media/java/android/media/MediaDescrambler.java - platform/frameworks/base - Git at Google

 /*
  * 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.
  */

 package android.media;

 import android.annotation.NonNull;
 import android.media.MediaCasException.UnsupportedCasException;
 import android.os.IBinder;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.os.RemoteException;
 import android.os.ServiceSpecificException;
 import android.util.Log;

 import java.nio.ByteBuffer;

 /**
  * MediaDescrambler class can be used in conjunction with {@link android.media.MediaCodec}
  * and {@link android.media.MediaExtractor} to decode media data scrambled by conditional
  * access (CA) systems such as those in the ISO/IEC13818-1.
  *
  * A MediaDescrambler object is initialized from a session opened by a MediaCas object,
  * and can be used to descramble media streams scrambled with that session's keys.
  *
  * Scrambling schemes are identified by 16-bit unsigned integer as in CA_system_id.
  *
  */
 public final class MediaDescrambler implements AutoCloseable {
     private static final String TAG = "MediaDescrambler";
     private IDescrambler mIDescrambler;

     private final void validateInternalStates() {
         if (mIDescrambler == null) {
             throw new IllegalStateException();
         }
     }

     private final void cleanupAndRethrowIllegalState() {
         mIDescrambler = null;
         throw new IllegalStateException();
     }

     /**
      * Class for parceling descrambling parameters over IDescrambler binder.
      */
     // This class currently is not used by Java binder. descramble() goes through
     // jni to use shared memory. However, the parcelable is still required for AIDL.
     static class DescrambleInfo implements Parcelable {
         private DescrambleInfo() {
         }

         private DescrambleInfo(Parcel in) {
         }

         @Override
         public int describeContents() {
             return 0;
         }

         @Override
         public void writeToParcel(Parcel dest, int flags) {
         }

         public static final Parcelable.Creator<DescrambleInfo> CREATOR
                 = new Parcelable.Creator<DescrambleInfo>() {
             public DescrambleInfo createFromParcel(Parcel in) {
                 return new DescrambleInfo(in);
             }

             public DescrambleInfo[] newArray(int size) {
                 return new DescrambleInfo[size];
             }
         };
     }

     /**
      * Instantiate a MediaDescrambler.
      *
      * @param CA_system_id The system id of the scrambling scheme.
      *
      * @throws UnsupportedCasException if the scrambling scheme is not supported.
      */
     public MediaDescrambler(int CA_system_id) throws UnsupportedCasException {
         try {
             mIDescrambler = MediaCas.getService().createDescrambler(CA_system_id);
         } catch(Exception e) {
             Log.e(TAG, "Failed to create descrambler: " + e);
             mIDescrambler = null;
         } finally {
             if (mIDescrambler == null) {
                 throw new UnsupportedCasException("Unsupported CA_system_id " + CA_system_id);
             }
         }
         native_setup(mIDescrambler.asBinder());
     }

     IBinder getBinder() {
         validateInternalStates();

         return mIDescrambler.asBinder();
     }

     /**
      * Query if the scrambling scheme requires the use of a secure decoder
      * to decode data of the given mime type.
      *
      * @param mime The mime type of the media data
      *
      * @throws IllegalStateException if the descrambler instance is not valid.
      */
     public final boolean requiresSecureDecoderComponent(@NonNull String mime) {
         validateInternalStates();

         try {
             return mIDescrambler.requiresSecureDecoderComponent(mime);
         } catch (RemoteException e) {
             cleanupAndRethrowIllegalState();
         }
         return true;
     }

