sync/syncable/nigori_util.cc

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "sync/syncable/nigori_util.h"
   6
   7 #include <queue>
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/json/json_writer.h"
  12 #include "sync/syncable/directory.h"
  13 #include "sync/syncable/entry.h"
  14 #include "sync/syncable/nigori_handler.h"
  15 #include "sync/syncable/mutable_entry.h"
  16 #include "sync/syncable/syncable_util.h"
  17 #include "sync/syncable/syncable_write_transaction.h"
  18 #include "sync/util/cryptographer.h"
  19
  20 namespace syncer {
  21 namespace syncable {
  22
  23 bool ProcessUnsyncedChangesForEncryption(
  24     WriteTransaction* const trans) {
  25   NigoriHandler* nigori_handler = trans->directory()->GetNigoriHandler();
  26   ModelTypeSet encrypted_types = nigori_handler->GetEncryptedTypes(trans);
  27   Cryptographer* cryptographer = trans->directory()->GetCryptographer(trans);
  28   DCHECK(cryptographer->is_ready());
  29
  30   // Get list of all datatypes with unsynced changes. It's possible that our
  31   // local changes need to be encrypted if encryption for that datatype was
  32   // just turned on (and vice versa).
  33   // Note: we do not attempt to re-encrypt data with a new key here as key
  34   // changes in this code path are likely due to consistency issues (we have
  35   // to be updated to a key we already have, e.g. an old key).
  36   std::vector<int64> handles;
  37   GetUnsyncedEntries(trans, &handles);
  38   for (size_t i = 0; i < handles.size(); ++i) {
  39     MutableEntry entry(trans, GET_BY_HANDLE, handles[i]);
  40     const sync_pb::EntitySpecifics& specifics = entry.Get(SPECIFICS);
  41     // Ignore types that don't need encryption or entries that are already
  42     // encrypted.
  43     if (!SpecificsNeedsEncryption(encrypted_types, specifics))
  44       continue;
  45     if (!UpdateEntryWithEncryption(trans, specifics, &entry))
  46       return false;
  47   }
  48   return true;
  49 }
  50
  51 bool VerifyUnsyncedChangesAreEncrypted(
  52     BaseTransaction* const trans,
  53     ModelTypeSet encrypted_types) {
  54   std::vector<int64> handles;
  55   GetUnsyncedEntries(trans, &handles);
  56   for (size_t i = 0; i < handles.size(); ++i) {
  57     Entry entry(trans, GET_BY_HANDLE, handles[i]);
  58     if (!entry.good()) {
  59       NOTREACHED();
  60       return false;
  61     }
  62     if (EntryNeedsEncryption(encrypted_types, entry))
  63       return false;
  64   }
  65   return true;
  66 }
  67
  68 bool EntryNeedsEncryption(ModelTypeSet encrypted_types,
  69                           const Entry& entry) {
  70   if (!entry.Get(UNIQUE_SERVER_TAG).empty())
  71     return false;  // We don't encrypt unique server nodes.
  72   ModelType type = entry.GetModelType();
  73   if (type == PASSWORDS || IsControlType(type))
  74     return false;
  75   // Checking NON_UNIQUE_NAME is not necessary for the correctness of encrypting
  76   // the data, nor for determining if data is encrypted. We simply ensure it has
  77   // been overwritten to avoid any possible leaks of sensitive data.
  78   return SpecificsNeedsEncryption(encrypted_types, entry.Get(SPECIFICS)) ||
  79          (encrypted_types.Has(type) &&
  80           entry.Get(NON_UNIQUE_NAME) != kEncryptedString);
  81 }
  82
  83 bool SpecificsNeedsEncryption(ModelTypeSet encrypted_types,
  84                               const sync_pb::EntitySpecifics& specifics) {
  85   const ModelType type = GetModelTypeFromSpecifics(specifics);
  86   if (type == PASSWORDS || IsControlType(type))
  87     return false;  // These types have their own encryption schemes.
  88   if (!encrypted_types.Has(type))
  89     return false;  // This type does not require encryption
  90   return !specifics.has_encrypted();
  91 }
  92
  93 // Mainly for testing.
  94 bool VerifyDataTypeEncryptionForTest(
  95     BaseTransaction* const trans,
  96     ModelType type,
  97     bool is_encrypted) {
  98   Cryptographer* cryptographer = trans->directory()->GetCryptographer(trans);
  99   if (type == PASSWORDS || IsControlType(type)) {
 100     NOTREACHED();
 101     return true;
 102   }
 103   std::string type_tag = ModelTypeToRootTag(type);
 104   Entry type_root(trans, GET_BY_SERVER_TAG, type_tag);
 105   if (!type_root.good()) {
 106     NOTREACHED();
 107     return false;
 108   }
 109
 110   std::queue<Id> to_visit;
 111   Id id_string;
 112   if (!trans->directory()->GetFirstChildId(
 113           trans, type_root.Get(ID), &id_string)) {
 114     NOTREACHED();
 115     return false;
 116   }
 117   to_visit.push(id_string);
 118   while (!to_visit.empty()) {
 119     id_string = to_visit.front();
 120     to_visit.pop();
 121     if (id_string.IsRoot())
 122       continue;
 123
 124     Entry child(trans, GET_BY_ID, id_string);
 125     if (!child.good()) {
 126       NOTREACHED();
 127       return false;
 128     }
 129     if (child.Get(IS_DIR)) {
 130       Id child_id_string;
 131       if (!trans->directory()->GetFirstChildId(
 132               trans, child.Get(ID), &child_id_string)) {
 133         NOTREACHED();
 134         return false;
 135       }
 136       // Traverse the children.
