1 /*
2  * Copyright (C) 2012 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 package android.media;
18 
19 import android.annotation.NonNull;
20 import android.media.MediaCryptoException;
21 import java.util.UUID;
22 
23 /**
24  * MediaCrypto class can be used in conjunction with {@link android.media.MediaCodec}
25  * to decode encrypted media data.
26  *
27  * Crypto schemes are assigned 16 byte UUIDs,
28  * the method {@link #isCryptoSchemeSupported} can be used to query if a given
29  * scheme is supported on the device.
30  *
31  */
32 public final class MediaCrypto {
33     /**
34      * Query if the given scheme identified by its UUID is supported on
35      * this device.
36      * @param uuid The UUID of the crypto scheme.
37      */
isCryptoSchemeSupported(@onNull UUID uuid)38     public static final boolean isCryptoSchemeSupported(@NonNull UUID uuid) {
39         return isCryptoSchemeSupportedNative(getByteArrayFromUUID(uuid));
40     }
41 
42     @NonNull
getByteArrayFromUUID(@onNull UUID uuid)43     private static final byte[] getByteArrayFromUUID(@NonNull UUID uuid) {
44         long msb = uuid.getMostSignificantBits();
45         long lsb = uuid.getLeastSignificantBits();
46 
47         byte[] uuidBytes = new byte[16];
48         for (int i = 0; i < 8; ++i) {
49             uuidBytes[i] = (byte)(msb >>> (8 * (7 - i)));
50             uuidBytes[8 + i] = (byte)(lsb >>> (8 * (7 - i)));
51         }
52 
53         return uuidBytes;
54     }
55 
isCryptoSchemeSupportedNative(@onNull byte[] uuid)56     private static final native boolean isCryptoSchemeSupportedNative(@NonNull byte[] uuid);
57 
58     /**
59      * Instantiate a MediaCrypto object and associate it with a MediaDrm session
60      *
61      * @param uuid The UUID of the crypto scheme.
62      * @param sessionId The MediaDrm sessionId to associate with this
63      * MediaCrypto session. The sessionId may be changed after the MediaCrypto
64      * is created using {@link #setMediaDrmSession}
65      */
MediaCrypto(@onNull UUID uuid, @NonNull byte[] sessionId)66     public MediaCrypto(@NonNull UUID uuid, @NonNull byte[] sessionId) throws MediaCryptoException {
67         native_setup(getByteArrayFromUUID(uuid), sessionId);
68     }
69 
70     /**
71      * Query if the crypto scheme requires the use of a secure decoder
72      * to decode data of the given mime type.
73      * @param mime The mime type of the media data
74      */
requiresSecureDecoderComponent(@onNull String mime)75     public final native boolean requiresSecureDecoderComponent(@NonNull String mime);
76 
77     /**
78      * Associate a new MediaDrm session with this MediaCrypto instance.
79      *
80      * <p>The MediaDrm session is used to securely load decryption keys for a
81      * crypto scheme. The crypto keys loaded through the MediaDrm session
82      * may be selected for use during the decryption operation performed
83      * by {@link android.media.MediaCodec#queueSecureInputBuffer} by specifying
84      * their key IDs in the {@link android.media.MediaCodec.CryptoInfo#key} field.
85      *
86      * @param sessionId The MediaDrm sessionId to associate with this MediaCrypto
87      *         instance. The session's scheme must match the scheme UUID used when
88      *         constructing this MediaCrypto instance.
89      * @throws MediaCryptoException on failure to set the sessionId
90      */
setMediaDrmSession(@onNull byte[] sessionId)91     public final native void setMediaDrmSession(@NonNull byte[] sessionId)
92         throws MediaCryptoException;
93 
94     @Override
finalize()95     protected void finalize() {
96         native_finalize();
97     }
98 
release()99     public native final void release();
native_init()100     private static native final void native_init();
101 
native_setup(@onNull byte[] uuid, @NonNull byte[] initData)102     private native final void native_setup(@NonNull byte[] uuid, @NonNull byte[] initData)
103         throws MediaCryptoException;
104 
native_finalize()105     private native final void native_finalize();
106 
107     static {
108         System.loadLibrary("media_jni");
native_init()109         native_init();
110     }
111 
112     private long mNativeContext;
113 }
114