// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "extensions/browser/sandboxed_unpacker.h"

#include <stddef.h>
#include <stdint.h>

#include <set>
#include <tuple>
#include <utility>
#include <vector>

#include "base/bind.h"
#include "base/command_line.h"
#include "base/files/file_enumerator.h"
#include "base/files/file_util.h"
#include "base/i18n/rtl.h"
#include "base/json/json_string_value_serializer.h"
#include "base/metrics/histogram_macros.h"
#include "base/path_service.h"
#include "base/sequenced_task_runner.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/utf_string_conversions.h"
#include "base/task/post_task.h"
#include "base/timer/elapsed_timer.h"
#include "build/build_config.h"
#include "components/crx_file/crx_verifier.h"
#include "content/public/browser/browser_task_traits.h"
#include "content/public/browser/browser_thread.h"
#include "extensions/browser/api/declarative_net_request/index_helper.h"
#include "extensions/browser/computed_hashes.h"
#include "extensions/browser/extension_file_task_runner.h"
#include "extensions/browser/install/crx_install_error.h"
#include "extensions/browser/install/sandboxed_unpacker_failure_reason.h"
#include "extensions/browser/zipfile_installer.h"
#include "extensions/common/api/declarative_net_request/dnr_manifest_data.h"
#include "extensions/common/constants.h"
#include "extensions/common/extension.h"
#include "extensions/common/extension_l10n_util.h"
#include "extensions/common/extension_resource_path_normalizer.h"
#include "extensions/common/extension_utility_types.h"
#include "extensions/common/extensions_client.h"
#include "extensions/common/features/feature_channel.h"
#include "extensions/common/features/feature_session_type.h"
#include "extensions/common/file_util.h"
#include "extensions/common/manifest_constants.h"
#include "extensions/common/manifest_handlers/default_locale_handler.h"
#include "extensions/common/manifest_handlers/icons_handler.h"
#include "extensions/common/switches.h"
#include "extensions/strings/grit/extensions_strings.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/gfx/codec/png_codec.h"

using base::ASCIIToUTF16;
using content::BrowserThread;

namespace extensions {
namespace {

// Work horse for FindWritableTempLocation. Creates a temp file in the folder
// and uses NormalizeFilePath to check if the path is junction free.
bool VerifyJunctionFreeLocation(base::FilePath* temp_dir) {
  if (temp_dir->empty())
    return false;

  base::FilePath temp_file;
  if (!base::CreateTemporaryFileInDir(*temp_dir, &temp_file)) {
    LOG(ERROR) << temp_dir->value() << " is not writable";
    return false;
  }

  // NormalizeFilePath requires a non-empty file, so write some data.
  // If you change the exit points of this function please make sure all
  // exit points delete this temp file!
  if (base::WriteFile(temp_file, ".", 1) != 1) {
    base::DeleteFile(temp_file, false);
    return false;
  }

  base::FilePath normalized_temp_file;
  bool normalized = base::NormalizeFilePath(temp_file, &normalized_temp_file);
  if (!normalized) {
    // If |temp_file| contains a link, the sandbox will block all file
    // system operations, and the install will fail.
    LOG(ERROR) << temp_dir->value() << " seem to be on remote drive.";
  } else {
    *temp_dir = normalized_temp_file.DirName();
  }

  // Clean up the temp file.
  base::DeleteFile(temp_file, false);

  return normalized;
}

// This function tries to find a location for unpacking the extension archive
// that is writable and does not lie on a shared drive so that the sandboxed
// unpacking process can write there. If no such location exists we can not
// proceed and should fail.
// The result will be written to |temp_dir|. The function will write to this
// parameter even if it returns false.
bool FindWritableTempLocation(const base::FilePath& extensions_dir,
                              base::FilePath* temp_dir) {
// On ChromeOS, we will only attempt to unpack extension in cryptohome (profile)
// directory to provide additional security/privacy and speed up the rest of
// the extension install process.
#if !defined(OS_CHROMEOS)
  base::PathService::Get(base::DIR_TEMP, temp_dir);
  if (VerifyJunctionFreeLocation(temp_dir))
    return true;
#endif

  *temp_dir = file_util::GetInstallTempDir(extensions_dir);
  if (VerifyJunctionFreeLocation(temp_dir))
    return true;
  // Neither paths is link free chances are good installation will fail.
  LOG(ERROR) << "Both the %TEMP% folder and the profile seem to be on "
             << "remote drives or read-only. Installation can not complete!";
  return false;
}

std::set<base::FilePath> GetMessageCatalogPathsToBeSanitized(
    const base::FilePath& locales_path) {
  // Not all folders under _locales have to be valid locales.
  base::FileEnumerator locales(locales_path, /*recursive=*/false,
                               base::FileEnumerator::DIRECTORIES);

  std::set<base::FilePath> message_catalog_paths;
  std::set<std::string> all_locales;
  extension_l10n_util::GetAllLocales(&all_locales);
  base::FilePath locale_path;
  while (!(locale_path = locales.Next()).empty()) {
    if (!extension_l10n_util::ShouldSkipValidation(locales_path, locale_path,
                                                   all_locales)) {
      message_catalog_paths.insert(locale_path.Append(kMessagesFilename));
    }
  }
  return message_catalog_paths;
}

