dom/media/eme/MediaKeys.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_mediakeys_h__
   8 #define mozilla_dom_mediakeys_h__
   9
  10 #include "DecoderDoctorLogger.h"
  11 #include "mozilla/Attributes.h"
  12 #include "mozilla/DetailedPromise.h"
  13 #include "mozilla/RefPtr.h"
  14 #include "mozilla/WeakPtr.h"
  15 #include "mozilla/dom/MediaKeyStatusMapBinding.h"  // For MediaKeyStatus
  16 #include "mozilla/dom/MediaKeySystemAccessBinding.h"
  17 #include "mozilla/dom/MediaKeysBinding.h"
  18 #include "mozilla/dom/Promise.h"
  19 #include "nsCOMPtr.h"
  20 #include "nsCycleCollectionParticipant.h"
  21 #include "nsIObserver.h"
  22 #include "nsRefPtrHashtable.h"
  23 #include "nsTHashMap.h"
  24 #include "nsWrapperCache.h"
  25
  26 namespace mozilla {
  27
  28 class CDMProxy;
  29
  30 namespace dom {
  31 class MediaKeys;
  32 }  // namespace dom
  33 DDLoggedTypeName(dom::MediaKeys);
  34
  35 namespace dom {
  36
  37 class ArrayBufferViewOrArrayBuffer;
  38 class MediaKeySession;
  39 struct MediaKeysPolicy;
  40 class HTMLMediaElement;
  41
  42 typedef nsRefPtrHashtable<nsStringHashKey, MediaKeySession> KeySessionHashMap;
  43 typedef nsRefPtrHashtable<nsUint32HashKey, dom::DetailedPromise> PromiseHashMap;
  44 typedef nsRefPtrHashtable<nsUint32HashKey, MediaKeySession>
  45     PendingKeySessionsHashMap;
  46 typedef nsTHashMap<nsUint32HashKey, uint32_t> PendingPromiseIdTokenHashMap;
  47 typedef uint32_t PromiseId;
  48
  49 // This class is used on the main thread only.
  50 // Note: its addref/release is not (and can't be) thread safe!
  51 class MediaKeys final : public nsIObserver,
  52                         public nsWrapperCache,
  53                         public SupportsWeakPtr,
  54                         public DecoderDoctorLifeLogger<MediaKeys> {
  55   ~MediaKeys();
  56
  57  public:
  58   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  59   NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(MediaKeys)
  60
  61   NS_DECL_NSIOBSERVER
  62
  63   MediaKeys(nsPIDOMWindowInner* aParentWindow, const nsAString& aKeySystem,
  64             const MediaKeySystemConfiguration& aConfig);
  65
  66   already_AddRefed<DetailedPromise> Init(ErrorResult& aRv);
  67
  68   nsPIDOMWindowInner* GetParentObject() const;
  69
  70   JSObject* WrapObject(JSContext* aCx,
  71                        JS::Handle<JSObject*> aGivenProto) override;
  72
  73   nsresult Bind(HTMLMediaElement* aElement);
  74   void Unbind();
  75
  76   // Checks if there's any activity happening that could capture the media
  77   // the keys are associated with and then expose that media outside of the
  78   // origin it is in.
  79   //
  80   // This method does not return the results of the check, but the MediaKeys
  81   // will notify mProxy of the results using `NotifyOutputProtectionStatus`.
  82   void CheckIsElementCapturePossible();
  83
  84   // Javascript: readonly attribute DOMString keySystem;
  85   void GetKeySystem(nsString& retval) const;
  86
  87   // JavaScript: MediaKeys.createSession()
  88   already_AddRefed<MediaKeySession> CreateSession(
  89       MediaKeySessionType aSessionType, ErrorResult& aRv);
  90
  91   // JavaScript: MediaKeys.SetServerCertificate()
  92   already_AddRefed<DetailedPromise> SetServerCertificate(
  93       const ArrayBufferViewOrArrayBuffer& aServerCertificate, ErrorResult& aRv);
  94
  95   already_AddRefed<MediaKeySession> GetSession(const nsAString& aSessionId);
  96
  97   // Removes and returns MediaKeySession from the set of sessions awaiting
  98   // their sessionId to be assigned.
  99   already_AddRefed<MediaKeySession> GetPendingSession(uint32_t aToken);
 100
 101   // Called once a Init() operation succeeds.
 102   void OnCDMCreated(PromiseId aId, const uint32_t aPluginId);
 103
 104   // Called once the CDM generates a sessionId while servicing a
 105   // MediaKeySession.generateRequest() or MediaKeySession.load() call,
 106   // once the sessionId of a MediaKeySession is known.
 107   void OnSessionIdReady(MediaKeySession* aSession);
 108
 109   // Called once a LoadSession succeeds.
 110   void OnSessionLoaded(PromiseId aId, bool aSuccess);
 111
 112   // Called once a session has closed.
 113   void OnSessionClosed(MediaKeySession* aSession);
 114
 115   CDMProxy* GetCDMProxy() { return mProxy; }
 116
 117   // Makes a new promise, or nullptr on failure.
 118   already_AddRefed<DetailedPromise> MakePromise(ErrorResult& aRv,
 119                                                 const nsACString& aName);
 120   // Stores promise in mPromises, returning an ID that can be used to retrieve
 121   // it later. The ID is passed to the CDM, so that it can signal specific
 122   // promises to be resolved.
