extensions/common/file_util.cc

   1 // Copyright 2013 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 "extensions/common/file_util.h"
   6
   7 #include <map>
   8 #include <set>
   9 #include <string>
  10 #include <utility>
  11 #include <vector>
  12
  13 #include "base/files/file_enumerator.h"
  14 #include "base/files/file_path.h"
  15 #include "base/files/file_util.h"
  16 #include "base/files/scoped_temp_dir.h"
  17 #include "base/json/json_file_value_serializer.h"
  18 #include "base/logging.h"
  19 #include "base/memory/scoped_ptr.h"
  20 #include "base/strings/stringprintf.h"
  21 #include "base/strings/utf_string_conversions.h"
  22 #include "base/threading/thread_restrictions.h"
  23 #include "extensions/common/constants.h"
  24 #include "extensions/common/extension.h"
  25 #include "extensions/common/extension_icon_set.h"
  26 #include "extensions/common/extension_l10n_util.h"
  27 #include "extensions/common/install_warning.h"
  28 #include "extensions/common/manifest.h"
  29 #include "extensions/common/manifest_constants.h"
  30 #include "extensions/common/manifest_handler.h"
  31 #include "extensions/common/manifest_handlers/icons_handler.h"
  32 #include "extensions/common/message_bundle.h"
  33 #include "grit/extensions_strings.h"
  34 #include "net/base/escape.h"
  35 #include "ui/base/l10n/l10n_util.h"
  36 #include "url/gurl.h"
  37
  38 namespace extensions {
  39 namespace file_util {
  40 namespace {
  41
  42 // Returns true if the given file path exists and is not zero-length.
  43 bool ValidateFilePath(const base::FilePath& path) {
  44   int64 size = 0;
  45   if (!base::PathExists(path) ||
  46       !base::GetFileSize(path, &size) ||
  47       size == 0) {
  48     return false;
  49   }
  50
  51   return true;
  52 }
  53
  54 }  // namespace
  55
  56 const base::FilePath::CharType kTempDirectoryName[] = FILE_PATH_LITERAL("Temp");
  57
  58 base::FilePath InstallExtension(const base::FilePath& unpacked_source_dir,
  59                                 const std::string& id,
  60                                 const std::string& version,
  61                                 const base::FilePath& extensions_dir) {
  62   base::FilePath extension_dir = extensions_dir.AppendASCII(id);
  63   base::FilePath version_dir;
  64
  65   // Create the extension directory if it doesn't exist already.
  66   if (!base::PathExists(extension_dir)) {
  67     if (!base::CreateDirectory(extension_dir))
  68       return base::FilePath();
  69   }
  70
  71   // Get a temp directory on the same file system as the profile.
  72   base::FilePath install_temp_dir = GetInstallTempDir(extensions_dir);
  73   base::ScopedTempDir extension_temp_dir;
  74   if (install_temp_dir.empty() ||
  75       !extension_temp_dir.CreateUniqueTempDirUnderPath(install_temp_dir)) {
  76     LOG(ERROR) << "Creating of temp dir under in the profile failed.";
  77     return base::FilePath();
  78   }
  79   base::FilePath crx_temp_source =
  80       extension_temp_dir.path().Append(unpacked_source_dir.BaseName());
  81   if (!base::Move(unpacked_source_dir, crx_temp_source)) {
  82     LOG(ERROR) << "Moving extension from : " << unpacked_source_dir.value()
  83                << " to : " << crx_temp_source.value() << " failed.";
  84     return base::FilePath();
  85   }
  86
  87   // Try to find a free directory. There can be legitimate conflicts in the case
  88   // of overinstallation of the same version.
  89   const int kMaxAttempts = 100;
  90   for (int i = 0; i < kMaxAttempts; ++i) {
  91     base::FilePath candidate = extension_dir.AppendASCII(
  92         base::StringPrintf("%s_%u", version.c_str(), i));
  93     if (!base::PathExists(candidate)) {
  94       version_dir = candidate;
  95       break;
  96     }
  97   }
  98
  99   if (version_dir.empty()) {
 100     LOG(ERROR) << "Could not find a home for extension " << id << " with "
 101                << "version " << version << ".";
 102     return base::FilePath();
 103   }
 104
 105   if (!base::Move(crx_temp_source, version_dir)) {
 106     LOG(ERROR) << "Installing extension from : " << crx_temp_source.value()
 107                << " into : " << version_dir.value() << " failed.";
 108     return base::FilePath();
 109   }
 110
 111   return version_dir;
 112 }
 113
 114 void UninstallExtension(const base::FilePath& extensions_dir,
 115                         const std::string& id) {
 116   // We don't care about the return value. If this fails (and it can, due to
 117   // plugins that aren't unloaded yet), it will get cleaned up by
 118   // ExtensionGarbageCollector::GarbageCollectExtensions.
