419 lines
15 KiB
C++
419 lines
15 KiB
C++
// Copyright 2017 Google Inc. All rights reserved.
|
|
//
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file or at
|
|
// https://developers.google.com/open-source/licenses/bsd
|
|
|
|
#include "packager/media/crypto/encryption_handler.h"
|
|
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
|
|
#include <limits>
|
|
|
|
#include "packager/media/base/aes_encryptor.h"
|
|
#include "packager/media/base/aes_pattern_cryptor.h"
|
|
#include "packager/media/base/key_source.h"
|
|
#include "packager/media/base/video_stream_info.h"
|
|
#include "packager/media/codecs/video_slice_header_parser.h"
|
|
#include "packager/media/codecs/vp8_parser.h"
|
|
#include "packager/media/codecs/vp9_parser.h"
|
|
|
|
namespace shaka {
|
|
namespace media {
|
|
|
|
namespace {
|
|
const size_t kCencBlockSize = 16u;
|
|
|
|
// Adds one or more subsamples to |*subsamples|. This may add more than one
|
|
// if one of the values overflows the integer in the subsample.
|
|
void AddSubsample(uint64_t clear_bytes,
|
|
uint64_t cipher_bytes,
|
|
DecryptConfig* decrypt_config) {
|
|
CHECK_LT(cipher_bytes, std::numeric_limits<uint32_t>::max());
|
|
const uint64_t kUInt16Max = std::numeric_limits<uint16_t>::max();
|
|
while (clear_bytes > kUInt16Max) {
|
|
decrypt_config->AddSubsample(kUInt16Max, 0);
|
|
clear_bytes -= kUInt16Max;
|
|
}
|
|
|
|
if (clear_bytes > 0 || cipher_bytes > 0)
|
|
decrypt_config->AddSubsample(clear_bytes, cipher_bytes);
|
|
}
|
|
|
|
Codec GetVideoCodec(const StreamInfo& stream_info) {
|
|
if (stream_info.stream_type() != kStreamVideo) return kUnknownCodec;
|
|
const VideoStreamInfo& video_stream_info =
|
|
static_cast<const VideoStreamInfo&>(stream_info);
|
|
return video_stream_info.codec();
|
|
}
|
|
|
|
uint8_t GetNaluLengthSize(const StreamInfo& stream_info) {
|
|
if (stream_info.stream_type() != kStreamVideo)
|
|
return 0;
|
|
|
|
const VideoStreamInfo& video_stream_info =
|
|
static_cast<const VideoStreamInfo&>(stream_info);
|
|
return video_stream_info.nalu_length_size();
|
|
}
|
|
|
|
KeySource::TrackType GetTrackTypeForEncryption(const StreamInfo& stream_info,
|
|
uint32_t max_sd_pixels,
|
|
uint32_t max_hd_pixels,
|
|
uint32_t max_uhd1_pixels) {
|
|
if (stream_info.stream_type() == kStreamAudio)
|
|
return KeySource::TRACK_TYPE_AUDIO;
|
|
|
|
if (stream_info.stream_type() != kStreamVideo)
|
|
return KeySource::TRACK_TYPE_UNKNOWN;
|
|
|
|
DCHECK_EQ(kStreamVideo, stream_info.stream_type());
|
|
const VideoStreamInfo& video_stream_info =
|
|
static_cast<const VideoStreamInfo&>(stream_info);
|
|
uint32_t pixels = video_stream_info.width() * video_stream_info.height();
|
|
if (pixels <= max_sd_pixels) {
|
|
return KeySource::TRACK_TYPE_SD;
|
|
} else if (pixels <= max_hd_pixels) {
|
|
return KeySource::TRACK_TYPE_HD;
|
|
} else if (pixels <= max_uhd1_pixels) {
|
|
return KeySource::TRACK_TYPE_UHD1;
|
|
}
|
|
return KeySource::TRACK_TYPE_UHD2;
|
|
}
|
|
} // namespace
|
|
|
|
EncryptionHandler::EncryptionHandler(
|
|
const EncryptionOptions& encryption_options,
|
|
KeySource* key_source)
|
|
: encryption_options_(encryption_options), key_source_(key_source) {}
|
|
|
|