 137       to_visit.push(child_id_string);
 138     }
 139     const sync_pb::EntitySpecifics& specifics = child.Get(SPECIFICS);
 140     DCHECK_EQ(type, child.GetModelType());
 141     DCHECK_EQ(type, GetModelTypeFromSpecifics(specifics));
 142     // We don't encrypt the server's permanent items.
 143     if (child.Get(UNIQUE_SERVER_TAG).empty()) {
 144       if (specifics.has_encrypted() != is_encrypted)
 145         return false;
 146       if (specifics.has_encrypted()) {
 147         if (child.Get(NON_UNIQUE_NAME) != kEncryptedString)
 148           return false;
 149         if (!cryptographer->CanDecryptUsingDefaultKey(specifics.encrypted()))
 150           return false;
 151       }
 152     }
 153     // Push the successor.
 154     to_visit.push(child.GetSuccessorId());
 155   }
 156   return true;
 157 }
 158
 159 bool UpdateEntryWithEncryption(
 160     BaseTransaction* const trans,
 161     const sync_pb::EntitySpecifics& new_specifics,
 162     syncable::MutableEntry* entry) {
 163   NigoriHandler* nigori_handler = trans->directory()->GetNigoriHandler();
 164   Cryptographer* cryptographer = trans->directory()->GetCryptographer(trans);
 165   ModelType type = GetModelTypeFromSpecifics(new_specifics);
 166   DCHECK_GE(type, FIRST_REAL_MODEL_TYPE);
 167   const sync_pb::EntitySpecifics& old_specifics = entry->Get(SPECIFICS);
 168   const ModelTypeSet encrypted_types = nigori_handler->GetEncryptedTypes(trans);
 169   // It's possible the nigori lost the set of encrypted types. If the current
 170   // specifics are already encrypted, we want to ensure we continue encrypting.
 171   bool was_encrypted = old_specifics.has_encrypted();
 172   sync_pb::EntitySpecifics generated_specifics;
 173   if (new_specifics.has_encrypted()) {
 174     NOTREACHED() << "New specifics already has an encrypted blob.";
 175     return false;
 176   }
 177   if ((!SpecificsNeedsEncryption(encrypted_types, new_specifics) &&
 178        !was_encrypted) ||
 179       !cryptographer->is_initialized()) {
 180     // No encryption required or we are unable to encrypt.
 181     generated_specifics.CopyFrom(new_specifics);
 182   } else {
 183     // Encrypt new_specifics into generated_specifics.
 184     if (VLOG_IS_ON(2)) {
 185       scoped_ptr<DictionaryValue> value(entry->ToValue(NULL));
 186       std::string info;
 187       base::JSONWriter::WriteWithOptions(value.get(),
 188                                          base::JSONWriter::OPTIONS_PRETTY_PRINT,
 189                                          &info);
 190       DVLOG(2) << "Encrypting specifics of type "
 191                << ModelTypeToString(type)
 192                << " with content: "
 193                << info;
 194     }
 195     // Only copy over the old specifics if it is of the right type and already
 196     // encrypted. The first time we encrypt a node we start from scratch, hence
 197     // removing all the unencrypted data, but from then on we only want to
 198     // update the node if the data changes or the encryption key changes.
 199     if (GetModelTypeFromSpecifics(old_specifics) == type &&
 200         was_encrypted) {
 201       generated_specifics.CopyFrom(old_specifics);
 202     } else {
 203       AddDefaultFieldValue(type, &generated_specifics);
 204     }
 205     // Does not change anything if underlying encrypted blob was already up
 206     // to date and encrypted with the default key.
 207     if (!cryptographer->Encrypt(new_specifics,
 208                                 generated_specifics.mutable_encrypted())) {
 209       NOTREACHED() << "Could not encrypt data for node of type "
 210                    << ModelTypeToString(type);
 211       return false;
 212     }
 213   }
 214
 215   // It's possible this entry was encrypted but didn't properly overwrite the
 216   // non_unique_name (see crbug.com/96314).
 217   bool encrypted_without_overwriting_name = (was_encrypted &&
 218       entry->Get(syncable::NON_UNIQUE_NAME) != kEncryptedString);
 219
 220   // If we're encrypted but the name wasn't overwritten properly we still want
 221   // to rewrite the entry, irrespective of whether the specifics match.
