Source/modules/encryptedmedia/MediaKeySession.cpp - chromium/blink - Git at Google

 /*
  * 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
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "MediaKeySession.h"

 #if ENABLE(ENCRYPTED_MEDIA_V2)

 #include "CDM.h"
 #include "Event.h"
 #include "GenericEventQueue.h"
 #include "MediaKeyError.h"
 #include "MediaKeyMessageEvent.h"
 #include "MediaKeys.h"

 namespace WebCore {

 PassRefPtr<MediaKeySession> MediaKeySession::create(ScriptExecutionContext* context, MediaKeys* keys, const String& keySystem)
 {
     return adoptRef(new MediaKeySession(context, keys, keySystem));
 }

 MediaKeySession::MediaKeySession(ScriptExecutionContext* context, MediaKeys* keys, const String& keySystem)
     : ContextDestructionObserver(context)
     , m_keys(keys)
     , m_keySystem(keySystem)
     , m_asyncEventQueue(GenericEventQueue::create(this))
     , m_session(keys->cdm()->createSession())
     , m_keyRequestTimer(this, &MediaKeySession::keyRequestTimerFired)
     , m_addKeyTimer(this, &MediaKeySession::addKeyTimerFired)
 {
 }

 MediaKeySession::~MediaKeySession()
 {
     close();
 }

 void MediaKeySession::setError(MediaKeyError* error)
 {
     m_error = error;
 }

 void MediaKeySession::close()
 {
     if (m_session)
         m_session->releaseKeys();
     m_session = 0;
     m_asyncEventQueue->cancelAllEvents();
 }

 const String& MediaKeySession::sessionId() const
 {
     return m_session->sessionId();
 }

 void MediaKeySession::generateKeyRequest(const String& mimeType, Uint8Array* initData)
 {
     m_pendingKeyRequests.append(PendingKeyRequest(mimeType, initData));
     m_keyRequestTimer.startOneShot(0);
 }

 void MediaKeySession::keyRequestTimerFired(Timer<MediaKeySession>*)
 {
     ASSERT(m_pendingKeyRequests.size());
     if (!m_session)
         return;

     while (!m_pendingKeyRequests.isEmpty()) {
         PendingKeyRequest request = m_pendingKeyRequests.takeFirst();

         // NOTE: Continued from step 5 in MediaKeys::createSession().
         // The user agent will asynchronously execute the following steps in the task:

         // 1. Let cdm be the cdm loaded in the MediaKeys constructor.
         // 2. Let destinationURL be null.
         String destinationURL;
         MediaKeyError::Code errorCode = 0;
         unsigned long systemCode = 0;

         // 3. Use cdm to generate a key request and follow the steps for the first matching condition from the following list:

         RefPtr<Uint8Array> keyRequest = m_session->generateKeyRequest(request.mimeType, request.initData.get(), destinationURL, errorCode, systemCode);

         // Otherwise [if a request is not successfully generated]:
         if (!keyRequest) {
             // 3.1. Create a new MediaKeyError object with the following attributes:
             //      code = the appropriate MediaKeyError code
             //      systemCode = a Key System-specific value, if provided, and 0 otherwise
             RefPtr<MediaKeyError> error = MediaKeyError::create(errorCode, systemCode).get();

             // 3.2. Set the MediaKeySession object's error attribute to the error object created in the previous step.
             setError(error.get());

             // 3.3. queue a task to fire a simple event named keyerror at the MediaKeySession object.
             RefPtr<Event> event = Event::create(eventNames().webkitkeyerrorEvent, false, false);
             event->setTarget(this);
             m_asyncEventQueue->enqueueEvent(event.release());