// Callback for ComputedHashes::Create, compute hashes for all files except
// _metadata directory (e.g. computed_hashes.json itself).
bool ShouldComputeHashesForResource(
    const base::FilePath& relative_resource_path) {
  std::vector<base::FilePath::StringType> components;
  relative_resource_path.GetComponents(&components);
  return !components.empty() && components[0] != kMetadataFolder;
}

base::Optional<crx_file::VerifierFormat> g_verifier_format_override_for_test;

}  // namespace

SandboxedUnpackerClient::SandboxedUnpackerClient()
    : RefCountedDeleteOnSequence<SandboxedUnpackerClient>(
          content::GetUIThreadTaskRunner({})) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
}

void SandboxedUnpackerClient::ShouldComputeHashesForOffWebstoreExtension(
    scoped_refptr<const Extension> extension,
    base::OnceCallback<void(bool)> callback) {
  std::move(callback).Run(false);
}

SandboxedUnpacker::ScopedVerifierFormatOverrideForTest::
    ScopedVerifierFormatOverrideForTest(crx_file::VerifierFormat format) {
  DCHECK(!g_verifier_format_override_for_test.has_value());
  g_verifier_format_override_for_test = format;
}

SandboxedUnpacker::ScopedVerifierFormatOverrideForTest::
    ~ScopedVerifierFormatOverrideForTest() {
  g_verifier_format_override_for_test.reset();
}

SandboxedUnpacker::SandboxedUnpacker(
    Manifest::Location location,
    int creation_flags,
    const base::FilePath& extensions_dir,
    const scoped_refptr<base::SequencedTaskRunner>& unpacker_io_task_runner,
    SandboxedUnpackerClient* client)
    : client_(client),
      extensions_dir_(extensions_dir),
      location_(location),
      creation_flags_(creation_flags),
      unpacker_io_task_runner_(unpacker_io_task_runner) {
  // Tracking for crbug.com/692069. The location must be valid. If it's invalid,
  // the utility process kills itself for a bad IPC.
  CHECK_GT(location, Manifest::INVALID_LOCATION);
  CHECK_LT(location, Manifest::NUM_LOCATIONS);
}

bool SandboxedUnpacker::CreateTempDirectory() {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());

  base::FilePath temp_dir;
  if (!FindWritableTempLocation(extensions_dir_, &temp_dir)) {
    ReportFailure(SandboxedUnpackerFailureReason::COULD_NOT_GET_TEMP_DIRECTORY,
                  l10n_util::GetStringFUTF16(
                      IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
                      ASCIIToUTF16("COULD_NOT_GET_TEMP_DIRECTORY")));
    return false;
  }

  if (!temp_dir_.CreateUniqueTempDirUnderPath(temp_dir)) {
    ReportFailure(
        SandboxedUnpackerFailureReason::COULD_NOT_CREATE_TEMP_DIRECTORY,
        l10n_util::GetStringFUTF16(
            IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
            ASCIIToUTF16("COULD_NOT_CREATE_TEMP_DIRECTORY")));
    return false;
  }

  return true;
}

void SandboxedUnpacker::StartWithCrx(const CRXFileInfo& crx_info) {
  // We assume that we are started on the thread that the client wants us
  // to do file IO on.
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());

  std::string expected_hash;
  if (!crx_info.expected_hash.empty() &&
      base::CommandLine::ForCurrentProcess()->HasSwitch(
          extensions::switches::kEnableCrxHashCheck)) {
    expected_hash = base::ToLowerASCII(crx_info.expected_hash);
  }

  if (!CreateTempDirectory())
    return;  // ReportFailure() already called.

  // Initialize the path that will eventually contain the unpacked extension.
  extension_root_ = temp_dir_.GetPath().AppendASCII(kTempExtensionName);

  // Extract the public key and validate the package.
  if (!ValidateSignature(crx_info.path, expected_hash,
                         g_verifier_format_override_for_test.value_or(
                             crx_info.required_format)))
    return;  // ValidateSignature() already reported the error.

  // Copy the crx file into our working directory.
  base::FilePath temp_crx_path =
      temp_dir_.GetPath().Append(crx_info.path.BaseName());

  if (!base::CopyFile(crx_info.path, temp_crx_path)) {
    // Failed to copy extension file to temporary directory.
    ReportFailure(
        SandboxedUnpackerFailureReason::
            FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY,
        l10n_util::GetStringFUTF16(
            IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
            ASCIIToUTF16("FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY")));
    return;
  }

  // The utility process will have access to the directory passed to
  // SandboxedUnpacker.  That directory should not contain a symlink or NTFS
  // reparse point.  When the path is used, following the link/reparse point
  // will cause file system access outside the sandbox path, and the sandbox
  // will deny the operation.
  base::FilePath link_free_crx_path;
  if (!base::NormalizeFilePath(temp_crx_path, &link_free_crx_path)) {
    LOG(ERROR) << "Could not get the normalized path of "
               << temp_crx_path.value();
    ReportFailure(
        SandboxedUnpackerFailureReason::COULD_NOT_GET_SANDBOX_FRIENDLY_PATH,
        l10n_util::GetStringUTF16(IDS_EXTENSION_UNPACK_FAILED));
    return;
  }

