/*----------------------------------------------------------------------
| AP4_OmaDcfAtomDecrypter::DecryptAtoms
+---------------------------------------------------------------------*/
AP4_Result
AP4_OmaDcfAtomDecrypter::DecryptAtoms(AP4_AtomParent& atoms,
AP4_Processor::ProgressListener* /*listener*/,
AP4_BlockCipherFactory* block_cipher_factory,
AP4_ProtectionKeyMap& key_map)
{
// default factory
if (block_cipher_factory == NULL) {
block_cipher_factory = &AP4_DefaultBlockCipherFactory::Instance;
}
unsigned int index = 1;
for (AP4_List<AP4_Atom>::Item* item = atoms.GetChildren().FirstItem();
item;
item = item->GetNext()) {
AP4_Atom* atom = item->GetData();
if (atom->GetType() != AP4_ATOM_TYPE_ODRM) continue;
// check that we have the key
const AP4_DataBuffer* key = key_map.GetKey(index++);
if (key == NULL) return AP4_ERROR_INVALID_PARAMETERS;
// check that we have all the atoms we need
AP4_ContainerAtom* odrm = AP4_DYNAMIC_CAST(AP4_ContainerAtom, atom);
if (odrm == NULL) continue; // not enough info
AP4_OdheAtom* odhe = AP4_DYNAMIC_CAST(AP4_OdheAtom, odrm->GetChild(AP4_ATOM_TYPE_ODHE));
if (odhe == NULL) continue; // not enough info
AP4_OddaAtom* odda = AP4_DYNAMIC_CAST(AP4_OddaAtom, odrm->GetChild(AP4_ATOM_TYPE_ODDA));;
if (odda == NULL) continue; // not enough info
AP4_OhdrAtom* ohdr = AP4_DYNAMIC_CAST(AP4_OhdrAtom, odhe->GetChild(AP4_ATOM_TYPE_OHDR));
if (ohdr == NULL) continue; // not enough info
// do nothing if the atom is not encrypted
if (ohdr->GetEncryptionMethod() == AP4_OMA_DCF_ENCRYPTION_METHOD_NULL) {
continue;
}
// create the byte stream
AP4_ByteStream* cipher_stream = NULL;
AP4_Result result = CreateDecryptingStream(*odrm,
key->GetData(),
key->GetDataSize(),
block_cipher_factory,
cipher_stream);
if (AP4_SUCCEEDED(result)) {
// replace the odda atom's payload with the decrypted stream
odda->SetEncryptedPayload(*cipher_stream, ohdr->GetPlaintextLength());
cipher_stream->Release();
// the atom will now be in the clear
ohdr->SetEncryptionMethod(AP4_OMA_DCF_ENCRYPTION_METHOD_NULL);
ohdr->SetPaddingScheme(AP4_OMA_DCF_PADDING_SCHEME_NONE);
}
}
return AP4_SUCCESS;
}
/*----------------------------------------------------------------------
| DumpTrackData
+---------------------------------------------------------------------*/
void
DumpTrackData(const char* mp4_filename,
AP4_File& mp4_file,
const AP4_Array<AP4_Ordinal>& tracks_to_dump,
const AP4_ProtectionKeyMap& key_map)
{
// dump all the tracks that need to be dumped
AP4_Cardinal tracks_to_dump_count = tracks_to_dump.ItemCount();
for (AP4_Ordinal i=0; i<tracks_to_dump_count; i++) {
// get the track
AP4_Ordinal track_id = tracks_to_dump[i];
AP4_Track* track = mp4_file.GetMovie()->GetTrack(track_id);
if (track == NULL) {
fprintf(stderr, "track not found (id = %d)", track_id);
return;
}
// get the sample description
AP4_SampleDescription* sample_description = track->GetSampleDescription(0);
if (sample_description == NULL) {
fprintf(stderr, "WARNING: unable to parse sample description\n");
}
// get the dump data byte stream
AP4_ByteStream* dump = CreateTrackDumpByteStream(mp4_filename, track_id);
if (dump == NULL) return;
printf("\nDumping data for track %d:\n", track_id);
switch(sample_description ?
sample_description->GetType() :
AP4_SampleDescription::TYPE_UNKNOWN) {
case AP4_SampleDescription::TYPE_PROTECTED:
{
const AP4_DataBuffer* key = key_map.GetKey(track_id);
if (key == NULL) {
fprintf(stderr,
"WARNING: No key found for encrypted track %d... "
"dumping encrypted samples\n",
track_id);
DumpSamples(track, dump);
} else {
DecryptAndDumpSamples(track, sample_description, key->GetData(), key->GetDataSize(), dump);
}
}
break;
default:
DumpSamples(track, dump);
}
dump->Release();
}
}
/*----------------------------------------------------------------------
| CheckWarning
+---------------------------------------------------------------------*/
static bool
CheckWarning(AP4_ByteStream& stream, AP4_ProtectionKeyMap& key_map, Method method)
{
AP4_File file(stream,
AP4_DefaultAtomFactory::Instance,
true);
AP4_Movie* movie = file.GetMovie();
if (!movie) {
if (method != METHOD_MPEG_CENC && method != METHOD_PIFF_CBC && method != METHOD_PIFF_CTR) {
fprintf(stderr, "WARNING: no movie atom found in input file\n");
return false;
}
}
bool warning = false;
switch (method) {
case METHOD_MPEG_CENC:
case METHOD_PIFF_CBC:
case METHOD_PIFF_CTR:
if (movie && !movie->HasFragments()) {
fprintf(stderr, "WARNING: MPEG-CENC method only applies to fragmented files\n");
warning = true;
}
break;
default:
break;
}
if (movie) {
for (unsigned int i=0; i<movie->GetTracks().ItemCount(); i++) {
AP4_Track* track;
AP4_Result result = movie->GetTracks().Get(i, track);
if (AP4_FAILED(result)) return false;
const AP4_DataBuffer* key = key_map.GetKey(track->GetId());
if (key == NULL) {
fprintf(stderr, "WARNING: track ID %d will not be encrypted\n", track->GetId());
warning = true;
}
}
}
stream.Seek(0);
return warning;
}
