blob: 6f4b963b1400dda37c41768dff0f7cbcc4c2360a [file] [log] [blame]
// 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 "chrome/renderer/extensions/resource_request_policy.h"
#include "base/logging.h"
#include "base/strings/stringprintf.h"
#include "chrome/common/extensions/chrome_manifest_url_handlers.h"
#include "chrome/common/url_constants.h"
#include "extensions/common/constants.h"
#include "extensions/common/extension.h"
#include "extensions/common/manifest_constants.h"
#include "extensions/common/manifest_handlers/icons_handler.h"
#include "extensions/common/manifest_handlers/web_accessible_resources_info.h"
#include "extensions/common/manifest_handlers/webview_info.h"
#include "extensions/renderer/dispatcher.h"
#include "extensions/renderer/renderer_extension_registry.h"
#include "third_party/blink/public/platform/url_conversion.h"
#include "third_party/blink/public/platform/web_string.h"
#include "third_party/blink/public/platform/web_url.h"
#include "third_party/blink/public/web/web_console_message.h"
#include "third_party/blink/public/web/web_document.h"
#include "third_party/blink/public/web/web_local_frame.h"
#include "ui/base/page_transition_types.h"
#include "url/gurl.h"
#include "url/origin.h"
namespace extensions {
ResourceRequestPolicy::ResourceRequestPolicy(Dispatcher* dispatcher)
: dispatcher_(dispatcher) {}
ResourceRequestPolicy::~ResourceRequestPolicy() = default;
void ResourceRequestPolicy::OnExtensionLoaded(const Extension& extension) {
if (WebAccessibleResourcesInfo::HasWebAccessibleResources(&extension) ||
WebviewInfo::HasWebviewAccessibleResources(
extension, dispatcher_->webview_partition_id()) ||
// Hosted app icons are accessible.
// TODO(devlin): Should we incorporate this into
// WebAccessibleResourcesInfo?
(extension.is_hosted_app() && !IconsInfo::GetIcons(&extension).empty())) {
web_accessible_ids_.insert(extension.id());
}
}
void ResourceRequestPolicy::OnExtensionUnloaded(
const ExtensionId& extension_id) {
web_accessible_ids_.erase(extension_id);
}
// This method does a security check whether chrome-extension:// URLs can be
// requested by the renderer. Since this is in an untrusted process, the browser
// has a similar check to enforce the policy, in case this process is exploited.
// If you are changing this function, ensure equivalent checks are added to
// extension_protocols.cc's AllowExtensionResourceLoad.
bool ResourceRequestPolicy::CanRequestResource(
const GURL& resource_url,
blink::WebLocalFrame* frame,
ui::PageTransition transition_type) {
CHECK(resource_url.SchemeIs(kExtensionScheme));
GURL frame_url = frame->GetDocument().Url();
// The page_origin may be GURL("null") for unique origins like data URLs,
// but this is ok for the checks below. We only care if it matches the
// current extension or has a devtools scheme.
GURL page_origin = url::Origin(frame->Top()->GetSecurityOrigin()).GetURL();
GURL extension_origin = resource_url.GetOrigin();
// We always allow loads in the following cases, regardless of web accessible
// resources:
// Empty urls (needed for some edge cases when we have empty urls).
if (frame_url.is_empty())
return true;
// Extensions requesting their own resources (frame_url check is for images,
// page_url check is for iframes).
// TODO(devlin): We should be checking the ancestor chain, not just the
// top-level frame. Additionally, we should be checking the security origin
// of the frame, to account for about:blank subframes being scripted by an
// extension parent (though we'll still need the frame origin check for
// sandboxed frames).
if (frame_url.GetOrigin() == extension_origin ||
page_origin == extension_origin) {
return true;
}
if (!ui::PageTransitionIsWebTriggerable(transition_type))
return true;
// Unreachable web page error page (to allow showing the icon of the
// unreachable app on this page).
if (frame_url == content::kUnreachableWebDataURL)
return true;
bool is_dev_tools = page_origin.SchemeIs(content::kChromeDevToolsScheme);
// Note: we check |web_accessible_ids_| (rather than first looking up the
// extension in the registry and checking that) to be more resistant against
// timing attacks. This way, determining access for an extension that isn't
// installed takes the same amount of time as determining access for an
// extension with no web accessible resources. We aren't worried about any
// extensions with web accessible resources, since those are inherently
// identifiable.
if (!is_dev_tools && !web_accessible_ids_.count(extension_origin.host()))
return false;
const Extension* extension =
RendererExtensionRegistry::Get()->GetExtensionOrAppByURL(resource_url);
if (is_dev_tools) {
// Allow the load in the case of a non-existent extension. We'll just get a
// 404 from the browser process.
// TODO(devlin): Can this happen? Does devtools potentially make requests
// to non-existent extensions?
if (!extension)
return true;
// Devtools (chrome-extension:// URLs are loaded into frames of devtools to
// support the devtools extension APIs).
if (!chrome_manifest_urls::GetDevToolsPage(extension).is_empty())
return true;
}
DCHECK(extension);
// Disallow loading of packaged resources for hosted apps. We don't allow
// hybrid hosted/packaged apps. The one exception is access to icons, since
// some extensions want to be able to do things like create their own
// launchers.
base::StringPiece resource_root_relative_path =
resource_url.path_piece().empty() ? base::StringPiece()
: resource_url.path_piece().substr(1);
if (extension->is_hosted_app() &&
!IconsInfo::GetIcons(extension)
.ContainsPath(resource_root_relative_path)) {
LOG(ERROR) << "Denying load of " << resource_url.spec() << " from "
<< "hosted app.";
return false;
}
// Disallow loading of extension resources which are not explicitly listed
// as web or WebView accessible if the manifest version is 2 or greater.
if (!WebAccessibleResourcesInfo::IsResourceWebAccessible(
extension, resource_url.path()) &&
!WebviewInfo::IsResourceWebviewAccessible(
extension, dispatcher_->webview_partition_id(),
resource_url.path())) {
std::string message = base::StringPrintf(
"Denying load of %s. Resources must be listed in the "
"web_accessible_resources manifest key in order to be loaded by "
"pages outside the extension.",
resource_url.spec().c_str());
frame->AddMessageToConsole(
blink::WebConsoleMessage(blink::WebConsoleMessage::kLevelError,
blink::WebString::FromUTF8(message)));
return false;
}
return true;
}
} // namespace extensions