[Sync] Move 'sync' target to sync/

chrome/browser/sync/util/cryptographer.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 CHROME_BROWSER_SYNC_UTIL_CRYPTOGRAPHER_H_
-#define CHROME_BROWSER_SYNC_UTIL_CRYPTOGRAPHER_H_
-#pragma once
-
-#include <map>
-#include <string>
-
-#include "base/gtest_prod_util.h"
-#include "base/memory/linked_ptr.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/observer_list.h"
-#include "chrome/browser/sync/syncable/model_type.h"
-#include "chrome/browser/sync/util/nigori.h"
-#include "sync/protocol/encryption.pb.h"
-#include "sync/protocol/nigori_specifics.pb.h"
-
-namespace browser_sync {
-
-class Encryptor;
-
-extern const char kNigoriTag[];
-
-// The parameters used to initialize a Nigori instance.
-struct KeyParams {
-  std::string hostname;
-  std::string username;
-  std::string password;
-};
-
-// This class manages the Nigori objects used to encrypt and decrypt sensitive
-// sync data (eg. passwords). Each Nigori object knows how to handle data
-// protected with a particular passphrase.
-//
-// Whenever an update to the Nigori sync node is received from the server,
-// SetPendingKeys should be called with the encrypted contents of that node.
-// Most likely, an updated Nigori node means that a new passphrase has been set
-// and that future node updates won't be decryptable. To remedy this, the user
-// should be prompted for the new passphrase and DecryptPendingKeys be called.
-//
-// Whenever a update to an encrypted node is received from the server,
-// CanDecrypt should be used to verify whether the Cryptographer can decrypt
-// that node. If it cannot, then the application of that update should be
-// delayed until after it can be decrypted.
-class Cryptographer {
- public:
-  // All Observer methods are done synchronously, so they're called
-  // under a transaction (since all Cryptographer operations are done
-  // under a transaction).
-  class Observer {
-   public:
-    // Called when the set of encrypted types or the encrypt
-    // everything flag has been changed.  Note that this doesn't
-    // necessarily mean that encryption has completed for the given
-    // types.
-    //
-    // |encrypted_types| will always be a superset of
-    // SensitiveTypes().  If |encrypt_everything| is true,
-    // |encrypted_types| will be the set of all known types.
-    //
-    // Until this function is called, observers can assume that the
-    // set of encrypted types is SensitiveTypes() and that the encrypt
-    // everything flag is false.
-    virtual void OnEncryptedTypesChanged(
-        syncable::ModelTypeSet encrypted_types,
-        bool encrypt_everything) = 0;
-
-   protected:
-    virtual ~Observer();
-  };
-
-  // Does not take ownership of |encryptor|.
-  explicit Cryptographer(Encryptor* encryptor);
-  ~Cryptographer();
-
-  // When update on cryptographer is called this enum tells if the
-  // cryptographer was succesfully able to update using the nigori node or if
-  // it needs a key to decrypt the nigori node.
-  enum UpdateResult {
-    SUCCESS,
-    NEEDS_PASSPHRASE
-  };
-
-  // Manage observers.
-  void AddObserver(Observer* observer);
-  void RemoveObserver(Observer* observer);
-
-  // |restored_bootstrap_token| can be provided via this method to bootstrap
-  // Cryptographer instance into the ready state (is_ready will be true).
-  // It must be a string that was previously built by the
-  // GetSerializedBootstrapToken function.  It is possible that the token is no
-  // longer valid (due to server key change), in which case the normal
-  // decryption code paths will fail and the user will need to provide a new
-  // passphrase.
-  // It is an error to call this if is_ready() == true, though it is fair to
-  // never call Bootstrap at all.
-  void Bootstrap(const std::string& restored_bootstrap_token);
-
-  // Returns whether we can decrypt |encrypted| using the keys we currently know
-  // about.
-  bool CanDecrypt(const sync_pb::EncryptedData& encrypted) const;
-
-  // Returns whether |encrypted| can be decrypted using the default encryption
-  // key.
-  bool CanDecryptUsingDefaultKey(const sync_pb::EncryptedData& encrypted) const;
-
-  // Encrypts |message| into |encrypted|. Does not overwrite |encrypted| if
-  // |message| already matches the decrypted data within |encrypted| and
-  // |encrypted| was encrypted with the current default key. This avoids
-  // unnecessarily modifying |encrypted| if the change had no practical effect.
-  // Returns true unless encryption fails or |message| isn't valid (e.g. a
-  // required field isn't set).
-  bool Encrypt(const ::google::protobuf::MessageLite& message,
-               sync_pb::EncryptedData* encrypted) const;
-
-  // Decrypts |encrypted| into |message|. Returns true unless decryption fails,
-  // or |message| fails to parse the decrypted data.
-  bool Decrypt(const sync_pb::EncryptedData& encrypted,
-               ::google::protobuf::MessageLite* message) const;
-
-  // Decrypts |encrypted| and returns plaintext decrypted data. If decryption
-  // fails, returns empty string.
-  std::string DecryptToString(const sync_pb::EncryptedData& encrypted) const;
-
-  // Encrypts the set of currently known keys into |encrypted|. Returns true if
-  // successful.
-  bool GetKeys(sync_pb::EncryptedData* encrypted) const;
-
-  // Creates a new Nigori instance using |params|. If successful, |params| will
-  // become the default encryption key and be used for all future calls to
-  // Encrypt.
