replicant-frameworks_native/include/media/drm/DrmAPI.h
Jeff Tinker b84d1cad1d Correct native API documentation related to MediaDrm offline use case
These doc updates were made previously to the java API but some
did not make it into the native API.

Change-Id: I9b7bfcd77bc593685254baca1c148deb7e1f91c7
related-to-bug: 8621588
2013-05-07 15:16:40 -07:00

331 lines
16 KiB
C++

/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef DRM_API_H_
#define DRM_API_H_
#include <utils/List.h>
#include <utils/String8.h>
#include <utils/Vector.h>
#include <utils/KeyedVector.h>
#include <utils/RefBase.h>
#include <utils/Mutex.h>
#include <media/stagefright/foundation/ABase.h>
// Loadable DrmEngine shared libraries should define the entry points
// createDrmFactory and createCryptoFactory as shown below:
//
// extern "C" {
// extern android::DrmFactory *createDrmFactory();
// extern android::CryptoFactory *createCryptoFactory();
// }
namespace android {
class DrmPlugin;
class DrmPluginListener;
// DRMs are implemented in DrmEngine plugins, which are dynamically
// loadable shared libraries that implement the entry points
// createDrmFactory and createCryptoFactory. createDrmFactory
// constructs and returns an instance of a DrmFactory object. Similarly,
// createCryptoFactory creates an instance of a CryptoFactory object.
// When a MediaCrypto or MediaDrm object needs to be constructed, all
// available DrmEngines present in the plugins directory on the device
// are scanned for a matching DrmEngine that can support the crypto
// scheme. When a match is found, the DrmEngine's createCryptoPlugin and
// createDrmPlugin methods are used to create CryptoPlugin or
// DrmPlugin instances to support that DRM scheme.
class DrmFactory {
public:
DrmFactory() {}
virtual ~DrmFactory() {}
// DrmFactory::isCryptoSchemeSupported can be called to determine
// if the plugin factory is able to construct plugins that support a
// given crypto scheme, which is specified by a UUID.
virtual bool isCryptoSchemeSupported(const uint8_t uuid[16]) = 0;
// Construct a DrmPlugin for the crypto scheme specified by UUID.
virtual status_t createDrmPlugin(
const uint8_t uuid[16], DrmPlugin **plugin) = 0;
private:
DrmFactory(const DrmFactory &);
DrmFactory &operator=(const DrmFactory &);
};
class DrmPlugin {
public:
enum EventType {
kDrmPluginEventProvisionRequired = 1,
kDrmPluginEventKeyNeeded,
kDrmPluginEventKeyExpired,
kDrmPluginEventVendorDefined
};
// Drm keys can be for offline content or for online streaming.
// Offline keys are persisted on the device and may be used when the device
// is disconnected from the network. The Release type is used to request
// that offline keys be no longer restricted to offline use.
enum KeyType {
kKeyType_Offline,
kKeyType_Streaming,
kKeyType_Release
};
DrmPlugin() {}
virtual ~DrmPlugin() {}
// Open a new session with the DrmPlugin object. A session ID is returned
// in the sessionId parameter.
virtual status_t openSession(Vector<uint8_t> &sessionId) = 0;
// Close a session on the DrmPlugin object.
virtual status_t closeSession(Vector<uint8_t> const &sessionId) = 0;
// A key request/response exchange occurs between the app and a License
// Server to obtain the keys required to decrypt the content. getKeyRequest()
// is used to obtain an opaque key request blob that is delivered to the
// license server.
//
// The scope parameter may be a sessionId or a keySetId, depending on the
// specified keyType. When the keyType is kKeyType_Offline or
// kKeyType_Streaming, scope should be set to the sessionId the keys will be
// provided to. When the keyType is kKeyType_Release, scope should be set to
// the keySetId of the keys being released. Releasing keys from a device
// invalidates them for all sessions.
//
// The init data passed to getKeyRequest is container-specific and its
// meaning is interpreted based on the mime type provided in the mimeType
// parameter to getKeyRequest. It could contain, for example, the content
// ID, key ID or other data obtained from the content metadata that is required
// in generating the key request. Init may be null when keyType is
// kKeyType_Release.
