Restrict WEBM Key ID data to 128-bits for Android

content/browser/media/cdm/browser_cdm_manager.cc

Index: content/browser/media/cdm/browser_cdm_manager.cc
diff --git a/content/browser/media/cdm/browser_cdm_manager.cc b/content/browser/media/cdm/browser_cdm_manager.cc
index 8f1e78ae84324ea41406913c2d156bda8fa0774b..bf5e6f58d9f79edf33c7a47921102fdee169da34 100644
--- a/content/browser/media/cdm/browser_cdm_manager.cc
+++ b/content/browser/media/cdm/browser_cdm_manager.cc
@@ -36,6 +36,11 @@ using media::MediaKeys;
 
 namespace {
 
+#if defined(OS_ANDROID)
+// Android only supports 128-bit key IDs.
+const size_t kMaxKeyIdLength = 128 / 8;

[ddorwin, 2015/04/29 21:19:56]

We could always have a limit (i.e. 1024 or whatever we do elsewhere) and set it
to 128 on Android. Then, we would always have some checks, not have to ifdef
below, and allow other devices to add similar limits.

If left this way, we should rename the constant since it is the AndroidMax...

[jrummell, 2015/05/15 00:52:59]

Renamed. The existing global limit is not currently based on content type.

+#endif
+
 // The ID used in this class is a concatenation of |render_frame_id| and
 // |cdm_id|, i.e. (render_frame_id << 32) + cdm_id.
 
@@ -344,6 +349,14 @@ void BrowserCdmManager::OnCreateSessionAndGenerateRequest(
     promise->reject(MediaKeys::INVALID_ACCESS_ERROR, 0, "Init data too long.");
     return;
   }
+#if defined(OS_ANDROID)
+  if (init_data_type == INIT_DATA_TYPE_WEBM &&
+      init_data.size() > kMaxKeyIdLength) {
+    promise->reject(MediaKeys::INVALID_ACCESS_ERROR, 0,
+                    "Init data for WEBM too long.");

[ddorwin, 2015/04/29 21:19:56]

"'webm' initData is too long."

[jrummell, 2015/05/15 00:52:59]

Done.

+    return;
+  }
+#endif
 
   media::EmeInitDataType eme_init_data_type;
   switch (init_data_type) {