Warn/error on making KDMs using recipient certs whose validity periods

lie outside those of the KDMs (#2423).

1 files changed, 60 insertions, 0 deletions

diff --git a/src/lib/kdm_util.cc b/src/lib/kdm_util.cc
new file mode 100644
index 000000000..bf112ce11
--- /dev/null
+++ b/src/lib/kdm_util.cc
@@ -0,0 +1,60 @@
+/*
+    Copyright (C) 2023 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "kdm_util.h"
+#include "screen.h"
+#include <dcp/certificate.h>
+#include <boost/optional.hpp>
+
+#include "i18n.h"
+
+
+using std::list;
+using std::pair;
+using std::shared_ptr;
+using std::string;
+using boost::optional;
+
+
+KDMCertificatePeriod
+check_kdm_and_certificate_validity_periods(dcp::Certificate const& recipient, dcp::LocalTime kdm_from, dcp::LocalTime kdm_to)
+{
+	auto overlaps = [](dcp::LocalTime from_a, dcp::LocalTime to_a, dcp::LocalTime from_b, dcp::LocalTime to_b) {
+		return std::max(from_a, from_b) < std::min(to_a, to_b);
+	};
+
+	auto contains = [](dcp::LocalTime bigger_from, dcp::LocalTime bigger_to, dcp::LocalTime smaller_from, dcp::LocalTime smaller_to) {
+		return bigger_from <= smaller_from && bigger_to >= smaller_to;
+	};
+
+	if (contains(recipient.not_before(), recipient.not_after(), kdm_from, kdm_to)) {
+		return KDMCertificatePeriod::KDM_WITHIN_CERTIFICATE;
+	}
+
+	if (overlaps(recipient.not_before(), recipient.not_after(), kdm_from, kdm_to)) {
+		/* The KDM overlaps the certificate validity: maybe not the end of the world */
+		return KDMCertificatePeriod::KDM_OVERLAPS_CERTIFICATE;
+	} else {
+		/* The KDM validity is totally outside the certificate validity: bad news */
+		return KDMCertificatePeriod::KDM_OUTSIDE_CERTIFICATE;
+	}
+}
+