Use a HMAC context to write HMAC stuff to encrypted MXFs.

6 files changed, 25 insertions, 7 deletions

diff --git a/src/asset_writer.cc b/src/asset_writer.cc
index 13adc50e..7a3e9882 100644
--- a/src/asset_writer.cc
+++ b/src/asset_writer.cc
@@ -33,13 +33,14 @@ using namespace dcp;
  *  @param mxf MXF that we are writing.
  *  @param file File to write to.
  */
-AssetWriter::AssetWriter (MXF* mxf, boost::filesystem::path file)
+AssetWriter::AssetWriter (MXF* mxf, boost::filesystem::path file, Standard standard)
 	: _mxf (mxf)
 	, _file (file)
 	, _frames_written (0)
 	, _finalized (false)
 	, _started (false)
 	, _encryption_context (0)
+	, _hmac_context (0)
 {
 	if (mxf->key ()) {
 		_encryption_context = new ASDCP::AESEncContext;
@@ -53,12 +54,26 @@ AssetWriter::AssetWriter (MXF* mxf, boost::filesystem::path file)
 		if (ASDCP_FAILURE (_encryption_context->SetIVec (rng.FillRandom (cbc_buffer, ASDCP::CBC_BLOCK_SIZE)))) {
 			throw MiscError ("could not set up CBC initialization vector");
 		}
+
+		_hmac_context = 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_context->InitKey (mxf->key()->value(), type))) {
+			throw MiscError ("could not set up HMAC context");
+		}
 	}
 }
 
 AssetWriter::~AssetWriter ()
 {
 	delete _encryption_context;
+	delete _hmac_context;
 }
 
 /** @return true if anything was written by this writer */
diff --git a/src/asset_writer.h b/src/asset_writer.h
index 4266c719..183619d2 100644
--- a/src/asset_writer.h
+++ b/src/asset_writer.h
@@ -24,10 +24,12 @@
 #ifndef LIBDCP_ASSET_WRITER_H
 #define LIBDCP_ASSET_WRITER_H
 
+#include "types.h"
 #include <boost/filesystem.hpp>
 
 namespace ASDCP {
 	class AESEncContext;
+	class HMACContext;
 }
 
 namespace dcp {
@@ -51,7 +53,7 @@ public:
 	}
 
 protected:
-	AssetWriter (MXF* mxf, boost::filesystem::path file);
+	AssetWriter (MXF* mxf, boost::filesystem::path file, Standard standard);
 
 	/** MXF that we are writing */
 	MXF* _mxf;
@@ -66,6 +68,7 @@ protected:
 	/** true if something has been written to this asset */
 	bool _started;
 	ASDCP::AESEncContext* _encryption_context;
+	ASDCP::HMACContext* _hmac_context;
 };
 
 }
diff --git a/src/mono_picture_asset_writer.cc b/src/mono_picture_asset_writer.cc
index 564a5ea1..54339ed5 100644
--- a/src/mono_picture_asset_writer.cc
+++ b/src/mono_picture_asset_writer.cc
@@ -74,7 +74,7 @@ MonoPictureAssetWriter::write (uint8_t* data, int size)
 	uint64_t const before_offset = _state->mxf_writer.Tell ();
 
 	string hash;
-	ASDCP::Result_t const r = _state->mxf_writer.WriteFrame (_state->frame_buffer, _encryption_context, 0, &hash);
+	ASDCP::Result_t const r = _state->mxf_writer.WriteFrame (_state->frame_buffer, _encryption_context, _hmac_context, &hash);
 	if (ASDCP_FAILURE (r)) {
 		boost::throw_exception (MXFFileError ("error in writing video MXF", _file.string(), r));
 	}
diff --git a/src/picture_asset_writer.cc b/src/picture_asset_writer.cc
index 3bb6a597..24e925f8 100644
--- a/src/picture_asset_writer.cc
+++ b/src/picture_asset_writer.cc
@@ -32,7 +32,7 @@ using boost::shared_ptr;
 using namespace dcp;
 
 PictureAssetWriter::PictureAssetWriter (PictureAsset* asset, boost::filesystem::path file, Standard standard, bool overwrite)
-	: AssetWriter (asset, file)
+	: AssetWriter (asset, file, standard)
 	, _picture_asset (asset)
 	, _standard (standard)
 	, _overwrite (overwrite)
diff --git a/src/sound_asset_writer.cc b/src/sound_asset_writer.cc
index f1e17615..a716b654 100644
--- a/src/sound_asset_writer.cc
+++ b/src/sound_asset_writer.cc
@@ -37,7 +37,7 @@ struct SoundAssetWriter::ASDCPState
 };
 
 SoundAssetWriter::SoundAssetWriter (SoundAsset* asset, boost::filesystem::path file, Standard standard)
-	: AssetWriter (asset, file)
+	: AssetWriter (asset, file, standard)
 	, _state (new SoundAssetWriter::ASDCPState)
 	, _sound_asset (asset)
 	, _frame_buffer_offset (0)
@@ -105,7 +105,7 @@ SoundAssetWriter::write (float const * const * data, int frames)
 void
 SoundAssetWriter::write_current_frame ()
 {
-	ASDCP::Result_t const r = _state->mxf_writer.WriteFrame (_state->frame_buffer, _encryption_context, 0);
+	ASDCP::Result_t const r = _state->mxf_writer.WriteFrame (_state->frame_buffer, _encryption_context, _hmac_context);
 	if (ASDCP_FAILURE (r)) {
 		boost::throw_exception (MiscError (String::compose ("could not write audio MXF frame (%1)", int (r))));
 	}
diff --git a/src/stereo_picture_asset_writer.cc b/src/stereo_picture_asset_writer.cc
index 322c7b00..aaa82b2a 100644
--- a/src/stereo_picture_asset_writer.cc
+++ b/src/stereo_picture_asset_writer.cc
@@ -76,7 +76,7 @@ StereoPictureAssetWriter::write (uint8_t* data, int size)
 		_state->frame_buffer,
 		_next_eye == EYE_LEFT ? ASDCP::JP2K::SP_LEFT : ASDCP::JP2K::SP_RIGHT,
 		_encryption_context,
-		0,
+		_hmac_context,
 		&hash
 		);