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      1 // Copyright 2013 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef CONTENT_RENDERER_MEDIA_CRYPTO_PROXY_DECRYPTOR_H_
      6 #define CONTENT_RENDERER_MEDIA_CRYPTO_PROXY_DECRYPTOR_H_
      7 
      8 #include <map>
      9 #include <string>
     10 #include <vector>
     11 
     12 #include "base/basictypes.h"
     13 #include "base/memory/scoped_ptr.h"
     14 #include "base/memory/weak_ptr.h"
     15 #include "base/synchronization/lock.h"
     16 #include "media/base/decryptor.h"
     17 #include "media/base/media_keys.h"
     18 
     19 class GURL;
     20 
     21 namespace blink {
     22 #if defined(ENABLE_PEPPER_CDMS)
     23 class WebFrame;
     24 class WebMediaPlayerClient;
     25 #endif  // defined(ENABLE_PEPPER_CDMS)
     26 }
     27 
     28 namespace content {
     29 
     30 #if defined(OS_ANDROID)
     31 class RendererMediaPlayerManager;
     32 #endif  // defined(OS_ANDROID)
     33 
     34 // ProxyDecryptor is for EME v0.1b only. It should not be used for the WD API.
     35 // A decryptor proxy that creates a real decryptor object on demand and
     36 // forwards decryptor calls to it.
     37 //
     38 // Now that the Pepper API calls use session ID to match responses with
     39 // requests, this class maintains a mapping between session ID and web session
     40 // ID. Callers of this class expect web session IDs in the responses.
     41 // Session IDs are internal unique references to the session. Web session IDs
     42 // are the CDM generated ID for the session, and are what are visible to users.
     43 //
     44 // TODO(xhwang): Currently we don't support run-time switching among decryptor
     45 // objects. Fix this when needed.
     46 // TODO(xhwang): The ProxyDecryptor is not a Decryptor. Find a better name!
     47 class ProxyDecryptor {
     48  public:
     49   // These are similar to the callbacks in media_keys.h, but pass back the
     50   // web session ID rather than the internal session ID.
     51   typedef base::Callback<void(const std::string& session_id)> KeyAddedCB;
     52   typedef base::Callback<void(const std::string& session_id,
     53                               media::MediaKeys::KeyError error_code,
     54                               int system_code)> KeyErrorCB;
     55   typedef base::Callback<void(const std::string& session_id,
     56                               const std::vector<uint8>& message,
     57                               const std::string& default_url)> KeyMessageCB;
     58 
     59   ProxyDecryptor(
     60 #if defined(ENABLE_PEPPER_CDMS)
     61       blink::WebMediaPlayerClient* web_media_player_client,
     62       blink::WebFrame* web_frame,
     63 #elif defined(OS_ANDROID)
     64       RendererMediaPlayerManager* manager,
     65       int media_keys_id,
     66 #endif  // defined(ENABLE_PEPPER_CDMS)
     67       const KeyAddedCB& key_added_cb,
     68       const KeyErrorCB& key_error_cb,
     69       const KeyMessageCB& key_message_cb);
     70   virtual ~ProxyDecryptor();
     71 
     72   // Only call this once.
     73   bool InitializeCDM(const std::string& key_system, const GURL& frame_url);
     74 
     75   // Requests the ProxyDecryptor to notify the decryptor when it's ready through
     76   // the |decryptor_ready_cb| provided.
     77   // If |decryptor_ready_cb| is null, the existing callback will be fired with
     78   // NULL immediately and reset.
     79   void SetDecryptorReadyCB(const media::DecryptorReadyCB& decryptor_ready_cb);
     80 
     81   // May only be called after InitializeCDM() succeeds.
     82   bool GenerateKeyRequest(const std::string& type,
     83                           const uint8* init_data,
     84                           int init_data_length);
     85   void AddKey(const uint8* key, int key_length,
     86               const uint8* init_data, int init_data_length,
     87               const std::string& session_id);
     88   void CancelKeyRequest(const std::string& session_id);
     89 
     90  private:
     91   // Session_id <-> web_session_id map.
     92   typedef std::map<uint32, std::string> SessionIdMap;
     93 
     94   // Helper function to create MediaKeys to handle the given |key_system|.
     95   scoped_ptr<media::MediaKeys> CreateMediaKeys(const std::string& key_system,
     96                                                const GURL& frame_url);
     97 
     98   // Callbacks for firing session events.
     99   void OnSessionCreated(uint32 session_id, const std::string& web_session_id);
    100   void OnSessionMessage(uint32 session_id,
    101                         const std::vector<uint8>& message,
    102                         const std::string& default_url);
    103   void OnSessionReady(uint32 session_id);
    104   void OnSessionClosed(uint32 session_id);
    105   void OnSessionError(uint32 session_id,
    106                       media::MediaKeys::KeyError error_code,
    107                       int system_code);
    108 
    109   // Helper function to determine session_id for the provided |web_session_id|.
    110   uint32 LookupSessionId(const std::string& web_session_id);
    111 
    112   // Helper function to determine web_session_id for the provided |session_id|.
    113   // The returned web_session_id is only valid on the main thread, and should be
    114   // stored by copy.
    115   const std::string& LookupWebSessionId(uint32 session_id);
    116 
    117   base::WeakPtrFactory<ProxyDecryptor> weak_ptr_factory_;
    118 
    119 #if defined(ENABLE_PEPPER_CDMS)
    120   // Callback for cleaning up a Pepper-based CDM.
    121   void DestroyHelperPlugin();
    122 
    123   // Needed to create the PpapiDecryptor.
    124   blink::WebMediaPlayerClient* web_media_player_client_;
    125   blink::WebFrame* web_frame_;
    126 #elif defined(OS_ANDROID)
    127   RendererMediaPlayerManager* manager_;
    128   int media_keys_id_;
    129 #endif  // defined(ENABLE_PEPPER_CDMS)
    130 
    131   // The real MediaKeys that manages key operations for the ProxyDecryptor.
    132   // This pointer is protected by the |lock_|.
    133   scoped_ptr<media::MediaKeys> media_keys_;
    134 
    135   // Callbacks for firing key events.
    136   KeyAddedCB key_added_cb_;
    137   KeyErrorCB key_error_cb_;
    138   KeyMessageCB key_message_cb_;
    139 
    140   // Protects the |decryptor_|. Note that |decryptor_| itself should be thread
    141   // safe as per the Decryptor interface.
    142   base::Lock lock_;
    143 
    144   media::DecryptorReadyCB decryptor_ready_cb_;
    145 
    146   // Session IDs are used to uniquely track sessions so that CDM callbacks
    147   // can get mapped to the correct session ID. Session ID should be unique
    148   // per renderer process for debugging purposes.
    149   static uint32 next_session_id_;
    150 
    151   SessionIdMap sessions_;
    152 
    153   bool is_clear_key_;
    154 
    155   DISALLOW_COPY_AND_ASSIGN(ProxyDecryptor);
    156 };
    157 
    158 }  // namespace content
    159 
    160 #endif  // CONTENT_RENDERER_MEDIA_CRYPTO_PROXY_DECRYPTOR_H_
    161