Merge pull request #8831 from brave/mpilgrim_webgl_extensions

Implement new WebGL extensions blocking logic

browser/farbling/brave_webgl_farbling_browsertest.cc

@@ -29,7 +29,7 @@
 using brave_shields::ControlType;
 
 const char kEmbeddedTestServerDirectory[] = "webgl";
-const char kTitleScript[] = "domAutomationController.send(document.title);";
+const char kTitleScript[] = "document.title";
 
 class BraveWebGLFarblingBrowserTest : public InProcessBrowserTest {
  public:
@@ -80,13 +80,6 @@ class BraveWebGLFarblingBrowserTest : public InProcessBrowserTest {
         embedded_test_server()->GetURL(domain, "/"));
   }
 
-  template <typename T>
-  std::string ExecScriptGetStr(const std::string& script, T* frame) {
-    std::string value;
-    EXPECT_TRUE(ExecuteScriptAndExtractString(frame, script, &value));
-    return value;
-  }
-
   content::WebContents* contents() {
     return browser()->tab_strip_model()->GetActiveWebContents();
   }
@@ -131,19 +124,20 @@ IN_PROC_BROWSER_TEST_F(BraveWebGLFarblingBrowserTest, FarbleGetParameterWebGL) {
   // relation to original data
   BlockFingerprinting(domain);
   NavigateToURLUntilLoadStop(url);
-  EXPECT_EQ(ExecScriptGetStr(kTitleScript, contents()), kExpectedRandomString);
+  EXPECT_EQ(EvalJs(contents(), kTitleScript).ExtractString(),
+            kExpectedRandomString);
   // second time, same as the first (tests that results are consistent for the
   // lifetime of a session, and that the PRNG properly resets itself at the
   // beginning of each calculation)
   NavigateToURLUntilLoadStop(url);
-  EXPECT_EQ(ExecScriptGetStr(kTitleScript, contents()), kExpectedRandomString);
+  EXPECT_EQ(EvalJs(contents(), kTitleScript).ExtractString(),
+            kExpectedRandomString);
 
-  std::string actual;
   // Farbling level: balanced (default)
   // WebGL getParameter of restricted values: original data
   SetFingerprintingDefault(domain);
   NavigateToURLUntilLoadStop(url);
-  actual = ExecScriptGetStr(kTitleScript, contents());
+  std::string actual = EvalJs(contents(), kTitleScript).ExtractString();
 
   // Farbling level: off
   // WebGL getParameter of restricted values: original data
@@ -152,8 +146,8 @@ IN_PROC_BROWSER_TEST_F(BraveWebGLFarblingBrowserTest, FarbleGetParameterWebGL) {
   // Since this value depends on the underlying hardware, we just test that the
   // results for "off" are the same as the results for "balanced", and that
   // they're different than the results for "maximum".
-  EXPECT_EQ(ExecScriptGetStr(kTitleScript, contents()), actual);
-  EXPECT_NE(kExpectedRandomString, actual);
+  EXPECT_EQ(EvalJs(contents(), kTitleScript).ExtractString(), actual);
+  EXPECT_NE(actual, kExpectedRandomString);
 }
 
 IN_PROC_BROWSER_TEST_F(BraveWebGLFarblingBrowserTest,
@@ -172,7 +166,7 @@ IN_PROC_BROWSER_TEST_F(BraveWebGLFarblingBrowserTest,
     AllowFingerprinting(domain);
     NavigateToURLUntilLoadStop(url);
     std::vector<int64_t> real_values =
-        SplitStringAsInts(ExecScriptGetStr(kTitleScript, contents()));
+        SplitStringAsInts(EvalJs(contents(), kTitleScript).ExtractString());
     ASSERT_EQ(real_values.size(), 12UL);
 
