# Copyright 1999-2019 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2


inherit autotools db-use eutils systemd tmpfiles user

DESCRIPTION="A milter providing DKIM signing and verification"

# The GPL-2 is for the init script, bug 425960.
LICENSE="BSD GPL-2 Sendmail-Open-Source"
KEYWORDS="~amd64 ~arm x86"
IUSE="berkdb ldap libressl lmdb lua memcached opendbx poll sasl selinux +ssl static-libs stats query_cache test unbound"

COMMON_DEPEND="|| ( mail-filter/libmilter mail-mta/sendmail )
	ssl? (
		!libressl? ( dev-libs/openssl:0= )
		libressl? ( dev-libs/libressl:0= )
	berkdb? ( >=sys-libs/db-3.2:* )
	opendbx? ( >=dev-db/opendbx-1.4.0 )
	lua? ( dev-lang/lua:5.1 )
	ldap? ( net-nds/openldap )
	lmdb? ( dev-db/lmdb )
	memcached? ( dev-libs/libmemcached )
	sasl? ( dev-libs/cyrus-sasl )
	unbound? ( >=net-dns/unbound-1.4.1:= net-dns/dnssec-root )
	!unbound? ( net-libs/ldns )"

	test? ( dev-lang/lua:5.1 )"

	selinux? ( sec-policy/selinux-dkim )"

REQUIRED_USE="sasl? ( ldap )
	stats? ( opendbx )
	query_cache? ( berkdb )"


pkg_setup() {
	# This user can read your private keys, and must therefore not be
	# shared with any other package.
	enewgroup opendkim
	enewuser opendkim -1 -1 -1 opendkim

src_prepare() {
	sed -e 's:/var/db/dkim:/var/lib/opendkim:g' \
		-i opendkim/opendkim.conf.sample opendkim/opendkim.conf.simple.in \
		|| die
	sed -e 's:dist_doc_DATA:dist_html_DATA:' \
		-i libopendkim/docs/Makefile.am \
		|| die

src_configure() {
	local myconf=()
	if use berkdb ; then
		myconf+=( --with-db-incdir=$(db_includedir) )
	if use unbound; then
		myconf+=( --with-unbound )
		myconf+=( --with-ldns )
	if use ldap; then
		myconf+=( $(use_with sasl) )

	# We install the our configuration filed under e.g. /etc/opendkim,
	# so the next line is necessary to point the daemon and all of its
	# documentation to the right location by default.
	myconf+=( --sysconfdir="${EPREFIX}/etc/${PN}" )

	econf \
		$(use_with berkdb db) \
		$(use_with opendbx odbx) \
		$(use_with lua) \
		$(use_enable lua rbl) \
		$(use_with ldap openldap) \
		$(use_with lmdb) \
		$(use_enable poll) \
		$(use_enable query_cache) \
		$(use_enable static-libs static) \
		$(use_enable stats) \
		$(use_with memcached libmemcached) \
		"${myconf[@]}" \
		--enable-filter \
		--enable-atps \
		--enable-identity_header \
		--enable-rate_limit \
		--enable-resign \
		--enable-replace_rules \
		--enable-default_sender \
		--enable-sender_macro \
		--enable-vbr \
		--disable-live-testing \

src_compile() {
	emake runstatedir=/run

src_install() {
	find "${D}" -name '*.la' -type f -delete || die

	dosbin stats/opendkim-reportstats

	newinitd "${S}/contrib/OpenRC/opendkim.openrc" "${PN}"
	systemd_newtmpfilesd "${S}/contrib/systemd/opendkim.tmpfiles" "${PN}.conf"
	systemd_newunit "contrib/systemd/opendkim.service" "${PN}.service"

	dodir /etc/opendkim
	keepdir /var/lib/opendkim

	# The OpenDKIM data (particularly, your keys) should be read-only to
	# the UserID that the daemon runs as.
	fowners root:opendkim /var/lib/opendkim
	fperms 750 /var/lib/opendkim