  // Make sure to create the directory where the extension will be unzipped, as
  // the unzipper service requires it.
  base::FilePath unzipped_dir =
      link_free_crx_path.DirName().AppendASCII(kTempExtensionName);
  base::File::Error error;
  if (!base::CreateDirectoryAndGetError(unzipped_dir, &error)) {
    LOG(ERROR) << "Failed to created directory " << unzipped_dir.value()
               << " with error " << error;
    ReportFailure(SandboxedUnpackerFailureReason::UNZIP_FAILED,
                  l10n_util::GetStringUTF16(IDS_EXTENSION_PACKAGE_UNZIP_ERROR));
    return;
  }

  Unzip(link_free_crx_path, unzipped_dir);
}

void SandboxedUnpacker::StartWithDirectory(const std::string& extension_id,
                                           const std::string& public_key,
                                           const base::FilePath& directory) {
  // We assume that we are started on the thread that the client wants us
  // to do file IO on.
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());

  extension_id_ = extension_id;
  public_key_ = public_key;
  if (!CreateTempDirectory())
    return;  // ReportFailure() already called.

  extension_root_ = temp_dir_.GetPath().AppendASCII(kTempExtensionName);

  if (!base::Move(directory, extension_root_)) {
    LOG(ERROR) << "Could not move " << directory.value() << " to "
               << extension_root_.value();
    ReportFailure(
        SandboxedUnpackerFailureReason::DIRECTORY_MOVE_FAILED,
        l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
                                   ASCIIToUTF16("DIRECTORY_MOVE_FAILED")));
    return;
  }

  Unpack(extension_root_);
}

SandboxedUnpacker::~SandboxedUnpacker() {
  // To avoid blocking shutdown, don't delete temporary directory here if it
  // hasn't been cleaned up or passed on to another owner yet.
  // This is OK because ExtensionGarbageCollector will take care of the leaked
  // |temp_dir_| eventually.
  temp_dir_.Take();

  // Make sure that members get deleted on the thread they were created.
  if (image_sanitizer_) {
    unpacker_io_task_runner_->DeleteSoon(FROM_HERE,
                                         std::move(image_sanitizer_));
  }
  if (json_file_sanitizer_) {
    unpacker_io_task_runner_->DeleteSoon(FROM_HERE,
                                         std::move(json_file_sanitizer_));
  }
}

void SandboxedUnpacker::Unzip(const base::FilePath& crx_path,
                              const base::FilePath& unzipped_dir) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());

  DCHECK(crx_path.DirName() == temp_dir_.GetPath());

  ZipFileInstaller::Create(base::BindOnce(&SandboxedUnpacker::UnzipDone, this))
      ->LoadFromZipFileInDir(crx_path, unzipped_dir);
}

void SandboxedUnpacker::UnzipDone(const base::FilePath& zip_file,
                                  const base::FilePath& unzip_dir,
                                  const std::string& error) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());

  if (!error.empty()) {
    ReportFailure(SandboxedUnpackerFailureReason::UNZIP_FAILED,
                  l10n_util::GetStringUTF16(IDS_EXTENSION_PACKAGE_UNZIP_ERROR));
    return;
  }

  Unpack(unzip_dir);
}

void SandboxedUnpacker::Unpack(const base::FilePath& directory) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());

  DCHECK(directory.DirName() == temp_dir_.GetPath());

  base::FilePath manifest_path = extension_root_.Append(kManifestFilename);

  ParseJsonFile(manifest_path,
                base::BindOnce(&SandboxedUnpacker::ReadManifestDone, this));
}

void SandboxedUnpacker::ReadManifestDone(
    base::Optional<base::Value> manifest,
    const base::Optional<std::string>& error) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  if (error) {
    ReportUnpackExtensionFailed(*error);
    return;
  }
  if (!manifest || !manifest->is_dict()) {
    ReportUnpackExtensionFailed(manifest_errors::kInvalidManifest);
    return;
  }

  std::string error_msg;
  scoped_refptr<Extension> extension(
      Extension::Create(extension_root_, location_,
                        base::Value::AsDictionaryValue(manifest.value()),
                        creation_flags_, extension_id_, &error_msg));
  if (!extension) {
    ReportUnpackExtensionFailed(error_msg);
    return;
  }

  std::vector<InstallWarning> warnings;
  if (!file_util::ValidateExtension(extension.get(), &error_msg, &warnings)) {
    ReportUnpackExtensionFailed(error_msg);
    return;
  }
  extension->AddInstallWarnings(std::move(warnings));

  UnpackExtensionSucceeded(std::move(manifest.value()));
}

void SandboxedUnpacker::UnpackExtensionSucceeded(base::Value manifest) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());

  base::Optional<base::Value> final_manifest(RewriteManifestFile(manifest));
  if (!final_manifest)
    return;

  std::unique_ptr<base::DictionaryValue> final_manifest_dict =
      base::DictionaryValue::From(
          base::Value::ToUniquePtrValue(std::move(final_manifest.value())));

  // Create an extension object that refers to the temporary location the
  // extension was unpacked to. We use this until the extension is finally
  // installed. For example, the install UI shows images from inside the
  // extension.