     // Farbling level: default
@@ -181,8 +175,59 @@ IN_PROC_BROWSER_TEST_F(BraveWebGLFarblingBrowserTest,
     SetFingerprintingDefault(domain);
     NavigateToURLUntilLoadStop(url);
     std::vector<int64_t> farbled_values =
-        SplitStringAsInts(ExecScriptGetStr(kTitleScript, contents()));
+        SplitStringAsInts(EvalJs(contents(), kTitleScript).ExtractString());
     ASSERT_EQ(farbled_values.size(), 12UL);
     ASSERT_EQ(DiffsAsString(real_values, farbled_values), expected_diff);
   }
 }
+
+IN_PROC_BROWSER_TEST_F(BraveWebGLFarblingBrowserTest, GetSupportedExtensions) {
+  std::string domain = "a.com";
+  GURL url =
+      embedded_test_server()->GetURL(domain, "/getSupportedExtensions.html");
+  const std::string kSupportedExtensionsMax = "WEBGL_debug_renderer_info";
+  // Farbling level: maximum
+  // WebGL getSupportedExtensions returns abbreviated list
+  BlockFingerprinting(domain);
+  NavigateToURLUntilLoadStop(url);
+  EXPECT_EQ(EvalJs(contents(), kTitleScript).ExtractString(),
+            kSupportedExtensionsMax);
+
+  // Farbling level: off
+  // WebGL getSupportedExtensions is real
+  AllowFingerprinting(domain);
+  NavigateToURLUntilLoadStop(url);
+  std::string actual = EvalJs(contents(), kTitleScript).ExtractString();
+  EXPECT_NE(actual, kSupportedExtensionsMax);
+
+  // Farbling level: balanced (default)
+  // WebGL getSupportedExtensions is real
+  SetFingerprintingDefault(domain);
+  NavigateToURLUntilLoadStop(url);
+  EXPECT_EQ(EvalJs(contents(), kTitleScript).ExtractString(), actual);
+}
+
+IN_PROC_BROWSER_TEST_F(BraveWebGLFarblingBrowserTest, GetExtension) {
+  std::string domain = "a.com";
+  GURL url = embedded_test_server()->GetURL(domain, "/getExtension.html");
+  const std::string kExpectedExtensionListMax = "WEBGL_debug_renderer_info";
+  // Farbling level: maximum
+  // WebGL getExtension returns null for most names
+  BlockFingerprinting(domain);
+  NavigateToURLUntilLoadStop(url);
+  EXPECT_EQ(EvalJs(contents(), kTitleScript).ExtractString(),
+            kExpectedExtensionListMax);
+
+  // Farbling level: off
+  // WebGL getExtension returns real objects
+  AllowFingerprinting(domain);
+  NavigateToURLUntilLoadStop(url);
+  std::string actual = EvalJs(contents(), kTitleScript).ExtractString();
+  EXPECT_NE(actual, kExpectedExtensionListMax);
+
+  // Farbling level: balanced (default)
+  // WebGL getExtension returns real objects
+  SetFingerprintingDefault(domain);
+  NavigateToURLUntilLoadStop(url);
+  EXPECT_EQ(EvalJs(contents(), kTitleScript).ExtractString(), actual);
+}

chromium_src/third_party/blink/renderer/DEPS

@@ -13,6 +13,7 @@ include_rules = [
   "+../../../../../../../third_party/blink/renderer/modules/mediastream",
   "+../../../../../../../third_party/blink/renderer/modules/quota",
   "+../../../../../../../third_party/blink/renderer/modules/storage",
+  "+../../../../../../third_party/blink/renderer/modules/webgl",
   "+../../../../../../../third_party/blink/renderer/modules/webaudio",
   "+../../../../../../../../third_party/blink/renderer/modules/canvas/canvas2d",
   "+../../../../../../../third_party/blink/renderer/platform/graphics",

chromium_src/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc

@@ -3,6 +3,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#include "third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.h"
 #include "third_party/blink/public/platform/web_content_settings_client.h"
 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/execution_context/execution_context.h"
@@ -77,7 +78,42 @@ bool AllowFingerprintingForHost(blink::CanvasRenderingContextHost* host) {
                    *(Host()->GetTopExecutionContext())) \
                    .GenerateRandomString("UNMASKED_VENDOR_WEBGL", 8)));
 
