135 lines
4.3 KiB
C++
135 lines
4.3 KiB
C++
// Copyright 2015 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/formats/webm/encryptor.h"
|
|
|
|
#include "packager/media/base/aes_encryptor.h"
|
|
#include "packager/media/base/media_sample.h"
|
|
|
|
namespace edash_packager {
|
|
namespace media {
|
|
namespace webm {
|
|
namespace {
|
|
|
|
// Generate 64bit IV by default.
|
|
const size_t kDefaultIvSize = 8u;
|
|
|
|
Status CreateContentEncryption(mkvmuxer::Track* track, EncryptionKey* key) {
|
|
if (!track->AddContentEncoding()) {
|
|
return Status(error::INTERNAL_ERROR,
|
|
"Could not add ContentEncoding to track.");
|
|
}
|
|
|
|
mkvmuxer::ContentEncoding* const encoding =
|
|
track->GetContentEncodingByIndex(0);
|
|
if (!encoding) {
|
|
return Status(error::INTERNAL_ERROR,
|
|
"Could not add ContentEncoding to track.");
|
|
}
|
|
|
|
mkvmuxer::ContentEncAESSettings* const aes = encoding->enc_aes_settings();
|
|
if (!aes) {
|
|
return Status(error::INTERNAL_ERROR,
|
|
"Error getting ContentEncAESSettings.");
|
|
}
|
|
if (aes->cipher_mode() != mkvmuxer::ContentEncAESSettings::kCTR) {
|
|
return Status(error::INTERNAL_ERROR, "Cipher Mode is not CTR.");
|
|
}
|
|
|
|
if (!key->key_id.empty() &&
|
|
!encoding->SetEncryptionID(
|
|
reinterpret_cast<const uint8*>(key->key_id.data()),
|
|
key->key_id.size())) {
|
|
return Status(error::INTERNAL_ERROR, "Error setting encryption ID.");
|
|
}
|
|
return Status::OK;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
Encryptor::Encryptor() {}
|
|
|
|
Encryptor::~Encryptor() {}
|
|
|
|
Status Encryptor::Initialize(MuxerListener* muxer_listener,
|
|
KeySource::TrackType track_type,
|
|
KeySource* key_source) {
|
|
DCHECK(key_source);
|
|
return CreateEncryptor(muxer_listener, track_type, key_source);
|
|
}
|
|
|
|
Status Encryptor::AddTrackInfo(mkvmuxer::Track* track) {
|
|
DCHECK(key_);
|
|
return CreateContentEncryption(track, key_.get());
|
|
}
|
|
|
|
Status Encryptor::EncryptFrame(scoped_refptr<MediaSample> sample,
|
|
bool encrypt_frame) {
|
|
DCHECK(encryptor_);
|
|
|
|
const size_t sample_size = sample->data_size();
|
|
if (encrypt_frame) {
|
|
// | 1 | iv | enc_data |
|
|
const size_t iv_size = encryptor_->iv().size();
|
|
sample->resize_data(sample_size + iv_size + 1);
|
|
uint8_t* sample_data = sample->writable_data();
|
|
|
|
// Encrypt the data in-place.
|
|
if (!encryptor_->Crypt(sample_data, sample_size, sample_data)) {
|
|
return Status(error::MUXER_FAILURE, "Failed to encrypt the frame.");
|
|
}
|
|
|
|
// First move the sample data to after the IV; then write the IV and signal
|
|
// byte.
|
|
memmove(sample_data + iv_size + 1, sample_data, sample_size);
|
|
sample_data[0] = 0x01;
|
|
memcpy(sample_data + 1, encryptor_->iv().data(), iv_size);
|
|
|
|
encryptor_->UpdateIv();
|
|
} else {
|
|
// | 0 | data |
|
|
sample->resize_data(sample_size + 1);
|
|
uint8_t* sample_data = sample->writable_data();
|
|
memmove(sample_data + 1, sample_data, sample_size);
|
|
sample_data[0] = 0x00;
|
|
}
|
|
|
|
return Status::OK;
|
|
}
|
|
|
|
Status Encryptor::CreateEncryptor(MuxerListener* muxer_listener,
|
|
KeySource::TrackType track_type,
|
|
KeySource* key_source) {
|
|
scoped_ptr<EncryptionKey> encryption_key(new EncryptionKey());
|
|
Status status = key_source->GetKey(track_type, encryption_key.get());
|
|
if (!status.ok())
|
|
return status;
|
|
|
|
scoped_ptr<AesCtrEncryptor> encryptor(new AesCtrEncryptor());
|
|
const bool initialized = encryption_key->iv.empty()
|
|
? encryptor->InitializeWithRandomIv(
|
|
encryption_key->key, kDefaultIvSize)
|
|
: encryptor->InitializeWithIv(
|
|
encryption_key->key, encryption_key->iv);
|
|
if (!initialized)
|
|
return Status(error::INTERNAL_ERROR, "Failed to create the encryptor.");
|
|
|
|
if (muxer_listener) {
|
|
const bool kInitialEncryptionInfo = true;
|
|
muxer_listener->OnEncryptionInfoReady(kInitialEncryptionInfo,
|
|
encryption_key->key_id,
|
|
encryption_key->key_system_info);
|
|
}
|
|
|
|
key_ = encryption_key.Pass();
|
|
encryptor_ = encryptor.Pass();
|
|
return Status::OK;
|
|
}
|
|
|
|
} // namespace webm
|
|
} // namespace media
|
|
} // namespace edash_packager
|