  // Localize manifest now, so confirm UI gets correct extension name.

  // TODO(rdevlin.cronin): Continue removing std::string errors and replacing
  // with base::string16
  std::string utf8_error;
  if (!extension_l10n_util::LocalizeExtension(
          extension_root_, final_manifest_dict.get(),
          extension_l10n_util::GzippedMessagesPermission::kDisallow,
          &utf8_error)) {
    ReportFailure(
        SandboxedUnpackerFailureReason::COULD_NOT_LOCALIZE_EXTENSION,
        l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_ERROR_MESSAGE,
                                   base::UTF8ToUTF16(utf8_error)));
    return;
  }

  extension_ =
      Extension::Create(extension_root_, location_, *final_manifest_dict,
                        Extension::REQUIRE_KEY | creation_flags_, &utf8_error);

  if (!extension_.get()) {
    ReportFailure(SandboxedUnpackerFailureReason::INVALID_MANIFEST,
                  ASCIIToUTF16("Manifest is invalid: " + utf8_error));
    return;
  }

  // The install icon path may be empty, which is OK, but if it is not it should
  // be normalized successfully.
  const std::string& original_install_icon_path =
      IconsInfo::GetIcons(extension_.get())
          .Get(extension_misc::EXTENSION_ICON_LARGE,
               ExtensionIconSet::MATCH_BIGGER);
  if (!original_install_icon_path.empty() &&
      !NormalizeExtensionResourcePath(
          base::FilePath::FromUTF8Unsafe(original_install_icon_path),
          &install_icon_path_)) {
    // Invalid path for browser image.
    ReportFailure(
        SandboxedUnpackerFailureReason::INVALID_PATH_FOR_BROWSER_IMAGE,
        l10n_util::GetStringFUTF16(
            IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
            ASCIIToUTF16("INVALID_PATH_FOR_BROWSER_IMAGE")));
    return;
  }

  manifest_ = std::move(manifest);

  DCHECK(!image_sanitizer_);
  std::set<base::FilePath> image_paths =
      ExtensionsClient::Get()->GetBrowserImagePaths(extension_.get());
  image_sanitizer_ = ImageSanitizer::CreateAndStart(
      &data_decoder_, extension_root_, image_paths,
      base::BindRepeating(&SandboxedUnpacker::ImageSanitizerDecodedImage, this),
      base::BindOnce(&SandboxedUnpacker::ImageSanitizationDone, this));
}

void SandboxedUnpacker::ImageSanitizerDecodedImage(const base::FilePath& path,
                                                   SkBitmap image) {
  if (path == install_icon_path_)
    install_icon_ = image;
}

void SandboxedUnpacker::ImageSanitizationDone(
    ImageSanitizer::Status status,
    const base::FilePath& file_path_for_error) {
  if (status == ImageSanitizer::Status::kSuccess) {
    // Next step is to sanitize the message catalogs.
    ReadMessageCatalogs();
    return;
  }

  SandboxedUnpackerFailureReason failure_reason =
      SandboxedUnpackerFailureReason::UNPACKER_CLIENT_FAILED;
  base::string16 error;
  switch (status) {
    case ImageSanitizer::Status::kImagePathError:
      failure_reason =
          SandboxedUnpackerFailureReason::INVALID_PATH_FOR_BROWSER_IMAGE;
      error = l10n_util::GetStringFUTF16(
          IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
          ASCIIToUTF16("INVALID_PATH_FOR_BROWSER_IMAGE"));
      break;
    case ImageSanitizer::Status::kFileReadError:
    case ImageSanitizer::Status::kDecodingError:
      error = l10n_util::GetStringFUTF16(
          IDS_EXTENSION_PACKAGE_IMAGE_ERROR,
          base::i18n::GetDisplayStringInLTRDirectionality(
              file_path_for_error.BaseName().LossyDisplayName()));
      break;
    case ImageSanitizer::Status::kFileDeleteError:
      failure_reason =
          SandboxedUnpackerFailureReason::ERROR_REMOVING_OLD_IMAGE_FILE;
      error = l10n_util::GetStringFUTF16(
          IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
          ASCIIToUTF16("ERROR_REMOVING_OLD_IMAGE_FILE"));
      break;
    case ImageSanitizer::Status::kEncodingError:
      failure_reason =
          SandboxedUnpackerFailureReason::ERROR_RE_ENCODING_THEME_IMAGE;
      error = l10n_util::GetStringFUTF16(
          IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
          ASCIIToUTF16("ERROR_RE_ENCODING_THEME_IMAGE"));
      break;
    case ImageSanitizer::Status::kFileWriteError:
      failure_reason = SandboxedUnpackerFailureReason::ERROR_SAVING_THEME_IMAGE;
      error =
          l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
                                     ASCIIToUTF16("ERROR_SAVING_THEME_IMAGE"));
      break;
    case ImageSanitizer::Status::kServiceError:
      failure_reason = SandboxedUnpackerFailureReason::
          UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL;
      error = l10n_util::GetStringFUTF16(
          IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
          ASCIIToUTF16("ERROR_UTILITY_PROCESS_CRASH"));
      break;
    default:
      NOTREACHED();
      break;
  }