+#define getExtension getExtension_ChromiumImpl
+#define getSupportedExtensions getSupportedExtensions_ChromiumImpl
 #include "../../../../../../../third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc"
+#undef getSupportedExtensions
+#undef getExtension
+
+namespace blink {
+
+// If fingerprinting is disallowed, claim that the only supported extension is
+// WebGLDebugRendererInfo.
+base::Optional<Vector<String>>
+WebGLRenderingContextBase::getSupportedExtensions() {
+  base::Optional<Vector<String>> real_extensions =
+      getSupportedExtensions_ChromiumImpl();
+  if (real_extensions == base::nullopt)
+    return real_extensions;
+  if (AllowFingerprintingForHost(Host()))
+    return real_extensions;
+
+  Vector<String> fake_extensions;
+  fake_extensions.push_back(WebGLDebugRendererInfo::ExtensionName());
+  return fake_extensions;
+}
+
+// If fingerprinting is disallowed and they're asking for information about any
+// extension other than WebGLDebugRendererInfo, don't give it to them.
+ScriptValue WebGLRenderingContextBase::getExtension(ScriptState* script_state,
+                                                    const String& name) {
+  if (!AllowFingerprintingForHost(Host()))
+    if (name != WebGLDebugRendererInfo::ExtensionName())
+      return ScriptValue::CreateNull(script_state->GetIsolate());
+  return getExtension_ChromiumImpl(script_state, name);
+}
+
+}  // namespace blink
+
 #undef BRAVE_WEBGL_GET_PARAMETER_UNMASKED_RENDERER
 #undef BRAVE_WEBGL_GET_PARAMETER_UNMASKED_VENDOR
 #undef BRAVE_WEBGL_RENDERING_CONTEXT_BASE_STRING

chromium_src/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.h

@@ -0,0 +1,22 @@
+/* Copyright (c) 2021 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef BRAVE_CHROMIUM_SRC_THIRD_PARTY_BLINK_RENDERER_MODULES_WEBGL_WEBGL_RENDERING_CONTEXT_BASE_H_
+#define BRAVE_CHROMIUM_SRC_THIRD_PARTY_BLINK_RENDERER_MODULES_WEBGL_WEBGL_RENDERING_CONTEXT_BASE_H_
+
+#define getExtension                                           \
+  getExtension_ChromiumImpl(ScriptState*, const String& name); \
+  ScriptValue getExtension
+
+#define getSupportedExtensions           \
+  getSupportedExtensions_ChromiumImpl(); \
+  base::Optional<Vector<String>> getSupportedExtensions
+
+#include "../../../../../../third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.h"
+
+#undef getSupportedExtensions
+#undef getExtension
+
+#endif  // BRAVE_CHROMIUM_SRC_THIRD_PARTY_BLINK_RENDERER_MODULES_WEBGL_WEBGL_RENDERING_CONTEXT_BASE_H_

patches/third_party-blink-renderer-modules-webgl-webgl_rendering_context_base.cc.patch

@@ -1,5 +1,5 @@
 diff --git a/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc b/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc
-index 31a22fa48c001a07d1b848c107d22c7d1342c2a6..598a94a2cb71897c4ace95dbecfb8cd9bf57a51d 100644
+index 31a22fa48c001a07d1b848c107d22c7d1342c2a6..70adc89b0c804f28d8c94e6217d9dd650f97a5ac 100644
 --- a/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc
 +++ b/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc
 @@ -2920,6 +2920,7 @@ WebGLActiveInfo* WebGLRenderingContextBase::getActiveAttrib(
@@ -122,55 +122,47 @@ index 31a22fa48c001a07d1b848c107d22c7d1342c2a6..598a94a2cb71897c4ace95dbecfb8cd9
    return EnsureNotNull(shader->Source());
  }
 