-  bool AddKey(const KeyParams& params);
-
-  // Same as AddKey(..), but builds the new Nigori from a previously persisted
-  // bootstrap token. This can be useful when consuming a bootstrap token
-  // with a cryptographer that has already been initialized.
-  bool AddKeyFromBootstrapToken(const std::string restored_bootstrap_token);
-
-  // Decrypts |encrypted| and uses its contents to initialize Nigori instances.
-  // Returns true unless decryption of |encrypted| fails. The caller is
-  // responsible for checking that CanDecrypt(encrypted) == true.
-  bool SetKeys(const sync_pb::EncryptedData& encrypted);
-
-  // Makes a local copy of |encrypted| to later be decrypted by
-  // DecryptPendingKeys. This should only be used if CanDecrypt(encrypted) ==
-  // false.
-  void SetPendingKeys(const sync_pb::EncryptedData& encrypted);
-
-  // Makes |pending_keys_| available to callers that may want to cache its
-  // value for later use on the UI thread. It is illegal to call this if the
-  // cryptographer has no pending keys. Like other calls that access the
-  // cryptographer, this method must be called from within a transaction.
-  const sync_pb::EncryptedData& GetPendingKeys() const;
-
-  // Attempts to decrypt the set of keys that was copied in the previous call to
-  // SetPendingKeys using |params|. Returns true if the pending keys were
-  // successfully decrypted and installed.
-  bool DecryptPendingKeys(const KeyParams& params);
-
-  bool is_initialized() const { return !nigoris_.empty() && default_nigori_; }
-
-  // Returns whether this Cryptographer is ready to encrypt and decrypt data.
-  bool is_ready() const { return is_initialized() &&
-                          has_pending_keys() == false; }
-
-  // Returns whether there is a pending set of keys that needs to be decrypted.
-  bool has_pending_keys() const { return NULL != pending_keys_.get(); }
-
-  // Obtain a token that can be provided on construction to a future
-  // Cryptographer instance to bootstrap itself.  Returns false if such a token
-  // can't be created (i.e. if this Cryptograhper doesn't have valid keys).
-  bool GetBootstrapToken(std::string* token) const;
-
-  // Update the cryptographer based on the contents of the nigori specifics.
-  // This updates both the encryption keys and the set of encrypted types.
-  // Returns NEEDS_PASSPHRASE if was unable to decrypt the pending keys,
-  // SUCCESS otherwise.
-  UpdateResult Update(const sync_pb::NigoriSpecifics& nigori);
-
-  // The set of types that are always encrypted.
-  static syncable::ModelTypeSet SensitiveTypes();
-
-  // Reset our set of encrypted types based on the contents of the nigori
-  // specifics.
-  void UpdateEncryptedTypesFromNigori(const sync_pb::NigoriSpecifics& nigori);
-
-  // Update the nigori to reflect the current set of encrypted types.
-  void UpdateNigoriFromEncryptedTypes(sync_pb::NigoriSpecifics* nigori) const;
-
-  // Setter/getter for whether all current and future datatypes should
-  // be encrypted. Once set you cannot unset without reading from a
-  // new nigori node.  set_encrypt_everything() emits a notification
-  // the first time it's called.
-  void set_encrypt_everything();
-  bool encrypt_everything() const;
-
-  // Return the set of encrypted types.
-  syncable::ModelTypeSet GetEncryptedTypes() const;
-
-  // Forwards to MergeEncryptedTypes.
-  void MergeEncryptedTypesForTest(
-      syncable::ModelTypeSet encrypted_types);
-
- private:
-  FRIEND_TEST_ALL_PREFIXES(SyncCryptographerTest, PackUnpack);
-  typedef std::map<std::string, linked_ptr<const Nigori> > NigoriMap;
-
-  // Merges the given set of encrypted types with the existing set and emits a
-  // notification if necessary.
-  void MergeEncryptedTypes(syncable::ModelTypeSet encrypted_types);
-
-  void EmitEncryptedTypesChangedNotification();
-
-  // Helper method to instantiate Nigori instances for each set of key
-  // parameters in |bag| and setting the default encryption key to
-  // |default_key_name|.
-  void InstallKeys(const std::string& default_key_name,
-                   const sync_pb::NigoriKeyBag& bag);
-
-  bool AddKeyImpl(Nigori* nigori);
-
-  // Functions to serialize + encrypt a Nigori object in an opaque format for
-  // persistence by sync infrastructure.
-  bool PackBootstrapToken(const Nigori* nigori, std::string* pack_into) const;
-  Nigori* UnpackBootstrapToken(const std::string& token) const;
-
-  Encryptor* const encryptor_;
-
-  ObserverList<Observer> observers_;
-
-  NigoriMap nigoris_;  // The Nigoris we know about, mapped by key name.
-  NigoriMap::value_type* default_nigori_;  // The Nigori used for encryption.
-
-  scoped_ptr<sync_pb::EncryptedData> pending_keys_;
-
-  syncable::ModelTypeSet encrypted_types_;
-  bool encrypt_everything_;
-
-  DISALLOW_COPY_AND_ASSIGN(Cryptographer);
-};
-
-}  // namespace browser_sync
-
-#endif  // CHROME_BROWSER_SYNC_UTIL_CRYPTOGRAPHER_H_