// base subroutine for reading a KLV packet, assumes file position is at the first byte of the packet
Result_t
ASDCP::Read_EKLV_Packet(Kumu::FileReader& File, const ASDCP::Dictionary& Dict,
const ASDCP::WriterInfo& Info, Kumu::fpos_t& LastPosition, ASDCP::FrameBuffer& CtFrameBuf,
ui32_t FrameNum, ui32_t SequenceNum, ASDCP::FrameBuffer& FrameBuf,
const byte_t* EssenceUL, AESDecContext* Ctx, HMACContext* HMAC)
{
KLReader Reader;
Result_t result = Reader.ReadKLFromFile(File);
if ( KM_FAILURE(result) )
return result;
UL Key(Reader.Key());
ui64_t PacketLength = Reader.Length();
LastPosition = LastPosition + Reader.KLLength() + PacketLength;
if ( Key.MatchIgnoreStream(Dict.ul(MDD_CryptEssence)) ) // ignore the stream numbers
{
if ( ! Info.EncryptedEssence )
{
DefaultLogSink().Error("EKLV packet found, no Cryptographic Context in header.\n");
return RESULT_FORMAT;
}
// read encrypted triplet value into internal buffer
assert(PacketLength <= 0xFFFFFFFFL);
CtFrameBuf.Capacity((ui32_t) PacketLength);
ui32_t read_count;
result = File.Read(CtFrameBuf.Data(), (ui32_t) PacketLength, &read_count);
if ( ASDCP_FAILURE(result) )
return result;
if ( read_count != PacketLength )
{
DefaultLogSink().Error("read length is smaller than EKLV packet length.\n");
return RESULT_FORMAT;
}
CtFrameBuf.Size((ui32_t) PacketLength);
// should be const but mxflib::ReadBER is not
byte_t* ess_p = CtFrameBuf.Data();
// read context ID length
if ( ! Kumu::read_test_BER(&ess_p, UUIDlen) )
return RESULT_FORMAT;
// test the context ID
if ( memcmp(ess_p, Info.ContextID, UUIDlen) != 0 )
{
DefaultLogSink().Error("Packet's Cryptographic Context ID does not match the header.\n");
return RESULT_FORMAT;
}
ess_p += UUIDlen;
// read PlaintextOffset length
if ( ! Kumu::read_test_BER(&ess_p, sizeof(ui64_t)) )
return RESULT_FORMAT;
ui32_t PlaintextOffset = (ui32_t)KM_i64_BE(Kumu::cp2i<ui64_t>(ess_p));
ess_p += sizeof(ui64_t);
// read essence UL length
if ( ! Kumu::read_test_BER(&ess_p, SMPTE_UL_LENGTH) )
return RESULT_FORMAT;
// test essence UL
if ( ! UL(ess_p).MatchIgnoreStream(EssenceUL) ) // ignore the stream number
{
char strbuf[IntBufferLen];
const MDDEntry* Entry = Dict.FindUL(Key.Value());
if ( Entry == 0 )
{
DefaultLogSink().Warn("Unexpected Essence UL found: %s.\n", Key.EncodeString(strbuf, IntBufferLen));
}
else
{
DefaultLogSink().Warn("Unexpected Essence UL found: %s.\n", Entry->name);
}
return RESULT_FORMAT;
}
ess_p += SMPTE_UL_LENGTH;
// read SourceLength length
if ( ! Kumu::read_test_BER(&ess_p, sizeof(ui64_t)) )
return RESULT_FORMAT;
ui32_t SourceLength = (ui32_t)KM_i64_BE(Kumu::cp2i<ui64_t>(ess_p));
ess_p += sizeof(ui64_t);
assert(SourceLength);
if ( FrameBuf.Capacity() < SourceLength )
{
DefaultLogSink().Error("FrameBuf.Capacity: %u SourceLength: %u\n", FrameBuf.Capacity(), SourceLength);
return RESULT_SMALLBUF;
}
ui32_t esv_length = calc_esv_length(SourceLength, PlaintextOffset);
// read ESV length
if ( ! Kumu::read_test_BER(&ess_p, esv_length) )
{
DefaultLogSink().Error("read_test_BER did not return %u\n", esv_length);
return RESULT_FORMAT;
}
ui32_t tmp_len = esv_length + (Info.UsesHMAC ? klv_intpack_size : 0);
if ( PacketLength < tmp_len )
{
DefaultLogSink().Error("Frame length is larger than EKLV packet length.\n");
return RESULT_FORMAT;
}
if ( Ctx )
{
// wrap the pointer and length as a FrameBuffer for use by
// DecryptFrameBuffer() and TestValues()
FrameBuffer TmpWrapper;
TmpWrapper.SetData(ess_p, tmp_len);
TmpWrapper.Size(tmp_len);
TmpWrapper.SourceLength(SourceLength);
TmpWrapper.PlaintextOffset(PlaintextOffset);
result = DecryptFrameBuffer(TmpWrapper, FrameBuf, Ctx);
FrameBuf.FrameNumber(FrameNum);
// detect and test integrity pack
if ( ASDCP_SUCCESS(result) && Info.UsesHMAC && HMAC )
{
IntegrityPack IntPack;
result = IntPack.TestValues(TmpWrapper, Info.AssetUUID, SequenceNum, HMAC);
}
}
else // return ciphertext to caller