 119   base::DeleteFile(extensions_dir.AppendASCII(id), true);  // recursive.
 120 }
 121
 122 scoped_refptr<Extension> LoadExtension(const base::FilePath& extension_path,
 123                                        Manifest::Location location,
 124                                        int flags,
 125                                        std::string* error) {
 126   return LoadExtension(extension_path, std::string(), location, flags, error);
 127 }
 128
 129 scoped_refptr<Extension> LoadExtension(const base::FilePath& extension_path,
 130                                        const std::string& extension_id,
 131                                        Manifest::Location location,
 132                                        int flags,
 133                                        std::string* error) {
 134   scoped_ptr<base::DictionaryValue> manifest(
 135       LoadManifest(extension_path, error));
 136   if (!manifest.get())
 137     return NULL;
 138   if (!extension_l10n_util::LocalizeExtension(
 139           extension_path, manifest.get(), error)) {
 140     return NULL;
 141   }
 142
 143   scoped_refptr<Extension> extension(Extension::Create(
 144       extension_path, location, *manifest, flags, extension_id, error));
 145   if (!extension.get())
 146     return NULL;
 147
 148   std::vector<InstallWarning> warnings;
 149   if (!ValidateExtension(extension.get(), error, &warnings))
 150     return NULL;
 151   extension->AddInstallWarnings(warnings);
 152
 153   return extension;
 154 }
 155
 156 base::DictionaryValue* LoadManifest(const base::FilePath& extension_path,
 157                                     std::string* error) {
 158   return LoadManifest(extension_path, kManifestFilename, error);
 159 }
 160
 161 base::DictionaryValue* LoadManifest(
 162     const base::FilePath& extension_path,
 163     const base::FilePath::CharType* manifest_filename,
 164     std::string* error) {
 165   base::FilePath manifest_path = extension_path.Append(manifest_filename);
 166   if (!base::PathExists(manifest_path)) {
 167     *error = l10n_util::GetStringUTF8(IDS_EXTENSION_MANIFEST_UNREADABLE);
 168     return NULL;
 169   }
 170
 171   JSONFileValueSerializer serializer(manifest_path);
 172   scoped_ptr<base::Value> root(serializer.Deserialize(NULL, error));
 173   if (!root.get()) {
 174     if (error->empty()) {
 175       // If |error| is empty, than the file could not be read.
 176       // It would be cleaner to have the JSON reader give a specific error
 177       // in this case, but other code tests for a file error with
 178       // error->empty().  For now, be consistent.
 179       *error = l10n_util::GetStringUTF8(IDS_EXTENSION_MANIFEST_UNREADABLE);
 180     } else {
 181       *error = base::StringPrintf(
 182           "%s  %s", manifest_errors::kManifestParseError, error->c_str());
 183     }
 184     return NULL;
 185   }
 186
 187   if (!root->IsType(base::Value::TYPE_DICTIONARY)) {
 188     *error = l10n_util::GetStringUTF8(IDS_EXTENSION_MANIFEST_INVALID);
 189     return NULL;
 190   }
 191
 192   return static_cast<base::DictionaryValue*>(root.release());
 193 }
 194
 195 bool ValidateExtension(const Extension* extension,
 196                        std::string* error,
 197                        std::vector<InstallWarning>* warnings) {
 198   // Ask registered manifest handlers to validate their paths.
 199   if (!ManifestHandler::ValidateExtension(extension, error, warnings))
 200     return false;
 201
 202   // Check children of extension root to see if any of them start with _ and is
 203   // not on the reserved list. We only warn, and do not block the loading of the
 204   // extension.
 205   std::string warning;
 206   if (!CheckForIllegalFilenames(extension->path(), &warning))
 207     warnings->push_back(InstallWarning(warning));
 208
 209   // Check that extensions don't include private key files.
 210   std::vector<base::FilePath> private_keys =
 211       FindPrivateKeyFiles(extension->path());
 212   if (extension->creation_flags() & Extension::ERROR_ON_PRIVATE_KEY) {
 213     if (!private_keys.empty()) {
 214       // Only print one of the private keys because l10n_util doesn't have a way
 215       // to translate a list of strings.
 216       *error =
 217           l10n_util::GetStringFUTF8(IDS_EXTENSION_CONTAINS_PRIVATE_KEY,
 218                                     private_keys.front().LossyDisplayName());
 219       return false;
 220     }
 221   } else {
 222     for (size_t i = 0; i < private_keys.size(); ++i) {
 223       warnings->push_back(InstallWarning(
 224           l10n_util::GetStringFUTF8(IDS_EXTENSION_CONTAINS_PRIVATE_KEY,
 225                                     private_keys[i].LossyDisplayName())));
 226     }
 227     // Only warn; don't block loading the extension.
