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 "chrome/browser/extensions/external_registry_loader_win.h"
6
7 #include "base/bind.h"
8 #include "base/file_util.h"
9 #include "base/files/file_path.h"
10 #include "base/files/scoped_file.h"
11 #include "base/metrics/histogram.h"
12 #include "base/strings/string_util.h"
13 #include "base/strings/utf_string_conversions.h"
14 #include "base/time/time.h"
15 #include "base/values.h"
16 #include "base/version.h"
17 #include "base/win/registry.h"
18 #include "chrome/browser/extensions/external_provider_impl.h"
19 #include "content/public/browser/browser_thread.h"
20 #include "extensions/common/extension.h"
21
22 using content::BrowserThread;
23
24 namespace {
25
26 // The Registry subkey that contains information about external extensions.
27 const char kRegistryExtensions[] = "Software\\Google\\Chrome\\Extensions";
28
29 // Registry value of the key that defines the installation parameter.
30 const wchar_t kRegistryExtensionInstallParam[] = L"install_parameter";
31
32 // Registry value of the key that defines the path to the .crx file.
33 const wchar_t kRegistryExtensionPath[] = L"path";
34
35 // Registry value of that key that defines the current version of the .crx file.
36 const wchar_t kRegistryExtensionVersion[] = L"version";
37
38 // Registry value of the key that defines an external update URL.
39 const wchar_t kRegistryExtensionUpdateUrl[] = L"update_url";
40
CanOpenFileForReading(const base::FilePath & path)41 bool CanOpenFileForReading(const base::FilePath& path) {
42 base::ScopedFILE file_handle(base::OpenFile(path, "rb"));
43 return file_handle.get() != NULL;
44 }
45
46 } // namespace
47
48 namespace extensions {
49
StartLoading()50 void ExternalRegistryLoader::StartLoading() {
51 CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
52 BrowserThread::PostTask(
53 BrowserThread::FILE, FROM_HERE,
54 base::Bind(&ExternalRegistryLoader::LoadOnFileThread, this));
55 }
56
LoadOnFileThread()57 void ExternalRegistryLoader::LoadOnFileThread() {
58 CHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
59 base::TimeTicks start_time = base::TimeTicks::Now();
60 scoped_ptr<base::DictionaryValue> prefs(new base::DictionaryValue);
61
62 // A map of IDs, to weed out duplicates between HKCU and HKLM.
63 std::set<base::string16> keys;
64 base::win::RegistryKeyIterator iterator_machine_key(
65 HKEY_LOCAL_MACHINE, base::ASCIIToWide(kRegistryExtensions).c_str());
66 for (; iterator_machine_key.Valid(); ++iterator_machine_key)
67 keys.insert(iterator_machine_key.Name());
68 base::win::RegistryKeyIterator iterator_user_key(
69 HKEY_CURRENT_USER, base::ASCIIToWide(kRegistryExtensions).c_str());
70 for (; iterator_user_key.Valid(); ++iterator_user_key)
71 keys.insert(iterator_user_key.Name());
72
73 // Iterate over the keys found, first trying HKLM, then HKCU, as per Windows
74 // policy conventions. We only fall back to HKCU if the HKLM key cannot be
75 // opened, not if the data within the key is invalid, for example.
76 for (std::set<base::string16>::const_iterator it = keys.begin();
77 it != keys.end(); ++it) {
78 base::win::RegKey key;
79 base::string16 key_path = base::ASCIIToWide(kRegistryExtensions);
80 key_path.append(L"\\");
81 key_path.append(*it);
82 if (key.Open(HKEY_LOCAL_MACHINE,
83 key_path.c_str(), KEY_READ) != ERROR_SUCCESS) {
84 if (key.Open(HKEY_CURRENT_USER,
85 key_path.c_str(), KEY_READ) != ERROR_SUCCESS) {
86 LOG(ERROR) << "Unable to read registry key at path (HKLM & HKCU): "
87 << key_path << ".";
88 continue;
89 }
90 }
91
92 std::string id = base::UTF16ToASCII(*it);
93 StringToLowerASCII(&id);
94 if (!Extension::IdIsValid(id)) {
95 LOG(ERROR) << "Invalid id value " << id
96 << " for key " << key_path << ".";
97 continue;
98 }
99
100 base::string16 extension_dist_id;
101 if (key.ReadValue(kRegistryExtensionInstallParam, &extension_dist_id) ==
102 ERROR_SUCCESS) {
103 prefs->SetString(id + "." + ExternalProviderImpl::kInstallParam,
104 base::UTF16ToASCII(extension_dist_id));
105 }
106
107 // If there is an update URL present, copy it to prefs and ignore
108 // path and version keys for this entry.
109 base::string16 extension_update_url;
110 if (key.ReadValue(kRegistryExtensionUpdateUrl, &extension_update_url)
111 == ERROR_SUCCESS) {
112 prefs->SetString(
113 id + "." + ExternalProviderImpl::kExternalUpdateUrl,
114 base::UTF16ToASCII(extension_update_url));
115 continue;
116 }
117
118 base::string16 extension_path_str;
119 if (key.ReadValue(kRegistryExtensionPath, &extension_path_str)
120 != ERROR_SUCCESS) {
121 // TODO(erikkay): find a way to get this into about:extensions
122 LOG(ERROR) << "Missing value " << kRegistryExtensionPath
123 << " for key " << key_path << ".";
124 continue;
125 }
126
127 base::FilePath extension_path(extension_path_str);
128 if (!extension_path.IsAbsolute()) {
129 LOG(ERROR) << "File path " << extension_path_str
130 << " needs to be absolute in key "
131 << key_path;
132 continue;
133 }
134
135 if (!base::PathExists(extension_path)) {
136 LOG(ERROR) << "File " << extension_path_str
137 << " for key " << key_path
138 << " does not exist or is not readable.";
139 continue;
140 }
141
142 if (!CanOpenFileForReading(extension_path)) {
143 LOG(ERROR) << "File " << extension_path_str
144 << " for key " << key_path << " can not be read. "
145 << "Check that users who should have the extension "
146 << "installed have permission to read it.";
147 continue;
148 }
149
150 base::string16 extension_version;
151 if (key.ReadValue(kRegistryExtensionVersion, &extension_version)
152 != ERROR_SUCCESS) {
153 // TODO(erikkay): find a way to get this into about:extensions
154 LOG(ERROR) << "Missing value " << kRegistryExtensionVersion
155 << " for key " << key_path << ".";
156 continue;
157 }
158
159 Version version(base::UTF16ToASCII(extension_version));
160 if (!version.IsValid()) {
161 LOG(ERROR) << "Invalid version value " << extension_version
162 << " for key " << key_path << ".";
163 continue;
164 }
165
166 prefs->SetString(
167 id + "." + ExternalProviderImpl::kExternalVersion,
168 base::UTF16ToASCII(extension_version));
169 prefs->SetString(
170 id + "." + ExternalProviderImpl::kExternalCrx,
171 extension_path_str);
172 }
173
174 prefs_.reset(prefs.release());
175 HISTOGRAM_TIMES("Extensions.ExternalRegistryLoaderWin",
176 base::TimeTicks::Now() - start_time);
177 BrowserThread::PostTask(
178 BrowserThread::UI, FROM_HERE,
179 base::Bind(&ExternalRegistryLoader::LoadFinished, this));
180 }
181
182 } // namespace extensions
183