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.GetSpecifics();
  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.GetUniqueServerTag().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.GetSpecifics()) ||
  79          (encrypted_types.Has(type) &&
  80           entry.GetNonUniqueName() != 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   Entry type_root(trans, GET_TYPE_ROOT, type);
 104   if (!type_root.good()) {
 105     NOTREACHED();
 106     return false;
 107   }
 108
 109   std::queue<Id> to_visit;
 110   Id id_string = type_root.GetFirstChildId();
 111   to_visit.push(id_string);
 112   while (!to_visit.empty()) {
 113     id_string = to_visit.front();
 114     to_visit.pop();
 115     if (id_string.IsNull())
 116       continue;
 117
 118     Entry child(trans, GET_BY_ID, id_string);
 119     if (!child.good()) {
 120       NOTREACHED();
 121       return false;
 122     }
 123     if (child.GetIsDir()) {
 124       Id child_id_string = child.GetFirstChildId();
 125       // Traverse the children.
 126       to_visit.push(child_id_string);
 127     }
 128     const sync_pb::EntitySpecifics& specifics = child.GetSpecifics();
 129     DCHECK_EQ(type, child.GetModelType());
 130     DCHECK_EQ(type, GetModelTypeFromSpecifics(specifics));
 131     // We don't encrypt the server's permanent items.
 132     if (child.GetUniqueServerTag().empty()) {
 133       if (specifics.has_encrypted() != is_encrypted)
 134         return false;
 135       if (specifics.has_encrypted()) {
 136         if (child.GetNonUniqueName() != kEncryptedString)
 137           return false;
 138         if (!cryptographer->CanDecryptUsingDefaultKey(specifics.encrypted()))
 139           return false;
 140       }
 141     }
 142     // Push the successor.
 143     to_visit.push(child.GetSuccessorId());
 144   }
 145   return true;
 146 }
 147
 148 bool UpdateEntryWithEncryption(
 149     BaseTransaction* const trans,
 150     const sync_pb::EntitySpecifics& new_specifics,
 151     syncable::MutableEntry* entry) {
 152   NigoriHandler* nigori_handler = trans->directory()->GetNigoriHandler();
 153   Cryptographer* cryptographer = trans->directory()->GetCryptographer(trans);
 154   ModelType type = GetModelTypeFromSpecifics(new_specifics);
 155   DCHECK_GE(type, FIRST_REAL_MODEL_TYPE);
 156   const sync_pb::EntitySpecifics& old_specifics = entry->GetSpecifics();
 157   const ModelTypeSet encrypted_types =
 158       nigori_handler?
 159           nigori_handler->GetEncryptedTypes(trans) : ModelTypeSet();
 160   // It's possible the nigori lost the set of encrypted types. If the current
 161   // specifics are already encrypted, we want to ensure we continue encrypting.
 162   bool was_encrypted = old_specifics.has_encrypted();
 163   sync_pb::EntitySpecifics generated_specifics;
 164   if (new_specifics.has_encrypted()) {
 165     NOTREACHED() << "New specifics already has an encrypted blob.";
 166     return false;
 167   }
 168   if ((!SpecificsNeedsEncryption(encrypted_types, new_specifics) &&
 169        !was_encrypted) ||
 170       !cryptographer || !cryptographer->is_initialized()) {
 171     // No encryption required or we are unable to encrypt.
 172     generated_specifics.CopyFrom(new_specifics);
 173   } else {
 174     // Encrypt new_specifics into generated_specifics.
 175     if (VLOG_IS_ON(2)) {
 176       scoped_ptr<base::DictionaryValue> value(entry->ToValue(NULL));
 177       std::string info;
 178       base::JSONWriter::WriteWithOptions(value.get(),
 179                                          base::JSONWriter::OPTIONS_PRETTY_PRINT,
 180                                          &info);
 181       DVLOG(2) << "Encrypting specifics of type "
 182                << ModelTypeToString(type)
 183                << " with content: "
 184                << info;
 185     }
 186     // Only copy over the old specifics if it is of the right type and already
 187     // encrypted. The first time we encrypt a node we start from scratch, hence
 188     // removing all the unencrypted data, but from then on we only want to
 189     // update the node if the data changes or the encryption key changes.
 190     if (GetModelTypeFromSpecifics(old_specifics) == type &&
 191         was_encrypted) {
 192       generated_specifics.CopyFrom(old_specifics);
 193     } else {
 194       AddDefaultFieldValue(type, &generated_specifics);
 195     }
 196     // Does not change anything if underlying encrypted blob was already up
 197     // to date and encrypted with the default key.
 198     if (!cryptographer->Encrypt(new_specifics,
 199                                 generated_specifics.mutable_encrypted())) {
 200       NOTREACHED() << "Could not encrypt data for node of type "
 201                    << ModelTypeToString(type);
 202       return false;
 203     }
 204   }
 205
 206   // It's possible this entry was encrypted but didn't properly overwrite the
 207   // non_unique_name (see crbug.com/96314).
 208   bool encrypted_without_overwriting_name = (was_encrypted &&
 209       entry->GetNonUniqueName() != kEncryptedString);
 210
 211   // If we're encrypted but the name wasn't overwritten properly we still want
 212   // to rewrite the entry, irrespective of whether the specifics match.
 213   if (!encrypted_without_overwriting_name &&
 214       old_specifics.SerializeAsString() ==
 215           generated_specifics.SerializeAsString()) {
 216     DVLOG(2) << "Specifics of type " << ModelTypeToString(type)
 217              << " already match, dropping change.";
 218     return true;
 219   }
 220
 221   if (generated_specifics.has_encrypted()) {
 222     // Overwrite the possibly sensitive non-specifics data.
