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