             // 3.4. Abort the task.
             continue;
         }

         // 4. queue a task to fire a simple event named keymessage at the new object
         //    The event is of type MediaKeyMessageEvent and has:
         //    message = key request
         //    destinationURL = destinationURL
         MediaKeyMessageEventInit init;
         init.bubbles = false;
         init.cancelable = false;
         init.message = keyRequest;
         init.destinationURL = destinationURL;
         RefPtr<MediaKeyMessageEvent> event = MediaKeyMessageEvent::create(eventNames().webkitkeymessageEvent, init);
         event->setTarget(this);
         m_asyncEventQueue->enqueueEvent(event);
     }
 }

 void MediaKeySession::update(Uint8Array* key, ExceptionCode& ec)
 {
     // From <http://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/encrypted-media.html#dom-addkey>:
     // The addKey(key) method must run the following steps:
     // 1. If the first or second argument [sic] is null or an empty array, throw an INVALID_ACCESS_ERR.
     // NOTE: the reference to a "second argument" is a spec bug.
     if (!key || !key->length()) {
         ec = INVALID_ACCESS_ERR;
         return;
     }

     // 2. Schedule a task to handle the call, providing key.
     m_pendingKeys.append(key);
     m_addKeyTimer.startOneShot(0);
 }

 void MediaKeySession::addKeyTimerFired(Timer<MediaKeySession>*)
 {
     ASSERT(m_pendingKeys.size());
     if (!m_session)
         return;

     while (!m_pendingKeys.isEmpty()) {
         RefPtr<Uint8Array> pendingKey = m_pendingKeys.takeFirst();
         unsigned short errorCode = 0;
         unsigned long systemCode = 0;

         // NOTE: Continued from step 2. of MediaKeySession::update()
         // 2.1. Let cdm be the cdm loaded in the MediaKeys constructor.
         // NOTE: This is m_session.
         // 2.2. Let 'did store key' be false.
         bool didStoreKey = false;
         // 2.3. Let 'next message' be null.
         RefPtr<Uint8Array> nextMessage;
         // 2.4. Use cdm to handle key.
         didStoreKey = m_session->update(pendingKey.get(), nextMessage, errorCode, systemCode);
         // 2.5. If did store key is true and the media element is waiting for a key, queue a task to attempt to resume playback.
         // TODO: Find and restart the media element

         // 2.6. If next message is not null, queue a task to fire a simple event named keymessage at the MediaKeySession object.
         //      The event is of type MediaKeyMessageEvent and has:
         //      message = next message
         //      destinationURL = null
         if (nextMessage) {
             MediaKeyMessageEventInit init;
             init.bubbles = false;
             init.cancelable = false;
             init.message = nextMessage;
             RefPtr<MediaKeyMessageEvent> event = MediaKeyMessageEvent::create(eventNames().webkitkeymessageEvent, init);
             event->setTarget(this);
             m_asyncEventQueue->enqueueEvent(event);
         }

         // 2.7. If did store key is true, queue a task to fire a simple event named keyadded at the MediaKeySession object.
         if (didStoreKey) {
             RefPtr<Event> keyaddedEvent = Event::create(eventNames().webkitkeyaddedEvent, false, false);
             keyaddedEvent->setTarget(this);
             m_asyncEventQueue->enqueueEvent(keyaddedEvent);
         }

         // 2.8. If any of the preceding steps in the task failed
         if (!didStoreKey) {
             // 2.8.1. Create a new MediaKeyError object with the following attributes:
             //        code = the appropriate MediaKeyError code
             //        systemCode = a Key System-specific value, if provided, and 0 otherwise
             RefPtr<MediaKeyError> error = MediaKeyError::create(errorCode, systemCode).get();

             // 2.8.2. Set the MediaKeySession object's error attribute to the error object created in the previous step.
             setError(error.get());

             // 2.8.3. queue a task to fire a simple event named keyerror at the MediaKeySession object.
             RefPtr<Event> keyerrorEvent = Event::create(eventNames().webkitkeyerrorEvent, false, false);
             keyerrorEvent->setTarget(this);
             m_asyncEventQueue->enqueueEvent(keyerrorEvent.release());

             // 2.8.4. Abort the task.
             // NOTE: no-op
         }
     }
 }

 const AtomicString& MediaKeySession::interfaceName() const
 {
     return eventNames().interfaceForMediaKeySession;
 }

 ScriptExecutionContext* MediaKeySession::scriptExecutionContext() const
 {
     return ContextDestructionObserver::scriptExecutionContext();
 }