 123   PromiseId StorePromise(DetailedPromise* aPromise);
 124
 125   // Stores a map from promise id to pending session token. Using this
 126   // mapping, when a promise is rejected via its ID, we can check if the
 127   // promise corresponds to a pending session and retrieve that session
 128   // via the mapped-to token, and remove the pending session from the
 129   // list of sessions awaiting a session id.
 130   void ConnectPendingPromiseIdWithToken(PromiseId aId, uint32_t aToken);
 131
 132   // Reject promise with the given exception.
 133   void RejectPromise(PromiseId aId, ErrorResult&& aException,
 134                      const nsCString& aReason);
 135   // Resolves promise with "undefined".
 136   void ResolvePromise(PromiseId aId);
 137
 138   void Shutdown();
 139
 140   // Called by CDMProxy when CDM crashes or shuts down. It is different from
 141   // Shutdown which is called from the script/dom side.
 142   void Terminated();
 143
 144   // Returns true if this MediaKeys has been bound to a media element.
 145   bool IsBoundToMediaElement() const;
 146
 147   // Indicates to a MediaKeys instance that the inner window parent of that
 148   // instance is being destroyed, this should prompt the keys to shutdown.
 149   void OnInnerWindowDestroy();
 150
 151   void GetSessionsInfo(nsString& sessionsInfo);
 152
 153   // JavaScript: MediaKeys.GetStatusForPolicy()
 154   already_AddRefed<Promise> GetStatusForPolicy(const MediaKeysPolicy& aPolicy,
 155                                                ErrorResult& aR);
 156   // Called by CDMProxy when CDM successfully GetStatusForPolicy.
 157   void ResolvePromiseWithKeyStatus(PromiseId aId,
 158                                    dom::MediaKeyStatus aMediaKeyStatus);
 159
 160   template <typename T>
 161   void ResolvePromiseWithResult(PromiseId aId, const T& aResult) {
 162     RefPtr<DetailedPromise> promise(RetrievePromise(aId));
 163     if (!promise) {
 164       return;
 165     }
 166     promise->MaybeResolve(aResult);
 167   }
 168
 169   // The topic used for requests related to mediakeys -- observe this to be
 170   // notified of such requests.
 171   constexpr static const char* kMediaKeysRequestTopic = "mediakeys-request";
 172
 173  private:
 174   // Instantiate CDMProxy instance.
 175   // It could be MediaDrmCDMProxy (Widevine on Fennec) or ChromiumCDMProxy (the
 176   // rest).
 177   already_AddRefed<CDMProxy> CreateCDMProxy();
 178
 179   // Removes promise from mPromises, and returns it.
 180   already_AddRefed<DetailedPromise> RetrievePromise(PromiseId aId);
 181
 182   // Helpers to connect and disconnect to the parent inner window. An inner
 183   // window should track (via weak ptr) MediaKeys created within it so we can
 184   // ensure MediaKeys are shutdown if that window is destroyed.
 185   void ConnectInnerWindow();
 186   void DisconnectInnerWindow();
 187
 188   // Owning ref to proxy. The proxy has a weak reference back to the MediaKeys,
 189   // and the MediaKeys destructor clears the proxy's reference to the MediaKeys.
 190   RefPtr<CDMProxy> mProxy;
 191
 192   // The HTMLMediaElement the MediaKeys are associated with. Note that a
 193   // MediaKeys instance may not be associated with any HTMLMediaElement so
 194   // this can be null (we also cannot rely on a media element to drive shutdown
 195   // for this reason).
 196   RefPtr<HTMLMediaElement> mElement;
 197
 198   // The  inner window associated with an instance of MediaKeys. We will
 199   // shutdown the media keys when this Window is destroyed. We do this from the
 200   // window rather than a document to address the case where media keys can be
 201   // created in an about:blank document that then performs an async load -- this
 202   // recreates the document, but the inner window is preserved in such a case.
 203   // See https://bugzilla.mozilla.org/show_bug.cgi?id=1675360 for more info.
 204   nsCOMPtr<nsPIDOMWindowInner> mParent;
 205   const nsString mKeySystem;
 206   KeySessionHashMap mKeySessions;
 207   PromiseHashMap mPromises;
 208   PendingKeySessionsHashMap mPendingSessions;
 209   PromiseId mCreatePromiseId;
 210
 211   // The principal of the relevant settings object.
 212   RefPtr<nsIPrincipal> mPrincipal;
 213   // The principal of the top level page. This can differ from mPrincipal if
 214   // we're in an iframe.
 215   RefPtr<nsIPrincipal> mTopLevelPrincipal;
 216
 217   const MediaKeySystemConfiguration mConfig;
 218
 219   PendingPromiseIdTokenHashMap mPromiseIdToken;
 220
 221   // The topic a MediaKeys instance will observe to receive updates from
 222   // EncryptedMediaChild.
 223   constexpr static const char* kMediaKeysResponseTopic = "mediakeys-response";
 224   // Tracks if we've added an observer for responses from the associated
 225   // EncryptedMediaChild. When true an observer is already in place, otherwise
 226   // the observer has not yet been added.
 227   bool mObserverAdded = false;
 228   // Stores the json request we will send to EncryptedMediaChild when querying
 229   // output protection. Lazily populated upon first use.
 230   nsString mCaptureCheckRequestJson;
 231 };
 232
 233 }  // namespace dom
 234 }  // namespace mozilla
 235
 236 #endif  // mozilla_dom_mediakeys_h__