1 files changed, 80 insertions, 0 deletions
diff --git a/src/encryption_context.cc b/src/encryption_context.cc
new file mode 100644
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+++ b/src/encryption_context.cc
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+/*
+    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
+
+    This file is part of libdcp.
+
+    libdcp 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.
+
+    libdcp 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 libdcp.  If not, see <http://www.gnu.org/licenses/>.
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of portions of this program with the
+    OpenSSL library under certain conditions as described in each
+    individual source file, and distribute linked combinations
+    including the two.
+
+    You must obey the GNU General Public License in all respects
+    for all of the code used other than OpenSSL.  If you modify
+    file(s) with this exception, you may extend this exception to your
+    version of the file(s), but you are not obligated to do so.  If you
+    do not wish to do so, delete this exception statement from your
+    version.  If you delete this exception statement from all source
+    files in the program, then also delete it here.
+*/
+
+#include "encryption_context.h"
+#include "exceptions.h"
+#include <asdcp/AS_DCP.h>
+#include <asdcp/KM_prng.h>
+
+using boost::optional;
+using namespace dcp;
+
+EncryptionContext::EncryptionContext (optional<Key> key, Standard standard)
+	: _encryption (0)
+	, _hmac (0)
+{
+	if (!key) {
+		return;
+	}
+
+	_encryption = new ASDCP::AESEncContext;
+	if (ASDCP_FAILURE (_encryption->InitKey (key->value ()))) {
+		throw MiscError ("could not set up encryption context");
+	}
+
+	uint8_t cbc_buffer[ASDCP::CBC_BLOCK_SIZE];
+
+	Kumu::FortunaRNG rng;
+	if (ASDCP_FAILURE (_encryption->SetIVec (rng.FillRandom (cbc_buffer, ASDCP::CBC_BLOCK_SIZE)))) {
+		throw MiscError ("could not set up CBC initialization vector");
+	}
+
+	_hmac = new ASDCP::HMACContext;
+
+	ASDCP::LabelSet_t type;
+	if (standard == INTEROP) {
+		type = ASDCP::LS_MXF_INTEROP;
+	} else {
+		type = ASDCP::LS_MXF_SMPTE;
+	}
+
+	if (ASDCP_FAILURE (_hmac->InitKey (key->value(), type))) {
+		throw MiscError ("could not set up HMAC context");
+	}
+}
+
+EncryptionContext::~EncryptionContext ()
+{
+	delete _encryption;
+	delete _hmac;
+}