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
EndsWithSpace(const std::string & string)16 bool EndsWithSpace(const std::string& string) {
17 return !string.empty() && *string.rbegin() == ' ';
18 }
19
20 }
21
DecryptPasswordSpecifics(const sync_pb::EntitySpecifics & specifics,Cryptographer * crypto)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.
SyncAPINameToServerName(const std::string & syncer_name,std::string * out)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.
ServerNameToSyncAPIName(const std::string & server_name,std::string * out)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.
IsNameServerIllegalAfterTrimming(const std::string & name)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.
AreSpecificsEqual(const Cryptographer * cryptographer,const sync_pb::EntitySpecifics & left,const sync_pb::EntitySpecifics & right)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
108