File manager: support for zipping selected files.

chrome/browser/chromeos/extensions/zip_file_creator.h

+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_EXTENSIONS_ZIP_FILE_CREATOR_H_
+#define CHROME_BROWSER_CHROMEOS_EXTENSIONS_ZIP_FILE_CREATOR_H_
+
+#include <string>
+
+#include "base/file_path.h"
+#include "base/memory/ref_counted.h"
+#include "chrome/common/extensions/extension.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/utility_process_host_client.h"
+
+namespace extensions {
+
+// ZipFileCreator creates a ZIP file from a specified list of files and
+// directories under a common parent directory. This is done in a sandboxed
+// subprocess to protect the browser process from handling arbitrary input data
+// from untrusted sources.

[Jorge Lucangeli Obes, 2012/11/13 21:03:35]

How is the subprocess sandboxed? The utility process is not sandboxed by
default. Moreover, you cannot sandbox a process that needs to access the file
system, which the implementation of zip::ZipFiles does.

The safe way to do this is to pass the utility process a set of file
descriptors, not a set of file names.

+//
+// Lifetime management:
+//
+// This class is ref-counted by each call it makes to itself on another thread,
+// and by UtilityProcessHost.
+//
+// Additionally, we hold a reference to our own client so that it lives at least
+// long enough to receive the result of zip file creation.
+class ZipFileCreator : public content::UtilityProcessHostClient {
+ public:
+  class Observer {
+   public:
+    virtual void OnZipDone(bool success) = 0;
+
+   protected:
+    virtual ~Observer() {}
+  };
+
+  // Creates a zip file from the specified list of files and directories.
+  ZipFileCreator(Observer* observer,
+                 const FilePath& src_dir,
+                 const std::vector<FilePath>& src_relative_paths,
+                 const FilePath& dest_file);
+
+  // Start creating the zip file. The client is called with the results.
+  void Start();
+
+ private:
+  class ProcessHostClient;
+  friend class ProcessHostClient;
+
+  virtual ~ZipFileCreator();
+
+  // Starts the utility process that creates the zip file.
+  void StartProcessOnIOThread();
+
+  // UtilityProcessHostClient
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+  virtual void OnProcessCrashed(int exit_code) OVERRIDE;
+
+  // IPC message handlers.
+  void OnCreateZipFileSucceeded();
+  void OnCreateZipFileFailed();
+
+  void ReportDone(bool success);
+
+  // The observer's thread. This is the thread we respond on.
+  content::BrowserThread::ID thread_identifier_;
+
+  // The observer.
+  Observer* observer_;
+
+  // The source directory for input files.
+  FilePath src_dir_;
+
+  // The list of source files paths to be included in the zip file.
+  // Entries are relative paths under directory |src_dir_|.
+  std::vector<FilePath> src_relative_paths_;
+
+  // The output zip file.
+  FilePath dest_file_;
+
+  // Whether we've received a response from the utility process yet.
+  bool got_response_;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_ZIP_FILE_CREATOR_H_