decrypt_config.h

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef PACKAGER_MEDIA_BASE_DECRYPT_CONFIG_H_
#define PACKAGER_MEDIA_BASE_DECRYPT_CONFIG_H_

#include <stdint.h>

#include <string>
#include <vector>

#include "packager/base/macros.h"
#include "packager/media/base/fourccs.h"

namespace shaka {
namespace media {

struct SubsampleEntry {
  SubsampleEntry()
    : clear_bytes(0), cipher_bytes(0) {}
  SubsampleEntry(uint16_t clear_bytes, uint32_t cipher_bytes)
    : clear_bytes(clear_bytes), cipher_bytes(cipher_bytes) {}

  uint16_t clear_bytes;
  uint32_t cipher_bytes;
};

class DecryptConfig {
 public:
  static const size_t kDecryptionKeySize = 16;

  DecryptConfig(const std::vector<uint8_t>& key_id,
                const std::vector<uint8_t>& iv,
                const std::vector<SubsampleEntry>& subsamples);

  DecryptConfig(const std::vector<uint8_t>& key_id,
                const std::vector<uint8_t>& iv,
                const std::vector<SubsampleEntry>& subsamples,
                FourCC protection_scheme,
                uint8_t crypt_byte_block,
                uint8_t skip_byte_block);

  ~DecryptConfig();

  void AddSubsample(uint16_t clear_bytes, uint32_t cipher_bytes) {
    subsamples_.emplace_back(clear_bytes, cipher_bytes);
  }

  size_t GetTotalSizeOfSubsamples() const;

  const std::vector<uint8_t>& key_id() const { return key_id_; }
  const std::vector<uint8_t>& iv() const { return iv_; }
  const std::vector<SubsampleEntry>& subsamples() const { return subsamples_; }
  FourCC protection_scheme() const { return protection_scheme_; }
  uint8_t crypt_byte_block() const { return crypt_byte_block_; }
  uint8_t skip_byte_block() const { return skip_byte_block_; }

 private:
  const std::vector<uint8_t> key_id_;

  // Initialization vector.
  const std::vector<uint8_t> iv_;

  // Subsample information. May be empty for some formats, meaning entire frame
  // (less data ignored by data_offset_) is encrypted.
  std::vector<SubsampleEntry> subsamples_;

  const FourCC protection_scheme_;
  // For pattern-based protection schemes, like CENS and CBCS.
  const uint8_t crypt_byte_block_;
  const uint8_t skip_byte_block_;

  DISALLOW_COPY_AND_ASSIGN(DecryptConfig);
};

}  // namespace media
}  // namespace shaka

#endif  // PACKAGER_MEDIA_BASE_DECRYPT_CONFIG_H_