Bug 1101304 - Handle CORS in EME - r=cpearce

dom/html/HTMLMediaElement.cpp

@@ -3303,6 +3303,15 @@ bool HTMLMediaElement::ShouldCheckAllowOrigin()
   return mCORSMode != CORS_NONE;
 }
 
+bool HTMLMediaElement::IsCORSSameOrigin()
+{
+  bool subsumes;
+  nsRefPtr<nsIPrincipal> principal = GetCurrentPrincipal();
+  return
+    (NS_SUCCEEDED(NodePrincipal()->Subsumes(principal, &subsumes)) && subsumes) ||
+    ShouldCheckAllowOrigin();
+}
+
 void HTMLMediaElement::UpdateReadyStateForData(MediaDecoderOwner::NextFrameStatus aNextFrame)
 {
   mLastNextFrameStatus = aNextFrame;
@@ -3648,22 +3657,13 @@ void HTMLMediaElement::NotifyDecoderPrincipalChanged()
 {
   nsRefPtr<nsIPrincipal> principal = GetCurrentPrincipal();
 
-  bool subsumes;
-  mDecoder->UpdateSameOriginStatus(
-    !principal ||
-    (NS_SUCCEEDED(NodePrincipal()->Subsumes(principal, &subsumes)) && subsumes) ||
-    mCORSMode != CORS_NONE);
+  mDecoder->UpdateSameOriginStatus(!principal || IsCORSSameOrigin());
 
   for (uint32_t i = 0; i < mOutputStreams.Length(); ++i) {
     OutputMediaStream* ms = &mOutputStreams[i];
     ms->mStream->SetCORSMode(mCORSMode);
     ms->mStream->CombineWithPrincipal(principal);
   }
-#ifdef MOZ_EME
-  if (mMediaKeys && NS_FAILED(mMediaKeys->CheckPrincipals())) {
-    mMediaKeys->Shutdown();
-  }
-#endif
 }
 
 void HTMLMediaElement::UpdateMediaSize(nsIntSize size)
@@ -4307,8 +4307,6 @@ HTMLMediaElement::SetMediaKeys(mozilla::dom::MediaKeys* aMediaKeys,
     if (mDecoder) {
       mDecoder->SetCDMProxy(mMediaKeys->GetCDMProxy());
     }
-    // Update the same-origin status.
-    NotifyDecoderPrincipalChanged();
   }
   promise->MaybeResolve(JS::UndefinedHandleValue);
   return promise.forget();
@@ -4341,8 +4339,13 @@ void
 HTMLMediaElement::DispatchEncrypted(const nsTArray<uint8_t>& aInitData,
                                     const nsAString& aInitDataType)
 {
-  nsRefPtr<MediaEncryptedEvent> event(
-    MediaEncryptedEvent::Constructor(this, aInitDataType, aInitData));
+  nsRefPtr<MediaEncryptedEvent> event;
+  if (IsCORSSameOrigin()) {
+    event = MediaEncryptedEvent::Constructor(this, aInitDataType, aInitData);
+  } else {
+    event = MediaEncryptedEvent::Constructor(this);
+  }
+
   nsRefPtr<AsyncEventDispatcher> asyncDispatcher =
     new AsyncEventDispatcher(this, event);
   asyncDispatcher->PostDOMEvent();

dom/html/HTMLMediaElement.h

@@ -245,6 +245,10 @@ public:
   // Check if the media element had crossorigin set when loading started
   bool ShouldCheckAllowOrigin();
 
+  // Returns true if the currently loaded resource is CORS same-origin with
+  // respect to the document.
+  bool IsCORSSameOrigin();
+
   // Is the media element potentially playing as defined by the HTML 5 specification.
   // http://www.whatwg.org/specs/web-apps/current-work/#potentially-playing
   bool IsPotentiallyPlaying() const;

dom/media/eme/MediaEncryptedEvent.cpp

@@ -51,6 +51,15 @@ MediaEncryptedEvent::WrapObjectInternal(JSContext* aCx)
   return MediaEncryptedEventBinding::Wrap(aCx, this);
 }
 
+already_AddRefed<MediaEncryptedEvent>
+MediaEncryptedEvent::Constructor(EventTarget* aOwner)
+{
+  nsRefPtr<MediaEncryptedEvent> e = new MediaEncryptedEvent(aOwner);
+  e->InitEvent(NS_LITERAL_STRING("encrypted"), false, false);
+  e->SetTrusted(true);
+  return e.forget();
+}
+
 already_AddRefed<MediaEncryptedEvent>
 MediaEncryptedEvent::Constructor(EventTarget* aOwner,
                                  const nsAString& aInitDataType,

dom/media/eme/MediaEncryptedEvent.h

@@ -38,6 +38,9 @@ public:
 
   virtual JSObject* WrapObjectInternal(JSContext* aCx) MOZ_OVERRIDE;
 
+  static already_AddRefed<MediaEncryptedEvent>
+  Constructor(EventTarget* aOwner);
+
   static already_AddRefed<MediaEncryptedEvent>
   Constructor(EventTarget* aOwner,
               const nsAString& aInitDataType,

dom/media/eme/MediaKeys.cpp

@@ -433,33 +433,6 @@ MediaKeys::Bind(HTMLMediaElement* aElement)
   }
 
   mElement = aElement;
-  nsresult rv = CheckPrincipals();
-  if (NS_FAILED(rv)) {
-    mElement = nullptr;
-    return rv;
-  }
-
-  return NS_OK;
-}
-
-nsresult
-MediaKeys::CheckPrincipals()
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  if (!IsBoundToMediaElement()) {
-    return NS_ERROR_FAILURE;
-  }
-
-  nsRefPtr<nsIPrincipal> elementPrincipal(mElement->GetCurrentPrincipal());
-  nsRefPtr<nsIPrincipal> elementTopLevelPrincipal(mElement->GetTopLevelPrincipal());
-  if (!elementPrincipal ||
-      !mPrincipal ||
-      !elementPrincipal->Equals(mPrincipal) ||
-      !elementTopLevelPrincipal ||
-      !mTopLevelPrincipal ||
-      !elementTopLevelPrincipal->Equals(mTopLevelPrincipal)) {
-    return NS_ERROR_FAILURE;
-  }
 
   return NS_OK;
 }

dom/media/eme/MediaKeys.h

@@ -117,10 +117,6 @@ public:
   // Returns true if this MediaKeys has been bound to a media element.
   bool IsBoundToMediaElement() const;
 
-  // Return NS_OK if the principals are the same as when the MediaKeys
-  // was created, failure otherwise.
-  nsresult CheckPrincipals();
-
 private:
 
   bool IsInPrivateBrowsing();