-@@ -3868,6 +3883,7 @@ base::Optional<Vector<String>>
- WebGLRenderingContextBase::getSupportedExtensions() {
-   if (isContextLost())
-     return base::nullopt;
-+  BRAVE_WEBGL_RENDERING_CONTEXT_BASE_NULLOPT
-
-   Vector<String> result;
-
-@@ -3890,6 +3906,7 @@ ScriptValue WebGLRenderingContextBase::getTexParameter(
+@@ -3890,6 +3905,7 @@ ScriptValue WebGLRenderingContextBase::getTexParameter(
      GLenum pname) {
    if (isContextLost())
      return ScriptValue::CreateNull(script_state->GetIsolate());
 +  BRAVE_WEBGL_RENDERING_CONTEXT_BASE_SCRIPT_VALUE
    if (!ValidateTextureBinding("getTexParameter", target))
      return ScriptValue::CreateNull(script_state->GetIsolate());
    switch (pname) {
-@@ -3924,6 +3941,7 @@ ScriptValue WebGLRenderingContextBase::getUniform(
+@@ -3924,6 +3940,7 @@ ScriptValue WebGLRenderingContextBase::getUniform(
      const WebGLUniformLocation* uniform_location) {
    if (!ValidateWebGLProgramOrShader("getUniform", program))
      return ScriptValue::CreateNull(script_state->GetIsolate());
 +  BRAVE_WEBGL_RENDERING_CONTEXT_BASE_SCRIPT_VALUE
    DCHECK(uniform_location);
    if (uniform_location->Program() != program) {
      SynthesizeGLError(GL_INVALID_OPERATION, "getUniform",
-@@ -4183,6 +4201,7 @@ WebGLUniformLocation* WebGLRenderingContextBase::getUniformLocation(
+@@ -4183,6 +4200,7 @@ WebGLUniformLocation* WebGLRenderingContextBase::getUniformLocation(
      const String& name) {
    if (!ValidateWebGLProgramOrShader("getUniformLocation", program))
      return nullptr;
 +  BRAVE_WEBGL_RENDERING_CONTEXT_BASE_NULLPTR
    if (!ValidateLocationLength("getUniformLocation", name))
      return nullptr;
    if (!ValidateString("getUniformLocation", name))
-@@ -4207,6 +4226,7 @@ ScriptValue WebGLRenderingContextBase::getVertexAttrib(
+@@ -4207,6 +4225,7 @@ ScriptValue WebGLRenderingContextBase::getVertexAttrib(
      GLenum pname) {
    if (isContextLost())
      return ScriptValue::CreateNull(script_state->GetIsolate());
 +  BRAVE_WEBGL_RENDERING_CONTEXT_BASE_SCRIPT_VALUE
    if (index >= max_vertex_attribs_) {
      SynthesizeGLError(GL_INVALID_VALUE, "getVertexAttrib",
                        "index out of range");
-@@ -4284,6 +4304,7 @@ int64_t WebGLRenderingContextBase::getVertexAttribOffset(GLuint index,
+@@ -4284,6 +4303,7 @@ int64_t WebGLRenderingContextBase::getVertexAttribOffset(GLuint index,
                                                           GLenum pname) {
    if (isContextLost())
      return 0;
 +  BRAVE_WEBGL_RENDERING_CONTEXT_BASE_ZERO
    GLvoid* result = nullptr;
    // NOTE: If pname is ever a value that returns more than 1 element
    // this will corrupt memory.
-@@ -4631,6 +4652,7 @@ void WebGLRenderingContextBase::ReadPixelsHelper(GLint x,
+@@ -4631,6 +4651,7 @@ void WebGLRenderingContextBase::ReadPixelsHelper(GLint x,
                                                   int64_t offset) {
    if (isContextLost())
      return;

test/data/webgl/getExtension.html

@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>WebGL getExtension() test</title>
+    <meta charset="utf-8">
+  </head>
+  <body>
+    <canvas id="test" width="8" height="8"></canvas>
+    <script>
+      var canvas = document.getElementById("test");
+      var gl = canvas.getContext("webgl");
+      var ext_list = [];
+      for (const [i, name] of Object.entries(gl.getSupportedExtensions())) {
+        ext_list = ext_list.concat(gl.getExtension(name) ? name : null);
+      }
+      document.title = ext_list.join("");
+    </script>
+  </body>
+</html>
+
+      }

test/data/webgl/getSupportedExtensions.html

@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>WebGL getSupportedExtensions() test</title>
+    <meta charset="utf-8">
+  </head>
+  <body>
+    <canvas id="test" width="8" height="8"></canvas>
+    <script>
+      var canvas = document.getElementById("test");
+      var gl = canvas.getContext("webgl");
+      var ext_list = gl.getSupportedExtensions();
+      document.title = ext_list.join(",");
+    </script>
+  </body>
+</html>