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_constants.h"
  14 #include "extensions/common/manifest_handlers/icons_handler.h"
  15 #include "extensions/common/manifest_handlers/web_accessible_resources_info.h"
  16 #include "extensions/common/manifest_handlers/webview_info.h"
  17 #include "extensions/renderer/dispatcher.h"
  18 #include "extensions/renderer/renderer_extension_registry.h"
  19 #include "third_party/WebKit/public/platform/WebString.h"
  20 #include "third_party/WebKit/public/web/WebConsoleMessage.h"
  21 #include "third_party/WebKit/public/web/WebDocument.h"
  22 #include "third_party/WebKit/public/web/WebFrame.h"
  23 #include "ui/base/page_transition_types.h"
  24 #include "url/gurl.h"
  25
  26 namespace extensions {
  27
  28 ResourceRequestPolicy::ResourceRequestPolicy(Dispatcher* dispatcher)
  29     : dispatcher_(dispatcher) {}
  30
  31 // This method does a security check whether chrome-extension:// URLs can be
  32 // requested by the renderer. Since this is in an untrusted process, the browser
  33 // has a similar check to enforce the policy, in case this process is exploited.
  34 // If you are changing this function, ensure equivalent checks are added to
  35 // extension_protocols.cc's AllowExtensionResourceLoad.
  36 bool ResourceRequestPolicy::CanRequestResource(
  37     const GURL& resource_url,
  38     blink::WebFrame* frame,
  39     ui::PageTransition transition_type) {
  40   CHECK(resource_url.SchemeIs(kExtensionScheme));
  41
  42   const Extension* extension =
  43       RendererExtensionRegistry::Get()->GetExtensionOrAppByURL(resource_url);
  44   if (!extension) {
  45     // Allow the load in the case of a non-existent extension. We'll just get a
  46     // 404 from the browser process.
  47     return true;
  48   }
  49
  50   // Disallow loading of packaged resources for hosted apps. We don't allow
  51   // hybrid hosted/packaged apps. The one exception is access to icons, since
  52   // some extensions want to be able to do things like create their own
  53   // launchers.
  54   std::string resource_root_relative_path =
  55       resource_url.path().empty() ? std::string()
  56       : resource_url.path().substr(1);
  57   if (extension->is_hosted_app() &&
  58       !IconsInfo::GetIcons(extension)
  59           .ContainsPath(resource_root_relative_path)) {
  60     LOG(ERROR) << "Denying load of " << resource_url.spec() << " from "
  61                << "hosted app.";
  62     return false;
  63   }
  64
  65   // Disallow loading of extension resources which are not explicitly listed
  66   // as web or WebView accessible if the manifest version is 2 or greater.
  67   if (!WebAccessibleResourcesInfo::IsResourceWebAccessible(
  68           extension, resource_url.path()) &&
  69       !WebviewInfo::IsResourceWebviewAccessible(
  70           extension, dispatcher_->webview_partition_id(),
  71           resource_url.path())) {
  72     GURL frame_url = frame->document().url();
  73
  74     // The page_origin may be GURL("null") for unique origins like data URLs,
  75     // but this is ok for the checks below.  We only care if it matches the
  76     // current extension or has a devtools scheme.
  77     GURL page_origin = GURL(frame->top()->securityOrigin().toString());
  78
  79     // Exceptions are:
  80     // - empty origin (needed for some edge cases when we have empty origins)
  81     bool is_empty_origin = frame_url.is_empty();
  82     // - extensions requesting their own resources (frame_url check is for
  83     //     images, page_url check is for iframes)
  84     bool is_own_resource = frame_url.GetOrigin() == extension->url() ||
  85                            page_origin == extension->url();
  86     // - devtools (chrome-extension:// URLs are loaded into frames of devtools
  87     //     to support the devtools extension APIs)
  88     bool is_dev_tools =
  89         page_origin.SchemeIs(content::kChromeDevToolsScheme) &&
  90         !chrome_manifest_urls::GetDevToolsPage(extension).is_empty();
  91     bool transition_allowed =
  92         !ui::PageTransitionIsWebTriggerable(transition_type);
  93     // - unreachable web page error page (to allow showing the icon of the
  94     //   unreachable app on this page)
  95     bool is_error_page = frame_url == GURL(content::kUnreachableWebDataURL);
  96
  97     if (!is_empty_origin && !is_own_resource &&
  98         !is_dev_tools && !transition_allowed && !is_error_page) {
  99       std::string message = base::StringPrintf(
 100           "Denying load of %s. Resources must be listed in the "
 101           "web_accessible_resources manifest key in order to be loaded by "
 102           "pages outside the extension.",
 103           resource_url.spec().c_str());
 104       frame->addMessageToConsole(
 105           blink::WebConsoleMessage(blink::WebConsoleMessage::LevelError,
 106                                     blink::WebString::fromUTF8(message)));
 107       return false;
 108     }
 109   }
 110
 111   return true;
 112 }
 113
 114 bool ResourceRequestPolicy::CanRequestExtensionResourceScheme(
 115     const GURL& resource_url,
 116     blink::WebFrame* frame) {
 117   CHECK(resource_url.SchemeIs(kExtensionResourceScheme));
 118
 119   GURL frame_url = frame->document().url();
 120   if (!frame_url.is_empty() && !frame_url.SchemeIs(kExtensionScheme)) {
 121     std::string message = base::StringPrintf(
 122         "Denying load of %s. chrome-extension-resources:// can only be "
 123         "loaded from extensions.",
 124       resource_url.spec().c_str());
 125     frame->addMessageToConsole(
 126         blink::WebConsoleMessage(blink::WebConsoleMessage::LevelError,
 127                                   blink::WebString::fromUTF8(message)));
 128     return false;
 129   }
 130
 131   return true;
 132 }
 133
 134 }  // namespace extensions