 222   if (!encrypted_without_overwriting_name &&
 223       old_specifics.SerializeAsString() ==
 224           generated_specifics.SerializeAsString()) {
 225     DVLOG(2) << "Specifics of type " << ModelTypeToString(type)
 226              << " already match, dropping change.";
 227     return true;
 228   }
 229
 230   if (generated_specifics.has_encrypted()) {
 231     // Overwrite the possibly sensitive non-specifics data.
 232     entry->Put(syncable::NON_UNIQUE_NAME, kEncryptedString);
 233     // For bookmarks we actually put bogus data into the unencrypted specifics,
 234     // else the server will try to do it for us.
 235     if (type == BOOKMARKS) {
 236       sync_pb::BookmarkSpecifics* bookmark_specifics =
 237           generated_specifics.mutable_bookmark();
 238       if (!entry->Get(syncable::IS_DIR))
 239         bookmark_specifics->set_url(kEncryptedString);
 240       bookmark_specifics->set_title(kEncryptedString);
 241     }
 242   }
 243   entry->Put(syncable::SPECIFICS, generated_specifics);
 244   DVLOG(1) << "Overwriting specifics of type "
 245            << ModelTypeToString(type)
 246            << " and marking for syncing.";
 247   syncable::MarkForSyncing(entry);
 248   return true;
 249 }
 250
 251 void UpdateNigoriFromEncryptedTypes(ModelTypeSet encrypted_types,
 252                                     bool encrypt_everything,
 253                                     sync_pb::NigoriSpecifics* nigori) {
 254   nigori->set_encrypt_everything(encrypt_everything);
 255   COMPILE_ASSERT(17, MODEL_TYPE_COUNT);
 256   nigori->set_encrypt_bookmarks(
 257       encrypted_types.Has(BOOKMARKS));
 258   nigori->set_encrypt_preferences(
 259       encrypted_types.Has(PREFERENCES));
 260   nigori->set_encrypt_autofill_profile(
 261       encrypted_types.Has(AUTOFILL_PROFILE));
 262   nigori->set_encrypt_autofill(encrypted_types.Has(AUTOFILL));
 263   nigori->set_encrypt_themes(encrypted_types.Has(THEMES));
 264   nigori->set_encrypt_typed_urls(
 265       encrypted_types.Has(TYPED_URLS));
 266   nigori->set_encrypt_extension_settings(
 267       encrypted_types.Has(EXTENSION_SETTINGS));
 268   nigori->set_encrypt_extensions(
 269       encrypted_types.Has(EXTENSIONS));
 270   nigori->set_encrypt_search_engines(
 271       encrypted_types.Has(SEARCH_ENGINES));
 272   nigori->set_encrypt_sessions(encrypted_types.Has(SESSIONS));
 273   nigori->set_encrypt_app_settings(
 274       encrypted_types.Has(APP_SETTINGS));
 275   nigori->set_encrypt_apps(encrypted_types.Has(APPS));
 276   nigori->set_encrypt_app_notifications(
 277       encrypted_types.Has(APP_NOTIFICATIONS));
 278 }
 279
 280 ModelTypeSet GetEncryptedTypesFromNigori(
 281     const sync_pb::NigoriSpecifics& nigori) {
 282   if (nigori.encrypt_everything())
 283     return ModelTypeSet::All();
 284
 285   ModelTypeSet encrypted_types;
 286   COMPILE_ASSERT(17, MODEL_TYPE_COUNT);
 287   if (nigori.encrypt_bookmarks())
 288     encrypted_types.Put(BOOKMARKS);
 289   if (nigori.encrypt_preferences())
 290     encrypted_types.Put(PREFERENCES);
 291   if (nigori.encrypt_autofill_profile())
 292     encrypted_types.Put(AUTOFILL_PROFILE);
 293   if (nigori.encrypt_autofill())
 294     encrypted_types.Put(AUTOFILL);
 295   if (nigori.encrypt_themes())
 296     encrypted_types.Put(THEMES);
 297   if (nigori.encrypt_typed_urls())
 298     encrypted_types.Put(TYPED_URLS);
 299   if (nigori.encrypt_extension_settings())
 300     encrypted_types.Put(EXTENSION_SETTINGS);
 301   if (nigori.encrypt_extensions())
 302     encrypted_types.Put(EXTENSIONS);
 303   if (nigori.encrypt_search_engines())
 304     encrypted_types.Put(SEARCH_ENGINES);
 305   if (nigori.encrypt_sessions())
 306     encrypted_types.Put(SESSIONS);
 307   if (nigori.encrypt_app_settings())
 308     encrypted_types.Put(APP_SETTINGS);
 309   if (nigori.encrypt_apps())
 310     encrypted_types.Put(APPS);
 311   if (nigori.encrypt_app_notifications())
 312     encrypted_types.Put(APP_NOTIFICATIONS);
 313   return encrypted_types;
 314 }
 315
 316 }  // namespace syncable
 317 }  // namespace syncer