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

[libdcp.git] / src / asset_writer.cc

diff --git a/src/asset_writer.cc b/src/asset_writer.cc
index 13adc50eceeff69ad3684c8c75696e0aeed014b0..7a3e9882ee17634a861b85c8214934480200ee06 100644 (file)
--- 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 */