key_source.h

// Copyright 2014 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

#ifndef MEDIA_BASE_KEY_SOURCE_H_
#define MEDIA_BASE_KEY_SOURCE_H_

#include <string>
#include <vector>

#include "packager/base/memory/scoped_ptr.h"
#include "packager/media/base/protection_system_specific_info.h"
#include "packager/media/base/status.h"

namespace edash_packager {
namespace media {

const uint8_t kWidevineSystemId[] = {0xed, 0xef, 0x8b, 0xa9, 0x79, 0xd6,
                                     0x4a, 0xce, 0xa3, 0xc8, 0x27, 0xdc,
                                     0xd5, 0x1d, 0x21, 0xed};

struct EncryptionKey {
  EncryptionKey();
  ~EncryptionKey();

  std::vector<ProtectionSystemSpecificInfo> key_system_info;
  std::vector<uint8_t> key_id;
  std::vector<uint8_t> key;
  std::vector<uint8_t> iv;
};

class KeySource {
 public:
  enum TrackType {
    TRACK_TYPE_UNKNOWN = 0,
    TRACK_TYPE_SD = 1,
    TRACK_TYPE_HD = 2,
    TRACK_TYPE_AUDIO = 3,
    TRACK_TYPE_UNSPECIFIED = 4,
    NUM_VALID_TRACK_TYPES = 4
  };

  virtual ~KeySource();

  virtual Status FetchKeys(const std::vector<uint8_t>& content_id,
                           const std::string& policy);

  virtual Status FetchKeys(const std::vector<uint8_t>& pssh_box);

  virtual Status FetchKeys(const std::vector<std::vector<uint8_t>>& key_ids);

  virtual Status FetchKeys(uint32_t asset_id);

  virtual Status GetKey(TrackType track_type, EncryptionKey* key);

  virtual Status GetKey(const std::vector<uint8_t>& key_id, EncryptionKey* key);

  virtual Status GetCryptoPeriodKey(uint32_t crypto_period_index,
                                    TrackType track_type,
                                    EncryptionKey* key);

  static scoped_ptr<KeySource> CreateFromHexStrings(
      const std::string& key_id_hex,
      const std::string& key_hex,
      const std::string& pssh_data_hex,
      const std::string& iv_hex);

  static TrackType GetTrackTypeFromString(const std::string& track_type_string);

  static std::string TrackTypeToString(TrackType track_type);

 protected:
  KeySource();

 private:
  explicit KeySource(scoped_ptr<EncryptionKey> encryption_key);

  scoped_ptr<EncryptionKey> encryption_key_;

  DISALLOW_COPY_AND_ASSIGN(KeySource);
};

}  // namespace media
}  // namespace edash_packager

#endif  // MEDIA_BASE_KEY_SOURCE_H_