sync/internal_api/syncapi_internal.cc

   1 // Copyright (c) 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/internal_api/syncapi_internal.h"
   6
   7 #include "base/memory/scoped_ptr.h"
   8 #include "sync/protocol/attachments.pb.h"
   9 #include "sync/protocol/password_specifics.pb.h"
  10 #include "sync/protocol/sync.pb.h"
  11 #include "sync/util/cryptographer.h"
  12
  13 namespace syncer {
  14
  15 namespace {
  16
  17 bool EndsWithSpace(const std::string& string) {
  18   return !string.empty() && *string.rbegin() == ' ';
  19 }
  20
  21 }
  22
  23 sync_pb::PasswordSpecificsData* DecryptPasswordSpecifics(
  24     const sync_pb::EntitySpecifics& specifics, Cryptographer* crypto) {
  25   if (!specifics.has_password())
  26     return NULL;
  27   const sync_pb::PasswordSpecifics& password_specifics = specifics.password();
  28   if (!password_specifics.has_encrypted())
  29     return NULL;
  30   const sync_pb::EncryptedData& encrypted = password_specifics.encrypted();
  31   scoped_ptr<sync_pb::PasswordSpecificsData> data(
  32       new sync_pb::PasswordSpecificsData);
  33   if (!crypto->Decrypt(encrypted, data.get()))
  34     return NULL;
  35   return data.release();
  36 }
  37
  38 // The list of names which are reserved for use by the server.
  39 static const char* kForbiddenServerNames[] = { "", ".", ".." };
  40
  41 // When taking a name from the syncapi, append a space if it matches the
  42 // pattern of a server-illegal name followed by zero or more spaces.
  43 void SyncAPINameToServerName(const std::string& syncer_name,
  44                              std::string* out) {
  45   *out = syncer_name;
  46   if (IsNameServerIllegalAfterTrimming(*out))
  47     out->append(" ");
  48 }
  49
  50 // In the reverse direction, if a server name matches the pattern of a
  51 // server-illegal name followed by one or more spaces, remove the trailing
  52 // space.
  53 void ServerNameToSyncAPIName(const std::string& server_name,
  54                              std::string* out) {
  55   CHECK(out);
  56   int length_to_copy = server_name.length();
  57   if (IsNameServerIllegalAfterTrimming(server_name) &&
  58       EndsWithSpace(server_name)) {
  59     --length_to_copy;
  60   }
  61   *out = server_name.substr(0, length_to_copy);
  62 }
  63
  64 // Checks whether |name| is a server-illegal name followed by zero or more space
  65 // characters.  The three server-illegal names are the empty string, dot, and
  66 // dot-dot.  Very long names (>255 bytes in UTF-8 Normalization Form C) are
  67 // also illegal, but are not considered here.
  68 bool IsNameServerIllegalAfterTrimming(const std::string& name) {
  69   size_t untrimmed_count = name.find_last_not_of(' ') + 1;
  70   for (size_t i = 0; i < arraysize(kForbiddenServerNames); ++i) {
  71     if (name.compare(0, untrimmed_count, kForbiddenServerNames[i]) == 0)
  72       return true;
  73   }
  74   return false;
  75 }
  76
  77 // Compare the values of two EntitySpecifics, accounting for encryption.
  78 bool AreSpecificsEqual(const Cryptographer* cryptographer,
  79                        const sync_pb::EntitySpecifics& left,
  80                        const sync_pb::EntitySpecifics& right) {
  81   // Note that we can't compare encrypted strings directly as they are seeded
  82   // with a random value.
  83   std::string left_plaintext, right_plaintext;
  84   if (left.has_encrypted()) {
  85     if (!cryptographer->CanDecrypt(left.encrypted())) {
  86       NOTREACHED() << "Attempting to compare undecryptable data.";
  87       return false;
  88     }
  89     left_plaintext = cryptographer->DecryptToString(left.encrypted());
  90   } else {
  91     left_plaintext = left.SerializeAsString();
  92   }
  93   if (right.has_encrypted()) {
  94     if (!cryptographer->CanDecrypt(right.encrypted())) {
  95       NOTREACHED() << "Attempting to compare undecryptable data.";
  96       return false;
  97     }
  98     right_plaintext = cryptographer->DecryptToString(right.encrypted());
  99   } else {
 100     right_plaintext = right.SerializeAsString();
 101   }
 102   if (left_plaintext == right_plaintext) {
 103     return true;
 104   }
 105   return false;
 106 }
 107
 108 bool AreAttachmentMetadataEqual(const sync_pb::AttachmentMetadata& left,
 109                                 const sync_pb::AttachmentMetadata& right) {
 110   if (left.SerializeAsString() == right.SerializeAsString()) {
 111     return true;
 112   }
 113   return false;
 114 }
 115
 116 }  // namespace syncer