	# Tweak the "simple" example configuration a bit before installing
	# it unconditionally.
	local cf="${T}/opendkim.conf"
	# Some MTAs are known to break DKIM signatures with "simple"
	# canonicalization [1], so we choose the "relaxed" policy
	# over OpenDKIM's current default settings.
	# [1] https://wordtothewise.com/2016/12/dkim-canonicalization-or-why-microsoft-breaks-your-mail/
	sed -E -e 's:^(Canonicalization)[[:space:]]+.*:\1\trelaxed/relaxed:' \
		"${S}/opendkim/opendkim.conf.simple" >"${cf}" || die
	cat >>"${cf}" <<EOT || die

# The UMask is really only used for the PID file (root:root) and the
# local UNIX socket, if you're using one. It should be 0117 for the
# socket.
UMask			0117
UserID			opendkim

# For use with unbound
#TrustAnchorFile	/etc/dnssec/root-anchors.txt
	insinto /etc/opendkim
	doins "${cf}"

pkg_postinst() {
	tmpfiles_process "${PN}.conf"
	if [[ -z ${REPLACING_VERSION} ]]; then
		elog "If you want to sign your mail messages and need some help"
		elog "please run:"
		elog "	emerge --config ${CATEGORY}/${PN}"
		elog "It will help you create your key and give you hints on how"
		elog "to configure your DNS and MTA."

		elog "If you are using a local (UNIX) socket, then you will"
		elog "need to make sure that your MTA has read/write access"
		elog "to the socket file. This is best accomplished by creating"
		elog "a completely-new group with only your MTA user and the"
		elog "\"opendkim\" user in it. Step-by-step instructions can be"
		elog "found on our Wiki, at https://wiki.gentoo.org/wiki/OpenDKIM ."
		ewarn "The user account for the OpenDKIM daemon has changed"
		ewarn "from \"milter\" to \"opendkim\" to prevent unrelated services"
		ewarn "from being able to read your private keys. You should"
		ewarn "adjust your existing configuration to use the \"opendkim\""
		ewarn "user and group, and change the permissions on"
		ewarn "${ROOT}var/lib/opendkim to root:opendkim with mode 0750."
		ewarn "The owner and group of the files within that directory"
		ewarn "will likely need to be adjusted as well."

pkg_config() {
	local selector keysize pubkey

	read -p "Enter the selector name (default ${HOSTNAME}): " selector
	[[ -n "${selector}" ]] || selector="${HOSTNAME}"
	if [[ -z "${selector}" ]]; then
		eerror "Oddly enough, you don't have a HOSTNAME."
		return 1
	if [[ -f "${ROOT}var/lib/opendkim/${selector}.private" ]]; then
		ewarn "The private key for this selector already exists."
		# Generate the private and public keys. Note that opendkim-genkeys
		# sets umask=077 on its own to keep these safe. However, we want
		# them to be readable (only!) to the opendkim user, and we manage
		# that by changing their groups and making everything group-readable.
		opendkim-genkey -b ${keysize} -D "${ROOT}"var/lib/opendkim/ \
			-s "${selector}" -d '(your domain)' && \
			chgrp --no-dereference opendkim \
				"${ROOT}var/lib/opendkim/${selector}".{private,txt} || \
				{ eerror "Failed to create private and public keys."; return 1; }
		chmod g+r "${ROOT}var/lib/opendkim/${selector}".{private,txt}

	# opendkim selector configuration
	einfo "Make sure you have the following settings in your /etc/opendkim/opendkim.conf:"
	einfo "  Keyfile /var/lib/opendkim/${selector}.private"
	einfo "  Selector ${selector}"

	# MTA configuration
	einfo "If you are using Postfix, add following lines to your main.cf:"
	einfo "  smtpd_milters	   = unix:/run/opendkim/opendkim.sock"
	einfo "  non_smtpd_milters = unix:/run/opendkim/opendkim.sock"
	einfo "  and read http://www.postfix.org/MILTER_README.html"

	# DNS configuration
	einfo "After you configured your MTA, publish your key by adding this TXT record to your domain:"
	cat "${ROOT}var/lib/opendkim/${selector}.txt"
	einfo "t=y signifies you only test the DKIM on your domain. See following page for the complete list of tags:"
	einfo "  http://www.dkim.org/specs/rfc4871-dkimbase.html#key-text"