MediaCas: add plugin APIs

/*

 * Copyright (C) 2017 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 CAS_API_H_

#define CAS_API_H_

#include <vector>

#include <utils/String8.h>

//  Loadable CasPlugin shared libraries should define the entry points

//  as shown below:

//

//  extern "C" {

//      extern android::CasFactory *createCasFactory();

//      extern android::DescramblerFactory *createDescramblerFactory();

//  }

namespace android {

struct CasPlugin;

struct CasPluginDescriptor {

    int32_t CA_system_id;

    String8 name;

};

typedef std::vector<uint8_t> CasData;

typedef std::vector<uint8_t> CasSessionId;

typedef std::vector<uint8_t> CasEmm;

typedef std::vector<uint8_t> CasEcm;

typedef void (*CasPluginCallback)(

        void *appData,

        int32_t event,

        int32_t arg,

        uint8_t *data,

        size_t size);

struct CasFactory {

    CasFactory() {}

    virtual ~CasFactory() {}

    // Determine if the plugin can handle the CA scheme identified by CA_system_id.

    virtual bool isSystemIdSupported(

            int32_t CA_system_id) const = 0;

    // Get a list of the CA schemes supported by the plugin.

    virtual status_t queryPlugins(

            std::vector<CasPluginDescriptor> *descriptors) const = 0;

    // Construct a new instance of a CasPlugin given a CA_system_id

    virtual status_t createPlugin(

            int32_t CA_system_id,

            uint64_t appData,

            CasPluginCallback callback,

            CasPlugin **plugin) = 0;

private:

    CasFactory(const CasFactory &);

    CasFactory &operator=(const CasFactory &); /* NOLINT */

};

struct CasPlugin {

    CasPlugin() {}

    virtual ~CasPlugin() {}

    // Provide the CA private data from a CA_descriptor in the conditional

    // access table to a CasPlugin.

    virtual status_t setPrivateData(

            const CasData &privateData) = 0;

    // Open a session for descrambling a program. The session will receive the

    // ECM stream corresponding to the CA_PID for the program.

    virtual status_t openSession(

            uint16_t program_number,

            CasSessionId *sessionId) = 0;

    // Open a session for descrambling an elementary stream inside a program.

    // The session will receive the ECM stream corresponding to the CA_PID for

    // the stream.

    virtual status_t openSession(

            uint16_t program_number,

            uint16_t elementary_PID,

            CasSessionId *sessionId) = 0;

    // Close a previously opened session.

    virtual status_t closeSession(

            const CasSessionId &sessionId) = 0;

    // Provide the CA private data from a CA_descriptor in the program map

    // table to a CasPlugin.

    virtual status_t setSessionPrivateData(

            const CasSessionId &sessionId,

            const CasData &privateData) = 0;

    // Process an ECM from the ECM stream for this session’s elementary stream.

    virtual status_t processEcm(

            const CasSessionId &sessionId,

            const CasEcm &ecm) = 0;

    // Process an in-band EMM from the EMM stream.

    virtual status_t processEmm(

            const CasEmm &emm) = 0;

    // Deliver an event to the CasPlugin. The format of the event is specific

    // to the CA scheme and is opaque to the framework.

    virtual status_t sendEvent(

            int32_t event,

            int32_t arg,

            const CasData &eventData) = 0;

    // Native implementation of the MediaCas Java API provision method.

    virtual status_t provision(

            const String8 &provisionString) = 0;

    // Native implementation of the MediaCas Java API refreshEntitlements method

    virtual status_t refreshEntitlements(

            int32_t refreshType,

            const CasData &refreshData) = 0;

private:

    CasPlugin(const CasPlugin &);

    CasPlugin &operator=(const CasPlugin &); /* NOLINT */

};

extern "C" {

    extern android::CasFactory *createCasFactory();

}

} // namespace android

#endif // CAS_API_H_

/*

 * Copyright (C) 2017 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 DESCRAMBLER_API_H_

#define DESCRAMBLER_API_H_

#include <media/stagefright/MediaErrors.h>

#include <media/cas/CasAPI.h>

namespace android {

struct AString;

struct DescramblerPlugin;

struct DescramblerFactory {

    DescramblerFactory() {}

    virtual ~DescramblerFactory() {}

    // Determine if the plugin can handle the CA scheme identified by CA_system_id.

    virtual bool isSystemIdSupported(

            int32_t CA_system_id) const = 0;

    // Construct a new instance of a DescramblerPlugin given a CA_system_id

    virtual status_t createPlugin(

            int32_t CA_system_id, DescramblerPlugin **plugin) = 0;

private:

    DescramblerFactory(const DescramblerFactory &);

    DescramblerFactory &operator=(const DescramblerFactory &);

};

struct DescramblerPlugin {

    enum ScramblingControl {

        kScrambling_Unscrambled = 0,

        kScrambling_Reserved    = 1,

        kScrambling_EvenKey     = 2,

        kScrambling_OddKey      = 3,

    };

    struct SubSample {

        uint32_t mNumBytesOfClearData;

        uint32_t mNumBytesOfEncryptedData;

    };

    DescramblerPlugin() {}

    virtual ~DescramblerPlugin() {}

    // If this method returns false, a non-secure decoder will be used to

    // decode the data after decryption. The decrypt API below will have

    // to support insecure decryption of the data (secure = false) for

    // media data of the given mime type.

    virtual bool requiresSecureDecoderComponent(const char *mime) const = 0;

    // A MediaCas session may be associated with a MediaCrypto session.  The

    // associated MediaCas session is used to load decryption keys

    // into the crypto/cas plugin.  The keys are then referenced by key-id

    // in the 'key' parameter to the decrypt() method.

    // Should return NO_ERROR on success, ERROR_DRM_SESSION_NOT_OPENED if

    // the session is not opened and a code from MediaErrors.h otherwise.

    virtual status_t setMediaCasSession(const CasSessionId& sessionId) = 0;

    // If the error returned falls into the range

    // ERROR_DRM_VENDOR_MIN..ERROR_DRM_VENDOR_MAX, errorDetailMsg should be

    // filled in with an appropriate string.

    // At the java level these special errors will then trigger a

    // MediaCodec.CryptoException that gives clients access to both

    // the error code and the errorDetailMsg.

    // Returns a non-negative result to indicate the number of bytes written

    // to the dstPtr, or a negative result to indicate an error.

    virtual ssize_t descramble(

            bool secure,

            ScramblingControl scramblingControl,

            size_t numSubSamples,

            const SubSample *subSamples,

            const void *srcPtr,

            int32_t srcOffset,

            void *dstPtr,

            int32_t dstOffset,

            AString *errorDetailMsg) = 0;

private:

    DescramblerPlugin(const DescramblerPlugin &);

    DescramblerPlugin &operator=(const DescramblerPlugin &);

};

}  // namespace android

extern "C" {

    extern android::DescramblerFactory *createDescramblerFactory();

}

#endif  // DESCRAMBLER_API_H_