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/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 base::char16 kRegistryExtensions[] =
  29     L"Software\\Google\\Chrome\\Extensions";
  30
  31 // Registry value of the key that defines the installation parameter.
  32 const base::char16 kRegistryExtensionInstallParam[] = L"install_parameter";
  33
  34 // Registry value of the key that defines the path to the .crx file.
  35 const base::char16 kRegistryExtensionPath[] = L"path";
  36
  37 // Registry value of that key that defines the current version of the .crx file.
  38 const base::char16 kRegistryExtensionVersion[] = L"version";
  39
  40 // Registry value of the key that defines an external update URL.
  41 const base::char16 kRegistryExtensionUpdateUrl[] = L"update_url";
  42
  43 bool CanOpenFileForReading(const base::FilePath& path) {
  44   base::ScopedFILE file_handle(base::OpenFile(path, "rb"));
  45   return file_handle.get() != NULL;
  46 }
  47
  48 std::string MakePrefName(const std::string& extension_id,
  49                          const std::string& pref_name) {
  50   return base::StringPrintf("%s.%s", extension_id.c_str(), pref_name.c_str());
  51 }
  52
  53 }  // namespace
  54
  55 namespace extensions {
  56
  57 void ExternalRegistryLoader::StartLoading() {
  58   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  59   BrowserThread::PostTask(
  60       BrowserThread::FILE, FROM_HERE,
  61       base::Bind(&ExternalRegistryLoader::LoadOnFileThread, this));
  62 }
  63
  64 void ExternalRegistryLoader::LoadOnFileThread() {
  65   CHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  66   base::TimeTicks start_time = base::TimeTicks::Now();
  67   scoped_ptr<base::DictionaryValue> prefs(new base::DictionaryValue);
  68
  69   // A map of IDs, to weed out duplicates between HKCU and HKLM.
  70   std::set<base::string16> keys;
  71   base::win::RegistryKeyIterator iterator_machine_key(
  72       HKEY_LOCAL_MACHINE,
  73       kRegistryExtensions,
  74       KEY_WOW64_32KEY);
  75   for (; iterator_machine_key.Valid(); ++iterator_machine_key)
  76     keys.insert(iterator_machine_key.Name());
  77   base::win::RegistryKeyIterator iterator_user_key(
  78       HKEY_CURRENT_USER, kRegistryExtensions);
  79   for (; iterator_user_key.Valid(); ++iterator_user_key)
  80     keys.insert(iterator_user_key.Name());
  81
  82   // Iterate over the keys found, first trying HKLM, then HKCU, as per Windows
  83   // policy conventions. We only fall back to HKCU if the HKLM key cannot be
  84   // opened, not if the data within the key is invalid, for example.
  85   for (std::set<base::string16>::const_iterator it = keys.begin();
  86        it != keys.end(); ++it) {
  87     base::win::RegKey key;
  88     base::string16 key_path = kRegistryExtensions;
  89     key_path.append(L"\\");
  90     key_path.append(*it);
  91     if (key.Open(HKEY_LOCAL_MACHINE,
  92                  key_path.c_str(),
  93                  KEY_READ | KEY_WOW64_32KEY) != ERROR_SUCCESS &&
  94         key.Open(HKEY_CURRENT_USER, key_path.c_str(), KEY_READ) !=
  95             ERROR_SUCCESS) {
  96       LOG(ERROR) << "Unable to read registry key at path (HKLM & HKCU): "
  97                  << key_path << ".";
  98       continue;
  99     }
 100
 101     std::string id = base::UTF16ToASCII(*it);
 102     base::StringToLowerASCII(&id);
 103     if (!crx_file::id_util::IdIsValid(id)) {
 104       LOG(ERROR) << "Invalid id value " << id
 105                  << " for key " << key_path << ".";
 106       continue;
 107     }
 108
 109     base::string16 extension_dist_id;
 110     if (key.ReadValue(kRegistryExtensionInstallParam, &extension_dist_id) ==
 111         ERROR_SUCCESS) {
 112       prefs->SetString(MakePrefName(id, ExternalProviderImpl::kInstallParam),
 113                        base::UTF16ToASCII(extension_dist_id));
 114     }
 115
 116     // If there is an update URL present, copy it to prefs and ignore
 117     // path and version keys for this entry.
 118     base::string16 extension_update_url;
 119     if (key.ReadValue(kRegistryExtensionUpdateUrl, &extension_update_url)
 120         == ERROR_SUCCESS) {
 121       prefs->SetString(
 122           MakePrefName(id, ExternalProviderImpl::kExternalUpdateUrl),
 123           base::UTF16ToASCII(extension_update_url));
 124       continue;
 125     }
 126
 127     base::string16 extension_path_str;
 128     if (key.ReadValue(kRegistryExtensionPath, &extension_path_str)
 129         != ERROR_SUCCESS) {
 130       // TODO(erikkay): find a way to get this into about:extensions
 131       LOG(ERROR) << "Missing value " << kRegistryExtensionPath
 132                  << " for key " << key_path << ".";
 133       continue;
 134     }
 135
 136     base::FilePath extension_path(extension_path_str);
 137     if (!extension_path.IsAbsolute()) {
 138       LOG(ERROR) << "File path " << extension_path_str
 139                  << " needs to be absolute in key "
 140                  << key_path;
 141       continue;
 142     }
 143
 144     if (!base::PathExists(extension_path)) {
 145       LOG(ERROR) << "File " << extension_path_str
 146                  << " for key " << key_path
 147                  << " does not exist or is not readable.";
 148       continue;
 149     }
 150
 151     if (!CanOpenFileForReading(extension_path)) {
 152       LOG(ERROR) << "File " << extension_path_str
 153                  << " for key " << key_path << " can not be read. "
 154                  << "Check that users who should have the extension "
 155                  << "installed have permission to read it.";
 156       continue;
 157     }
 158
 159     base::string16 extension_version;
 160     if (key.ReadValue(kRegistryExtensionVersion, &extension_version)
 161         != ERROR_SUCCESS) {
 162       // TODO(erikkay): find a way to get this into about:extensions
 163       LOG(ERROR) << "Missing value " << kRegistryExtensionVersion
 164                  << " for key " << key_path << ".";
 165       continue;
 166     }
 167
 168     Version version(base::UTF16ToASCII(extension_version));
 169     if (!version.IsValid()) {
 170       LOG(ERROR) << "Invalid version value " << extension_version
 171                  << " for key " << key_path << ".";
 172       continue;
 173     }
 174
 175     prefs->SetString(
 176         MakePrefName(id, ExternalProviderImpl::kExternalVersion),
 177         base::UTF16ToASCII(extension_version));
 178     prefs->SetString(
 179         MakePrefName(id, ExternalProviderImpl::kExternalCrx),
 180         extension_path_str);
 181     prefs->SetBoolean(
 182         MakePrefName(id, ExternalProviderImpl::kMayBeUntrusted),
 183         true);
 184   }
 185
 186   prefs_.reset(prefs.release());
 187   LOCAL_HISTOGRAM_TIMES("Extensions.ExternalRegistryLoaderWin",
 188                         base::TimeTicks::Now() - start_time);
 189   BrowserThread::PostTask(
 190       BrowserThread::UI, FROM_HERE,
 191       base::Bind(&ExternalRegistryLoader::LoadFinished, this));
 192 }
 193
 194 }  // namespace extensions