Various encryption-related stuff.

[libdcp.git] / src / mxf_asset.cc

diff --git a/src/mxf_asset.cc b/src/mxf_asset.cc
index 54c204e7ec67ffa9bcd9af88c427fb77b7c8b95e..bcfe60854500fe731c2f67acac54e23f543bc37b 100644 (file)
--- a/src/mxf_asset.cc
+++ b/src/mxf_asset.cc
@@ -46,46 +46,25 @@ using namespace libdcp;
 MXFAsset::MXFAsset (string directory, string file_name)
        : Asset (directory, file_name)
        , _progress (0)
-       , _encrypted (false)
        , _encryption_context (0)
        , _decryption_context (0)
 {
 
 }
 
-MXFAsset::MXFAsset (string directory, string file_name, boost::signals2::signal<void (float)>* progress, int edit_rate, int intrinsic_duration, bool encrypted)
+MXFAsset::MXFAsset (string directory, string file_name, boost::signals2::signal<void (float)>* progress, int edit_rate, int intrinsic_duration) 
        : Asset (directory, file_name, edit_rate, intrinsic_duration)
        , _progress (progress)
-       , _encrypted (encrypted)
        , _encryption_context (0)
        , _decryption_context (0)
 {
-       if (_encrypted) {
-               /* Generate an encryption key and a UUID for it */
-               _key_id = make_uuid ();
-               uint8_t key_buffer[ASDCP::KeyLen];
-               Kumu::FortunaRNG rng;
-               rng.FillRandom (key_buffer, ASDCP::KeyLen);
-               char key_string[ASDCP::KeyLen * 4];
-               Kumu::bin2hex (key_buffer, ASDCP::KeyLen, key_string, ASDCP::KeyLen * 4);
-               _key_value = key_string;
-                       
-               _encryption_context = new ASDCP::AESEncContext;
-               if (ASDCP_FAILURE (_encryption_context->InitKey (key_buffer))) {
-                       throw MiscError ("could not set up encryption context");
-               }
-
-               uint8_t cbc_buffer[ASDCP::CBC_BLOCK_SIZE];
-               
-               if (ASDCP_FAILURE (_encryption_context->SetIVec (rng.FillRandom (cbc_buffer, ASDCP::CBC_BLOCK_SIZE)))) {
-                       throw MiscError ("could not set up CBC initialization vector");
-               }
-       }
+       
 }
 
 MXFAsset::~MXFAsset ()
 {
        delete _encryption_context;
+       delete _decryption_context;
 }
 
 void
@@ -104,7 +83,7 @@ MXFAsset::fill_writer_info (ASDCP::WriterInfo* writer_info, string uuid, bool in
        Kumu::hex2bin (uuid.c_str(), writer_info->AssetUUID, Kumu::UUID_Length, &c);
        assert (c == Kumu::UUID_Length);
 
-       if (_encrypted) {
+       if (_key) {
                Kumu::GenRandomUUID (writer_info->ContextID);
                writer_info->EncryptedEssence = true;
 
@@ -159,16 +138,35 @@ MXFAsset::write_to_cpl (xmlpp::Element* node, bool interop) const
        a->add_child ("IntrinsicDuration")->add_child_text (lexical_cast<string> (_intrinsic_duration));
        a->add_child ("EntryPoint")->add_child_text (lexical_cast<string> (_entry_point));
        a->add_child ("Duration")->add_child_text (lexical_cast<string> (_duration));
-       if (_encrypted) {
+       if (!_key_id.empty ()) {
                a->add_child("KeyId")->add_child_text ("urn:uuid:" + _key_id);
        }
 }
 
 void
-MXFAsset::set_kdm_cipher (KDMCipher cipher)
+MXFAsset::set_key (Key key)
 {
+       _key = key;
+
+       if (_key_id.empty ()) {
+               /* No key ID so far; we now need one */
+               _key_id = make_uuid ();
+       }
+       
        _decryption_context = new ASDCP::AESDecContext;
-       if (ASDCP_FAILURE (_decryption_context->InitKey (cipher.key_raw ()))) {
+       if (ASDCP_FAILURE (_decryption_context->InitKey (_key->value ()))) {
                throw MiscError ("could not set up decryption context");
        }
+
+       _encryption_context = new ASDCP::AESEncContext;
+       if (ASDCP_FAILURE (_encryption_context->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_context->SetIVec (rng.FillRandom (cbc_buffer, ASDCP::CBC_BLOCK_SIZE)))) {
+               throw MiscError ("could not set up CBC initialization vector");
+       }
 }