EME: Check for invalid Key System names on addition

media/base/key_systems.cc

 // Copyright 2013 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 "media/base/key_systems.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 148 matching lines @@
   if (IsExternalClearKey(key_system))
     return true;
 
   // Chromecast defines behaviors for Cast clients within its reverse domain.
   const char kChromecastRoot[] = "com.chromecast";
   if (IsChildKeySystemOf(key_system, kChromecastRoot))
     return true;
 
   // Implementations that do not have a specification or appropriate glue code
   // can use the "x-" prefix to avoid conflicting with and advertising support
   // for real key system names. Use is discouraged.

[xhwang, 2016/05/20 17:10:14]

OOC, where do we use this?

[ddorwin, 2016/05/20 17:19:27]

Platform key systems on Android TV.

[xhwang, 2016/05/20 17:22:31]

Acknowledged.

   const char kExcludedPrefix[] = "x-";
   if (key_system.find(kExcludedPrefix, 0, arraysize(kExcludedPrefix) - 1) == 0)
     return true;
 
   return false;
 }
 
 class KeySystemsImpl : public KeySystems {
  public:
   static KeySystemsImpl* GetInstance();
@@ skipping 190 matching lines @@
     DCHECK(!properties->GetKeySystemName().empty());
     DCHECK(properties->GetPersistentLicenseSessionSupport() !=
            EmeSessionTypeSupport::INVALID);
     DCHECK(properties->GetPersistentReleaseMessageSessionSupport() !=
            EmeSessionTypeSupport::INVALID);
     DCHECK(properties->GetPersistentStateSupport() !=
            EmeFeatureSupport::INVALID);
     DCHECK(properties->GetDistinctiveIdentifierSupport() !=
            EmeFeatureSupport::INVALID);
 
+    if (!IsPotentiallySupportedKeySystem(properties->GetKeySystemName())) {
+      // If you encounter this path, see the comments for the above function.

[xhwang, 2016/05/20 17:10:14]

nit: which above function?

[ddorwin, 2016/05/20 17:19:27]

The one in the if statement. Is there a better way to reference it without using
its name?

[xhwang, 2016/05/20 17:22:31]

I see. When I see "above function" I was looking at UpdateSupportedKeySystems()
:) I guess this is okay.

[ddorwin, 2016/05/20 22:47:20]

I improved it a tiny bit.

+      DLOG(ERROR) << "Unsupported name '" << properties->GetKeySystemName()
+                  << "'. See code comments.";
+      continue;
+    }
+
     // Supporting persistent state is a prerequsite for supporting persistent
     // sessions.
     if (properties->GetPersistentStateSupport() ==
         EmeFeatureSupport::NOT_SUPPORTED) {
       DCHECK(properties->GetPersistentLicenseSessionSupport() ==
              EmeSessionTypeSupport::NOT_SUPPORTED);
       DCHECK(properties->GetPersistentReleaseMessageSessionSupport() ==
              EmeSessionTypeSupport::NOT_SUPPORTED);
     }
 
@@ skipping 150 matching lines @@
                                           uint32_t codecs_mask) {
   RegisterMimeType(mime_type, static_cast<EmeCodec>(codecs_mask));
 }
 
 bool KeySystemsImpl::IsSupportedKeySystem(const std::string& key_system) const {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (!key_system_properties_map_.count(key_system))
     return false;
 
-  // TODO(ddorwin): Move this to where we add key systems when prefixed EME is
-  // removed (crbug.com/249976).
-  if (!IsPotentiallySupportedKeySystem(key_system)) {
-    // If you encounter this path, see the comments for the above function.
-    DLOG(ERROR) << "Unrecognized key system " << key_system
-                << ". See code comments.";
-    return false;
-  }
-
   return true;
 }
 
 EmeConfigRule KeySystemsImpl::GetContentTypeConfigRule(
     const std::string& key_system,
     EmeMediaType media_type,
     const std::string& container_mime_type,
     const std::vector<std::string>& codecs) const {
   DCHECK(thread_checker_.CalledOnValidThread());
 
@@ skipping 161 matching lines @@
                                uint32_t mask) {
   KeySystemsImpl::GetInstance()->AddCodecMask(media_type, codec, mask);
 }
 
 MEDIA_EXPORT void AddMimeTypeCodecMask(const std::string& mime_type,
                                        uint32_t mask) {
   KeySystemsImpl::GetInstance()->AddMimeTypeCodecMask(mime_type, mask);
 }
 
 }  // namespace media