  ReportFailure(failure_reason, error);
}

void SandboxedUnpacker::ReadMessageCatalogs() {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  if (LocaleInfo::GetDefaultLocale(extension_.get()).empty()) {
    MessageCatalogsSanitized(JsonFileSanitizer::Status::kSuccess,
                             std::string());
    return;
  }

  // Get the paths to the message catalogs we should sanitize on the file task
  // runner.
  base::FilePath locales_path = extension_root_.Append(kLocaleFolder);

  base::PostTaskAndReplyWithResult(
      extensions::GetExtensionFileTaskRunner().get(), FROM_HERE,
      base::BindOnce(&GetMessageCatalogPathsToBeSanitized, locales_path),
      base::BindOnce(&SandboxedUnpacker::SanitizeMessageCatalogs, this));
}

void SandboxedUnpacker::SanitizeMessageCatalogs(
    const std::set<base::FilePath>& message_catalog_paths) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  json_file_sanitizer_ = JsonFileSanitizer::CreateAndStart(
      &data_decoder_, message_catalog_paths,
      base::BindOnce(&SandboxedUnpacker::MessageCatalogsSanitized, this));
}

void SandboxedUnpacker::MessageCatalogsSanitized(
    JsonFileSanitizer::Status status,
    const std::string& error_msg) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  if (status == JsonFileSanitizer::Status::kSuccess) {
    IndexAndPersistJSONRulesetsIfNeeded();
    return;
  }

  SandboxedUnpackerFailureReason failure_reason =
      SandboxedUnpackerFailureReason::UNPACKER_CLIENT_FAILED;
  base::string16 error;
  switch (status) {
    case JsonFileSanitizer::Status::kFileReadError:
    case JsonFileSanitizer::Status::kDecodingError:
      failure_reason = SandboxedUnpackerFailureReason::INVALID_CATALOG_DATA;
      error = l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
                                         ASCIIToUTF16("INVALID_CATALOG_DATA"));
      break;
    case JsonFileSanitizer::Status::kSerializingError:
      failure_reason =
          SandboxedUnpackerFailureReason::ERROR_SERIALIZING_CATALOG;
      error =
          l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
                                     ASCIIToUTF16("ERROR_SERIALIZING_CATALOG"));
      break;
    case JsonFileSanitizer::Status::kFileDeleteError:
    case JsonFileSanitizer::Status::kFileWriteError:
      failure_reason = SandboxedUnpackerFailureReason::ERROR_SAVING_CATALOG;
      error = l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
                                         ASCIIToUTF16("ERROR_SAVING_CATALOG"));
      break;
    default:
      NOTREACHED();
      break;
  }

  ReportFailure(failure_reason, error);
}

void SandboxedUnpacker::IndexAndPersistJSONRulesetsIfNeeded() {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  DCHECK(extension_);

  declarative_net_request::IndexHelper::IndexStaticRulesets(
      *extension_,
      base::BindOnce(&SandboxedUnpacker::OnJSONRulesetsIndexed, this));
}

void SandboxedUnpacker::OnJSONRulesetsIndexed(
    declarative_net_request::IndexHelper::Result result) {
  if (result.error) {
    ReportFailure(
        SandboxedUnpackerFailureReason::ERROR_INDEXING_DNR_RULESET,
        l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_ERROR_MESSAGE,
                                   base::UTF8ToUTF16(*result.error)));
    return;
  }

  if (!result.warnings.empty())
    extension_->AddInstallWarnings(std::move(result.warnings));

  ruleset_checksums_ = std::move(result.ruleset_checksums);

  CheckComputeHashes();
}

void SandboxedUnpacker::CheckComputeHashes() {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  client_->ShouldComputeHashesForOffWebstoreExtension(
      extension_, base::BindOnce(&SandboxedUnpacker::MaybeComputeHashes, this));
}

void SandboxedUnpacker::MaybeComputeHashes(bool should_compute) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  if (!should_compute) {
    ReportSuccess();
    return;
  }

  base::ElapsedTimer timer;

  base::Optional<ComputedHashes::Data> computed_hashes_data =
      ComputedHashes::Compute(
          extension_->path(),
          extension_misc::kContentVerificationDefaultBlockSize,
          IsCancelledCallback(),
          base::BindRepeating(&ShouldComputeHashesForResource));
  bool success =
      computed_hashes_data &&
      ComputedHashes(std::move(*computed_hashes_data))
          .WriteToFile(file_util::GetComputedHashesPath(extension_->path()));
  UMA_HISTOGRAM_BOOLEAN(
      "Extensions.ContentVerification.ComputeHashesOnInstallResult", success);
  if (success) {
    UMA_HISTOGRAM_TIMES(
        "Extensions.ContentVerification.ComputeHashesOnInstallTime",
        timer.Elapsed());
  } else {
    LOG(ERROR) << "[extension " << extension_->id()
               << "] Failed to create computed_hashes.json";
  }