EncryptionHandler::~EncryptionHandler() {}
|
|
|
|
Status EncryptionHandler::InitializeInternal() {
|
|
if (num_input_streams() != 1 || next_output_stream_index() != 1) {
|
|
return Status(error::INVALID_ARGUMENT,
|
|
"Expects exactly one input and output.");
|
|
}
|
|
return Status::OK;
|
|
}
|
|
|
|
Status EncryptionHandler::Process(std::unique_ptr<StreamData> stream_data) {
|
|
Status status;
|
|
switch (stream_data->stream_data_type) {
|
|
case StreamDataType::kStreamInfo:
|
|
status = ProcessStreamInfo(stream_data->stream_info.get());
|
|
break;
|
|
case StreamDataType::kSegmentInfo:
|
|
new_segment_ = true;
|
|
if (remaining_clear_lead_ > 0)
|
|
remaining_clear_lead_ -= stream_data->segment_info->duration;
|
|
else
|
|
stream_data->segment_info->is_encrypted = true;
|
|
break;
|
|
case StreamDataType::kMediaSample:
|
|
status = ProcessMediaSample(stream_data->media_sample.get());
|
|
break;
|
|
default:
|
|
VLOG(3) << "Stream data type "
|
|
<< static_cast<int>(stream_data->stream_data_type) << " ignored.";
|
|
break;
|
|
}
|
|
return status.ok() ? Dispatch(std::move(stream_data)) : status;
|
|
}
|
|
|
|
Status EncryptionHandler::ProcessStreamInfo(StreamInfo* stream_info) {
|
|
if (stream_info->is_encrypted()) {
|
|
return Status(error::INVALID_ARGUMENT,
|
|
"Input stream is already encrypted.");
|
|
}
|
|
|
|
remaining_clear_lead_ =
|
|
encryption_options_.clear_lead_in_seconds * stream_info->time_scale();
|
|
crypto_period_duration_ =
|
|
encryption_options_.crypto_period_duration_in_seconds *
|
|
stream_info->time_scale();
|
|
nalu_length_size_ = GetNaluLengthSize(*stream_info);
|
|
video_codec_ = GetVideoCodec(*stream_info);
|
|
track_type_ = GetTrackTypeForEncryption(
|
|
*stream_info, encryption_options_.max_sd_pixels,
|
|
encryption_options_.max_hd_pixels, encryption_options_.max_uhd1_pixels);
|
|
switch (video_codec_) {
|
|
case kCodecVP8:
|
|
vpx_parser_.reset(new VP8Parser);
|
|
break;
|
|
case kCodecVP9:
|
|
vpx_parser_.reset(new VP9Parser);
|
|
break;
|
|
case kCodecH264:
|
|
header_parser_.reset(new H264VideoSliceHeaderParser);
|
|
break;
|
|
case kCodecHVC1:
|
|
FALLTHROUGH_INTENDED;
|
|
case kCodecHEV1:
|
|
header_parser_.reset(new H265VideoSliceHeaderParser);
|
|
break;
|
|
default:
|
|
// Expect an audio codec with nalu length size == 0.
|
|
if (nalu_length_size_ > 0) {
|
|
LOG(WARNING) << "Unknown video codec '" << video_codec_ << "'";
|
|
return Status(error::ENCRYPTION_FAILURE, "Unknown video codec.");
|
|
}
|
|
}
|
|
if (header_parser_ &&
|
|
!header_parser_->Initialize(stream_info->codec_config())) {
|
|
return Status(error::ENCRYPTION_FAILURE, "Fail to read SPS and PPS data.");
|
|
}
|
|
|
|
// Set up protection pattern.
|
|
if (encryption_options_.protection_scheme == FOURCC_cbcs ||
|
|
encryption_options_.protection_scheme == FOURCC_cens) {
|
|
if (stream_info->stream_type() == kStreamVideo) {
|
|
// Use 1:9 pattern for video.
|
|
crypt_byte_block_ = 1u;
|
|
skip_byte_block_ = 9u;
|
|
} else {
|
|
// Tracks other than video are protected using whole-block full-sample
|
|
// encryption, which is essentially a pattern of 1:0. Note that this may
|
|
// not be the same as the non-pattern based encryption counterparts, e.g.