 }

 #endif
	/*
	* 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
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "MediaKeySession.h"

	#if ENABLE(ENCRYPTED_MEDIA_V2)

	#include "CDM.h"
	#include "Event.h"
	#include "GenericEventQueue.h"
	#include "MediaKeyError.h"
	#include "MediaKeyMessageEvent.h"
	#include "MediaKeys.h"

	namespace WebCore {

	PassRefPtr<MediaKeySession> MediaKeySession::create(ScriptExecutionContext* context, MediaKeys* keys, const String& keySystem)
	{
	return adoptRef(new MediaKeySession(context, keys, keySystem));
	}

	MediaKeySession::MediaKeySession(ScriptExecutionContext* context, MediaKeys* keys, const String& keySystem)
	: ContextDestructionObserver(context)
	, m_keys(keys)
	, m_keySystem(keySystem)
	, m_asyncEventQueue(GenericEventQueue::create(this))
	, m_session(keys->cdm()->createSession())
	, m_keyRequestTimer(this, &MediaKeySession::keyRequestTimerFired)
	, m_addKeyTimer(this, &MediaKeySession::addKeyTimerFired)
	{
	}

	MediaKeySession::~MediaKeySession()
	{
	close();
	}

	void MediaKeySession::setError(MediaKeyError* error)
	{
	m_error = error;
	}

	void MediaKeySession::close()
	{
	if (m_session)
	m_session->releaseKeys();
	m_session = 0;
	m_asyncEventQueue->cancelAllEvents();
	}

	const String& MediaKeySession::sessionId() const
	{
	return m_session->sessionId();
	}

	void MediaKeySession::generateKeyRequest(const String& mimeType, Uint8Array* initData)
	{
	m_pendingKeyRequests.append(PendingKeyRequest(mimeType, initData));
	m_keyRequestTimer.startOneShot(0);
	}

	void MediaKeySession::keyRequestTimerFired(Timer<MediaKeySession>*)
	{
	ASSERT(m_pendingKeyRequests.size());
	if (!m_session)
	return;

	while (!m_pendingKeyRequests.isEmpty()) {
	PendingKeyRequest request = m_pendingKeyRequests.takeFirst();

	// NOTE: Continued from step 5 in MediaKeys::createSession().
	// The user agent will asynchronously execute the following steps in the task:

	// 1. Let cdm be the cdm loaded in the MediaKeys constructor.
	// 2. Let destinationURL be null.
	String destinationURL;
	MediaKeyError::Code errorCode = 0;
	unsigned long systemCode = 0;

	// 3. Use cdm to generate a key request and follow the steps for the first matching condition from the following list:

	RefPtr<Uint8Array> keyRequest = m_session->generateKeyRequest(request.mimeType, request.initData.get(), destinationURL, errorCode, systemCode);

	// Otherwise [if a request is not successfully generated]:
	if (!keyRequest) {
	// 3.1. Create a new MediaKeyError object with the following attributes:
	// code = the appropriate MediaKeyError code
	// systemCode = a Key System-specific value, if provided, and 0 otherwise
	RefPtr<MediaKeyError> error = MediaKeyError::create(errorCode, systemCode).get();

	// 3.2. Set the MediaKeySession object's error attribute to the error object created in the previous step.
	setError(error.get());

	// 3.3. queue a task to fire a simple event named keyerror at the MediaKeySession object.
	RefPtr<Event> event = Event::create(eventNames().webkitkeyerrorEvent, false, false);
	event->setTarget(this);
	m_asyncEventQueue->enqueueEvent(event.release());

