
# a human-readable output of the trust stores.
check_for_tool () {
	command -v $1 2>&1 > /dev/null
	if [ $? -ne 0 ]
	then
		echo "Required tool $1 wasn't found." > /dev/stderr
		die "Path is ${PATH}."
	fi
}

prologue () {
	check_for_tool cfssl-trust
	check_for_tool certdump
	check_for_tool mktemp

	# This release script expects to be run from the repo's top level.
	cd "$(git rev-parse --show-toplevel)" || exit 1
}

###########
# RELEASE #
###########

release () {
	if [ "$(basename $(pwd))" != "cfssl_trust" ]
	then
		die "release.sh should be called from the cfssl_trust repository."
	elif [ "$(pwd)" != "$(git rev-parse --show-toplevel)" ]
	then
		die "release.sh should be called from the git toplevel ($(git rev-parse --show-toplevel), cwd=$(pwd))."
	fi

	echo "Rolling trust store release at $(date +'%FT%T%z')."

	## Step 1: roll the intermediate store.
	#
	# NB: the variables shouldn't be quoted in the command line invocations.
	# The shell will interpret these as empty arguments. The most common
	# symptom of this would be seeing the error "time: invalid duration" ---
	# Go's time.ParseDuration function can't handle empty strings.
	echo "$ cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -b int release ${EXPIRATION_WINDOW}"
	cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -b int release ${EXPIRATION_WINDOW}

	# After the intermediate store is rolled, we'll need to collect the
	# new version number. cfssl-trust reports these in reverse
	# chronological order, so we can grab the first one and remove the
	# leading dash. This will serve as our release branch in git.
	LATEST_RELEASE="$(cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} releases | awk ' NR==1 { print $2 }')"

	## Step 2: roll the root store.
	#
	# The same caveats from step 1 apply
	echo "$ cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -b ca release ${EXPIRATION_WINDOW}"
	cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -b ca release ${EXPIRATION_WINDOW}

	# Step 3: add any additional roots or intermediates.
	if [ -n "${NEW_ROOTS:-}" ]
	then
		echo "Adding new roots:"
		certdump ${NEW_ROOTS}
		cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -b ca -r ${LATEST_RELEASE} import ${NEW_ROOTS}
	fi

	if [ -n "${NEW_INTERMEDIATES:-}" ]
	then
		echo "Adding new intermediates:"
		certdump ${NEW_INTERMEDIATES}
		cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -b int -r ${LATEST_RELEASE} import ${NEW_INTERMEDIATES}
	fi

	# Add the database changes to the release git branch.
	git add cert.db

	## Step 4: write the trust stores to disk.
	#
	# They also should be added to the release git branch.
	echo "$ cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -r ${LATEST_RELEASE} -b int bundle int-bundle.crt"
	cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -r ${LATEST_RELEASE} -b int bundle int-bundle.crt
	echo "$ cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -r ${LATEST_RELEASE} -b ca bundle ca-bundle.crt"
	cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} -r ${LATEST_RELEASE} -b ca  bundle ca-bundle.crt

  	## Step 5: Silent early exit if no changes
  	#
  	# if we are allowing the script to silently complete without a release, we want see
  	# any changes to bundles and if not, exit with the "No_Changes" code for the caller
  	if [ "${ALLOW_SKIP_PR}" = "true" ] && [ -z "`git diff int-bundle.crt ca-bundle.crt | cat`" ]
  	then
    	   echo "No_Changes"
    	   exit 0
  	fi
	
	git add int-bundle.crt ca-bundle.crt

	## Step 6: update the human-readable trust store lists.
	#
	# These lists should also be added to git.
	echo "$ certdump ca-bundle.crt  > certdata/ca-bundle.txt"
	certdump ca-bundle.crt  > certdata/ca-bundle.txt
	echo "$ certdump int-bundle.crt > certdata/int-bundle.txt"
	certdump int-bundle.crt > certdata/int-bundle.txt
	git add certdata/ca-bundle.txt certdata/int-bundle.txt

	echo "$ git status --porcelain -uno"
	git status --porcelain -uno
}

####################################
# execute: does the actual release #
####################################
execute () {
	TEMPFILE="$(mktemp)" || exit
	release | tee "$TEMPFILE"

	# If we note that there are no changes from the release command, exit early
	if grep -q No_Changes "$TEMPFILE";
	then
	   exit 0
	fi

	LATEST_RELEASE="$(cfssl-trust ${DATABASE_PATH} ${CONFIG_PATH} releases | awk ' NR==1 { print $2 }')"
	git checkout -b release/${LATEST_RELEASE}
	printf "Trust store release ${LATEST_RELEASE}\n\n$(cat ${TEMPFILE})" | git commit -F-
	rm ${TEMPFILE}

	git tag trust-store-${LATEST_RELEASE}

	if [ -n "${NOPUSH:-}" ]
	then
		exit 0
	fi

	git push --set-upstream origin release/${LATEST_RELEASE}
	git push origin trust-store-${LATEST_RELEASE}
}

prologue
execute