|
|
// in 'cens' for full sample encryption, the whole sample is encrypted up
|
|
// to the last 16-byte boundary, see 23001-7:2016(E) 9.7; while in 'cenc'
|
|
// for full sample encryption, the last partial 16-byte block is also
|
|
// encrypted, see 23001-7:2016(E) 9.4.2. Another difference is the use of
|
|
// constant iv.
|
|
crypt_byte_block_ = 1u;
|
|
skip_byte_block_ = 0u;
|
|
}
|
|
} else {
|
|
// Not using pattern encryption.
|
|
crypt_byte_block_ = 0u;
|
|
skip_byte_block_ = 0u;
|
|
}
|
|
|
|
stream_info->set_is_encrypted(true);
|
|
return Status::OK;
|
|
}
|
|
|
|
Status EncryptionHandler::ProcessMediaSample(MediaSample* sample) {
|
|
// We need to parse the frame (which also updates the vpx parser) even if the
|
|
// frame is not encrypted as the next (encrypted) frame may be dependent on
|
|
// this clear frame.
|
|
std::vector<VPxFrameInfo> vpx_frames;
|
|
if (vpx_parser_ &&
|
|
!vpx_parser_->Parse(sample->data(), sample->data_size(), &vpx_frames)) {
|
|
return Status(error::ENCRYPTION_FAILURE, "Failed to parse vpx frame.");
|
|
}
|
|
if (remaining_clear_lead_ > 0)
|
|
return Status::OK;
|
|
|
|
Status status;
|
|
if (new_segment_) {
|
|
EncryptionKey encryption_key;
|
|
bool create_encryptor = false;
|
|
if (crypto_period_duration_ != 0) {
|
|
const int64_t current_crypto_period_index =
|
|
sample->dts() / crypto_period_duration_;
|
|
if (current_crypto_period_index != prev_crypto_period_index_) {
|
|
status = key_source_->GetCryptoPeriodKey(current_crypto_period_index,
|
|
track_type_, &encryption_key);
|
|
if (!status.ok())
|
|
return status;
|
|
create_encryptor = true;
|
|
}
|
|
} else if (!encryptor_) {
|
|
status = key_source_->GetKey(track_type_, &encryption_key);
|
|
if (!status.ok())
|
|
return status;
|
|
create_encryptor = true;
|
|
}
|
|
if (create_encryptor && !CreateEncryptor(&encryption_key))
|
|
return Status(error::ENCRYPTION_FAILURE, "Failed to create encryptor");
|
|
new_segment_ = false;
|
|
}
|
|
|
|
std::unique_ptr<DecryptConfig> decrypt_config(new DecryptConfig(
|
|
key_id_, encryptor_->iv(), std::vector<SubsampleEntry>(),
|
|
encryption_options_.protection_scheme, crypt_byte_block_,
|
|
skip_byte_block_));
|
|
if (vpx_parser_) {
|
|
if (!EncryptVpxFrame(vpx_frames, sample, decrypt_config.get()))
|
|
return Status(error::ENCRYPTION_FAILURE, "Failed to encrypt VPx frames.");
|
|
DCHECK_EQ(decrypt_config->GetTotalSizeOfSubsamples(), sample->data_size());
|
|
} else if (nalu_length_size_ > 0) {
|
|
if (!EncryptNalFrame(sample, decrypt_config.get())) {
|
|
return Status(error::ENCRYPTION_FAILURE,
|
|
"Failed to encrypt video frames.");
|
|
}
|
|
DCHECK_EQ(decrypt_config->GetTotalSizeOfSubsamples(), sample->data_size());
|
|
} else {
|
|
DCHECK_LE(crypt_byte_block_, 1u);
|
|
DCHECK_EQ(skip_byte_block_, 0u);
|
|
EncryptBytes(sample->writable_data(), sample->data_size());
|
|
}
|
|
sample->set_decrypt_config(std::move(decrypt_config));
