shaka-packager/packager/media/crypto/encryption_handler.h

102 lines
3.7 KiB
C++

// Copyright 2017 Google LLC. 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
#ifndef PACKAGER_MEDIA_CRYPTO_ENCRYPTION_HANDLER_H_
#define PACKAGER_MEDIA_CRYPTO_ENCRYPTION_HANDLER_H_
#include <packager/media/base/key_source.h>
#include <packager/media/base/media_handler.h>
#include <packager/media/public/crypto_params.h>
namespace shaka {
namespace media {
class AesCryptor;
class AesEncryptorFactory;
class SubsampleGenerator;
struct EncryptionKey;
class EncryptionHandler : public MediaHandler {
public:
EncryptionHandler(const EncryptionParams& encryption_params,
KeySource* key_source);
~EncryptionHandler() override;
protected:
/// @name MediaHandler implementation overrides.
/// @{
Status InitializeInternal() override;
Status Process(std::unique_ptr<StreamData> stream_data) override;
/// @}
private:
friend class EncryptionHandlerTest;
EncryptionHandler(const EncryptionHandler&) = delete;
EncryptionHandler& operator=(const EncryptionHandler&) = delete;
// Processes |stream_info| and sets up stream specific variables.
Status ProcessStreamInfo(const StreamInfo& stream_info);
// Processes media sample and encrypts it if needed.
Status ProcessMediaSample(std::shared_ptr<const MediaSample> clear_sample);
void SetupProtectionPattern(StreamType stream_type);
bool CreateEncryptor(const EncryptionKey& encryption_key);
// Encrypt an E-AC3 frame with size |source_size| according to SAMPLE-AES
// specification. |dest| should have at least |source_size| bytes.
bool SampleAesEncryptEac3Frame(const uint8_t* source,
size_t source_size,
uint8_t* dest);
// Encrypt an array with size |source_size|. |dest| should have at
// least |source_size| bytes.
void EncryptBytes(const uint8_t* source,
size_t source_size,
uint8_t* dest,
size_t dest_size);
// An E-AC3 frame comprises of one or more syncframes. This function extracts
// the syncframe sizes from the source bytes.
// Returns false if the frame is not well formed.
bool ExtractEac3SyncframeSizes(const uint8_t* source,
size_t source_size,
std::vector<size_t>* syncframe_sizes);
// Testing injections.
void InjectSubsampleGeneratorForTesting(
std::unique_ptr<SubsampleGenerator> generator);
void InjectEncryptorFactoryForTesting(
std::unique_ptr<AesEncryptorFactory> encryptor_factory);
const EncryptionParams encryption_params_;
const FourCC protection_scheme_ = FOURCC_NULL;
KeySource* key_source_ = nullptr;
std::string stream_label_;
// Current encryption config and encryptor.
std::shared_ptr<EncryptionConfig> encryption_config_;
std::unique_ptr<AesCryptor> encryptor_;
Codec codec_ = kUnknownCodec;
// Remaining clear lead in the stream's time scale.
int64_t remaining_clear_lead_ = 0;
// Crypto period duration in the stream's time scale.
int64_t crypto_period_duration_ = 0;
// Previous crypto period index if key rotation is enabled.
int64_t prev_crypto_period_index_ = -1;
bool check_new_crypto_period_ = false;
std::unique_ptr<SubsampleGenerator> subsample_generator_;
std::unique_ptr<AesEncryptorFactory> encryptor_factory_;
// Number of encrypted blocks (16-byte-block) in pattern based encryption.
uint8_t crypt_byte_block_ = 0;
/// Number of unencrypted blocks (16-byte-block) in pattern based encryption.
uint8_t skip_byte_block_ = 0;
};
} // namespace media
} // namespace shaka
#endif // PACKAGER_MEDIA_CRYPTO_ENCRYPTION_HANDLER_H_