chrome/browser/extensions/external_registry_loader_win.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 "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/memory/scoped_handle.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
  41 bool CanOpenFileForReading(const base::FilePath& path) {
  42   ScopedStdioHandle file_handle(base::OpenFile(path, "rb"));
  43   return file_handle.get() != NULL;
  44 }
  45
  46 }  // namespace
  47
  48 namespace extensions {
  49
  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
  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