  ReportSuccess();
}

data_decoder::mojom::JsonParser* SandboxedUnpacker::GetJsonParserPtr() {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  if (!json_parser_) {
    data_decoder_.GetService()->BindJsonParser(
        json_parser_.BindNewPipeAndPassReceiver());
    json_parser_.set_disconnect_handler(base::BindOnce(
        &SandboxedUnpacker::ReportFailure, this,
        SandboxedUnpackerFailureReason::
            UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL,
        l10n_util::GetStringFUTF16(
            IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
            ASCIIToUTF16("UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL")) +
            ASCIIToUTF16(". ") +
            l10n_util::GetStringUTF16(IDS_EXTENSION_INSTALL_PROCESS_CRASHED)));
  }
  return json_parser_.get();
}

void SandboxedUnpacker::ReportUnpackExtensionFailed(base::StringPiece error) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  ReportFailure(SandboxedUnpackerFailureReason::UNPACKER_CLIENT_FAILED,
                l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_ERROR_MESSAGE,
                                           base::UTF8ToUTF16(error)));
}

base::string16 SandboxedUnpacker::FailureReasonToString16(
    const SandboxedUnpackerFailureReason reason) {
  switch (reason) {
    case SandboxedUnpackerFailureReason::COULD_NOT_GET_TEMP_DIRECTORY:
      return ASCIIToUTF16("COULD_NOT_GET_TEMP_DIRECTORY");
    case SandboxedUnpackerFailureReason::COULD_NOT_CREATE_TEMP_DIRECTORY:
      return ASCIIToUTF16("COULD_NOT_CREATE_TEMP_DIRECTORY");
    case SandboxedUnpackerFailureReason::
        FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY:
      return ASCIIToUTF16("FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY");
    case SandboxedUnpackerFailureReason::COULD_NOT_GET_SANDBOX_FRIENDLY_PATH:
      return ASCIIToUTF16("COULD_NOT_GET_SANDBOX_FRIENDLY_PATH");
    case SandboxedUnpackerFailureReason::COULD_NOT_LOCALIZE_EXTENSION:
      return ASCIIToUTF16("COULD_NOT_LOCALIZE_EXTENSION");
    case SandboxedUnpackerFailureReason::INVALID_MANIFEST:
      return ASCIIToUTF16("INVALID_MANIFEST");
    case SandboxedUnpackerFailureReason::UNPACKER_CLIENT_FAILED:
      return ASCIIToUTF16("UNPACKER_CLIENT_FAILED");
    case SandboxedUnpackerFailureReason::
        UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL:
      return ASCIIToUTF16("UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL");

    case SandboxedUnpackerFailureReason::CRX_FILE_NOT_READABLE:
      return ASCIIToUTF16("CRX_FILE_NOT_READABLE");
    case SandboxedUnpackerFailureReason::CRX_HEADER_INVALID:
      return ASCIIToUTF16("CRX_HEADER_INVALID");
    case SandboxedUnpackerFailureReason::CRX_MAGIC_NUMBER_INVALID:
      return ASCIIToUTF16("CRX_MAGIC_NUMBER_INVALID");
    case SandboxedUnpackerFailureReason::CRX_VERSION_NUMBER_INVALID:
      return ASCIIToUTF16("CRX_VERSION_NUMBER_INVALID");
    case SandboxedUnpackerFailureReason::CRX_EXCESSIVELY_LARGE_KEY_OR_SIGNATURE:
      return ASCIIToUTF16("CRX_EXCESSIVELY_LARGE_KEY_OR_SIGNATURE");
    case SandboxedUnpackerFailureReason::CRX_ZERO_KEY_LENGTH:
      return ASCIIToUTF16("CRX_ZERO_KEY_LENGTH");
    case SandboxedUnpackerFailureReason::CRX_ZERO_SIGNATURE_LENGTH:
      return ASCIIToUTF16("CRX_ZERO_SIGNATURE_LENGTH");
    case SandboxedUnpackerFailureReason::CRX_PUBLIC_KEY_INVALID:
      return ASCIIToUTF16("CRX_PUBLIC_KEY_INVALID");
    case SandboxedUnpackerFailureReason::CRX_SIGNATURE_INVALID:
      return ASCIIToUTF16("CRX_SIGNATURE_INVALID");
    case SandboxedUnpackerFailureReason::
        CRX_SIGNATURE_VERIFICATION_INITIALIZATION_FAILED:
      return ASCIIToUTF16("CRX_SIGNATURE_VERIFICATION_INITIALIZATION_FAILED");
    case SandboxedUnpackerFailureReason::CRX_SIGNATURE_VERIFICATION_FAILED:
      return ASCIIToUTF16("CRX_SIGNATURE_VERIFICATION_FAILED");
    case SandboxedUnpackerFailureReason::CRX_FILE_IS_DELTA_UPDATE:
      return ASCIIToUTF16("CRX_FILE_IS_DELTA_UPDATE");
    case SandboxedUnpackerFailureReason::CRX_EXPECTED_HASH_INVALID:
      return ASCIIToUTF16("CRX_EXPECTED_HASH_INVALID");