     /**
      * Associate a MediaCas session with this MediaDescrambler instance.
      * The MediaCas session is used to securely load decryption keys for
      * the descrambler. The crypto keys loaded through the MediaCas session
      * may be selected for use during the descrambling operation performed
      * by {@link android.media.MediaExtractor or @link
      * android.media.MediaCodec#queueSecureInputBuffer} by specifying even
      * or odd key in the {@link android.media.MediaCodec.CryptoInfo#key} field.
      *
      * @param session the MediaCas session to associate with this
      * MediaDescrambler instance.
      *
      * @throws IllegalStateException if the descrambler instance is not valid.
      * @throws MediaCasStateException for CAS-specific state exceptions.
      */
     public final void setMediaCasSession(@NonNull MediaCas.Session session) {
         validateInternalStates();

         try {
             mIDescrambler.setMediaCasSession(session.mSessionId);
         } catch (ServiceSpecificException e) {
             MediaCasStateException.throwExceptions(e);
         } catch (RemoteException e) {
             cleanupAndRethrowIllegalState();
         }
     }

     /**
      * Descramble a ByteBuffer of data described by a
      * {@link android.media.MediaCodec.CryptoInfo} structure.
      *
      * @param srcBuf ByteBuffer containing the scrambled data, which starts at
      * srcBuf.position().
      * @param dstBuf ByteBuffer to hold the descrambled data, which starts at
      * dstBuf.position().
      * @param cryptoInfo a {@link android.media.MediaCodec.CryptoInfo} structure
      * describing the subsamples contained in src.
      *
      * @return number of bytes that have been successfully descrambled, with negative
      * values indicating errors.
      *
      * @throws IllegalStateException if the descrambler instance is not valid.
      * @throws MediaCasStateException for CAS-specific state exceptions.
      */
     public final int descramble(
             @NonNull ByteBuffer srcBuf, @NonNull ByteBuffer dstBuf,
             @NonNull MediaCodec.CryptoInfo cryptoInfo) {
         validateInternalStates();

         if (cryptoInfo.numSubSamples <= 0) {
             throw new IllegalArgumentException(
                     "Invalid CryptoInfo: invalid numSubSamples=" + cryptoInfo.numSubSamples);
         } else if (cryptoInfo.numBytesOfClearData == null
                 && cryptoInfo.numBytesOfEncryptedData == null) {
             throw new IllegalArgumentException(
                     "Invalid CryptoInfo: clearData and encryptedData size arrays are both null!");
         } else if (cryptoInfo.numBytesOfClearData != null
                 && cryptoInfo.numBytesOfClearData.length < cryptoInfo.numSubSamples) {
             throw new IllegalArgumentException(
                     "Invalid CryptoInfo: numBytesOfClearData is too small!");
         } else if (cryptoInfo.numBytesOfEncryptedData != null
                 && cryptoInfo.numBytesOfEncryptedData.length < cryptoInfo.numSubSamples) {
             throw new IllegalArgumentException(
                     "Invalid CryptoInfo: numBytesOfEncryptedData is too small!");
         } else if (cryptoInfo.key == null || cryptoInfo.key.length != 16) {
             throw new IllegalArgumentException(
                     "Invalid CryptoInfo: key array is invalid!");
         }

         try {
             return native_descramble(
                     cryptoInfo.key[0],
                     cryptoInfo.numSubSamples,
                     cryptoInfo.numBytesOfClearData,
                     cryptoInfo.numBytesOfEncryptedData,
                     srcBuf, srcBuf.position(), srcBuf.limit(),
                     dstBuf, dstBuf.position(), dstBuf.limit());
         } catch (ServiceSpecificException e) {
             MediaCasStateException.throwExceptions(e);
         }
         return -1;
     }

     @Override
     public void close() {
         if (mIDescrambler != null) {
             try {
                 mIDescrambler.release();
             } catch (RemoteException e) {
             } finally {
                 mIDescrambler = null;
             }
         }
         native_release();
     }

     @Override
     protected void finalize() {
         close();
     }

     private static native final void native_init();
     private native final void native_setup(@NonNull IBinder decramblerBinder);
     private native final void native_release();
     private native final int native_descramble(
             byte key, int numSubSamples, int[] numBytesOfClearData, int[] numBytesOfEncryptedData,
             @NonNull ByteBuffer srcBuf, int srcOffset, int srcLimit,
             ByteBuffer dstBuf, int dstOffset, int dstLimit);

     static {
         System.loadLibrary("media_jni");
         native_init();
     }

     private long mNativeContext;
 }
	/*
	* 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.
	*/

	package android.media;

	import android.annotation.NonNull;
	import android.media.MediaCasException.UnsupportedCasException;
	import android.os.IBinder;
	import android.os.Parcel;
	import android.os.Parcelable;
	import android.os.RemoteException;
	import android.os.ServiceSpecificException;
	import android.util.Log;

	import java.nio.ByteBuffer;