 223     entry->PutNonUniqueName(kEncryptedString);
 224     // For bookmarks we actually put bogus data into the unencrypted specifics,
 225     // else the server will try to do it for us.
 226     if (type == BOOKMARKS) {
 227       sync_pb::BookmarkSpecifics* bookmark_specifics =
 228           generated_specifics.mutable_bookmark();
 229       if (!entry->GetIsDir())
 230         bookmark_specifics->set_url(kEncryptedString);
 231       bookmark_specifics->set_title(kEncryptedString);
 232     }
 233   }
 234   entry->PutSpecifics(generated_specifics);
 235   DVLOG(1) << "Overwriting specifics of type "
 236            << ModelTypeToString(type)
 237            << " and marking for syncing.";
 238   syncable::MarkForSyncing(entry);
 239   return true;
 240 }
 241
 242 void UpdateNigoriFromEncryptedTypes(ModelTypeSet encrypted_types,
 243                                     bool encrypt_everything,
 244                                     sync_pb::NigoriSpecifics* nigori) {
 245   nigori->set_encrypt_everything(encrypt_everything);
 246   static_assert(34 == MODEL_TYPE_COUNT, "update encrypted types");
 247   nigori->set_encrypt_bookmarks(
 248       encrypted_types.Has(BOOKMARKS));
 249   nigori->set_encrypt_preferences(
 250       encrypted_types.Has(PREFERENCES));
 251   nigori->set_encrypt_autofill_profile(
 252       encrypted_types.Has(AUTOFILL_PROFILE));
 253   nigori->set_encrypt_autofill(encrypted_types.Has(AUTOFILL));
 254   nigori->set_encrypt_themes(encrypted_types.Has(THEMES));
 255   nigori->set_encrypt_typed_urls(
 256       encrypted_types.Has(TYPED_URLS));
 257   nigori->set_encrypt_extension_settings(
 258       encrypted_types.Has(EXTENSION_SETTINGS));
 259   nigori->set_encrypt_extensions(
 260       encrypted_types.Has(EXTENSIONS));
 261   nigori->set_encrypt_search_engines(
 262       encrypted_types.Has(SEARCH_ENGINES));
 263   nigori->set_encrypt_sessions(encrypted_types.Has(SESSIONS));
 264   nigori->set_encrypt_app_settings(
 265       encrypted_types.Has(APP_SETTINGS));
 266   nigori->set_encrypt_apps(encrypted_types.Has(APPS));
 267   nigori->set_encrypt_app_notifications(
 268       encrypted_types.Has(APP_NOTIFICATIONS));
 269   nigori->set_encrypt_dictionary(encrypted_types.Has(DICTIONARY));
 270   nigori->set_encrypt_favicon_images(encrypted_types.Has(FAVICON_IMAGES));
 271   nigori->set_encrypt_favicon_tracking(encrypted_types.Has(FAVICON_TRACKING));
 272   nigori->set_encrypt_articles(encrypted_types.Has(ARTICLES));
 273   nigori->set_encrypt_app_list(encrypted_types.Has(APP_LIST));
 274 }
 275
 276 ModelTypeSet GetEncryptedTypesFromNigori(
 277     const sync_pb::NigoriSpecifics& nigori) {
 278   if (nigori.encrypt_everything())
 279     return ModelTypeSet::All();
 280
 281   ModelTypeSet encrypted_types;
 282   static_assert(34 == MODEL_TYPE_COUNT, "update encrypted types");
 283   if (nigori.encrypt_bookmarks())
 284     encrypted_types.Put(BOOKMARKS);
 285   if (nigori.encrypt_preferences())
 286     encrypted_types.Put(PREFERENCES);
 287   if (nigori.encrypt_autofill_profile())
 288     encrypted_types.Put(AUTOFILL_PROFILE);
 289   if (nigori.encrypt_autofill())
 290     encrypted_types.Put(AUTOFILL);
 291   if (nigori.encrypt_themes())
 292     encrypted_types.Put(THEMES);
 293   if (nigori.encrypt_typed_urls())
 294     encrypted_types.Put(TYPED_URLS);
 295   if (nigori.encrypt_extension_settings())
 296     encrypted_types.Put(EXTENSION_SETTINGS);
 297   if (nigori.encrypt_extensions())
 298     encrypted_types.Put(EXTENSIONS);
 299   if (nigori.encrypt_search_engines())
 300     encrypted_types.Put(SEARCH_ENGINES);
 301   if (nigori.encrypt_sessions())
 302     encrypted_types.Put(SESSIONS);
 303   if (nigori.encrypt_app_settings())
 304     encrypted_types.Put(APP_SETTINGS);
 305   if (nigori.encrypt_apps())
 306     encrypted_types.Put(APPS);
 307   if (nigori.encrypt_app_notifications())
 308     encrypted_types.Put(APP_NOTIFICATIONS);
 309   if (nigori.encrypt_dictionary())
 310     encrypted_types.Put(DICTIONARY);
 311   if (nigori.encrypt_favicon_images())
 312     encrypted_types.Put(FAVICON_IMAGES);
 313   if (nigori.encrypt_favicon_tracking())
 314     encrypted_types.Put(FAVICON_TRACKING);
 315   if (nigori.encrypt_articles())
 316     encrypted_types.Put(ARTICLES);
 317   if (nigori.encrypt_app_list())
 318     encrypted_types.Put(APP_LIST);
 319   return encrypted_types;
 320 }
 321
 322 }  // namespace syncable
 323 }  // namespace syncer