	// 3.4. Abort the task.
	continue;
	}

	// 4. queue a task to fire a simple event named keymessage at the new object
	// The event is of type MediaKeyMessageEvent and has:
	// message = key request
	// destinationURL = destinationURL
	MediaKeyMessageEventInit init;
	init.bubbles = false;
	init.cancelable = false;
	init.message = keyRequest;
	init.destinationURL = destinationURL;
	RefPtr<MediaKeyMessageEvent> event = MediaKeyMessageEvent::create(eventNames().webkitkeymessageEvent, init);
	event->setTarget(this);
	m_asyncEventQueue->enqueueEvent(event);
	}
	}

	void MediaKeySession::update(Uint8Array* key, ExceptionCode& ec)
	{
	// From <http://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/encrypted-media.html#dom-addkey>:
	// The addKey(key) method must run the following steps:
	// 1. If the first or second argument [sic] is null or an empty array, throw an INVALID_ACCESS_ERR.
	// NOTE: the reference to a "second argument" is a spec bug.
	if (!key \|\| !key->length()) {
	ec = INVALID_ACCESS_ERR;
	return;
	}

	// 2. Schedule a task to handle the call, providing key.
	m_pendingKeys.append(key);
	m_addKeyTimer.startOneShot(0);
	}

	void MediaKeySession::addKeyTimerFired(Timer<MediaKeySession>*)
	{
	ASSERT(m_pendingKeys.size());
	if (!m_session)
	return;

	while (!m_pendingKeys.isEmpty()) {
	RefPtr<Uint8Array> pendingKey = m_pendingKeys.takeFirst();
	unsigned short errorCode = 0;
	unsigned long systemCode = 0;

	// NOTE: Continued from step 2. of MediaKeySession::update()
	// 2.1. Let cdm be the cdm loaded in the MediaKeys constructor.
	// NOTE: This is m_session.
	// 2.2. Let 'did store key' be false.
	bool didStoreKey = false;
	// 2.3. Let 'next message' be null.
	RefPtr<Uint8Array> nextMessage;
	// 2.4. Use cdm to handle key.
	didStoreKey = m_session->update(pendingKey.get(), nextMessage, errorCode, systemCode);
	// 2.5. If did store key is true and the media element is waiting for a key, queue a task to attempt to resume playback.
	// TODO: Find and restart the media element

	// 2.6. If next message is not null, queue a task to fire a simple event named keymessage at the MediaKeySession object.
	// The event is of type MediaKeyMessageEvent and has:
	// message = next message
	// destinationURL = null
	if (nextMessage) {
	MediaKeyMessageEventInit init;
	init.bubbles = false;
	init.cancelable = false;
	init.message = nextMessage;
	RefPtr<MediaKeyMessageEvent> event = MediaKeyMessageEvent::create(eventNames().webkitkeymessageEvent, init);
	event->setTarget(this);
	m_asyncEventQueue->enqueueEvent(event);
	}

	// 2.7. If did store key is true, queue a task to fire a simple event named keyadded at the MediaKeySession object.
	if (didStoreKey) {
	RefPtr<Event> keyaddedEvent = Event::create(eventNames().webkitkeyaddedEvent, false, false);
	keyaddedEvent->setTarget(this);
	m_asyncEventQueue->enqueueEvent(keyaddedEvent);
	}

	// 2.8. If any of the preceding steps in the task failed
	if (!didStoreKey) {
	// 2.8.1. Create a new MediaKeyError object with the following attributes:
	// code = the appropriate MediaKeyError code
	// systemCode = a Key System-specific value, if provided, and 0 otherwise
	RefPtr<MediaKeyError> error = MediaKeyError::create(errorCode, systemCode).get();

	// 2.8.2. Set the MediaKeySession object's error attribute to the error object created in the previous step.
	setError(error.get());

	// 2.8.3. queue a task to fire a simple event named keyerror at the MediaKeySession object.
	RefPtr<Event> keyerrorEvent = Event::create(eventNames().webkitkeyerrorEvent, false, false);
	keyerrorEvent->setTarget(this);
	m_asyncEventQueue->enqueueEvent(keyerrorEvent.release());

	// 2.8.4. Abort the task.
	// NOTE: no-op
	}
	}
	}

	const AtomicString& MediaKeySession::interfaceName() const
	{
	return eventNames().interfaceForMediaKeySession;
	}

	ScriptExecutionContext* MediaKeySession::scriptExecutionContext() const
	{
	return ContextDestructionObserver::scriptExecutionContext();
	}

	}

	#endif