don't perturb pixels on google maps (#23416)

This is a temporary fix for Google Maps; we will revert it once a better fix is found.

Author: arthuredelstein

chromium_src/third_party/blink/renderer/modules/canvas/canvas2d/base_rendering_context_2d.cc

@@ -8,13 +8,30 @@
 #include "base/notreached.h"
 #include "brave/third_party/blink/renderer/core/farbling/brave_session_cache.h"
 #include "third_party/blink/renderer/platform/graphics/image_data_buffer.h"
+#include "third_party/blink/renderer/platform/weborigin/kurl.h"
 
-#define BRAVE_GET_IMAGE_DATA                                                  \
-  if (ExecutionContext* context = ExecutionContext::From(script_state)) {     \
-    SkPixmap image_data_pixmap = image_data->GetSkPixmap();                   \
-    brave::BraveSessionCache::From(*context).PerturbPixels(                   \
-        static_cast<const unsigned char*>(image_data_pixmap.writable_addr()), \
-        image_data_pixmap.computeByteSize());                                 \
+namespace {
+
+bool IsGoogleMaps(const blink::KURL& url) {
+  const auto host = url.Host();
+  if (!host.StartsWith("google.") && !host.Contains(".google.")) {
+    return false;
+  }
+  const auto path = url.GetPath();
+  return path.StartsWith("/maps/") || path == "/maps";
+}
+
+}  // namespace
+
+#define BRAVE_GET_IMAGE_DATA                                              \
+  if (ExecutionContext* context = ExecutionContext::From(script_state)) { \
+    if (!IsGoogleMaps(context->Url())) {                                  \
+      SkPixmap image_data_pixmap = image_data->GetSkPixmap();             \
+      brave::BraveSessionCache::From(*context).PerturbPixels(             \
+          static_cast<const unsigned char*>(                              \
+              image_data_pixmap.writable_addr()),                         \
+          image_data_pixmap.computeByteSize());                           \
+    }                                                                     \
   }
 
 #define BRAVE_BASE_RENDERING_CONTEXT_2D_MEASURE_TEXT         \

components/content_settings/renderer/brave_content_settings_agent_impl_browsertest.cc

@@ -21,6 +21,7 @@
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/content_settings/core/common/content_settings_types.h"
+#include "components/google/core/common/google_switches.h"
 #include "components/network_session_configurator/common/network_switches.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/test/browser_test.h"
@@ -31,10 +32,13 @@
 #include "net/http/http_request_headers.h"
 #include "net/test/embedded_test_server/default_handlers.h"
 #include "net/test/embedded_test_server/http_request.h"
+#include "net/test/embedded_test_server/request_handler_util.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "url/origin.h"
 
 using brave_shields::ControlType;
+using net::test_server::HttpRequest;
+using net::test_server::HttpResponse;
 
 namespace {
 
@@ -74,6 +78,7 @@ const int kExpectedImageDataHashFarblingBalanced = 172;
 const int kExpectedImageDataHashFarblingOff = 0;
 const int kExpectedImageDataHashFarblingMaximum =
     kExpectedImageDataHashFarblingBalanced;
+const int kExpectedImageDataHashFarblingBalancedGoogleCom = 182;
 
 const char kEmptyCookie[] = "";
 
@@ -97,6 +102,19 @@ GURL GetOriginURL(const GURL& url) {
   return url::Origin::Create(url).GetURL();
 }
 
+// Remaps requests from /maps/simple.html to /simple.html
+std::unique_ptr<HttpResponse> HandleGoogleMapsFileRequest(
+    const base::FilePath& server_root,
+    const HttpRequest& request) {
+  HttpRequest new_request(request);
+  if (!new_request.relative_url.starts_with("/maps")) {
+    // This handler is only relevant for a Google Maps url.
+    return nullptr;
+  }
+  new_request.relative_url = new_request.relative_url.substr(5);
+  return HandleFileRequest(server_root, new_request);
+}
+
 }  // namespace
 
 class BraveContentSettingsAgentImplBrowserTest : public InProcessBrowserTest {
@@ -117,6 +135,8 @@ class BraveContentSettingsAgentImplBrowserTest : public InProcessBrowserTest {
     https_server_.SetSSLConfig(net::EmbeddedTestServer::CERT_TEST_NAMES);
     https_server_.ServeFilesFromDirectory(test_data_dir);
     https_server_.AddDefaultHandlers(GetChromeTestDataDir());
+    https_server_.RegisterDefaultHandler(
+        base::BindRepeating(&HandleGoogleMapsFileRequest, test_data_dir));
     content::SetupCrossSiteRedirector(&https_server_);
     https_server_.RegisterRequestMonitor(base::BindRepeating(
         &BraveContentSettingsAgentImplBrowserTest::SaveReferrer,
@@ -143,6 +163,16 @@ class BraveContentSettingsAgentImplBrowserTest : public InProcessBrowserTest {
         ContentSettingsPattern::FromString("https://firstParty/*");
   }
 
+  void SetUpCommandLine(base::CommandLine* command_line) override {
+    // Since the HTTPS server only serves a valid cert for localhost,
+    // this is needed to load pages from "www.google.*" without an interstitial.
+    command_line->AppendSwitch(switches::kIgnoreCertificateErrors);
+
+    // The production code only allows known ports (80 for http and 443 for
+    // https), but the test server runs on a random port.
+    command_line->AppendSwitch(switches::kIgnoreGooglePortNumbers);
+  }
+
   void SaveReferrer(const net::test_server::HttpRequest& request) {
     base::AutoLock auto_lock(last_referrers_lock_);
 
@@ -430,6 +460,34 @@ IN_PROC_BROWSER_TEST_F(BraveContentSettingsAgentImplBrowserTest,
             content::EvalJs(contents(), kGetImageDataScript));
 }
 
+IN_PROC_BROWSER_TEST_F(BraveContentSettingsAgentImplBrowserTest,
+                       FarbleGetImageDataGoogleMapsException) {
+  // Farbling should be disabled on Google Maps
+  SetFingerprintingDefault();
+  ASSERT_TRUE(ui_test_utils::NavigateToURL(
+      browser(), https_server().GetURL("google.com", "/maps/simple.html")));
+  EXPECT_EQ(kExpectedImageDataHashFarblingOff,
+            content::EvalJs(contents(), kGetImageDataScript));
+
+  // Farbling should not be disabled on other Google things
+  ASSERT_TRUE(ui_test_utils::NavigateToURL(
+      browser(), https_server().GetURL("google.com", "/simple.html")));
+  EXPECT_EQ(kExpectedImageDataHashFarblingBalancedGoogleCom,
+            content::EvalJs(contents(), kGetImageDataScript));
+
+  // Farbling should be disabled on google.co.uk maps
+  ASSERT_TRUE(ui_test_utils::NavigateToURL(
+      browser(), https_server().GetURL("google.co.uk", "/maps/simple.html")));
+  EXPECT_EQ(kExpectedImageDataHashFarblingOff,
+            content::EvalJs(contents(), kGetImageDataScript));
+
+  // Farbling should be disabled on google.de maps
+  ASSERT_TRUE(ui_test_utils::NavigateToURL(
+      browser(), https_server().GetURL("google.de", "/maps/simple.html")));
+  EXPECT_EQ(kExpectedImageDataHashFarblingOff,
+            content::EvalJs(contents(), kGetImageDataScript));
+}
+
 class BraveContentSettingsAgentImplV2BrowserTest
     : public BraveContentSettingsAgentImplBrowserTest {
  public: