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 0bd8a78e68d3a8c6a1d57b9104e7afa973426cd7..4bc8e4f7d1836859b14dd5056ffab8dfe9ae2341 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 kAndroidMaxKeyIdLengthForWebM = 128 / 8;

[ddorwin, 2015/05/15 04:12:35]

I believe this key ID length applies to all containers, not just WebM. And, it's
an exact length, not a max.
Also, it's nice to include the units in the name.
Thus, something like kAndroidKeyIdBytes.

[jrummell, 2015/05/15 16:41:19]

Done.

+#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.
 
@@ -345,6 +350,14 @@ 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() > kAndroidMaxKeyIdLengthForWebM) {

[ddorwin, 2015/05/15 04:12:35]

s/>/!=/

Then update the message too.

[jrummell, 2015/05/15 16:41:19]

Done.

+    promise->reject(MediaKeys::INVALID_ACCESS_ERROR, 0,
+                    "'webm' initData is too long.");
+    return;
+  }
+#endif
 
   media::EmeInitDataType eme_init_data_type;
   switch (init_data_type) {