Bug 1607032: Spoof screen orientation and angle to primary values. r=tjr,geckoview-reviewers,owlish

Differential Revision: https://phabricator.services.mozilla.com/D220904

dom/base/ScreenOrientation.cpp

@@ -626,7 +626,7 @@ void ScreenOrientation::CleanupFullscreenListener() {
 OrientationType ScreenOrientation::DeviceType(CallerType aCallerType) const {
   if (nsContentUtils::ShouldResistFingerprinting(
           aCallerType, GetOwnerGlobal(), RFPTarget::ScreenOrientation)) {
-    return OrientationType::Landscape_primary;
+    return nsRFPService::OrientationSecondaryToPrimary(mType);
   }
   return mType;
 }
@@ -634,18 +634,13 @@ OrientationType ScreenOrientation::DeviceType(CallerType aCallerType) const {
 uint16_t ScreenOrientation::DeviceAngle(CallerType aCallerType) const {
   if (nsContentUtils::ShouldResistFingerprinting(
           aCallerType, GetOwnerGlobal(), RFPTarget::ScreenOrientation)) {
-    return 0;
+    return nsRFPService::OrientationSecondaryToPrimary(mAngle);
   }
   return mAngle;
 }
 
 OrientationType ScreenOrientation::GetType(CallerType aCallerType,
                                            ErrorResult& aRv) const {
-  if (nsContentUtils::ShouldResistFingerprinting(
-          aCallerType, GetOwnerGlobal(), RFPTarget::ScreenOrientation)) {
-    return OrientationType::Landscape_primary;
-  }
-
   Document* doc = GetResponsibleDocument();
   BrowsingContext* bc = doc ? doc->GetBrowsingContext() : nullptr;
   if (!bc) {
@@ -653,16 +648,16 @@ OrientationType ScreenOrientation::GetType(CallerType aCallerType,
     return OrientationType::Portrait_primary;
   }
 
-  return bc->GetCurrentOrientationType();
+  OrientationType orientation = bc->GetCurrentOrientationType();
+  if (nsContentUtils::ShouldResistFingerprinting(
+          aCallerType, GetOwnerGlobal(), RFPTarget::ScreenOrientation)) {
+    return nsRFPService::OrientationSecondaryToPrimary(orientation);
+  }
+  return orientation;
 }
 
 uint16_t ScreenOrientation::GetAngle(CallerType aCallerType,
                                      ErrorResult& aRv) const {
-  if (nsContentUtils::ShouldResistFingerprinting(
-          aCallerType, GetOwnerGlobal(), RFPTarget::ScreenOrientation)) {
-    return 0;
-  }
-
   Document* doc = GetResponsibleDocument();
   BrowsingContext* bc = doc ? doc->GetBrowsingContext() : nullptr;
   if (!bc) {
@@ -670,7 +665,12 @@ uint16_t ScreenOrientation::GetAngle(CallerType aCallerType,
     return 0;
   }
 
-  return bc->GetCurrentOrientationAngle();
+  uint16_t angle = static_cast<uint16_t>(bc->GetCurrentOrientationAngle());
+  if (nsContentUtils::ShouldResistFingerprinting(
+          aCallerType, GetOwnerGlobal(), RFPTarget::ScreenOrientation)) {
+    return nsRFPService::OrientationSecondaryToPrimary(angle);
+  }
+  return angle;
 }
 
 ScreenOrientation::LockPermission

dom/base/nsGlobalWindowInner.cpp

@@ -7263,11 +7263,12 @@ void nsGlobalWindowInner::InitWasOffline() { mWasOffline = NS_IsOffline(); }
 int16_t nsGlobalWindowInner::Orientation(CallerType aCallerType) {
   // GetOrientationAngle() returns 0, 90, 180 or 270.
   // window.orientation returns -90, 0, 90 or 180.
+  uint16_t screenAngle = Screen()->GetOrientationAngle();
   if (nsIGlobalObject::ShouldResistFingerprinting(
           aCallerType, RFPTarget::ScreenOrientation)) {
-    return 0;
+    screenAngle = nsRFPService::OrientationSecondaryToPrimary(screenAngle);
   }
-  int16_t angle = AssertedCast<int16_t>(Screen()->GetOrientationAngle());
+  int16_t angle = AssertedCast<int16_t>(screenAngle);
   return angle <= 180 ? angle : angle - 360;
 }
 