|
|
encryptor_->UpdateIv();
|
|
return Status::OK;
|
|
}
|
|
|
|
bool EncryptionHandler::CreateEncryptor(EncryptionKey* encryption_key) {
|
|
std::unique_ptr<AesCryptor> encryptor;
|
|
switch (encryption_options_.protection_scheme) {
|
|
case FOURCC_cenc:
|
|
encryptor.reset(new AesCtrEncryptor);
|
|
break;
|
|
case FOURCC_cbc1:
|
|
encryptor.reset(new AesCbcEncryptor(kNoPadding));
|
|
break;
|
|
case FOURCC_cens:
|
|
encryptor.reset(new AesPatternCryptor(
|
|
crypt_byte_block_, skip_byte_block_,
|
|
AesPatternCryptor::kEncryptIfCryptByteBlockRemaining,
|
|
AesCryptor::kDontUseConstantIv,
|
|
std::unique_ptr<AesCryptor>(new AesCtrEncryptor())));
|
|
break;
|
|
case FOURCC_cbcs:
|
|
encryptor.reset(new AesPatternCryptor(
|
|
crypt_byte_block_, skip_byte_block_,
|
|
AesPatternCryptor::kEncryptIfCryptByteBlockRemaining,
|
|
AesCryptor::kUseConstantIv,
|
|
std::unique_ptr<AesCryptor>(new AesCbcEncryptor(kNoPadding))));
|
|
break;
|
|
default:
|
|
LOG(ERROR) << "Unsupported protection scheme.";
|
|
return false;
|
|
}
|
|
|
|
if (encryption_key->iv.empty()) {
|
|
if (!AesCryptor::GenerateRandomIv(encryption_options_.protection_scheme,
|
|
&encryption_key->iv)) {
|
|
LOG(ERROR) << "Failed to generate random iv.";
|
|
return false;
|
|
}
|
|
}
|
|
const bool initialized =
|
|
encryptor->InitializeWithIv(encryption_key->key, encryption_key->iv);
|
|
encryptor_ = std::move(encryptor);
|
|
key_id_ = encryption_key->key_id;
|
|
return initialized;
|
|
}
|
|
|
|
bool EncryptionHandler::EncryptVpxFrame(const std::vector<VPxFrameInfo>& vpx_frames,
|
|
MediaSample* sample,
|
|
DecryptConfig* decrypt_config) {
|
|
uint8_t* data = sample->writable_data();
|
|
const bool is_superframe = vpx_frames.size() > 1;
|
|
for (const VPxFrameInfo& frame : vpx_frames) {
|
|
uint16_t clear_bytes =
|
|
static_cast<uint16_t>(frame.uncompressed_header_size);
|
|
uint32_t cipher_bytes = static_cast<uint32_t>(
|
|
frame.frame_size - frame.uncompressed_header_size);
|
|
|
|
// "VP Codec ISO Media File Format Binding" document requires that the
|
|
// encrypted bytes of each frame within the superframe must be block
|
|
// aligned so that the counter state can be computed for each frame
|
|
// within the superframe.
|
|
// ISO/IEC 23001-7:2016 10.2 'cbc1' 10.3 'cens'
|
|
// The BytesOfProtectedData size SHALL be a multiple of 16 bytes to
|
|
// avoid partial blocks in Subsamples.
|
|
if (is_superframe || encryption_options_.protection_scheme == FOURCC_cbc1 ||
|
|
encryption_options_.protection_scheme == FOURCC_cens) {
|
|
const uint16_t misalign_bytes = cipher_bytes % kCencBlockSize;
|
|
clear_bytes += misalign_bytes;
|
|
cipher_bytes -= misalign_bytes;
|
|
}
|
|
|
|
decrypt_config->AddSubsample(clear_bytes, cipher_bytes);
|
|
if (cipher_bytes > 0)
|
|
EncryptBytes(data + clear_bytes, cipher_bytes);
|
|
data += frame.frame_size;
|
|
}
|
|
// Add subsample for the superframe index if exists.
