Initial implementation of Encrypted Media Extensions in Chrome.

webkit/media/webmediaplayer_impl.cc

 // Copyright (c) 2012 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 "webkit/media/webmediaplayer_impl.h"
 
 #include <limits>
 #include <string>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/message_loop_proxy.h"
 #include "base/metrics/histogram.h"
+#include "base/string_number_conversions.h"
 #include "base/synchronization/waitable_event.h"
 #include "media/audio/null_audio_sink.h"
 #include "media/base/filter_collection.h"
 #include "media/base/limits.h"
 #include "media/base/media_log.h"
 #include "media/base/media_switches.h"
 #include "media/base/pipeline.h"
 #include "media/base/video_frame.h"
 #include "media/filters/audio_renderer_impl.h"
 #include "media/filters/video_renderer_base.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebVideoFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebRect.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebSize.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebURL.h"
 #include "v8/include/v8.h"
 #include "webkit/media/buffered_data_source.h"
 #include "webkit/media/filter_helpers.h"
+#include "webkit/media/mime_util.h"
 #include "webkit/media/webmediaplayer_delegate.h"
 #include "webkit/media/webmediaplayer_proxy.h"
 #include "webkit/media/webvideoframe_impl.h"
 
 using WebKit::WebCanvas;
 using WebKit::WebRect;
 using WebKit::WebSize;
 using media::NetworkEvent;
 using media::PipelineStatus;
 
@@ skipping 618 matching lines @@
     case WebKit::WebMediaPlayer::EosDecodeError:
       pipeline_status = media::PIPELINE_ERROR_DECODE;
       break;
     default:
       NOTIMPLEMENTED();
   }
 
   proxy_->DemuxerEndOfStream(pipeline_status);
 }
 
+WebKit::WebMediaPlayer::MediaKeyException
+WebMediaPlayerImpl::generateKeyRequest(const WebKit::WebString& key_system,
+                                       const unsigned char* init_data,
+                                       unsigned init_data_length) {
+  if (!mime_util::isKeySystemSupported(key_system))
+    return WebKit::WebMediaPlayer::KeySystemNotSupported;
+
+  MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
+                              &WebMediaPlayerImpl::generateKeyRequestTask,

[scherkus (not reviewing), 2012/04/13 02:43:59]

this (and rest of args) should be indented 4 spaces from "M" (i.e., 6 spaces
from start of line)

[ddorwin, 2012/04/13 21:48:49]

Done.
I misinterpreted your preferred style comment.

+                              AsWeakPtr(),
+                              key_system,
+                              init_data,
+                              init_data_length));
+
+  return WebKit::WebMediaPlayer::NoError;
+}
+
+WebKit::WebMediaPlayer::MediaKeyException WebMediaPlayerImpl::addKey(
+    const WebKit::WebString& key_system,
+    const unsigned char* key,
+    unsigned key_length,
+    const unsigned char* init_data,
+    unsigned init_data_length,
+    const WebKit::WebString& session_id) {
+  if (!mime_util::isKeySystemSupported(key_system))
+    return WebKit::WebMediaPlayer::KeySystemNotSupported;
+
+  MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
+                              &WebMediaPlayerImpl::addKeyTask,
+                              AsWeakPtr(),
+                              key_system,
+                              key,
+                              key_length,
+                              init_data,
+                              init_data_length,
+                              session_id));
+
+  return WebKit::WebMediaPlayer::NoError;
+}
+
+WebKit::WebMediaPlayer::MediaKeyException WebMediaPlayerImpl::cancelKeyRequest(
+    const WebKit::WebString& key_system,
+    const WebKit::WebString& session_id) {
+  if (!mime_util::isKeySystemSupported(key_system))
+    return WebKit::WebMediaPlayer::KeySystemNotSupported;
+
+  // TODO(ddorwin): Cancel the key request in the decrypter.
+
+  return WebKit::WebMediaPlayer::NoError;
+}
+
 void WebMediaPlayerImpl::WillDestroyCurrentMessageLoop() {
   Destroy();
   main_loop_ = NULL;
 }
 
 void WebMediaPlayerImpl::Repaint() {
   DCHECK_EQ(main_loop_, MessageLoop::current());
   GetClient()->repaint();
 }
 