//
// mimeType identifies the mime type of the content
//
// keyType specifies if the keys are to be used for streaming or offline content
//
// optionalParameters are included in the key request message to allow a
// client application to provide additional message parameters to the server.
//
// If successful, the opaque key request blob is returned to the caller.
virtual status_t
getKeyRequest(Vector<uint8_t> const &scope,
Vector<uint8_t> const &initData,
String8 const &mimeType, KeyType keyType,
KeyedVector<String8, String8> const &optionalParameters,
Vector<uint8_t> &request, String8 &defaultUrl) = 0;
//
// After a key response is received by the app, it is provided to the
// Drm plugin using provideKeyResponse.
//
// scope may be a sessionId or a keySetId depending on the type of the
// response. Scope should be set to the sessionId when the response is
// for either streaming or offline key requests. Scope should be set to the
// keySetId when the response is for a release request.
//
// When the response is for an offline key request, a keySetId is returned
// in the keySetId vector parameter that can be used to later restore the
// keys to a new session with the method restoreKeys. When the response is
// for a streaming or release request, no keySetId is returned.
//
virtual status_t provideKeyResponse(Vector<uint8_t> const &scope,
Vector<uint8_t> const &response,
Vector<uint8_t> &keySetId) = 0;
// Remove the current keys from a session
virtual status_t removeKeys(Vector<uint8_t> const &sessionId) = 0;
// Restore persisted offline keys into a new session. keySetId identifies
// the keys to load, obtained from a prior call to provideKeyResponse().
virtual status_t restoreKeys(Vector<uint8_t> const &sessionId,
Vector<uint8_t> const &keySetId) = 0;
// Request an informative description of the license for the session. The status
// is in the form of {name, value} pairs. Since DRM license policies vary by
// vendor, the specific status field names are determined by each DRM vendor.
// Refer to your DRM provider documentation for definitions of the field names
// for a particular DrmEngine.
virtual status_t
queryKeyStatus(Vector<uint8_t> const &sessionId,
KeyedVector<String8, String8> &infoMap) const = 0;
// A provision request/response exchange occurs between the app and a
// provisioning server to retrieve a device certificate. getProvisionRequest
// is used to obtain an opaque key request blob that is delivered to the
// provisioning server.
//
// If successful, the opaque provision request blob is returned to the caller.
virtual status_t getProvisionRequest(Vector<uint8_t> &request,
String8 &defaultUrl) = 0;
// After a provision response is received by the app, it is provided to the
// Drm plugin using provideProvisionResponse.
virtual status_t provideProvisionResponse(Vector<uint8_t> const &response) = 0;
// A means of enforcing the contractual requirement for a concurrent stream
// limit per subscriber across devices is provided via SecureStop. SecureStop
// is a means of securely monitoring the lifetime of sessions. Since playback
// on a device can be interrupted due to reboot, power failure, etc. a means
// of persisting the lifetime information on the device is needed.
//
// A signed version of the sessionID is written to persistent storage on the
// device when each MediaCrypto object is created. The sessionID is signed by
// the device private key to prevent tampering.
//
// In the normal case, playback will be completed, the session destroyed and
// the Secure Stops will be queried. The App queries secure stops and forwards
// the secure stop message to the server which verifies the signature and
// notifies the server side database that the session destruction has been
// confirmed. The persisted record on the client is only removed after positive
// confirmation that the server received the message using releaseSecureStops().
virtual status_t getSecureStops(List<Vector<uint8_t> > &secureStops) = 0;
virtual status_t releaseSecureStops(Vector<uint8_t> const &ssRelease) = 0;
// Read a property value given the device property string. There are a few forms
// of property access methods, depending on the data type returned.
// Since DRM plugin properties may vary, additional field names may be defined
// by each DRM vendor. Refer to your DRM provider documentation for definitions
// of its additional field names.
