chrome/renderer/extensions/resource_request_policy.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/renderer/extensions/resource_request_policy.h"
   6
   7 #include "base/logging.h"
   8 #include "base/strings/stringprintf.h"
   9 #include "chrome/common/extensions/chrome_manifest_url_handlers.h"
  10 #include "chrome/common/url_constants.h"
  11 #include "extensions/common/constants.h"
  12 #include "extensions/common/extension.h"
  13 #include "extensions/common/manifest_handlers/icons_handler.h"
  14 #include "extensions/common/manifest_handlers/web_accessible_resources_info.h"
  15 #include "extensions/renderer/renderer_extension_registry.h"
  16 #include "third_party/WebKit/public/platform/WebString.h"
  17 #include "third_party/WebKit/public/web/WebConsoleMessage.h"
  18 #include "third_party/WebKit/public/web/WebDocument.h"
  19 #include "third_party/WebKit/public/web/WebFrame.h"
  20 #include "ui/base/page_transition_types.h"
  21 #include "url/gurl.h"
  22
  23 namespace extensions {
  24
  25 // This method does a security check whether chrome-extension:// URLs can be
  26 // requested by the renderer. Since this is in an untrusted process, the browser
  27 // has a similar check to enforce the policy, in case this process is exploited.
  28 // If you are changing this function, ensure equivalent checks are added to
  29 // extension_protocols.cc's AllowExtensionResourceLoad.
  30
  31 // static
  32 bool ResourceRequestPolicy::CanRequestResource(
  33     const GURL& resource_url,
  34     blink::WebFrame* frame,
  35     ui::PageTransition transition_type) {
  36   CHECK(resource_url.SchemeIs(extensions::kExtensionScheme));
  37
  38   const Extension* extension =
  39       RendererExtensionRegistry::Get()->GetExtensionOrAppByURL(resource_url);
  40   if (!extension) {
  41     // Allow the load in the case of a non-existent extension. We'll just get a
  42     // 404 from the browser process.
  43     return true;
  44   }
  45
  46   // Disallow loading of packaged resources for hosted apps. We don't allow
  47   // hybrid hosted/packaged apps. The one exception is access to icons, since
  48   // some extensions want to be able to do things like create their own
  49   // launchers.
  50   std::string resource_root_relative_path =
  51       resource_url.path().empty() ? std::string()
  52                                   : resource_url.path().substr(1);
  53   if (extension->is_hosted_app() &&
  54       !IconsInfo::GetIcons(extension)
  55           .ContainsPath(resource_root_relative_path)) {
  56     LOG(ERROR) << "Denying load of " << resource_url.spec() << " from "
  57                << "hosted app.";
  58     return false;
  59   }
  60
  61   // Disallow loading of extension resources which are not explicitly listed
  62   // as web accessible if the manifest version is 2 or greater.
  63   if (!WebAccessibleResourcesInfo::IsResourceWebAccessible(
  64           extension, resource_url.path())) {
  65     GURL frame_url = frame->document().url();
  66
  67     // The page_origin may be GURL("null") for unique origins like data URLs,
  68     // but this is ok for the checks below.  We only care if it matches the
  69     // current extension or has a devtools scheme.
  70     GURL page_origin = GURL(frame->top()->securityOrigin().toString());
  71
  72     // Exceptions are:
  73     // - empty origin (needed for some edge cases when we have empty origins)
  74     bool is_empty_origin = frame_url.is_empty();
  75     // - extensions requesting their own resources (frame_url check is for
  76     //     images, page_url check is for iframes)
  77     bool is_own_resource = frame_url.GetOrigin() == extension->url() ||
  78                            page_origin == extension->url();
  79     // - devtools (chrome-extension:// URLs are loaded into frames of devtools
  80     //     to support the devtools extension APIs)
  81     bool is_dev_tools =
  82         page_origin.SchemeIs(content::kChromeDevToolsScheme) &&
  83         !chrome_manifest_urls::GetDevToolsPage(extension).is_empty();
  84     bool transition_allowed =
  85         !ui::PageTransitionIsWebTriggerable(transition_type);
  86     // - unreachable web page error page (to allow showing the icon of the
  87     //   unreachable app on this page)
  88     bool is_error_page = frame_url == GURL(content::kUnreachableWebDataURL);
  89
  90     if (!is_empty_origin && !is_own_resource &&
  91         !is_dev_tools && !transition_allowed && !is_error_page) {
  92       std::string message = base::StringPrintf(
  93           "Denying load of %s. Resources must be listed in the "
  94           "web_accessible_resources manifest key in order to be loaded by "
  95           "pages outside the extension.",
  96           resource_url.spec().c_str());
  97       frame->addMessageToConsole(
  98           blink::WebConsoleMessage(blink::WebConsoleMessage::LevelError,
  99                                     blink::WebString::fromUTF8(message)));
 100       return false;
 101     }
 102   }
 103
 104   return true;
 105 }
 106
 107 // static
 108 bool ResourceRequestPolicy::CanRequestExtensionResourceScheme(
 109     const GURL& resource_url,
 110     blink::WebFrame* frame) {
 111   CHECK(resource_url.SchemeIs(extensions::kExtensionResourceScheme));
 112
 113   GURL frame_url = frame->document().url();
 114   if (!frame_url.is_empty() &&
 115       !frame_url.SchemeIs(extensions::kExtensionScheme)) {
 116     std::string message = base::StringPrintf(
 117         "Denying load of %s. chrome-extension-resources:// can only be "
 118         "loaded from extensions.",
 119       resource_url.spec().c_str());
 120     frame->addMessageToConsole(
 121         blink::WebConsoleMessage(blink::WebConsoleMessage::LevelError,
 122                                   blink::WebString::fromUTF8(message)));
 123     return false;
 124   }
 125
 126   return true;
 127 }
 128
 129 ResourceRequestPolicy::ResourceRequestPolicy() {
 130 }
 131
 132 }  // namespace extensions