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/extension_set.h"
  14 #include "extensions/common/manifest_handlers/icons_handler.h"
  15 #include "extensions/common/manifest_handlers/web_accessible_resources_info.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     const ExtensionSet* loaded_extensions) {
  37   CHECK(resource_url.SchemeIs(extensions::kExtensionScheme));
  38
  39   const Extension* extension =
  40       loaded_extensions->GetExtensionOrAppByURL(resource_url);
  41   if (!extension) {
  42     // Allow the load in the case of a non-existent extension. We'll just get a
  43     // 404 from the browser process.
  44     return true;
  45   }
  46
  47   // Disallow loading of packaged resources for hosted apps. We don't allow
  48   // hybrid hosted/packaged apps. The one exception is access to icons, since
  49   // some extensions want to be able to do things like create their own
  50   // launchers.
  51   std::string resource_root_relative_path =
  52       resource_url.path().empty() ? std::string()
  53                                   : resource_url.path().substr(1);
  54   if (extension->is_hosted_app() &&
  55       !IconsInfo::GetIcons(extension)
  56           .ContainsPath(resource_root_relative_path)) {
  57     LOG(ERROR) << "Denying load of " << resource_url.spec() << " from "
  58                << "hosted app.";
  59     return false;
  60   }
  61
  62   // Disallow loading of extension resources which are not explicitly listed
  63   // as web accessible if the manifest version is 2 or greater.
  64   if (!WebAccessibleResourcesInfo::IsResourceWebAccessible(
  65           extension, resource_url.path())) {
  66     GURL frame_url = frame->document().url();
  67     GURL page_url = frame->top()->document().url();
  68
  69     // Exceptions are:
  70     // - empty origin (needed for some edge cases when we have empty origins)
  71     bool is_empty_origin = frame_url.is_empty();
  72     // - extensions requesting their own resources (frame_url check is for
  73     //     images, page_url check is for iframes)
  74     bool is_own_resource = frame_url.GetOrigin() == extension->url() ||
  75         page_url.GetOrigin() == extension->url();
  76     // - devtools (chrome-extension:// URLs are loaded into frames of devtools
  77     //     to support the devtools extension APIs)
  78     bool is_dev_tools =
  79         page_url.SchemeIs(content::kChromeDevToolsScheme) &&
  80         !chrome_manifest_urls::GetDevToolsPage(extension).is_empty();
  81     bool transition_allowed =
  82         !ui::PageTransitionIsWebTriggerable(transition_type);
  83     // - unreachable web page error page (to allow showing the icon of the
  84     //   unreachable app on this page)
  85     bool is_error_page = frame_url == GURL(content::kUnreachableWebDataURL);
  86
  87     if (!is_empty_origin && !is_own_resource &&
  88         !is_dev_tools && !transition_allowed && !is_error_page) {
  89       std::string message = base::StringPrintf(
  90           "Denying load of %s. Resources must be listed in the "
  91           "web_accessible_resources manifest key in order to be loaded by "
  92           "pages outside the extension.",
  93           resource_url.spec().c_str());
  94       frame->addMessageToConsole(
  95           blink::WebConsoleMessage(blink::WebConsoleMessage::LevelError,
  96                                     blink::WebString::fromUTF8(message)));
  97       return false;
  98     }
  99   }
 100
 101   return true;
 102 }
 103
 104 // static
 105 bool ResourceRequestPolicy::CanRequestExtensionResourceScheme(
 106     const GURL& resource_url,
 107     blink::WebFrame* frame) {
 108   CHECK(resource_url.SchemeIs(extensions::kExtensionResourceScheme));
 109
 110   GURL frame_url = frame->document().url();
 111   if (!frame_url.is_empty() &&
 112       !frame_url.SchemeIs(extensions::kExtensionScheme)) {
 113     std::string message = base::StringPrintf(
 114         "Denying load of %s. chrome-extension-resources:// can only be "
 115         "loaded from extensions.",
 116       resource_url.spec().c_str());
 117     frame->addMessageToConsole(
 118         blink::WebConsoleMessage(blink::WebConsoleMessage::LevelError,
 119                                   blink::WebString::fromUTF8(message)));
 120     return false;
 121   }
 122
 123   return true;
 124 }
 125
 126 ResourceRequestPolicy::ResourceRequestPolicy() {
 127 }
 128
 129 }  // namespace extensions