Restrict WEBM Key ID data to 128-bits for Android

content/browser/media/cdm/browser_cdm_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/media/cdm/browser_cdm_manager.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
@@ skipping 18 matching lines @@
 #include "content/public/common/renderer_preferences.h"
 #endif
 
 namespace content {
 
 using media::BrowserCdm;
 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.
 
 uint64 GetId(int render_frame_id, int cdm_id) {
   return (static_cast<uint64>(render_frame_id) << 32) +
          static_cast<uint64>(cdm_id);
 }
 
 bool IdBelongsToFrame(uint64 id, int render_frame_id) {
   return (id >> 32) == static_cast<uint64>(render_frame_id);
@@ skipping 288 matching lines @@
 
   scoped_ptr<NewSessionPromise> promise(
       new NewSessionPromise(this, render_frame_id, cdm_id, promise_id));
 
   if (init_data.size() > media::limits::kMaxInitDataLength) {
     LOG(WARNING) << "InitData for ID: " << cdm_id
                  << " too long: " << init_data.size();
     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) {
     case INIT_DATA_TYPE_WEBM:
       eme_init_data_type = media::EmeInitDataType::WEBM;
       break;
 #if defined(USE_PROPRIETARY_CODECS)
     case INIT_DATA_TYPE_CENC:
       eme_init_data_type = media::EmeInitDataType::CENC;
       break;
@@ skipping 217 matching lines @@
   }
 
   // Only the temporary session type is supported in browser CDM path.
   // TODO(xhwang): Add SessionType support if needed.
   cdm->CreateSessionAndGenerateRequest(media::MediaKeys::TEMPORARY_SESSION,
                                        init_data_type, init_data,
                                        promise.Pass());
 }
 
 }  // namespace content