 228   }
 229   return true;
 230 }
 231
 232 std::vector<base::FilePath> FindPrivateKeyFiles(
 233     const base::FilePath& extension_dir) {
 234   std::vector<base::FilePath> result;
 235   // Pattern matching only works at the root level, so filter manually.
 236   base::FileEnumerator traversal(
 237       extension_dir, /*recursive=*/true, base::FileEnumerator::FILES);
 238   for (base::FilePath current = traversal.Next(); !current.empty();
 239        current = traversal.Next()) {
 240     if (!current.MatchesExtension(kExtensionKeyFileExtension))
 241       continue;
 242
 243     std::string key_contents;
 244     if (!base::ReadFileToString(current, &key_contents)) {
 245       // If we can't read the file, assume it's not a private key.
 246       continue;
 247     }
 248     std::string key_bytes;
 249     if (!Extension::ParsePEMKeyBytes(key_contents, &key_bytes)) {
 250       // If we can't parse the key, assume it's ok too.
 251       continue;
 252     }
 253
 254     result.push_back(current);
 255   }
 256   return result;
 257 }
 258
 259 bool CheckForIllegalFilenames(const base::FilePath& extension_path,
 260                               std::string* error) {
 261   // Reserved underscore names.
 262   static const base::FilePath::CharType* reserved_names[] = {
 263       kLocaleFolder, kPlatformSpecificFolder, FILE_PATH_LITERAL("__MACOSX"), };
 264   CR_DEFINE_STATIC_LOCAL(
 265       std::set<base::FilePath::StringType>,
 266       reserved_underscore_names,
 267       (reserved_names, reserved_names + arraysize(reserved_names)));
 268
 269   // Enumerate all files and directories in the extension root.
 270   // There is a problem when using pattern "_*" with FileEnumerator, so we have
 271   // to cheat with find_first_of and match all.
 272   const int kFilesAndDirectories =
 273       base::FileEnumerator::DIRECTORIES | base::FileEnumerator::FILES;
 274   base::FileEnumerator all_files(extension_path, false, kFilesAndDirectories);
 275
 276   base::FilePath file;
 277   while (!(file = all_files.Next()).empty()) {
 278     base::FilePath::StringType filename = file.BaseName().value();
 279     // Skip all that don't start with "_".
 280     if (filename.find_first_of(FILE_PATH_LITERAL("_")) != 0)
 281       continue;
 282     if (reserved_underscore_names.find(filename) ==
 283         reserved_underscore_names.end()) {
 284       *error = base::StringPrintf(
 285           "Cannot load extension with file or directory name %s. "
 286           "Filenames starting with \"_\" are reserved for use by the system.",
 287           file.BaseName().AsUTF8Unsafe().c_str());
 288       return false;
 289     }
 290   }
 291
 292   return true;
 293 }
 294
 295 base::FilePath GetInstallTempDir(const base::FilePath& extensions_dir) {
 296   // We do file IO in this function, but only when the current profile's
 297   // Temp directory has never been used before, or in a rare error case.
 298   // Developers are not likely to see these situations often, so do an
 299   // explicit thread check.
 300   base::ThreadRestrictions::AssertIOAllowed();
 301
 302   // Create the temp directory as a sub-directory of the Extensions directory.
 303   // This guarantees it is on the same file system as the extension's eventual
 304   // install target.
 305   base::FilePath temp_path = extensions_dir.Append(kTempDirectoryName);
 306   if (base::PathExists(temp_path)) {
 307     if (!base::DirectoryExists(temp_path)) {
 308       DLOG(WARNING) << "Not a directory: " << temp_path.value();
 309       return base::FilePath();
 310     }
 311     if (!base::PathIsWritable(temp_path)) {
 312       DLOG(WARNING) << "Can't write to path: " << temp_path.value();
 313       return base::FilePath();
 314     }
 315     // This is a directory we can write to.
 316     return temp_path;
 317   }
 318
 319   // Directory doesn't exist, so create it.
 320   if (!base::CreateDirectory(temp_path)) {
 321     DLOG(WARNING) << "Couldn't create directory: " << temp_path.value();
 322     return base::FilePath();
 323   }
 324   return temp_path;
 325 }
 326
 327 void DeleteFile(const base::FilePath& path, bool recursive) {
 328   base::DeleteFile(path, recursive);
 329 }
 330
 331 base::FilePath ExtensionURLToRelativeFilePath(const GURL& url) {
 332   std::string url_path = url.path();
 333   if (url_path.empty() || url_path[0] != '/')
 334     return base::FilePath();
 335
 336   // Drop the leading slashes and convert %-encoded UTF8 to regular UTF8.