	/**
	* MediaDescrambler class can be used in conjunction with {@link android.media.MediaCodec}
	* and {@link android.media.MediaExtractor} to decode media data scrambled by conditional
	* access (CA) systems such as those in the ISO/IEC13818-1.
	*
	* A MediaDescrambler object is initialized from a session opened by a MediaCas object,
	* and can be used to descramble media streams scrambled with that session's keys.
	*
	* Scrambling schemes are identified by 16-bit unsigned integer as in CA_system_id.
	*
	*/
	public final class MediaDescrambler implements AutoCloseable {
	private static final String TAG = "MediaDescrambler";
	private IDescrambler mIDescrambler;

	private final void validateInternalStates() {
	if (mIDescrambler == null) {
	throw new IllegalStateException();
	}
	}

	private final void cleanupAndRethrowIllegalState() {
	mIDescrambler = null;
	throw new IllegalStateException();
	}

	/**
	* Class for parceling descrambling parameters over IDescrambler binder.
	*/
	// This class currently is not used by Java binder. descramble() goes through
	// jni to use shared memory. However, the parcelable is still required for AIDL.
	static class DescrambleInfo implements Parcelable {
	private DescrambleInfo() {
	}

	private DescrambleInfo(Parcel in) {
	}

	@Override
	public int describeContents() {
	return 0;
	}

	@Override
	public void writeToParcel(Parcel dest, int flags) {
	}

	public static final Parcelable.Creator<DescrambleInfo> CREATOR
	= new Parcelable.Creator<DescrambleInfo>() {
	public DescrambleInfo createFromParcel(Parcel in) {
	return new DescrambleInfo(in);
	}

	public DescrambleInfo[] newArray(int size) {
	return new DescrambleInfo[size];
	}
	};
	}

	/**
	* Instantiate a MediaDescrambler.
	*
	* @param CA_system_id The system id of the scrambling scheme.
	*
	* @throws UnsupportedCasException if the scrambling scheme is not supported.
	*/
	public MediaDescrambler(int CA_system_id) throws UnsupportedCasException {
	try {
	mIDescrambler = MediaCas.getService().createDescrambler(CA_system_id);
	} catch(Exception e) {
	Log.e(TAG, "Failed to create descrambler: " + e);
	mIDescrambler = null;
	} finally {
	if (mIDescrambler == null) {
	throw new UnsupportedCasException("Unsupported CA_system_id " + CA_system_id);
	}
	}
	native_setup(mIDescrambler.asBinder());
	}

	IBinder getBinder() {
	validateInternalStates();

	return mIDescrambler.asBinder();
	}

	/**
	* Query if the scrambling scheme requires the use of a secure decoder
	* to decode data of the given mime type.
	*
	* @param mime The mime type of the media data
	*
	* @throws IllegalStateException if the descrambler instance is not valid.
	*/
	public final boolean requiresSecureDecoderComponent(@NonNull String mime) {
	validateInternalStates();

	try {
	return mIDescrambler.requiresSecureDecoderComponent(mime);
	} catch (RemoteException e) {
	cleanupAndRethrowIllegalState();
	}
	return true;
	}

