DrmAPI.h revision 56c78c47d8c22621a8a23375d8a6c63d99a9335d 
1 /*
2 * Copyright (C) 2013 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 DRM_API_H_
18#define DRM_API_H_
19
20#include <utils/List.h>
21#include <utils/String8.h>
22#include <utils/Vector.h>
23#include <utils/KeyedVector.h>
24#include <utils/RefBase.h>
25#include <media/stagefright/foundation/ABase.h>
26
27//  Loadable DrmEngine shared libraries should define the entry points
28//  createDrmFactory and createCryptoFactory as shown below:
29//
30//  extern "C" {
31//      extern android::DrmFactory *createDrmFactory();
32//      extern android::CryptoFactory *createCryptoFactory();
33//  }
34
35namespace android {
36
37    struct DrmPlugin;
38
39    // DRMs are implemented in DrmEngine plugins, which are dynamically
40    // loadable shared libraries that implement the entry points
41    // createDrmFactory and createCryptoFactory.  createDrmFactory
42    // constructs and returns an instance of a DrmFactory object.  Similarly,
43    // createCryptoFactory creates an instance of a CryptoFactory object.
44    // When a MediaCrypto or MediaDrm object needs to be constructed, all
45    // available DrmEngines present in the plugins directory on the device
46    // are scanned for a matching DrmEngine that can support the crypto
47    // scheme.  When a match is found, the DrmEngine's createCryptoPlugin and
48    // createDrmPlugin methods are used to create CryptoPlugin or
49    // DrmPlugin instances to support that DRM scheme.
50
51    class DrmFactory {
52    public:
53        DrmFactory() {}
54        virtual ~DrmFactory() {}
55
56        // DrmFactory::isCryptoSchemeSupported can be called to determine
57        // if the plugin factory is able to construct plugins that support a
58        // given crypto scheme, which is specified by a UUID.
59        virtual bool isCryptoSchemeSupported(const uint8_t uuid[16]) = 0;
60
61        // Construct a DrmPlugin for the crypto scheme specified by UUID.
62        virtual status_t createDrmPlugin(
63                const uint8_t uuid[16], DrmPlugin **plugin) = 0;
64
65    private:
66        DrmFactory(const DrmFactory &);
67        DrmFactory &operator=(const DrmFactory &);
68    };
69
70    class DrmPlugin {
71    public:
72        enum EventType {
73            kDrmPluginEventProvisionRequired,
74            kDrmPluginEventLicenseNeeded,
75            kDrmPluginEventLicenseExpired,
76            kDrmPluginEventVendorDefined
77        };
78
79        // A license can be for offline content or for online streaming.
80        // Offline licenses are persisted on the device and may be used when the device
81        // is disconnected from the network.
82        enum LicenseType {
83            kLicenseType_Offline,
84            kLicenseType_Streaming
85        };
86
87        DrmPlugin() {}
88        virtual ~DrmPlugin() {}
89
90        // Open a new session with the DrmPlugin object.  A session ID is returned
91        // in the sessionId parameter.
92        virtual status_t openSession(Vector<uint8_t> &sessionId) = 0;
93
94        // Close a session on the DrmPlugin object.
95        virtual status_t closeSession(Vector<uint8_t> const &sessionId) = 0;
96
97        // A license request/response exchange occurs between the app and a License
98        // Server to obtain the keys required to decrypt the content.  getLicenseRequest()
99        // is used to obtain an opaque license request blob that is delivered to the
100        // license server.
101        //
102        // The init data passed to getLicenseRequest is container-specific and its
103        // meaning is interpreted based on the mime type provided in the mimeType
104        // parameter to getLicenseRequest.  It could contain, for example, the content
105        // ID, key ID or other data obtained from the content metadata that is required
106        // in generating the license request.
107        //
108        // licenseType specifes if the license is for streaming or offline content
109        //
110        // optionalParameters are included in the license server request message to
111        // allow a client application to provide additional message parameters to the
112        // server.
113        //
114        // If successful, the opaque license request blob is returned to the caller.