@@ skipping 232 matching lines @@
 WebKit::WebAudioSourceProvider* WebMediaPlayerImpl::audioSourceProvider() {
   return audio_source_provider_;
 }
 
 void WebMediaPlayerImpl::IncrementExternallyAllocatedMemory() {
   DCHECK_EQ(main_loop_, MessageLoop::current());
   incremented_externally_allocated_memory_ = true;
   v8::V8::AdjustAmountOfExternalAllocatedMemory(kPlayerExtraMemory);
 }
 
+void WebMediaPlayerImpl::generateKeyRequestTask(

[scherkus (not reviewing), 2012/04/13 02:43:59]

per email discussion just nuke these tasks for now

[ddorwin, 2012/04/13 21:48:49]

Done.

+    const WebKit::WebString& key_system,
+    const unsigned char* init_data,
+    unsigned init_data_length) {
+  // Every request call creates a unique ID.
+  // TODO(ddorwin): Move this to the CDM implementations since the CDMs may
+  // create their own IDs and since CDMs supporting multiple renderer processes

[scherkus (not reviewing), 2012/04/13 02:43:59]

I do have to say this is one area that makes me think may require spec
changes/clarifications

what are the restrictions on session ids, if any?

[ddorwin, 2012/04/13 21:48:49]

Filing a bug on this is on my task list (also affects the WebKit
implementation). I'll file it after I get this uploaded.

[ddorwin, 2012/04/13 22:29:03]

Filed: https://www.w3.org/Bugs/Public/show_bug.cgi?id=16739

+  // need globally unique IDs.
+  static uint32_t next_available_session_id = 1;
+  uint32_t session_id = next_available_session_id++;
+
+  WebKit::WebString sessionIdString(base::UintToString16(session_id));
+
+  DVLOG(1) << "generateKeyRequest: " << key_system.utf8().data() << ": "
+           << std::string(reinterpret_cast<const char*>(init_data),
+                          static_cast<size_t>(init_data_length))
+           << " [" << sessionIdString.utf8().data() << "]";
+
+  // TODO(ddorwin): Generate a key request in the decrypter and fire
+  // keyMessage when it completes.
+  // For now, just fire the event with the init_data as the request.
+  const unsigned char* message = init_data;
+  unsigned messageLength = init_data_length;
+
+  GetClient()->keyMessage(key_system, sessionIdString, message, messageLength);
+}
+
+void WebMediaPlayerImpl::addKeyTask(const WebKit::WebString& key_system,
+                                    const unsigned char* key,
+                                    unsigned key_length,
+                                    const unsigned char* init_data,
+                                    unsigned init_data_length,
+                                    const WebKit::WebString& session_id) {
+  DVLOG(1) << "addKey: " << key_system.utf8().data() << ": "
+           << std::string(reinterpret_cast<const char*>(key),
+                          static_cast<size_t>(key_length)) << ", "
+           << std::string(reinterpret_cast<const char*>(init_data),
+                          static_cast<size_t>(init_data_length))
+           << " [" << session_id.utf8().data() << "]";
+
+  // TODO(ddorwin): Add the key to the decrypter and fire keyAdded when it
+  // completes. Check the key length there.
+  // Temporarily, fire an error for invalid key length so we can test the error
+  // event and fire the keyAdded event in all other cases.
+  const int kSupportedKeyLength = 16;  // 128-bit key.
+  if (key_length != kSupportedKeyLength) {
+    DLOG(ERROR) << "invalid key length: " << key_length;
+    GetClient()->keyError(key_system, session_id,
+                          WebKit::WebMediaPlayerClient::UnknownError, 0);
+    return;
+  }
+
+  GetClient()->keyAdded(key_system, session_id);
+}
+
 }  // namespace webkit_media