/*
* 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_