1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415
|
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "extensions/browser/api/web_request/web_request_permissions.h"
#include <string_view>
#include "base/debug/crash_logging.h"
#include "base/metrics/histogram_macros.h"
#include "base/strings/string_util.h"
#include "build/chromeos_buildflags.h"
#include "content/public/browser/child_process_security_policy.h"
#include "content/public/common/url_constants.h"
#include "extensions/browser/api/extensions_api_client.h"
#include "extensions/browser/api/web_request/permission_helper.h"
#include "extensions/browser/api/web_request/web_request_api_constants.h"
#include "extensions/browser/api/web_request/web_request_info.h"
#include "extensions/browser/extension_navigation_ui_data.h"
#include "extensions/browser/extension_registry.h"
#include "extensions/browser/extension_util.h"
#include "extensions/browser/extensions_browser_client.h"
#include "extensions/browser/process_map.h"
#include "extensions/common/constants.h"
#include "extensions/common/extension.h"
#include "extensions/common/extension_id.h"
#include "extensions/common/extension_urls.h"
#include "extensions/common/manifest_handlers/incognito_info.h"
#include "extensions/common/permissions/permissions_data.h"
#include "services/network/public/mojom/fetch_api.mojom-shared.h"
#include "third_party/abseil-cpp/absl/strings/ascii.h"
#include "third_party/blink/public/common/loader/resource_type_util.h"
#include "url/gurl.h"
#include "url/origin.h"
using extensions::PermissionsData;
namespace {
// Returns true if the scheme is one we want to allow extensions to have access
// to. Extensions still need specific permissions for a given URL, which is
// covered by CanExtensionAccessURL.
// TODO(karandeepb): This allows more schemes than
// ExtensionWebRequestEventRouter::RequestFiler, which specifies the schemes
// allowed by web request event listeners. Consolidate the two.
bool HasWebRequestScheme(const GURL& url) {
return (url.SchemeIs(url::kAboutScheme) || url.SchemeIs(url::kFileScheme) ||
url.SchemeIs(url::kFileSystemScheme) ||
url.SchemeIs(url::kFtpScheme) || url.SchemeIsHTTPOrHTTPS() ||
url.SchemeIs(extensions::kExtensionScheme) || url.SchemeIsWSOrWSS() ||
url.SchemeIs(url::kUuidInPackageScheme));
}
PermissionsData::PageAccess GetHostAccessForURL(
const extensions::Extension& extension,
const GURL& url,
int tab_id) {
// about: URLs are not covered in host permissions, but are allowed
// anyway.
if (url.SchemeIs(url::kAboutScheme) ||
url::IsSameOriginWith(url, extension.url())) {
return PermissionsData::PageAccess::kAllowed;
}
return extension.permissions_data()->GetPageAccess(url, tab_id,
nullptr /*error*/);
}
bool IsWebRequestResourceTypeFrame(
extensions::WebRequestResourceType web_request_type) {
return web_request_type == extensions::WebRequestResourceType::MAIN_FRAME ||
web_request_type == extensions::WebRequestResourceType::SUB_FRAME;
}
PermissionsData::PageAccess CanExtensionAccessURLInternal(
extensions::PermissionHelper* permission_helper,
const extensions::ExtensionId& extension_id,
const GURL& url,
int tab_id,
bool crosses_incognito,
WebRequestPermissions::HostPermissionsCheck host_permissions_check,
const std::optional<url::Origin>& initiator,
const std::optional<extensions::WebRequestResourceType>& web_request_type) {
const extensions::Extension* extension =
permission_helper->extension_registry()->enabled_extensions().GetByID(
extension_id);
if (!extension) {
return PermissionsData::PageAccess::kDenied;
}
// Prevent viewing / modifying requests initiated by a host protected by
// policy.
if (initiator &&
extension->permissions_data()->IsPolicyBlockedHost(initiator->GetURL())) {
return PermissionsData::PageAccess::kDenied;
}
// Check if this event crosses incognito boundaries when it shouldn't.
if (crosses_incognito && !permission_helper->CanCrossIncognito(extension)) {
return PermissionsData::PageAccess::kDenied;
}
switch (host_permissions_check) {
case WebRequestPermissions::DO_NOT_CHECK_HOST:
return PermissionsData::PageAccess::kAllowed;
case WebRequestPermissions::REQUIRE_HOST_PERMISSION_FOR_URL: {
PermissionsData::PageAccess access =
GetHostAccessForURL(*extension, url, tab_id);
bool is_navigation_request =
web_request_type && IsWebRequestResourceTypeFrame(*web_request_type);
// For sub-resource (non-navigation) requests, if access to the host was
// withheld, check if the extension has access to the initiator. If it
// does, allow the extension to see the request. This is important for
// extensions with webRequest to work well with runtime host permissions.
if (!is_navigation_request &&
access == PermissionsData::PageAccess::kWithheld) {
PermissionsData::PageAccess initiator_access =
initiator
? GetHostAccessForURL(*extension, initiator->GetURL(), tab_id)
: PermissionsData::PageAccess::kDenied;
if (initiator_access == PermissionsData::PageAccess::kAllowed) {
access = PermissionsData::PageAccess::kAllowed;
}
}
return access;
}
case WebRequestPermissions::REQUIRE_HOST_PERMISSION_FOR_URL_AND_INITIATOR: {
PermissionsData::PageAccess request_access =
GetHostAccessForURL(*extension, url, tab_id);
bool is_navigation_request =
web_request_type && IsWebRequestResourceTypeFrame(*web_request_type);
// Only require access to the initiator for sub-resource (non-navigation)
// requests. See crbug.com/918137.
