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/files/file_path.h"
9 #include "base/files/file_util.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/stringprintf.h"
14 #include "base/strings/utf_string_conversions.h"
15 #include "base/time/time.h"
16 #include "base/values.h"
17 #include "base/version.h"
18 #include "base/win/registry.h"
19 #include "chrome/browser/extensions/external_provider_impl.h"
20 #include "components/crx_file/id_util.h"
21 #include "content/public/browser/browser_thread.h"
22
23 using content::BrowserThread;
24
25 namespace {
26
27 // The Registry subkey that contains information about external extensions.
28 const char kRegistryExtensions[] = "Software\\Google\\Chrome\\Extensions";
29
30 // Registry value of the key that defines the installation parameter.
31 const wchar_t kRegistryExtensionInstallParam[] = L"install_parameter";
32
33 // Registry value of the key that defines the path to the .crx file.
34 const wchar_t kRegistryExtensionPath[] = L"path";
35
36 // Registry value of that key that defines the current version of the .crx file.
37 const wchar_t kRegistryExtensionVersion[] = L"version";
38
39 // Registry value of the key that defines an external update URL.
40 const wchar_t kRegistryExtensionUpdateUrl[] = L"update_url";
41
CanOpenFileForReading(const base::FilePath & path)42 bool CanOpenFileForReading(const base::FilePath& path) {
43 base::ScopedFILE file_handle(base::OpenFile(path, "rb"));
44 return file_handle.get() != NULL;
45 }
46
MakePrefName(const std::string & extension_id,const std::string & pref_name)47 std::string MakePrefName(const std::string& extension_id,
48 const std::string& pref_name) {
49 return base::StringPrintf("%s.%s", extension_id.c_str(), pref_name.c_str());
50 }
51
52 } // namespace
53
54 namespace extensions {
55
StartLoading()56 void ExternalRegistryLoader::StartLoading() {
57 CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
58 BrowserThread::PostTask(
59 BrowserThread::FILE, FROM_HERE,
60 base::Bind(&ExternalRegistryLoader::LoadOnFileThread, this));
61 }
62
LoadOnFileThread()63 void ExternalRegistryLoader::LoadOnFileThread() {
64 CHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
65 base::TimeTicks start_time = base::TimeTicks::Now();
66 scoped_ptr<base::DictionaryValue> prefs(new base::DictionaryValue);
67
68 // A map of IDs, to weed out duplicates between HKCU and HKLM.
69 std::set<base::string16> keys;
70 base::win::RegistryKeyIterator iterator_machine_key(
71 HKEY_LOCAL_MACHINE, base::ASCIIToWide(kRegistryExtensions).c_str());
72 for (; iterator_machine_key.Valid(); ++iterator_machine_key)
73 keys.insert(iterator_machine_key.Name());
74 base::win::RegistryKeyIterator iterator_user_key(
75 HKEY_CURRENT_USER, base::ASCIIToWide(kRegistryExtensions).c_str());
76 for (; iterator_user_key.Valid(); ++iterator_user_key)
77 keys.insert(iterator_user_key.Name());
78
79 // Iterate over the keys found, first trying HKLM, then HKCU, as per Windows
80 // policy conventions. We only fall back to HKCU if the HKLM key cannot be
81 // opened, not if the data within the key is invalid, for example.
82 for (std::set<base::string16>::const_iterator it = keys.begin();
83 it != keys.end(); ++it) {
84 base::win::RegKey key;
85 base::string16 key_path = base::ASCIIToWide(kRegistryExtensions);
86 key_path.append(L"\\");
87 key_path.append(*it);
88 if (key.Open(HKEY_LOCAL_MACHINE,
89 key_path.c_str(), KEY_READ) != ERROR_SUCCESS) {
90 if (key.Open(HKEY_CURRENT_USER,
91 key_path.c_str(), KEY_READ) != ERROR_SUCCESS) {
92 LOG(ERROR) << "Unable to read registry key at path (HKLM & HKCU): "
93 << key_path << ".";
94 continue;
95 }
96 }
97
98 std::string id = base::UTF16ToASCII(*it);
99 base::StringToLowerASCII(&id);
100 if (!crx_file::id_util::IdIsValid(id)) {
101 LOG(ERROR) << "Invalid id value " << id
102 << " for key " << key_path << ".";
103 continue;
104 }
105
106 base::string16 extension_dist_id;
107 if (key.ReadValue(kRegistryExtensionInstallParam, &extension_dist_id) ==
108 ERROR_SUCCESS) {
109 prefs->SetString(MakePrefName(id, ExternalProviderImpl::kInstallParam),
110 base::UTF16ToASCII(extension_dist_id));
111 }
112
113 // If there is an update URL present, copy it to prefs and ignore
114 // path and version keys for this entry.
115 base::string16 extension_update_url;
116 if (key.ReadValue(kRegistryExtensionUpdateUrl, &extension_update_url)
117 == ERROR_SUCCESS) {
118 prefs->SetString(
119 MakePrefName(id, ExternalProviderImpl::kExternalUpdateUrl),
120 base::UTF16ToASCII(extension_update_url));
121 continue;
122 }
123
124 base::string16 extension_path_str;
125 if (key.ReadValue(kRegistryExtensionPath, &extension_path_str)
126 != ERROR_SUCCESS) {
127 // TODO(erikkay): find a way to get this into about:extensions
128 LOG(ERROR) << "Missing value " << kRegistryExtensionPath
129 << " for key " << key_path << ".";
130 continue;
131 }
132
133 base::FilePath extension_path(extension_path_str);
134 if (!extension_path.IsAbsolute()) {
135 LOG(ERROR) << "File path " << extension_path_str
136 << " needs to be absolute in key "
137 << key_path;
138 continue;
139 }
140
141 if (!base::PathExists(extension_path)) {
142 LOG(ERROR) << "File " << extension_path_str
143 << " for key " << key_path
144 << " does not exist or is not readable.";
145 continue;
146 }
147
148 if (!CanOpenFileForReading(extension_path)) {
149 LOG(ERROR) << "File " << extension_path_str
150 << " for key " << key_path << " can not be read. "
151 << "Check that users who should have the extension "
152 << "installed have permission to read it.";
153 continue;
154 }
155
156 base::string16 extension_version;
157 if (key.ReadValue(kRegistryExtensionVersion, &extension_version)
158 != ERROR_SUCCESS) {
159 // TODO(erikkay): find a way to get this into about:extensions
160 LOG(ERROR) << "Missing value " << kRegistryExtensionVersion
161 << " for key " << key_path << ".";
162 continue;
163 }
164
165 Version version(base::UTF16ToASCII(extension_version));
166 if (!version.IsValid()) {
167 LOG(ERROR) << "Invalid version value " << extension_version
168 << " for key " << key_path << ".";
169 continue;
170 }
171
172 prefs->SetString(
173 MakePrefName(id, ExternalProviderImpl::kExternalVersion),
174 base::UTF16ToASCII(extension_version));
175 prefs->SetString(
176 MakePrefName(id, ExternalProviderImpl::kExternalCrx),
177 extension_path_str);
178 prefs->SetBoolean(
179 MakePrefName(id, ExternalProviderImpl::kMayBeUntrusted),
180 true);
181 }
182
183 prefs_.reset(prefs.release());
184 LOCAL_HISTOGRAM_TIMES("Extensions.ExternalRegistryLoaderWin",
185 base::TimeTicks::Now() - start_time);
186 BrowserThread::PostTask(
187 BrowserThread::UI, FROM_HERE,
188 base::Bind(&ExternalRegistryLoader::LoadFinished, this));
189 }
190
191 } // namespace extensions
192