gecko-dev/dom/media/eme/MediaKeySystemAccess.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/dom/MediaKeySystemAccess.h"
#include "mozilla/dom/MediaKeySystemAccessBinding.h"
#include "mozilla/Preferences.h"
#include "nsContentTypeParser.h"
#ifdef MOZ_FMP4
#include "MP4Decoder.h"
#endif
#ifdef XP_WIN
#include "mozilla/WindowsVersion.h"
#endif
#include "nsContentCID.h"
#include "nsServiceManagerUtils.h"
#include "mozIGeckoMediaPluginService.h"
#include "VideoUtils.h"

namespace mozilla {
namespace dom {

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(MediaKeySystemAccess,
                                      mParent)
NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaKeySystemAccess)
NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaKeySystemAccess)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeySystemAccess)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

MediaKeySystemAccess::MediaKeySystemAccess(nsPIDOMWindow* aParent,
                                           const nsAString& aKeySystem)
  : mParent(aParent)
  , mKeySystem(aKeySystem)
{
}

MediaKeySystemAccess::~MediaKeySystemAccess()
{
}

JSObject*
MediaKeySystemAccess::WrapObject(JSContext* aCx)
{
  return MediaKeySystemAccessBinding::Wrap(aCx, this);
}

nsPIDOMWindow*
MediaKeySystemAccess::GetParentObject() const
{
  return mParent;
}

void
MediaKeySystemAccess::GetKeySystem(nsString& aRetVal) const
{
  aRetVal = mKeySystem;
}

already_AddRefed<Promise>
MediaKeySystemAccess::CreateMediaKeys(ErrorResult& aRv)
{
  nsRefPtr<MediaKeys> keys(new MediaKeys(mParent, mKeySystem));
  return keys->Init(aRv);
}

static bool
HaveGMPFor(mozIGeckoMediaPluginService* aGMPService,
           const nsCString& aKeySystem,
           const nsCString& aAPI,
           const nsCString& aTag = EmptyCString())
{
  nsTArray<nsCString> tags;
  tags.AppendElement(aKeySystem);
  if (!aTag.IsEmpty()) {
    tags.AppendElement(aTag);
  }
  // Note: EME plugins need a non-null nodeId here, as they must
  // not be shared across origins.
  bool hasPlugin = false;
  if (NS_FAILED(aGMPService->HasPluginForAPI(aAPI,
                                             &tags,
                                             &hasPlugin))) {
    return false;
  }
  return hasPlugin;
}

/* static */
bool
MediaKeySystemAccess::IsKeySystemSupported(const nsAString& aKeySystem)
{
  nsCOMPtr<mozIGeckoMediaPluginService> mps =
    do_GetService("@mozilla.org/gecko-media-plugin-service;1");
  if (NS_WARN_IF(!mps)) {
    return false;
  }

  if (aKeySystem.EqualsLiteral("org.w3.clearkey") &&
      HaveGMPFor(mps,
                 NS_LITERAL_CSTRING("org.w3.clearkey"),
                 NS_LITERAL_CSTRING("eme-decrypt"))) {
    return true;
  }

#ifdef XP_WIN
  if (aKeySystem.EqualsLiteral("com.adobe.access") &&
      Preferences::GetBool("media.eme.adobe-access.enabled", false) &&
      IsVistaOrLater() && // Win Vista and later only.
      HaveGMPFor(mps,
                 NS_LITERAL_CSTRING("com.adobe.access"),
                 NS_LITERAL_CSTRING("eme-decrypt"))) {
      return true;
  }
#endif

  return false;
}

static bool
IsPlayableWithGMP(mozIGeckoMediaPluginService* aGMPS,
                  const nsAString& aKeySystem,
                  const nsAString& aContentType)
{
#ifdef MOZ_FMP4
  nsContentTypeParser parser(aContentType);
  nsAutoString mimeType;
  nsresult rv = parser.GetType(mimeType);
  if (NS_FAILED(rv)) {
    return false;
  }

  if (!mimeType.EqualsLiteral("audio/mp4") &&
      !mimeType.EqualsLiteral("audio/x-m4a") &&
      !mimeType.EqualsLiteral("video/mp4")) {
    return false;
  }

  nsAutoString codecs;
  parser.GetParameter("codecs", codecs);

  NS_ConvertUTF16toUTF8 mimeTypeUTF8(mimeType);
  bool hasAAC = false;
  bool hasH264 = false;
  bool hasMP3 = false;
  if (!MP4Decoder::CanHandleMediaType(mimeTypeUTF8,
                                      codecs,
                                      hasAAC,
                                      hasH264,
                                      hasMP3) ||
      hasMP3) {
    return false;
  }
  return (!hasAAC || !HaveGMPFor(aGMPS,
                                 NS_ConvertUTF16toUTF8(aKeySystem),
                                 NS_LITERAL_CSTRING("eme-decrypt"),
                                 NS_LITERAL_CSTRING("aac"))) &&
         (!hasH264 || !HaveGMPFor(aGMPS,
                                  NS_ConvertUTF16toUTF8(aKeySystem),
                                  NS_LITERAL_CSTRING("eme-decrypt"),
                                  NS_LITERAL_CSTRING("h264")));
#else
  return false;
#endif
}

/* static */
bool
MediaKeySystemAccess::IsSupported(const nsAString& aKeySystem,
                                  const Sequence<MediaKeySystemOptions>& aOptions)
{
  nsCOMPtr<mozIGeckoMediaPluginService> mps =
    do_GetService("@mozilla.org/gecko-media-plugin-service;1");
  if (NS_WARN_IF(!mps)) {
    return false;
  }

  for (size_t i = 0; i < aOptions.Length(); i++) {
    const MediaKeySystemOptions& options = aOptions[i];
    if (!options.mInitDataType.EqualsLiteral("cenc")) {
      continue;
    }
    if (!options.mAudioCapability.IsEmpty() ||
        !options.mVideoCapability.IsEmpty()) {
      // Don't support any capabilites until we know we have a CDM with
      // capabilities...
      continue;
    }
    if (!options.mAudioType.IsEmpty() &&
        !IsPlayableWithGMP(mps, aKeySystem, options.mAudioType)) {
      continue;
    }
    if (!options.mVideoType.IsEmpty() &&
        !IsPlayableWithGMP(mps, aKeySystem, options.mVideoType)) {
      continue;
    }

    // Our sandbox provides an origin specific unique identifier, and the
    // ability to persist data. We don't yet have a way to turn those off
    // and on for specific GMPs/CDMs, so we don't check the uniqueidentifier
    // and stateful attributes here.

    return true;
  }
  return false;
}

} // namespace dom
} // namespace mozilla