//
// Standard values are:
// "vendor" [string] identifies the maker of the plugin
// "version" [string] identifies the version of the plugin
// "description" [string] describes the plugin
// 'deviceUniqueId' [byte array] The device unique identifier is established
// during device provisioning and provides a means of uniquely identifying
// each device.
virtual status_t getPropertyString(String8 const &name, String8 &value ) const = 0;
virtual status_t getPropertyByteArray(String8 const &name,
Vector<uint8_t> &value ) const = 0;
// Write a property value given the device property string. There are a few forms
// of property setting methods, depending on the data type.
// Since DRM plugin properties may vary, additional field names may be defined
// by each DRM vendor. Refer to your DRM provider documentation for definitions
// of its field names.
virtual status_t setPropertyString(String8 const &name,
String8 const &value ) = 0;
virtual status_t setPropertyByteArray(String8 const &name,
Vector<uint8_t> const &value ) = 0;
// The following methods implement operations on a CryptoSession to support
// encrypt, decrypt, sign verify operations on operator-provided
// session keys.
//
// The algorithm string conforms to JCA Standard Names for Cipher
// Transforms and is case insensitive. For example "AES/CBC/PKCS5Padding".
//
// Return OK if the algorithm is supported, otherwise return BAD_VALUE
//
virtual status_t setCipherAlgorithm(Vector<uint8_t> const &sessionId,
String8 const &algorithm) = 0;
//
// The algorithm string conforms to JCA Standard Names for Mac
// Algorithms and is case insensitive. For example "HmacSHA256".
//
// Return OK if the algorithm is supported, otherwise return BAD_VALUE
//
virtual status_t setMacAlgorithm(Vector<uint8_t> const &sessionId,
String8 const &algorithm) = 0;
// Encrypt the provided input buffer with the cipher algorithm
// specified by setCipherAlgorithm and the key selected by keyId,
// and return the encrypted data.
virtual status_t encrypt(Vector<uint8_t> const &sessionId,
Vector<uint8_t> const &keyId,
Vector<uint8_t> const &input,
Vector<uint8_t> const &iv,
Vector<uint8_t> &output) = 0;
// Decrypt the provided input buffer with the cipher algorithm
// specified by setCipherAlgorithm and the key selected by keyId,
// and return the decrypted data.
virtual status_t decrypt(Vector<uint8_t> const &sessionId,
Vector<uint8_t> const &keyId,
Vector<uint8_t> const &input,
Vector<uint8_t> const &iv,
Vector<uint8_t> &output) = 0;
// Compute a signature on the provided message using the mac algorithm
// specified by setMacAlgorithm and the key selected by keyId,
// and return the signature.
virtual status_t sign(Vector<uint8_t> const &sessionId,
Vector<uint8_t> const &keyId,
Vector<uint8_t> const &message,
Vector<uint8_t> &signature) = 0;
// Compute a signature on the provided message using the mac algorithm
// specified by setMacAlgorithm and the key selected by keyId,
// and compare with the expected result. Set result to true or
// false depending on the outcome.
virtual status_t verify(Vector<uint8_t> const &sessionId,
Vector<uint8_t> const &keyId,
Vector<uint8_t> const &message,
Vector<uint8_t> const &signature,
bool &match) = 0;
status_t setListener(const sp<DrmPluginListener>& listener) {
Mutex::Autolock lock(mEventLock);
mListener = listener;
return OK;
}
protected:
// Plugins call sendEvent to deliver events to the java app
void sendEvent(EventType eventType, int extra,
Vector<uint8_t> const *sessionId,
Vector<uint8_t> const *data);
private:
Mutex mEventLock;
sp<DrmPluginListener> mListener;
DISALLOW_EVIL_CONSTRUCTORS(DrmPlugin);
};
class DrmPluginListener: virtual public RefBase
{
public:
virtual void sendEvent(DrmPlugin::EventType eventType, int extra,
Vector<uint8_t> const *sesionId,
Vector<uint8_t> const *data) = 0;
};
inline void DrmPlugin::sendEvent(EventType eventType, int extra,
Vector<uint8_t> const *sessionId,
Vector<uint8_t> const *data) {
mEventLock.lock();
sp<DrmPluginListener> listener = mListener;
mEventLock.unlock();
if (listener != NULL) {
listener->sendEvent(eventType, extra, sessionId, data);
}
}
} // namespace android
#endif // DRM_API_H_