Bug 1284910 - Add scary boolean to mediaDeviceInfo. r=jesup

MozReview-Commit-ID: 2A7QZgUQH8l

--HG--
extra : rebase_source : 15f534bd11d1b8bb4e85de7bc8cac45c99654ce4

dom/media/MediaManager.cpp

@@ -743,7 +743,8 @@ protected:
 NS_IMPL_ISUPPORTS(MediaDevice, nsIMediaDevice)
 
 MediaDevice::MediaDevice(MediaEngineSource* aSource, bool aIsVideo)
-  : mMediaSource(aSource->GetMediaSource())
+  : mScary(aSource->GetScary())
+  , mMediaSource(aSource->GetMediaSource())
   , mSource(aSource)
   , mIsVideo(aIsVideo)
 {
@@ -881,6 +882,13 @@ MediaDevice::GetRawId(nsAString& aID)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+MediaDevice::GetScary(bool* aScary)
+{
+  *aScary = mScary;
+  return NS_OK;
+}
+
 void
 MediaDevice::SetId(const nsAString& aID)
 {

dom/media/MediaManager.h

@@ -94,6 +94,7 @@ protected:
   nsString mName;
   nsString mID;
   nsString mRawID;
+  bool mScary;
   dom::MediaSourceEnum mMediaSource;
   RefPtr<MediaEngineSource> mSource;
   RefPtr<MediaEngineSource::AllocationHandle> mAllocationHandle;

dom/media/nsIDOMNavigatorUserMedia.idl

@@ -13,6 +13,7 @@ interface nsIMediaDevice : nsISupports
   readonly attribute DOMString id;
   readonly attribute DOMString mediaSource;
   readonly attribute DOMString rawId;
+  readonly attribute boolean scary;
 };
 
 [scriptable, function, uuid(24544878-d35e-4962-8c5f-fb84e97bdfee)]

dom/media/webrtc/MediaEngine.h

@@ -214,6 +214,9 @@ public:
   /* Populate the UUID of this device in the nsACString */
   virtual void GetUUID(nsACString&) const = 0;
 
+  /* Override w/true if source does end-run around cross origin restrictions. */
+  virtual bool GetScary() const { return false; };
+
   class AllocationHandle
   {
   public:

dom/media/webrtc/MediaEngineRemoteVideoSource.cpp

@@ -29,10 +29,11 @@ NS_IMPL_ISUPPORTS0(MediaEngineRemoteVideoSource)
 
 MediaEngineRemoteVideoSource::MediaEngineRemoteVideoSource(
   int aIndex, mozilla::camera::CaptureEngine aCapEngine,
-  dom::MediaSourceEnum aMediaSource, const char* aMonitorName)
+  dom::MediaSourceEnum aMediaSource, bool aScary, const char* aMonitorName)
   : MediaEngineCameraVideoSource(aIndex, aMonitorName),
     mMediaSource(aMediaSource),
-    mCapEngine(aCapEngine)
+    mCapEngine(aCapEngine),
+    mScary(aScary)
 {
   MOZ_ASSERT(aMediaSource != dom::MediaSourceEnum::Other);
   mSettings.mWidth.Construct(0);

dom/media/webrtc/MediaEngineRemoteVideoSource.h

@@ -70,6 +70,7 @@ public:
   // MediaEngineCameraVideoSource
   MediaEngineRemoteVideoSource(int aIndex, mozilla::camera::CaptureEngine aCapEngine,
                                dom::MediaSourceEnum aMediaSource,
+                               bool aScary = false,
                                const char* aMonitorName = "RemoteVideo.Monitor");
 
   nsresult Allocate(const dom::MediaTrackConstraints& aConstraints,
@@ -103,6 +104,8 @@ public:
 
   void Shutdown() override;
 
+  bool GetScary() const override { return mScary; }
+
 protected:
   ~MediaEngineRemoteVideoSource() { }
 
@@ -125,6 +128,7 @@ private:
 
   // To only restart camera when needed, we keep track previous settings.
   webrtc::CaptureCapability mLastCapability;
+  bool mScary;
 };
 
 }

dom/media/webrtc/MediaEngineTabVideoSource.h

@@ -21,6 +21,11 @@ class MediaEngineTabVideoSource : public MediaEngineVideoSource, nsIDOMEventList
 
     void GetName(nsAString_internal&) const override;
     void GetUUID(nsACString_internal&) const override;
+
+    bool GetScary() const override {
+      return true;
+    }
+
     nsresult Allocate(const dom::MediaTrackConstraints &,
                       const mozilla::MediaEnginePrefs&,
                       const nsString& aDeviceId,

dom/media/webrtc/MediaEngineWebRTC.cpp

@@ -157,6 +157,7 @@ MediaEngineWebRTC::EnumerateVideoDevices(dom::MediaSourceEnum aMediaSource,
     return;
   }
 #endif
+  bool scaryKind = false; // flag sources with cross-origin exploit potential
 
   switch (aMediaSource) {
     case dom::MediaSourceEnum::Window:
@@ -167,9 +168,11 @@ MediaEngineWebRTC::EnumerateVideoDevices(dom::MediaSourceEnum aMediaSource,
       break;
     case dom::MediaSourceEnum::Screen:
       capEngine = mozilla::camera::ScreenEngine;
+      scaryKind = true;
       break;
     case dom::MediaSourceEnum::Browser:
       capEngine = mozilla::camera::BrowserEngine;
+      scaryKind = true;
       break;
     case dom::MediaSourceEnum::Camera:
       capEngine = mozilla::camera::CameraEngine;
@@ -196,6 +199,7 @@ MediaEngineWebRTC::EnumerateVideoDevices(dom::MediaSourceEnum aMediaSource,
   for (int i = 0; i < num; i++) {
     char deviceName[MediaEngineSource::kMaxDeviceNameLength];
     char uniqueId[MediaEngineSource::kMaxUniqueIdLength];
+    bool scaryWindow = false;
 
     // paranoia
     deviceName[0] = '\0';
@@ -215,6 +219,16 @@ MediaEngineWebRTC::EnumerateVideoDevices(dom::MediaSourceEnum aMediaSource,
 #ifdef DEBUG
     LOG(("  Capture Device Index %d, Name %s", i, deviceName));
 
+    if (aMediaSource == dom::MediaSourceEnum::Window) {
+      // TODO: Detect firefox windows
+      //scaryWindow = true;
+    }
+
+    if (aMediaSource == dom::MediaSourceEnum::Application) {
+      // TODO: Detect firefox application windows
+      //scaryWindow = true;
+    }
+
     webrtc::CaptureCapability cap;
     int numCaps = mozilla::camera::GetChildAndCall(
       &mozilla::camera::CamerasChild::NumberOfCapabilities,
@@ -247,7 +261,8 @@ MediaEngineWebRTC::EnumerateVideoDevices(dom::MediaSourceEnum aMediaSource,
       static_cast<MediaEngineRemoteVideoSource*>(vSource.get())->Refresh(i);
       aVSources->AppendElement(vSource.get());
     } else {
-      vSource = new MediaEngineRemoteVideoSource(i, capEngine, aMediaSource);
+      vSource = new MediaEngineRemoteVideoSource(i, capEngine, aMediaSource,
+                                                 scaryKind || scaryWindow);
       mVideoSources.Put(uuid, vSource); // Hashtable takes ownership.
       aVSources->AppendElement(vSource);
     }