Verify MediaKeys parameter values consistently

Source/modules/encryptedmedia/MediaKeys.cpp

 /*
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 23 matching lines @@
 #include "modules/encryptedmedia/MediaKeyMessageEvent.h"
 #include "platform/ContentType.h"
 #include "platform/Logging.h"
 #include "platform/MIMETypeRegistry.h"
 #include "platform/UUID.h"
 #include "platform/drm/ContentDecryptionModule.h"
 #include "wtf/HashSet.h"
 
 namespace WebCore {
 
+static bool isKeySystemSupportedWithContentType(const String& keySystem, const String& contentType)
+{
+    ASSERT(!keySystem.isEmpty());
+
+    ContentType type(contentType);
+    String codecs = type.parameter("codecs");
+    return MIMETypeRegistry::isSupportedEncryptedMediaMIMEType(keySystem, type.type(), codecs);
+}
+
 PassRefPtrWillBeRawPtr<MediaKeys> MediaKeys::create(ExecutionContext* context, const String& keySystem, ExceptionState& exceptionState)
 {
     // From <http://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#dom-media-keys-constructor>:
     // The MediaKeys(keySystem) constructor must run the following steps:
 
     // 1. If keySystem is null or an empty string, throw an InvalidAccessError exception and abort these steps.
     if (keySystem.isEmpty()) {
         exceptionState.throwDOMException(InvalidAccessError, "The key system provided is invalid.");
         return nullptr;
     }
 
     // 2. If keySystem is not one of the user agent's supported Key Systems, throw a NotSupportedError and abort these steps.
-    if (!ContentDecryptionModule::supportsKeySystem(keySystem)) {
+    if (!isKeySystemSupportedWithContentType(keySystem, "")) {
         exceptionState.throwDOMException(NotSupportedError, "The '" + keySystem + "' key system is not supported.");
         return nullptr;
     }
 
     // 3. Let cdm be the content decryption module corresponding to keySystem.
     // 4. Load cdm if necessary.
     OwnPtr<ContentDecryptionModule> cdm = ContentDecryptionModule::create(keySystem);
     if (!cdm) {
         exceptionState.throwDOMException(NotSupportedError, "A content decryption module could not be loaded for the '" + keySystem + "' key system.");
         return nullptr;
@@ skipping 34 matching lines @@
         return nullptr;
     }
 
     if (!initData || !initData->length()) {
         exceptionState.throwDOMException(InvalidAccessError, "The initData provided is null or empty.");
         return nullptr;
     }
 
     // 1. If type contains a MIME type that is not supported or is not supported by the keySystem,
     // throw a NOT_SUPPORTED_ERR exception and abort these steps.
-    if (!m_cdm->supportsMIMEType(contentType)) {
+    if (!isKeySystemSupportedWithContentType(m_keySystem, contentType)) {
         exceptionState.throwDOMException(NotSupportedError, "The type provided ('" + contentType + "') is unsupported.");
         return nullptr;
     }
 
     // 2. Create a new MediaKeySession object.
     RefPtrWillBeRawPtr<MediaKeySession> session = MediaKeySession::create(context, m_cdm.get(), m_weakFactory.createWeakPtr());
     // 2.1 Let the keySystem attribute be keySystem.
     ASSERT(!session->keySystem().isEmpty());
     // FIXME: 2.2 Let the state of the session be CREATED.
 
@@ skipping 12 matching lines @@
 bool MediaKeys::isTypeSupported(const String& keySystem, const String& contentType)
 {
     WTF_LOG(Media, "MediaKeys::isTypeSupported(%s, %s)", keySystem.ascii().data(), contentType.ascii().data());
 
     // 1. If keySystem is null or an empty string, return false and abort these steps.
     if (keySystem.isEmpty())
         return false;
 
     // 2. If keySystem contains an unrecognized or unsupported Key System, return false and abort
     // these steps. Key system string comparison is case-sensitive.
-    if (!MIMETypeRegistry::isSupportedEncryptedMediaMIMEType(keySystem, "", ""))
+    if (!isKeySystemSupportedWithContentType(keySystem, ""))
         return false;
 
     // 3. If contentType is null or an empty string, return true and abort these steps.
     if (contentType.isEmpty())
         return true;
 
     // 4. If the Key System specified by keySystem does not support decrypting the container and/or
     // codec specified by contentType, return false and abort these steps.
-    ContentType type(contentType);
-    String codecs = type.parameter("codecs");
-
-    return MIMETypeRegistry::isSupportedEncryptedMediaMIMEType(keySystem, type.type(), codecs);
+    return isKeySystemSupportedWithContentType(keySystem, contentType);
 }
 
 void MediaKeys::setMediaElement(HTMLMediaElement* element)
 {
     // FIXME: Cause HTMLMediaElement::setMediaKeys() to throw an exception if m_mediaElement is not 0
     // and remove the code that prevents the assert below in HTMLMediaElement.
     ASSERT(!m_mediaElement != !element);
     m_mediaElement = element;
 }
 
@@ skipping 25 matching lines @@
 
 void MediaKeys::contextDestroyed()
 {
     ContextLifecycleObserver::contextDestroyed();
 
     // We don't need the CDM anymore.
     m_cdm.clear();
 }
 
 }