Mark drags starting in web content as tainted to avoid file path forgery

ui/base/dragdrop/os_exchange_data_provider_win.cc

 // 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 "ui/base/dragdrop/os_exchange_data_provider_win.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/i18n/file_util_icu.h"
 #include "base/logging.h"
 #include "base/memory/scoped_handle.h"
 #include "base/pickle.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/scoped_hglobal.h"
 #include "grit/ui_strings.h"
 #include "net/base/net_util.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/clipboard/clipboard_util_win.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "url/gurl.h"
 
 namespace ui {
 
+static const OSExchangeData::CustomFormat& GetRendererTaintCustomType() {
+  CR_DEFINE_STATIC_LOCAL(
+      ui::OSExchangeData::CustomFormat,
+      format,
+      (ui::Clipboard::GetFormatType("chromium/x-renderer-taint")));
+  return format;
+}
+
 // Creates a new STGMEDIUM object to hold the specified text. The caller
 // owns the resulting object. The "Bytes" version does not NULL terminate, the
 // string version does.
 static STGMEDIUM* GetStorageForBytes(const void* data, size_t bytes);
 template <typename T>
 static STGMEDIUM* GetStorageForString(const std::basic_string<T>& data);
 // Creates the contents of an Internet Shortcut file for the given URL.
 static void GetInternetShortcutFileContents(const GURL& url, std::string* data);
 // Creates a valid file name given a suggested title and URL.
 static void CreateValidFileNameFromTitle(const GURL& url,
@@ skipping 226 matching lines @@
       source_object_(data_.get()) {
 }
 
 OSExchangeDataProviderWin::~OSExchangeDataProviderWin() {
 }
 
 OSExchangeData::Provider* OSExchangeDataProviderWin::Clone() const {
   return new OSExchangeDataProviderWin(data_object());
 }
 
+void OSExchangeDataProviderWin::MarkOriginatedFromRenderer() {
+  STGMEDIUM* storage = GetStorageForString(std::string());
+  data_->contents_.push_back(new DataObjectImpl::StoredDataInfo(
+      GetRendererTaintCustomType().ToFormatEtc(), storage));
+}
+
+bool OSExchangeDataProviderWin::DidOriginateFromRenderer() const {
+  return HasCustomFormat(GetRendererTaintCustomType());
+}
+
 void OSExchangeDataProviderWin::SetString(const base::string16& data) {
   STGMEDIUM* storage = GetStorageForString(data);
   data_->contents_.push_back(new DataObjectImpl::StoredDataInfo(
       Clipboard::GetPlainTextWFormatType().ToFormatEtc(), storage));
 
   // Also add the UTF8-encoded version.
   storage = GetStorageForString(base::UTF16ToUTF8(data));
   data_->contents_.push_back(new DataObjectImpl::StoredDataInfo(
       Clipboard::GetPlainTextFormatType().ToFormatEtc(), storage));
 }
@@ skipping 760 matching lines @@
 
 ///////////////////////////////////////////////////////////////////////////////
 // OSExchangeData, public:
 
 // static
 OSExchangeData::Provider* OSExchangeData::CreateProvider() {
   return new OSExchangeDataProviderWin();
 }
 
 }  // namespace ui