 337   std::string file_path = net::UnescapeURLComponent(url_path,
 338       net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS);
 339   size_t skip = file_path.find_first_not_of("/\\");
 340   if (skip != file_path.npos)
 341     file_path = file_path.substr(skip);
 342
 343   base::FilePath path = base::FilePath::FromUTF8Unsafe(file_path);
 344
 345   // It's still possible for someone to construct an annoying URL whose path
 346   // would still wind up not being considered relative at this point.
 347   // For example: chrome-extension://id/c:////foo.html
 348   if (path.IsAbsolute())
 349     return base::FilePath();
 350
 351   return path;
 352 }
 353
 354 base::FilePath ExtensionResourceURLToFilePath(const GURL& url,
 355                                               const base::FilePath& root) {
 356   std::string host = net::UnescapeURLComponent(url.host(),
 357       net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS);
 358   if (host.empty())
 359     return base::FilePath();
 360
 361   base::FilePath relative_path = ExtensionURLToRelativeFilePath(url);
 362   if (relative_path.empty())
 363     return base::FilePath();
 364
 365   base::FilePath path = root.AppendASCII(host).Append(relative_path);
 366   if (!base::PathExists(path))
 367     return base::FilePath();
 368   path = base::MakeAbsoluteFilePath(path);
 369   if (path.empty() || !root.IsParent(path))
 370     return base::FilePath();
 371   return path;
 372 }
 373
 374 bool ValidateExtensionIconSet(const ExtensionIconSet& icon_set,
 375                               const Extension* extension,
 376                               int error_message_id,
 377                               std::string* error) {
 378   for (ExtensionIconSet::IconMap::const_iterator iter = icon_set.map().begin();
 379        iter != icon_set.map().end();
 380        ++iter) {
 381     const base::FilePath path =
 382         extension->GetResource(iter->second).GetFilePath();
 383     if (!ValidateFilePath(path)) {
 384       *error = l10n_util::GetStringFUTF8(error_message_id,
 385                                          base::UTF8ToUTF16(iter->second));
 386       return false;
 387     }
 388   }
 389   return true;
 390 }
 391
 392 MessageBundle* LoadMessageBundle(
 393     const base::FilePath& extension_path,
 394     const std::string& default_locale,
 395     std::string* error) {
 396   error->clear();
 397   // Load locale information if available.
 398   base::FilePath locale_path = extension_path.Append(kLocaleFolder);
 399   if (!base::PathExists(locale_path))
 400     return NULL;
 401
 402   std::set<std::string> locales;
 403   if (!extension_l10n_util::GetValidLocales(locale_path, &locales, error))
 404     return NULL;
 405
 406   if (default_locale.empty() || locales.find(default_locale) == locales.end()) {
 407     *error = l10n_util::GetStringUTF8(
 408         IDS_EXTENSION_LOCALES_NO_DEFAULT_LOCALE_SPECIFIED);
 409     return NULL;
 410   }
 411
 412   MessageBundle* message_bundle =
 413       extension_l10n_util::LoadMessageCatalogs(
 414           locale_path,
 415           default_locale,
 416           extension_l10n_util::CurrentLocaleOrDefault(),
 417           locales,
 418           error);
 419
 420   return message_bundle;
 421 }
 422
 423 std::map<std::string, std::string>* LoadMessageBundleSubstitutionMap(
 424     const base::FilePath& extension_path,
 425     const std::string& extension_id,
 426     const std::string& default_locale) {
 427   std::map<std::string, std::string>* return_value =
 428       new std::map<std::string, std::string>();
 429   if (!default_locale.empty()) {
 430     // Touch disk only if extension is localized.
 431     std::string error;
 432     scoped_ptr<MessageBundle> bundle(
 433         LoadMessageBundle(extension_path, default_locale, &error));
 434
 435     if (bundle.get())
 436       *return_value = *bundle->dictionary();
 437   }
 438
 439   // Add @@extension_id reserved message here, so it's available to
 440   // non-localized extensions too.
 441   return_value->insert(
 442       std::make_pair(MessageBundle::kExtensionIdKey, extension_id));
 443
 444   return return_value;
 445 }
 446
 447 base::FilePath GetVerifiedContentsPath(const base::FilePath& extension_path) {
 448   return extension_path.Append(kMetadataFolder)
 449       .Append(kVerifiedContentsFilename);
 450 }
 451 base::FilePath GetComputedHashesPath(const base::FilePath& extension_path) {
 452   return extension_path.Append(kMetadataFolder).Append(kComputedHashesFilename);
 453 }
 454
 455 }  // namespace file_util
 456 }  // namespace extensions