115        virtual status_t
116            getLicenseRequest(Vector<uint8_t> const &sessionId,
117                              Vector<uint8_t> const &initData,
118                              String8 const &mimeType, LicenseType licenseType,
119                              KeyedVector<String8, String8> const &optionalParameters,
120                              Vector<uint8_t> &request, String8 &defaultUrl) = 0;
121
122        // After a license response is received by the app, it is provided to the
123        // Drm plugin using provideLicenseResponse.
124        virtual status_t provideLicenseResponse(Vector<uint8_t> const &sessionId,
125                                                Vector<uint8_t> const &response) = 0;
126
127        // Remove the keys associated with a license.
128        virtual status_t removeLicense(Vector<uint8_t> const &sessionId) = 0;
129
130        // Request an informative description of the license for the session.  The status
131        // is in the form of {name, value} pairs.  Since DRM license policies vary by
132        // vendor, the specific status field names are determined by each DRM vendor.
133        // Refer to your DRM provider documentation for definitions of the field names
134        // for a particular DrmEngine.
135        virtual status_t
136            queryLicenseStatus(Vector<uint8_t> const &sessionId,
137                               KeyedVector<String8, String8> &infoMap) const = 0;
138
139        // A provision request/response exchange occurs between the app and a
140        // provisioning server to retrieve a device certificate.  getProvisionRequest
141        // is used to obtain an opaque license request blob that is delivered to the
142        // provisioning server.
143        //
144        // If successful, the opaque provision request blob is returned to the caller.
145        virtual status_t getProvisionRequest(Vector<uint8_t> &request,
146                                             String8 &defaultUrl) = 0;
147
148        // After a provision response is received by the app, it is provided to the
149        // Drm plugin using provideProvisionResponse.
150        virtual status_t provideProvisionResponse(Vector<uint8_t> const &response) = 0;
151
152        // A means of enforcing the contractual requirement for a concurrent stream
153        // limit per subscriber across devices is provided via SecureStop.  SecureStop
154        // is a means of securely monitoring the lifetime of sessions. Since playback
155        // on a device can be interrupted due to reboot, power failure, etc. a means
156        // of persisting the lifetime information on the device is needed.
157        //
158        // A signed version of the sessionID is written to persistent storage on the
159        // device when each MediaCrypto object is created. The sessionID is signed by
160        // the device private key to prevent tampering.
161        //
162        // In the normal case, playback will be completed, the session destroyed and
163        // the Secure Stops will be queried. The App queries secure stops and forwards
164        // the secure stop message to the server which verifies the signature and
165        // notifies the server side database that the session destruction has been
166        // confirmed. The persisted record on the client is only removed after positive
167        // confirmation that the server received the message using releaseSecureStops().
168        virtual status_t getSecureStops(List<Vector<uint8_t> > &secureStops) = 0;
169        virtual status_t releaseSecureStops(Vector<uint8_t> const &ssRelease) = 0;
170
171        // Read a property value given the device property string.  There are a few forms
172        // of property access methods, depending on the data type returned.
173        // Since DRM plugin properties may vary, additional field names may be defined
174        // by each DRM vendor.  Refer to your DRM provider documentation for definitions
175        // of its additional field names.
176        //
177        // Standard values are:
178        //   "vendor" [string] identifies the maker of the plugin
179        //   "version" [string] identifies the version of the plugin
180        //   "description" [string] describes the plugin
181        //   'deviceUniqueId' [byte array] The device unique identifier is established
182        //   during device provisioning and provides a means of uniquely identifying
183        //   each device.
184        virtual status_t getPropertyString(String8 const &name, String8 &value ) const = 0;
185        virtual status_t getPropertyByteArray(String8 const &name,
186                                              Vector<uint8_t> &value ) const = 0;
187
188        // Write  a property value given the device property string.  There are a few forms
189        // of property setting methods, depending on the data type.
190        // Since DRM plugin properties may vary, additional field names may be defined
191        // by each DRM vendor.  Refer to your DRM provider documentation for definitions
192        // of its field names.
193        virtual status_t setPropertyString(String8 const &name,
194                                           String8 const &value ) = 0;
195        virtual status_t setPropertyByteArray(String8 const &name,
196                                              Vector<uint8_t> const &value ) = 0;
197
198        // TODO: provide way to send an event
199    private:
200        DISALLOW_EVIL_CONSTRUCTORS(DrmPlugin);
201    };
202
203}  // namespace android
204
205#endif // DRM_API_H_
206