Allow configuration of context ID used when encrypting MXFs.

2 files changed, 21 insertions, 1 deletions

diff --git a/src/mxf.cc b/src/mxf.cc
index 6ec634da..03e3d1d8 100644
--- a/src/mxf.cc
+++ b/src/mxf.cc
@@ -57,6 +57,12 @@ using boost::shared_ptr;
 using boost::dynamic_pointer_cast;
 using namespace dcp;
 
+MXF::MXF ()
+	: _context_id (make_uuid ())
+{
+
+}
+
 void
 MXF::fill_writer_info (ASDCP::WriterInfo* writer_info, string id, Standard standard) const
 {
@@ -76,7 +82,7 @@ MXF::fill_writer_info (ASDCP::WriterInfo* writer_info, string id, Standard stand
 	writer_info->UsesHMAC = true;
 
 	if (_key_id) {
-		Kumu::GenRandomUUID (writer_info->ContextID);
+		Kumu::hex2bin (_context_id.c_str(), writer_info->ContextID, Kumu::UUID_Length, &c);
 		writer_info->EncryptedEssence = true;
 
 		unsigned int c;
diff --git a/src/mxf.h b/src/mxf.h
index 73ada433..52d335ea 100644
--- a/src/mxf.h
+++ b/src/mxf.h
@@ -61,6 +61,7 @@ class PictureAssetWriter;
 class MXF
 {
 public:
+	MXF ();
 	virtual ~MXF () {}
 
 	/** @return true if the data is encrypted */
@@ -87,6 +88,18 @@ public:
 		return _key;
 	}
 
+	/** Set the context ID to be used when encrypting.
+	 *  @param id New ID.
+	 */
+	void set_context_id (std::string id) {
+		_context_id = id;
+	}
+
+	/** @return context ID used when encrypting; this starts off as a random value */
+	std::string context_id () const {
+		return _context_id;
+	}
+
 	/** Set the metadata that is written to the MXF file.
 	 *  @param m Metadata.
 	 */
@@ -114,6 +127,7 @@ protected:
 	boost::optional<std::string> _key_id;
 	/** Key used for encryption/decryption, if there is one */
 	boost::optional<Key> _key;
+	std::string _context_id;
 	MXFMetadata _metadata;
 };