• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef CLEARKEY_SESSION_LIBRARY_H_
18 #define CLEARKEY_SESSION_LIBRARY_H_
19 
20 #include <media/cas/CasAPI.h>
21 #include <media/cas/DescramblerAPI.h>
22 #include <openssl/aes.h>
23 #include <utils/KeyedVector.h>
24 #include <utils/Mutex.h>
25 
26 namespace android {
27 struct ABuffer;
28 
29 namespace clearkeycas {
30 class KeyFetcher;
31 
32 class ClearKeyCasSession {
33 public:
34     explicit ClearKeyCasSession(CasPlugin *plugin);
35 
36     virtual ~ClearKeyCasSession();
37 
38     ssize_t decrypt(
39             bool secure,
40             DescramblerPlugin::ScramblingControl scramblingControl,
41             size_t numSubSamples,
42             const DescramblerPlugin::SubSample *subSamples,
43             const void *srcPtr,
44             void *dstPtr,
45             AString * /* errorDetailMsg */);
46 
47     status_t updateECM(KeyFetcher *keyFetcher, void *ecm, size_t size);
48 
49 private:
50     enum {
51         kNumKeys = 2,
52     };
53     struct KeyInfo {
54         bool valid;
55         AES_KEY contentKey;
56     };
57     sp<ABuffer> mEcmBuffer;
58     Mutex mKeyLock;
59     CasPlugin* mPlugin;
60     KeyInfo mKeyInfo[kNumKeys];
61 
62     friend class ClearKeySessionLibrary;
63 
getPlugin()64     CasPlugin* getPlugin() const { return mPlugin; }
65     status_t decryptPayload(
66             const AES_KEY& key, size_t length, size_t offset, char* buffer) const;
67 
68     DISALLOW_EVIL_CONSTRUCTORS(ClearKeyCasSession);
69 };
70 
71 class ClearKeySessionLibrary {
72 public:
73     static ClearKeySessionLibrary* get();
74 
75     status_t addSession(CasPlugin *plugin, CasSessionId *sessionId);
76 
77     std::shared_ptr<ClearKeyCasSession> findSession(const CasSessionId& sessionId);
78 
79     void destroySession(const CasSessionId& sessionId);
80 
81     void destroyPlugin(CasPlugin *plugin);
82 
83 private:
84     static Mutex sSingletonLock;
85     static ClearKeySessionLibrary* sSingleton;
86 
87     Mutex mSessionsLock;
88     uint32_t mNextSessionId;
89     KeyedVector<CasSessionId, std::shared_ptr<ClearKeyCasSession>> mIDToSessionMap;
90 
91     ClearKeySessionLibrary();
92     DISALLOW_EVIL_CONSTRUCTORS(ClearKeySessionLibrary);
93 };
94 
95 } // namespace clearkeycas
96 } // namespace android
97 
98 #endif // CLEARKEY_SESSION_LIBRARY_H_
99