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