[Sync] Initial support for encrypting any datatype (no UI hookup yet).

chrome/browser/sync/engine/syncer_util.cc

 // Copyright (c) 2010 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 "chrome/browser/sync/engine/syncer_util.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "chrome/browser/sync/engine/conflict_resolver.h"
 #include "chrome/browser/sync/engine/syncer_proto_util.h"
 #include "chrome/browser/sync/engine/syncer_types.h"
 #include "chrome/browser/sync/engine/syncproto.h"
 #include "chrome/browser/sync/protocol/bookmark_specifics.pb.h"
 #include "chrome/browser/sync/protocol/nigori_specifics.pb.h"
 #include "chrome/browser/sync/protocol/sync.pb.h"
 #include "chrome/browser/sync/syncable/directory_manager.h"
 #include "chrome/browser/sync/syncable/model_type.h"
+#include "chrome/browser/sync/syncable/nigori_util.h"
 #include "chrome/browser/sync/syncable/syncable.h"
 #include "chrome/browser/sync/syncable/syncable_changes_version.h"
 
 using syncable::BASE_VERSION;
 using syncable::Blob;
 using syncable::CHANGES_VERSION;
 using syncable::CREATE;
 using syncable::CREATE_NEW_UPDATE_ITEM;
 using syncable::CTIME;
 using syncable::ComparePathNames;
@@ skipping 249 matching lines @@
     Directory::ChildHandles handles;
     trans->directory()->GetChildHandles(trans, id, &handles);
     if (!handles.empty()) {
       // If we have still-existing children, then we need to deal with
       // them before we can process this change.
       VLOG(1) << "Not deleting directory; it's not empty " << *entry;
       return CONFLICT;
     }
   }
 
-  // We intercept updates to the Nigori node and update the Cryptographer here
-  // because there is no Nigori ChangeProcessor.
+  // We intercept updates to the Nigori node, update the Cryptographer and
+  // encrypt any unsynced changes here because there is no Nigori
+  // ChangeProcessor.
   const sync_pb::EntitySpecifics& specifics = entry->Get(SERVER_SPECIFICS);
   if (specifics.HasExtension(sync_pb::nigori)) {
     const sync_pb::NigoriSpecifics& nigori =
         specifics.GetExtension(sync_pb::nigori);
     if (!nigori.encrypted().blob().empty()) {
       if (cryptographer->CanDecrypt(nigori.encrypted())) {
         cryptographer->SetKeys(nigori.encrypted());
       } else {
         cryptographer->SetPendingKeys(nigori.encrypted());
       }
     }
+
+    // Make sure any unsynced changes are properly encrypted as necessary.
+    syncable::ModelTypeSet encrypted_types =
+        syncable::GetEncryptedDatatypesFromNigori(nigori);
+    if (!syncable::ProcessUnsyncedChangesForEncryption(trans, encrypted_types,
+                                                       cryptographer)) {
+      // We were unable to encrypt the changes, possibly due to a missing
+      // passphrase.
+      return CONFLICT;
+    }
+
+    // Note that we don't bother to encrypt any synced data that now requires
+    // encryption. The machine that turned on encryption should encrypt
+    // everything itself. It's possible it could get interrupted during this
+    // process, but we currently reencrypt everything at startup as well,
+    // so as soon as a client is restarted with this datatype encrypted, all the
+    // data should be updated as necessary.
   }
 
   // Only apply updates that we can decrypt. Updates that can't be decrypted yet
   // will stay in conflict until the user provides a passphrase that lets the
   // Cryptographer decrypt them.
-  if (!entry->Get(SERVER_IS_DIR) && specifics.HasExtension(sync_pb::password)) {
-    const sync_pb::PasswordSpecifics& password =
-        specifics.GetExtension(sync_pb::password);
-    if (!cryptographer->CanDecrypt(password.encrypted())) {
+  if (!entry->Get(SERVER_IS_DIR)) {
+    if (specifics.has_encrypted() &&
+        !cryptographer->CanDecrypt(specifics.encrypted())) {
       // We can't decrypt this node yet.
       return CONFLICT;
+    } else if (specifics.HasExtension(sync_pb::password)) {
+      // Passwords use their own legacy encryption scheme.
+      const sync_pb::PasswordSpecifics& password =
+          specifics.GetExtension(sync_pb::password);
+      if (!cryptographer->CanDecrypt(password.encrypted())) {
+        return CONFLICT;
+      }
     }
   }
 
   SyncerUtil::UpdateLocalDataFromServerData(trans, entry);
 
   return SUCCESS;
 }
 
 namespace {
 // Helper to synthesize a new-style sync_pb::EntitySpecifics for use locally,
@@ skipping 539 matching lines @@
 
     // |update_entry| is considered to be somewhere after |candidate|, so store
     // it as the upper bound.
     closest_sibling = candidate.Get(ID);
   }
 
   return closest_sibling;
 }
 
 }  // namespace browser_sync