    case SandboxedUnpackerFailureReason::ERROR_SERIALIZING_MANIFEST_JSON:
      return ASCIIToUTF16("ERROR_SERIALIZING_MANIFEST_JSON");
    case SandboxedUnpackerFailureReason::ERROR_SAVING_MANIFEST_JSON:
      return ASCIIToUTF16("ERROR_SAVING_MANIFEST_JSON");

    case SandboxedUnpackerFailureReason::INVALID_PATH_FOR_BROWSER_IMAGE:
      return ASCIIToUTF16("INVALID_PATH_FOR_BROWSER_IMAGE");
    case SandboxedUnpackerFailureReason::ERROR_REMOVING_OLD_IMAGE_FILE:
      return ASCIIToUTF16("ERROR_REMOVING_OLD_IMAGE_FILE");
    case SandboxedUnpackerFailureReason::INVALID_PATH_FOR_BITMAP_IMAGE:
      return ASCIIToUTF16("INVALID_PATH_FOR_BITMAP_IMAGE");
    case SandboxedUnpackerFailureReason::ERROR_RE_ENCODING_THEME_IMAGE:
      return ASCIIToUTF16("ERROR_RE_ENCODING_THEME_IMAGE");
    case SandboxedUnpackerFailureReason::ERROR_SAVING_THEME_IMAGE:
      return ASCIIToUTF16("ERROR_SAVING_THEME_IMAGE");

    case SandboxedUnpackerFailureReason::INVALID_CATALOG_DATA:
      return ASCIIToUTF16("INVALID_CATALOG_DATA");
    case SandboxedUnpackerFailureReason::ERROR_SERIALIZING_CATALOG:
      return ASCIIToUTF16("ERROR_SERIALIZING_CATALOG");
    case SandboxedUnpackerFailureReason::ERROR_SAVING_CATALOG:
      return ASCIIToUTF16("ERROR_SAVING_CATALOG");

    case SandboxedUnpackerFailureReason::CRX_HASH_VERIFICATION_FAILED:
      return ASCIIToUTF16("CRX_HASH_VERIFICATION_FAILED");

    case SandboxedUnpackerFailureReason::UNZIP_FAILED:
      return ASCIIToUTF16("UNZIP_FAILED");
    case SandboxedUnpackerFailureReason::DIRECTORY_MOVE_FAILED:
      return ASCIIToUTF16("DIRECTORY_MOVE_FAILED");

    case SandboxedUnpackerFailureReason::ERROR_INDEXING_DNR_RULESET:
      return ASCIIToUTF16("ERROR_INDEXING_DNR_RULESET");

    case SandboxedUnpackerFailureReason::CRX_REQUIRED_PROOF_MISSING:
      return ASCIIToUTF16("CRX_REQUIRED_PROOF_MISSING");

    case SandboxedUnpackerFailureReason::DEPRECATED_ABORTED_DUE_TO_SHUTDOWN:
    case SandboxedUnpackerFailureReason::DEPRECATED_ERROR_PARSING_DNR_RULESET:
    case SandboxedUnpackerFailureReason::NUM_FAILURE_REASONS:
    default:
      NOTREACHED();
      return base::string16();
  }
}

void SandboxedUnpacker::FailWithPackageError(
    const SandboxedUnpackerFailureReason reason) {
  ReportFailure(reason,
                l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_ERROR_CODE,
                                           FailureReasonToString16(reason)));
}

bool SandboxedUnpacker::ValidateSignature(
    const base::FilePath& crx_path,
    const std::string& expected_hash,
    const crx_file::VerifierFormat required_format) {
  std::vector<uint8_t> hash;
  if (!expected_hash.empty()) {
    if (!base::HexStringToBytes(expected_hash, &hash)) {
      FailWithPackageError(
          SandboxedUnpackerFailureReason::CRX_EXPECTED_HASH_INVALID);
      return false;
    }
  }
  const crx_file::VerifierResult result = crx_file::Verify(
      crx_path, required_format, std::vector<std::vector<uint8_t>>(), hash,
      &public_key_, &extension_id_);

  switch (result) {
    case crx_file::VerifierResult::OK_FULL: {
      if (!expected_hash.empty())
        UMA_HISTOGRAM_BOOLEAN("Extensions.SandboxUnpackHashCheck", true);
      return true;
    }
    case crx_file::VerifierResult::OK_DELTA:
      FailWithPackageError(
          SandboxedUnpackerFailureReason::CRX_FILE_IS_DELTA_UPDATE);
      break;
    case crx_file::VerifierResult::ERROR_FILE_NOT_READABLE:
      FailWithPackageError(
          SandboxedUnpackerFailureReason::CRX_FILE_NOT_READABLE);
      break;
    case crx_file::VerifierResult::ERROR_HEADER_INVALID:
      FailWithPackageError(SandboxedUnpackerFailureReason::CRX_HEADER_INVALID);
      break;
    case crx_file::VerifierResult::ERROR_SIGNATURE_INITIALIZATION_FAILED:
      FailWithPackageError(
          SandboxedUnpackerFailureReason::
              CRX_SIGNATURE_VERIFICATION_INITIALIZATION_FAILED);
      break;
    case crx_file::VerifierResult::ERROR_SIGNATURE_VERIFICATION_FAILED:
      FailWithPackageError(
          SandboxedUnpackerFailureReason::CRX_SIGNATURE_VERIFICATION_FAILED);
      break;
    case crx_file::VerifierResult::ERROR_EXPECTED_HASH_INVALID:
      FailWithPackageError(
          SandboxedUnpackerFailureReason::CRX_EXPECTED_HASH_INVALID);
      break;
    case crx_file::VerifierResult::ERROR_REQUIRED_PROOF_MISSING:
      FailWithPackageError(
          SandboxedUnpackerFailureReason::CRX_REQUIRED_PROOF_MISSING);
      break;
    case crx_file::VerifierResult::ERROR_FILE_HASH_FAILED:
      // We should never get this result unless we had specifically asked for
      // verification of the crx file's hash.
      CHECK(!expected_hash.empty());
      UMA_HISTOGRAM_BOOLEAN("Extensions.SandboxUnpackHashCheck", false);
      FailWithPackageError(
          SandboxedUnpackerFailureReason::CRX_HASH_VERIFICATION_FAILED);
      break;
  }

