[Sync] Add support for performing a GetKey on startup.

sync/engine/download_updates_command.cc

 // 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.
 
 #include "sync/engine/download_updates_command.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "sync/engine/syncer.h"
 #include "sync/engine/syncer_proto_util.h"
 #include "sync/internal_api/public/base/model_type_payload_map.h"
 #include "sync/syncable/directory.h"
+#include "sync/syncable/read_transaction.h"
 
 using sync_pb::DebugInfo;
 
 namespace syncer {
 using sessions::StatusController;
 using sessions::SyncSession;
 using std::string;
 
 DownloadUpdatesCommand::DownloadUpdatesCommand(
     bool create_mobile_bookmarks_folder)
     : create_mobile_bookmarks_folder_(create_mobile_bookmarks_folder) {}
 
 DownloadUpdatesCommand::~DownloadUpdatesCommand() {}
 
+namespace {
+
+SyncerError HandleGetEncryptionKeyResponse(
+    const sync_pb::ClientToServerResponse& update_response,
+    syncable::Directory* dir) {
+  bool success = false;
+  if (!update_response.get_updates().has_encryption_key()) {
+    LOG(ERROR) << "Failed to receive encryption key from server.";
+    return SERVER_RESPONSE_VALIDATION_FAILED;
+  }
+  syncable::ReadTransaction trans(FROM_HERE, dir);
+  Cryptographer* cryptographer = dir->GetCryptographer(&trans);
+  success = cryptographer->SetKeystoreKey(
+      update_response.get_updates().encryption_key());
+
+  DVLOG(1) << "GetUpdates returned encryption key of length "
+           << update_response.get_updates().encryption_key().length()
+           << ". Cryptographer keystore key "
+           << (success ? "" : "not ") << "updated.";
+  return (success ? SYNCER_OK : SERVER_RESPONSE_VALIDATION_FAILED);
+}
+
+}  // namespace
+
 SyncerError DownloadUpdatesCommand::ExecuteImpl(SyncSession* session) {
   sync_pb::ClientToServerMessage client_to_server_message;
   sync_pb::ClientToServerResponse update_response;
 
   client_to_server_message.set_share(session->context()->account_name());
   client_to_server_message.set_message_contents(
       sync_pb::ClientToServerMessage::GET_UPDATES);
   sync_pb::GetUpdatesMessage* get_updates =
       client_to_server_message.mutable_get_updates();
   get_updates->set_create_mobile_bookmarks_folder(
@@ skipping 16 matching lines @@
     dir->GetDownloadProgress(it.Get(), progress_marker);
 
     // Set notification hint if present.
     ModelTypePayloadMap::const_iterator type_payload =
         type_payload_map.find(it.Get());
     if (type_payload != type_payload_map.end()) {
       progress_marker->set_notification_hint(type_payload->second);
     }
   }
 
+  bool need_encryption_key = false;
+  if (session->context()->keystore_encryption_enabled()) {
+    syncable::Directory* dir = session->context()->directory();
+    syncable::ReadTransaction trans(FROM_HERE, dir);
+    Cryptographer* cryptographer =
+        session->context()->directory()->GetCryptographer(&trans);
+    need_encryption_key = !cryptographer->HasKeystoreKey();
+    get_updates->set_need_encryption_key(need_encryption_key);
+
+  }
+
   // We want folders for our associated types, always.  If we were to set
   // this to false, the server would send just the non-container items
   // (e.g. Bookmark URLs but not their containing folders).
   get_updates->set_fetch_folders(true);
 
   // Set GetUpdatesMessage.GetUpdatesCallerInfo information.
   get_updates->mutable_caller_info()->set_source(
       session->source().updates_source);
   get_updates->mutable_caller_info()->set_notifications_enabled(
       session->context()->notifications_enabled());
@@ skipping 21 matching lines @@
     return result;
   }
 
   status->mutable_updates_response()->CopyFrom(update_response);
 
   DVLOG(1) << "GetUpdates "
            << " returned " << update_response.get_updates().entries_size()
            << " updates and indicated "
            << update_response.get_updates().changes_remaining()
            << " updates left on server.";
+
+  if (need_encryption_key) {
+    status->set_last_get_key_result(
+        HandleGetEncryptionKeyResponse(update_response, dir));
+  }
+
   return result;
 }
 
 void DownloadUpdatesCommand::AppendClientDebugInfoIfNeeded(
     sessions::SyncSession* session,
     DebugInfo* debug_info) {
   // We want to send the debug info only once per sync cycle. Check if it has
   // already been sent.
   if (!session->status_controller().debug_info_sent()) {
     DVLOG(1) << "Sending client debug info ...";
     // could be null in some unit tests.
     if (session->context()->debug_info_getter()) {
       session->context()->debug_info_getter()->GetAndClearDebugInfo(
           debug_info);
     }
     session->mutable_status_controller()->set_debug_info_sent();
   }
 }
 
 }  // namespace syncer