Bug 1382499 - Enhance fingerprinting resistance for Touch API r=arthuredelstein,bz

MozReview-Commit-ID: 8nzOkvIvwrD

--HG--
extra : rebase_source : 15cfa77ffc639838d6345fa4bffc7079d8d198e7

dom/events/Touch.cpp

@@ -160,6 +160,46 @@ Touch::ScreenY(CallerType aCallerType) const
   return mScreenPoint.y;
 }
 
+int32_t
+Touch::RadiusX(CallerType aCallerType) const
+{
+  if (nsContentUtils::ResistFingerprinting(aCallerType)) {
+    return 0;
+  }
+
+  return mRadius.x;
+}
+
+int32_t
+Touch::RadiusY(CallerType aCallerType) const
+{
+  if (nsContentUtils::ResistFingerprinting(aCallerType)) {
+    return 0;
+  }
+
+  return mRadius.y;
+}
+
+float
+Touch::RotationAngle(CallerType aCallerType) const
+{
+  if (nsContentUtils::ResistFingerprinting(aCallerType)) {
+    return 0.0f;
+  }
+
+  return mRotationAngle;
+}
+
+float
+Touch::Force(CallerType aCallerType) const
+{
+  if (nsContentUtils::ResistFingerprinting(aCallerType)) {
+    return 0.0f;
+  }
+
+  return mForce;
+}
+
 void
 Touch::InitializePoints(nsPresContext* aPresContext, WidgetEvent* aEvent)
 {
@@ -184,10 +224,10 @@ bool
 Touch::Equals(Touch* aTouch)
 {
   return mRefPoint == aTouch->mRefPoint &&
-         mForce == aTouch->Force() &&
-         mRotationAngle == aTouch->RotationAngle() &&
-         mRadius.x == aTouch->RadiusX() &&
-         mRadius.y == aTouch->RadiusY();
+         mForce == aTouch->mForce &&
+         mRotationAngle == aTouch->mRotationAngle &&
+         mRadius.x == aTouch->mRadius.x &&
+         mRadius.y == aTouch->mRadius.y;
 }
 
 JSObject*

dom/events/Touch.h

@@ -74,10 +74,10 @@ public:
   int32_t ClientY() const { return mClientPoint.y; }
   int32_t PageX() const { return mPagePoint.x; }
   int32_t PageY() const { return mPagePoint.y; }
-  int32_t RadiusX() const { return mRadius.x; }
-  int32_t RadiusY() const { return mRadius.y; }
-  float RotationAngle() const { return mRotationAngle; }
-  float Force() const { return mForce; }
+  int32_t RadiusX(CallerType aCallerType) const;
+  int32_t RadiusY(CallerType aCallerType) const;
+  float RotationAngle(CallerType aCallerType) const;
+  float Force(CallerType aCallerType) const;
 
   nsCOMPtr<EventTarget> mTarget;
   LayoutDeviceIntPoint mRefPoint;

dom/webidl/Touch.webidl

@@ -38,8 +38,12 @@ interface Touch {
   readonly    attribute long         clientY;
   readonly    attribute long         pageX;
   readonly    attribute long         pageY;
+  [NeedsCallerType]
   readonly    attribute long         radiusX;
+  [NeedsCallerType]
   readonly    attribute long         radiusY;
+  [NeedsCallerType]
   readonly    attribute float        rotationAngle;
+  [NeedsCallerType]
   readonly    attribute float        force;
 };

layout/base/PresShell.cpp

@@ -7107,8 +7107,8 @@ DispatchPointerFromMouseOrTouch(PresShell* aShell,
       event.pointerId = touch->Identifier();
       event.mRefPoint = touch->mRefPoint;
       event.mModifiers = touchEvent->mModifiers;
-      event.mWidth = touch->RadiusX();
-      event.mHeight = touch->RadiusY();
+      event.mWidth = touch->RadiusX(CallerType::System);
+      event.mHeight = touch->RadiusY(CallerType::System);
       event.tiltX = touch->tiltX;
       event.tiltY = touch->tiltY;
       event.mTime = touchEvent->mTime;

widget/InputData.cpp

@@ -6,6 +6,7 @@
 #include "InputData.h"
 
 #include "mozilla/dom/Touch.h"
+#include "nsContentUtils.h"
 #include "nsDebug.h"
 #include "nsThreadUtils.h"
 #include "mozilla/MouseEvents.h"
@@ -130,10 +131,10 @@ MultiTouchInput::MultiTouchInput(const WidgetTouchEvent& aTouchEvent)
 
     // Extract data from weird interfaces.
     int32_t identifier = domTouch->Identifier();
-    int32_t radiusX = domTouch->RadiusX();
-    int32_t radiusY = domTouch->RadiusY();
-    float rotationAngle = domTouch->RotationAngle();
-    float force = domTouch->Force();
+    int32_t radiusX = domTouch->RadiusX(CallerType::System);
+    int32_t radiusY = domTouch->RadiusY(CallerType::System);
+    float rotationAngle = domTouch->RotationAngle(CallerType::System);
+    float force = domTouch->Force(CallerType::System);
 
     SingleTouchData data(identifier,
                          ViewAs<ScreenPixel>(domTouch->mRefPoint,