  return false;
}

void SandboxedUnpacker::ReportFailure(
    const SandboxedUnpackerFailureReason reason,
    const base::string16& error) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());

  UMA_HISTOGRAM_ENUMERATION(
      "Extensions.SandboxUnpackFailureReason", reason,
      SandboxedUnpackerFailureReason::NUM_FAILURE_REASONS);
  Cleanup();

  client_->OnUnpackFailure(CrxInstallError(reason, error));
}

void SandboxedUnpacker::ReportSuccess() {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());

  UMA_HISTOGRAM_COUNTS_1M("Extensions.SandboxUnpackSuccess", 1);

  DCHECK(!temp_dir_.GetPath().empty());

  // Client takes ownership of temporary directory, manifest, and extension.
  client_->OnUnpackSuccess(
      temp_dir_.Take(), extension_root_,
      base::DictionaryValue::From(
          base::Value::ToUniquePtrValue(std::move(manifest_.value()))),
      extension_.get(), install_icon_, std::move(ruleset_checksums_));

  // Interestingly, the C++ standard doesn't guarantee that a moved-from vector
  // is empty.
  ruleset_checksums_.clear();

  extension_.reset();

  Cleanup();
}

base::Optional<base::Value> SandboxedUnpacker::RewriteManifestFile(
    const base::Value& manifest) {
  constexpr int64_t kMaxFingerprintSize = 1024;

  // Add the public key extracted earlier to the parsed manifest and overwrite
  // the original manifest. We do this to ensure the manifest doesn't contain an
  // exploitable bug that could be used to compromise the browser.
  DCHECK(!public_key_.empty());
  base::Value final_manifest = manifest.Clone();
  final_manifest.SetStringKey(manifest_keys::kPublicKey, public_key_);

  {
    std::string differential_fingerprint;
    if (base::ReadFileToStringWithMaxSize(
            extension_root_.Append(kDifferentialFingerprintFilename),
            &differential_fingerprint, kMaxFingerprintSize)) {
      final_manifest.SetStringKey(manifest_keys::kDifferentialFingerprint,
                                  std::move(differential_fingerprint));
    }
  }

  std::string manifest_json;
  JSONStringValueSerializer serializer(&manifest_json);
  serializer.set_pretty_print(true);
  if (!serializer.Serialize(final_manifest)) {
    // Error serializing manifest.json.
    ReportFailure(
        SandboxedUnpackerFailureReason::ERROR_SERIALIZING_MANIFEST_JSON,
        l10n_util::GetStringFUTF16(
            IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
            ASCIIToUTF16("ERROR_SERIALIZING_MANIFEST_JSON")));
    return base::nullopt;
  }

  base::FilePath manifest_path = extension_root_.Append(kManifestFilename);
  int size = base::checked_cast<int>(manifest_json.size());
  if (base::WriteFile(manifest_path, manifest_json.data(), size) != size) {
    // Error saving manifest.json.
    ReportFailure(
        SandboxedUnpackerFailureReason::ERROR_SAVING_MANIFEST_JSON,
        l10n_util::GetStringFUTF16(IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
                                   ASCIIToUTF16("ERROR_SAVING_MANIFEST_JSON")));
    return base::nullopt;
  }

  return std::move(final_manifest);
}

void SandboxedUnpacker::Cleanup() {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  if (temp_dir_.IsValid() && !temp_dir_.Delete()) {
    LOG(WARNING) << "Can not delete temp directory at "
                 << temp_dir_.GetPath().value();
  }
  image_sanitizer_.reset();
  json_file_sanitizer_.reset();
  json_parser_.reset();
}

void SandboxedUnpacker::ParseJsonFile(
    const base::FilePath& path,
    data_decoder::mojom::JsonParser::ParseCallback callback) {
  DCHECK(unpacker_io_task_runner_->RunsTasksInCurrentSequence());
  std::string contents;
  if (!base::ReadFileToString(path, &contents)) {
    std::move(callback).Run(
        /*value=*/base::nullopt,
        /*error=*/base::Optional<std::string>("File doesn't exist."));
    return;
  }

  GetJsonParserPtr()->Parse(contents, std::move(callback));
}

}  // namespace extensions