// TODO(karandeepb): Should service worker navigation preload requests be
// treated similarly?
if (is_navigation_request) {
return request_access;
}
if (request_access == PermissionsData::PageAccess::kDenied) {
return request_access;
}
if (!initiator || initiator->opaque()) {
return request_access;
}
DCHECK(request_access == PermissionsData::PageAccess::kWithheld ||
request_access == PermissionsData::PageAccess::kAllowed);
// Possible remaining states:
// ----------------------------------------------------
// | Initiator access| Request access| Expected access|
// ----------------------------------------------------
// | Withheld | Withheld | Withheld |
// | Withheld | Allowed | Withheld |
// | Allowed | Withheld | Allowed |
// | Allowed | Allowed | Allowed |
// | Denied | * | Denied |
// ----------------------------------------------------
// Note: The only interesting case is when the access to a sub-resource
// request is withheld but the access to initiator is allowed. In this
// case, we allow access to the request. This is important for extensions
// with webRequest to work well with runtime host permissions. See
// crbug.com/851722.
return GetHostAccessForURL(*extension, initiator->GetURL(), tab_id);
}
case WebRequestPermissions::REQUIRE_ALL_URLS:
return extension->permissions_data()
->active_permissions()
.HasEffectiveAccessToAllHosts()
? PermissionsData::PageAccess::kAllowed
: PermissionsData::PageAccess::kDenied;
}
NOTREACHED();
}
// Returns true if |request|.url is of the form clients[0-9]*.google.com.
bool IsSensitiveGoogleClientUrl(const extensions::WebRequestInfo& request) {
const GURL& url = request.url;
// TODO(battre) Merge this, CanExtensionAccessURL and
// PermissionsData::CanAccessPage into one function.
static constexpr char kGoogleCom[] = "google.com";
static constexpr char kClient[] = "clients";
constexpr size_t kGoogleComLength = std::size(kGoogleCom) - 1;
constexpr size_t kClientLength = std::size(kClient) - 1;
if (!url.DomainIs(kGoogleCom)) {
return false;
}
std::string_view host = url.host_piece();
while (base::EndsWith(host, ".")) {
host.remove_suffix(1u);
}
// Check for "clients[0-9]*.google.com" hosts.
// This protects requests to several internal services such as sync,
// extension update pings, captive portal detection, fraudulent certificate
// reporting, autofill and others.
//
// These URLs are only protected for requests from the browser, and not for
// requests from common renderers, because clients*.google.com are also used
// by websites.
std::string_view::size_type pos = host.rfind(kClient);
if (pos == std::string_view::npos) {
return false;
}
if (pos > 0 && host[pos - 1] != '.') {
return false;
}
for (std::string_view::const_iterator
i = host.begin() + pos + kClientLength,
end = host.end() - (kGoogleComLength + 1);
i != end; ++i) {
if (!absl::ascii_isdigit(static_cast<unsigned char>(*i))) {
return false;
}
}
return true;
}
bool IsMainFrameNavigationRequest(const extensions::WebRequestInfo& request) {
return request.is_navigation_request &&
request.web_request_type ==
extensions::WebRequestResourceType::MAIN_FRAME;
}
} // namespace
// static
bool WebRequestPermissions::HideRequest(
extensions::PermissionHelper* permission_helper,
const extensions::WebRequestInfo& request) {
if (!HasWebRequestScheme(request.url)) {
return true;
}
// Requests from <webview> are never hidden.
if (request.is_web_view) {
return false;
}
bool is_request_from_browser = request.render_process_id == -1;
if (is_request_from_browser) {
// Browser initiated service worker script requests (e.g., for update check)
// are not hidden.
if (request.is_service_worker_script) {
DCHECK(request.web_request_type ==
extensions::WebRequestResourceType::SCRIPT);
return false;
}
// Hide all non-navigation requests made by the browser. crbug.com/884932.
if (!request.is_navigation_request) {
return true;
}
DCHECK(request.web_request_type ==
extensions::WebRequestResourceType::MAIN_FRAME ||
request.web_request_type ==
extensions::WebRequestResourceType::SUB_FRAME ||
request.web_request_type ==
extensions::WebRequestResourceType::OBJECT);
// Hide sub-frame requests to clientsX.google.com.
