components/sync/nigori/nigori_sync_bridge_impl.h

// Copyright 2019 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 COMPONENTS_SYNC_NIGORI_NIGORI_SYNC_BRIDGE_IMPL_H_
#define COMPONENTS_SYNC_NIGORI_NIGORI_SYNC_BRIDGE_IMPL_H_

#include <memory>
#include <string>
#include <vector>

#include "base/macros.h"
#include "base/optional.h"
#include "base/sequence_checker.h"
#include "components/sync/base/cryptographer.h"
#include "components/sync/engine/sync_encryption_handler.h"
#include "components/sync/model/conflict_resolution.h"
#include "components/sync/model/model_error.h"
#include "components/sync/nigori/keystore_keys_handler.h"
#include "components/sync/nigori/nigori_sync_bridge.h"

namespace syncer {

class Encryptor;

// USS implementation of SyncEncryptionHandler.
// This class holds the current Nigori state and processes incoming changes and
// queries:
// 1. Serves observers of SyncEncryptionHandler interface.
// 2. Allows the passphrase manipulations (via SyncEncryptionHandler).
// 3. Communicates local and remote changes with a processor (via
// NigoriSyncBridge).
// 4. Handles keystore keys from a sync server (via KeystoreKeysHandler).
class NigoriSyncBridgeImpl : public KeystoreKeysHandler,
                             public NigoriSyncBridge,
                             public SyncEncryptionHandler {
 public:
  // |encryptor| must not be null and must outlive this object and any copies
  // of the Cryptographer exposed by this object.
  explicit NigoriSyncBridgeImpl(Encryptor* encryptor);
  ~NigoriSyncBridgeImpl() override;

  // SyncEncryptionHandler implementation.
  void AddObserver(Observer* observer) override;
  void RemoveObserver(Observer* observer) override;
  void Init() override;
  void SetEncryptionPassphrase(const std::string& passphrase) override;
  void SetDecryptionPassphrase(const std::string& passphrase) override;
  void EnableEncryptEverything() override;
  bool IsEncryptEverythingEnabled() const override;

  // KeystoreKeysHandler implementation.
  bool NeedKeystoreKey() const override;
  bool SetKeystoreKeys(const std::vector<std::string>& keys) override;

  // NigoriSyncBridge implementation.
  base::Optional<ModelError> MergeSyncData(
      const base::Optional<EntityData>& data) override;
  base::Optional<ModelError> ApplySyncChanges(const EntityData& data) override;
  std::unique_ptr<EntityData> GetData() override;
  ConflictResolution ResolveConflict(const EntityData& local_data,
                                     const EntityData& remote_data) override;
  void ApplyDisableSyncChanges() override;

  // TODO(crbug.com/922900): investigate whether we need this getter outside of
  // tests and decide whether this method should be a part of
  // SyncEncryptionHandler interface.
  const Cryptographer& GetCryptographerForTesting() const;

 private:
  // Base64 encoded keystore keys. The last element is the current keystore
  // key. These keys are not a part of Nigori node and are persisted
  // separately. Should be encrypted with OSCrypt before persisting.
  std::vector<std::string> keystore_keys_;

  Cryptographer cryptographer_;

  SEQUENCE_CHECKER(sequence_checker_);

  DISALLOW_COPY_AND_ASSIGN(NigoriSyncBridgeImpl);
};

}  // namespace syncer

#endif  // COMPONENTS_SYNC_NIGORI_NIGORI_SYNC_BRIDGE_IMPL_H_