--- /dev/null
+/*
+ Copyright (C) 2018 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 <dcp/data.h>
+
+namespace dcpomatic {
+
+boost::shared_array<unsigned char> random_iv ();
+dcp::Data encrypt (std::string plaintext, boost::shared_array<unsigned char const> key, boost::shared_array<unsigned char const> iv);
+std::string decrypt (dcp::Data ciphertext, boost::shared_array<unsigned char const> key, boost::shared_array<unsigned char const> iv);
+int crypto_key_length ();
+
+}
+