// TODO(crbug.com/40595750): Determine if the code here can be cleaned up
// since browser initiated non-navigation requests are now hidden from
// extensions.
if (request.web_request_type !=
extensions::WebRequestResourceType::MAIN_FRAME &&
IsSensitiveGoogleClientUrl(request)) {
return true;
}
}
// Hide requests from the Chrome WebStore App.
if (!is_request_from_browser &&
permission_helper->process_map()->Contains(extensions::kWebStoreAppId,
request.render_process_id)) {
return true;
}
// Hide requests initiated by the new Webstore domain, including requests that
// may be on subframes which have an opaque origin.
if (request.initiator) {
const auto& request_tuple_or_precursor_tuple =
request.initiator->GetTupleOrPrecursorTupleIfOpaque();
if (request_tuple_or_precursor_tuple ==
url::SchemeHostPort(extension_urls::GetNewWebstoreLaunchURL())) {
return true;
}
}
const GURL& url = request.url;
bool is_request_from_webui_renderer =
!is_request_from_browser &&
content::ChildProcessSecurityPolicy::GetInstance()->HasWebUIBindings(
request.render_process_id);
if (is_request_from_webui_renderer) {
#if DCHECK_IS_ON()
const bool is_network_request =
url.SchemeIsHTTPOrHTTPS() || url.SchemeIsWSOrWSS();
if (is_network_request) {
// WebUI renderers should never be making network requests, but we may
// make some exceptions for now. See https://crbug.com/829412 for
// details.
//
// The DCHECK helps avoid proliferation of such behavior.
DCHECK(request.initiator.has_value());
DCHECK(extensions::ExtensionsBrowserClient::Get()
->IsWebUIAllowedToMakeNetworkRequests(*request.initiator))
<< "Unsupported network request from "
<< request.initiator->GetURL().spec() << " for " << url.spec();
}
#endif // DCHECK_IS_ON()
// In any case, we treat the requests as sensitive to ensure that the Web
// Request API doesn't see them.
return true;
}
// Requests from chrome-untrusted:// are generally sensitive (because they
// are considered part of browser UI).
//
// Main frame navigations from chrome-untrusted:// to non-WebUI origins are an
// exception: These requests are inspectable by the Web Request API (e.g. by a
// content filtering extension) and therefore allowlisted.
if (request.initiator.has_value() &&
request.initiator->scheme() == content::kChromeUIUntrustedScheme) {
// The call to `HasWebRequestScheme()` with an early exit at the top already
// ensures that request.url does not point to a chrome-untrusted:// URL.
// Therefore, it's not necessary to check the scheme of request.url again.
bool allowlist = IsMainFrameNavigationRequest(request);
if (!allowlist) {
return true;
}
}
// Allow the extension embedder to hide the request.
if (permission_helper->ShouldHideBrowserNetworkRequest(request)) {
return true;
}
// Safebrowsing and Chrome Webstore URLs are always protected, i.e. also
// for requests from common renderers.
// TODO(crbug.com/40235977): it would be nice to be able to just use
// extension_urls::IsWebstoreDomain for the last two checks here, but the old
// webstore check specifically requires the path to be checked, not just the
// domain. However once the old webstore is turned down we can change it over
// during that cleanup.
if (extension_urls::IsWebstoreUpdateUrl(url) ||
extension_urls::IsWebstoreApiUrl(url) ||
extension_urls::IsBlocklistUpdateUrl(url) ||
extension_urls::IsSafeBrowsingUrl(url) ||
(url.DomainIs("chrome.google.com") &&
base::StartsWith(url.path_piece(), "/webstore",
base::CompareCase::SENSITIVE)) ||
url.DomainIs(extension_urls::GetNewWebstoreLaunchURL().host())) {
return true;
}
return false;
}
// static
PermissionsData::PageAccess WebRequestPermissions::CanExtensionAccessURL(
extensions::PermissionHelper* permission_helper,
const extensions::ExtensionId& extension_id,
const GURL& url,
int tab_id,
bool crosses_incognito,
HostPermissionsCheck host_permissions_check,
const std::optional<url::Origin>& initiator,
extensions::WebRequestResourceType web_request_type) {
return CanExtensionAccessURLInternal(
permission_helper, extension_id, url, tab_id, crosses_incognito,
host_permissions_check, initiator, web_request_type);
}
// static
bool WebRequestPermissions::CanExtensionAccessInitiator(
extensions::PermissionHelper* permission_helper,
const extensions::ExtensionId extension_id,
const std::optional<url::Origin>& initiator,
int tab_id,
bool crosses_incognito) {
if (!initiator) {
return true;
}
return CanExtensionAccessURLInternal(
permission_helper, extension_id, initiator->GetURL(), tab_id,
crosses_incognito,
WebRequestPermissions::REQUIRE_HOST_PERMISSION_FOR_URL,
std::nullopt /* initiator */, std::nullopt /* resource_type */) ==
PermissionsData::PageAccess::kAllowed;
}
|