dom/base/test/chrome/bug418986-1.js

@@ -32,9 +32,6 @@ var test = function (isContent) {
     ["screen.availTop", 0],
     ["screen.width", "outerWidth"],
     ["screen.height", "outerHeight"],
-    ["screen.orientation.type", "'landscape-primary'"],
-    ["screen.orientation.angle", 0],
-    ["screen.mozOrientation", "'landscape-primary'"],
     ["devicePixelRatio", 2],
   ];
 

hal/android/AndroidHal.cpp

@@ -79,19 +79,20 @@ void GetCurrentNetworkInformation(hal::NetworkInformation* aNetworkInfo) {
 
 static bool IsSupportedScreenOrientation(hal::ScreenOrientation aOrientation) {
   // The Android backend only supports these orientations.
-  static constexpr ScreenOrientation kSupportedOrientations[] = {
-      ScreenOrientation::PortraitPrimary,
-      ScreenOrientation::PortraitSecondary,
-      ScreenOrientation::PortraitPrimary | ScreenOrientation::PortraitSecondary,
-      ScreenOrientation::LandscapePrimary,
-      ScreenOrientation::LandscapeSecondary,
-      ScreenOrientation::LandscapePrimary |
-          ScreenOrientation::LandscapeSecondary,
-      ScreenOrientation::PortraitPrimary |
-          ScreenOrientation::PortraitSecondary |
-          ScreenOrientation::LandscapePrimary |
-          ScreenOrientation::LandscapeSecondary,
-      ScreenOrientation::Default,
+  static constexpr hal::ScreenOrientation kSupportedOrientations[] = {
+      hal::ScreenOrientation::PortraitPrimary,
+      hal::ScreenOrientation::PortraitSecondary,
+      hal::ScreenOrientation::PortraitPrimary |
+          hal::ScreenOrientation::PortraitSecondary,
+      hal::ScreenOrientation::LandscapePrimary,
+      hal::ScreenOrientation::LandscapeSecondary,
+      hal::ScreenOrientation::LandscapePrimary |
+          hal::ScreenOrientation::LandscapeSecondary,
+      hal::ScreenOrientation::PortraitPrimary |
+          hal::ScreenOrientation::PortraitSecondary |
+          hal::ScreenOrientation::LandscapePrimary |
+          hal::ScreenOrientation::LandscapeSecondary,
+      hal::ScreenOrientation::Default,
   };
   for (auto supportedOrientation : kSupportedOrientations) {
     if (aOrientation == supportedOrientation) {

toolkit/components/resistfingerprinting/nsRFPService.cpp

@@ -2381,3 +2381,28 @@ void nsRFPService::GetMediaDeviceGroup(nsString& aGroup,
       break;
   }
 }
+
+/* static */
+dom::OrientationType nsRFPService::OrientationSecondaryToPrimary(
+    dom::OrientationType aOrientation) {
+  switch (aOrientation) {
+    case dom::OrientationType::Landscape_secondary:
+      return dom::OrientationType::Landscape_primary;
+    case dom::OrientationType::Portrait_secondary:
+      return dom::OrientationType::Portrait_primary;
+    default:
+      return aOrientation;
+  }
+}
+
+/* static */
+uint16_t nsRFPService::OrientationSecondaryToPrimary(uint16_t aAngle) {
+  switch (aAngle) {
+    case 180:
+      return 0;
+    case 270:
+      return 90;
+    default:
+      return aAngle;
+  }
+}

toolkit/components/resistfingerprinting/nsRFPService.h

@@ -15,6 +15,7 @@
 #include "mozilla/gfx/Types.h"
 #include "mozilla/TypedEnumBits.h"
 #include "mozilla/dom/MediaDeviceInfoBinding.h"
+#include "mozilla/dom/ScreenOrientationBinding.h"
 #include "js/RealmOptions.h"
 #include "nsHashtablesFwd.h"
 #include "nsICookieJarSettings.h"
@@ -379,6 +380,14 @@ class nsRFPService final : public nsIObserver, public nsIRFPService {
   static void GetMediaDeviceGroup(nsString& aGroup,
                                   mozilla::dom::MediaDeviceKind aKind);
 
+  // Converts any OrientationType::SOMETHING_secondary to
+  // OrientationType::SOMETHING_primary
+  static mozilla::dom::OrientationType OrientationSecondaryToPrimary(
+      mozilla::dom::OrientationType aOrientation);
+
+  // Converts (exactly) 180 degrees to 0 degrees, 270 degrees to 90 degrees.
+  static uint16_t OrientationSecondaryToPrimary(uint16_t aAngle);
+
  private:
   nsresult Init();