	/**
	* Associate a MediaCas session with this MediaDescrambler instance.
	* The MediaCas session is used to securely load decryption keys for
	* the descrambler. The crypto keys loaded through the MediaCas session
	* may be selected for use during the descrambling operation performed
	* by {@link android.media.MediaExtractor or @link
	* android.media.MediaCodec#queueSecureInputBuffer} by specifying even
	* or odd key in the {@link android.media.MediaCodec.CryptoInfo#key} field.
	*
	* @param session the MediaCas session to associate with this
	* MediaDescrambler instance.
	*
	* @throws IllegalStateException if the descrambler instance is not valid.
	* @throws MediaCasStateException for CAS-specific state exceptions.
	*/
	public final void setMediaCasSession(@NonNull MediaCas.Session session) {
	validateInternalStates();

	try {
	mIDescrambler.setMediaCasSession(session.mSessionId);
	} catch (ServiceSpecificException e) {
	MediaCasStateException.throwExceptions(e);
	} catch (RemoteException e) {
	cleanupAndRethrowIllegalState();
	}
	}

	/**
	* Descramble a ByteBuffer of data described by a
	* {@link android.media.MediaCodec.CryptoInfo} structure.
	*
	* @param srcBuf ByteBuffer containing the scrambled data, which starts at
	* srcBuf.position().
	* @param dstBuf ByteBuffer to hold the descrambled data, which starts at
	* dstBuf.position().
	* @param cryptoInfo a {@link android.media.MediaCodec.CryptoInfo} structure
	* describing the subsamples contained in src.
	*
	* @return number of bytes that have been successfully descrambled, with negative
	* values indicating errors.
	*
	* @throws IllegalStateException if the descrambler instance is not valid.
	* @throws MediaCasStateException for CAS-specific state exceptions.
	*/
	public final int descramble(
	@NonNull ByteBuffer srcBuf, @NonNull ByteBuffer dstBuf,
	@NonNull MediaCodec.CryptoInfo cryptoInfo) {
	validateInternalStates();

	if (cryptoInfo.numSubSamples <= 0) {
	throw new IllegalArgumentException(
	"Invalid CryptoInfo: invalid numSubSamples=" + cryptoInfo.numSubSamples);
	} else if (cryptoInfo.numBytesOfClearData == null
	&& cryptoInfo.numBytesOfEncryptedData == null) {
	throw new IllegalArgumentException(
	"Invalid CryptoInfo: clearData and encryptedData size arrays are both null!");
	} else if (cryptoInfo.numBytesOfClearData != null
	&& cryptoInfo.numBytesOfClearData.length < cryptoInfo.numSubSamples) {
	throw new IllegalArgumentException(
	"Invalid CryptoInfo: numBytesOfClearData is too small!");
	} else if (cryptoInfo.numBytesOfEncryptedData != null
	&& cryptoInfo.numBytesOfEncryptedData.length < cryptoInfo.numSubSamples) {
	throw new IllegalArgumentException(
	"Invalid CryptoInfo: numBytesOfEncryptedData is too small!");
	} else if (cryptoInfo.key == null \|\| cryptoInfo.key.length != 16) {
	throw new IllegalArgumentException(
	"Invalid CryptoInfo: key array is invalid!");
	}

	try {
	return native_descramble(
	cryptoInfo.key[0],
	cryptoInfo.numSubSamples,
	cryptoInfo.numBytesOfClearData,
	cryptoInfo.numBytesOfEncryptedData,
	srcBuf, srcBuf.position(), srcBuf.limit(),
	dstBuf, dstBuf.position(), dstBuf.limit());
	} catch (ServiceSpecificException e) {
	MediaCasStateException.throwExceptions(e);
	}
	return -1;
	}

	@Override
	public void close() {
	if (mIDescrambler != null) {
	try {
	mIDescrambler.release();
	} catch (RemoteException e) {
	} finally {
	mIDescrambler = null;
	}
	}
	native_release();
	}

	@Override
	protected void finalize() {
	close();
	}

	private static native final void native_init();
	private native final void native_setup(@NonNull IBinder decramblerBinder);
	private native final void native_release();
	private native final int native_descramble(
	byte key, int numSubSamples, int[] numBytesOfClearData, int[] numBytesOfEncryptedData,
	@NonNull ByteBuffer srcBuf, int srcOffset, int srcLimit,
	ByteBuffer dstBuf, int dstOffset, int dstLimit);

	static {
	System.loadLibrary("media_jni");
	native_init();
	}

	private long mNativeContext;
	}