|
|
if (is_superframe) {
|
|
size_t index_size = sample->data() + sample->data_size() - data;
|
|
DCHECK_LE(index_size, 2 + vpx_frames.size() * 4);
|
|
DCHECK_GE(index_size, 2 + vpx_frames.size() * 1);
|
|
uint16_t clear_bytes = static_cast<uint16_t>(index_size);
|
|
uint32_t cipher_bytes = 0;
|
|
decrypt_config->AddSubsample(clear_bytes, cipher_bytes);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool EncryptionHandler::EncryptNalFrame(MediaSample* sample,
|
|
DecryptConfig* decrypt_config) {
|
|
const Nalu::CodecType nalu_type =
|
|
(video_codec_ == kCodecHVC1 || video_codec_ == kCodecHEV1) ? Nalu::kH265
|
|
: Nalu::kH264;
|
|
NaluReader reader(nalu_type, nalu_length_size_, sample->writable_data(),
|
|
sample->data_size());
|
|
|
|
// Store the current length of clear data. This is used to squash
|
|
// multiple unencrypted NAL units into fewer subsample entries.
|
|
uint64_t accumulated_clear_bytes = 0;
|
|
|
|
Nalu nalu;
|
|
NaluReader::Result result;
|
|
while ((result = reader.Advance(&nalu)) == NaluReader::kOk) {
|
|
if (nalu.is_video_slice()) {
|
|
// For video-slice NAL units, encrypt the video slice. This skips
|
|
// the frame header. If this is an unrecognized codec, the whole NAL unit
|
|
// will be encrypted.
|
|
const int64_t video_slice_header_size =
|
|
header_parser_ ? header_parser_->GetHeaderSize(nalu) : 0;
|
|
if (video_slice_header_size < 0) {
|
|
LOG(ERROR) << "Failed to read slice header.";
|
|
return false;
|
|
}
|
|
|
|
uint64_t current_clear_bytes =
|
|
nalu.header_size() + video_slice_header_size;
|
|
uint64_t cipher_bytes = nalu.payload_size() - video_slice_header_size;
|
|
|
|
// ISO/IEC 23001-7:2016 10.2 'cbc1' 10.3 'cens'
|
|
// The BytesOfProtectedData size SHALL be a multiple of 16 bytes to
|
|
// avoid partial blocks in Subsamples.
|
|
if (encryption_options_.protection_scheme == FOURCC_cbc1 ||
|
|
encryption_options_.protection_scheme == FOURCC_cens) {
|
|
const uint16_t misalign_bytes = cipher_bytes % kCencBlockSize;
|
|
current_clear_bytes += misalign_bytes;
|
|
cipher_bytes -= misalign_bytes;
|
|
}
|
|
|
|
const uint8_t* nalu_data = nalu.data() + current_clear_bytes;
|
|
EncryptBytes(const_cast<uint8_t*>(nalu_data), cipher_bytes);
|
|
|
|
AddSubsample(
|
|
accumulated_clear_bytes + nalu_length_size_ + current_clear_bytes,
|
|
cipher_bytes, decrypt_config);
|
|
accumulated_clear_bytes = 0;
|
|
} else {
|
|
// For non-video-slice NAL units, don't encrypt.
|
|
accumulated_clear_bytes +=
|
|
nalu_length_size_ + nalu.header_size() + nalu.payload_size();
|
|
}
|
|
}
|
|
if (result != NaluReader::kEOStream) {
|
|
LOG(ERROR) << "Failed to parse NAL units.";
|
|
return false;
|
|
}
|
|
AddSubsample(accumulated_clear_bytes, 0, decrypt_config);
|
|
return true;
|
|
}
|
|
|
|
void EncryptionHandler::EncryptBytes(uint8_t* data, size_t size) {
|
|
DCHECK(encryptor_);
|
|
CHECK(encryptor_->Crypt(data, size, data));
|
|
}
|
|
|
|
void EncryptionHandler::InjectVpxParserForTesting(
|
|
std::unique_ptr<VPxParser> vpx_parser) {
|
|
vpx_parser_ = std::move(vpx_parser);
|
|
}
|
|
|
|
void EncryptionHandler::InjectVideoSliceHeaderParserForTesting(
|
|
std::unique_ptr<VideoSliceHeaderParser> header_parser) {
|
|
header_parser_ = std::move(header_parser);
|
|
}
|
|
|
|
} // namespace media
|
|
} // namespace shaka
|