{
if ( FrameBuf.Capacity() < tmp_len )
{
char intbuf[IntBufferLen];
DefaultLogSink().Error("FrameBuf.Capacity: %u FrameLength: %s\n",
FrameBuf.Capacity(), ui64sz(PacketLength, intbuf));
return RESULT_SMALLBUF;
}
memcpy(FrameBuf.Data(), ess_p, tmp_len);
FrameBuf.Size(tmp_len);
FrameBuf.FrameNumber(FrameNum);
FrameBuf.SourceLength(SourceLength);
FrameBuf.PlaintextOffset(PlaintextOffset);
}
}
else if ( Key.MatchIgnoreStream(EssenceUL) ) // ignore the stream number
{ // read plaintext frame
if ( FrameBuf.Capacity() < PacketLength )
{
char intbuf[IntBufferLen];
DefaultLogSink().Error("FrameBuf.Capacity: %u FrameLength: %s\n",
FrameBuf.Capacity(), ui64sz(PacketLength, intbuf));
return RESULT_SMALLBUF;
}
// read the data into the supplied buffer
ui32_t read_count;
assert(PacketLength <= 0xFFFFFFFFL);
result = File.Read(FrameBuf.Data(), (ui32_t) PacketLength, &read_count);
if ( ASDCP_FAILURE(result) )
return result;
if ( read_count != PacketLength )
{
char intbuf1[IntBufferLen];
char intbuf2[IntBufferLen];
DefaultLogSink().Error("read_count: %s != FrameLength: %s\n",
ui64sz(read_count, intbuf1),
ui64sz(PacketLength, intbuf2) );
return RESULT_READFAIL;
}
FrameBuf.FrameNumber(FrameNum);
FrameBuf.Size(read_count);
}
else
{
char strbuf[IntBufferLen];
const MDDEntry* Entry = Dict.FindUL(Key.Value());
if ( Entry == 0 )
{
DefaultLogSink().Warn("Unexpected Essence UL found: %s.\n", Key.EncodeString(strbuf, IntBufferLen));
}
else
{
DefaultLogSink().Warn("Unexpected Essence UL found: %s.\n", Entry->name);
}
return RESULT_FORMAT;
}
return result;
}
ASDCP::Result_t
ASDCP::MPEG2::Parser::h__Parser::ReadFrame(FrameBuffer& FB)
{
Result_t result = RESULT_OK;
ui32_t write_offset = 0;
ui32_t read_count = 0;
FB.Size(0);
if ( m_EOF )
return RESULT_ENDOFFILE;
// Data is read in VESReadSize chunks. Each chunk is parsed, and the
// process is stopped when a Sequence or Picture header is found or when
// the input file is exhausted. The partial next frame is cached for the
// next call.
m_ParserDelegate.Reset();
m_Parser.Reset();
if ( m_TmpBuffer.Size() > 0 )
{
memcpy(FB.Data(), m_TmpBuffer.RoData(), m_TmpBuffer.Size());
result = m_Parser.Parse(FB.RoData(), m_TmpBuffer.Size());
write_offset = m_TmpBuffer.Size();
m_TmpBuffer.Size(0);
}
while ( ! m_ParserDelegate.m_CompletePicture && result == RESULT_OK )
{
if ( FB.Capacity() < ( write_offset + VESReadSize ) )
{
DefaultLogSink().Error("FrameBuf.Capacity: %u FrameLength: %u\n",
FB.Capacity(), ( write_offset + VESReadSize ));
return RESULT_SMALLBUF;
}
result = m_FileReader.Read(FB.Data() + write_offset, VESReadSize, &read_count);
if ( result == RESULT_ENDOFFILE || read_count == 0 )
{
m_EOF = true;
if ( write_offset > 0 )
result = RESULT_OK;
}
if ( ASDCP_SUCCESS(result) )
{
result = m_Parser.Parse(FB.RoData() + write_offset, read_count);
write_offset += read_count;
}
if ( m_EOF )
break;
}
assert(m_ParserDelegate.m_FrameSize <= write_offset);
if ( ASDCP_SUCCESS(result)
&& m_ParserDelegate.m_FrameSize < write_offset )
{
assert(m_TmpBuffer.Size() == 0);
ui32_t diff = write_offset - m_ParserDelegate.m_FrameSize;
assert(diff <= m_TmpBuffer.Capacity());
memcpy(m_TmpBuffer.Data(), FB.RoData() + m_ParserDelegate.m_FrameSize, diff);
m_TmpBuffer.Size(diff);
}
if ( ASDCP_SUCCESS(result) )
{
const byte_t* p = FB.RoData();
if ( p[0] != 0 || p[1] != 0 || p[2] != 1 || ! ( p[3] == SEQ_START || p[3] == PIC_START ) )
{
DefaultLogSink().Error("Frame buffer does not begin with a PIC or SEQ start code.\n");
return RESULT_RAW_FORMAT;
}
}
if ( ASDCP_SUCCESS(result) )
{
FB.Size(m_ParserDelegate.m_FrameSize);
FB.TemporalOffset(m_ParserDelegate.m_TemporalRef);
FB.FrameType(m_ParserDelegate.m_FrameType);
FB.PlaintextOffset(m_ParserDelegate.m_PlaintextOffset);
FB.FrameNumber(m_FrameNumber++);
FB.GOPStart(m_ParserDelegate.m_HasGOP);
FB.ClosedGOP(m_ParserDelegate.m_ClosedGOP);
}
return result;
}
