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
17package android.media;
18
19import android.annotation.NonNull;
20import android.media.MediaCryptoException;
21import 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 */
32public 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     */
38    public static final boolean isCryptoSchemeSupported(@NonNull UUID uuid) {
39        return isCryptoSchemeSupportedNative(getByteArrayFromUUID(uuid));
40    }
41
42    @NonNull
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
56    private static final native boolean isCryptoSchemeSupportedNative(@NonNull byte[] uuid);
57
58    /**
59     * Instantiate a MediaCrypto object using opaque, crypto scheme specific
60     * data.
61     * @param uuid The UUID of the crypto scheme.
62     * @param initData Opaque initialization data specific to the crypto scheme.
63     */
64    public MediaCrypto(@NonNull UUID uuid, @NonNull byte[] initData) throws MediaCryptoException {
65        native_setup(getByteArrayFromUUID(uuid), initData);
66    }
67
68    /**
69     * Query if the crypto scheme requires the use of a secure decoder
70     * to decode data of the given mime type.
71     * @param mime The mime type of the media data
72     */
73    public final native boolean requiresSecureDecoderComponent(@NonNull String mime);
74
75    /**
76     * Associate a MediaDrm session with this MediaCrypto instance.  The
77     * MediaDrm session is used to securely load decryption keys for a
78     * crypto scheme.  The crypto keys loaded through the MediaDrm session
79     * may be selected for use during the decryption operation performed
80     * by {@link android.media.MediaCodec#queueSecureInputBuffer} by specifying
81     * their key ids in the {@link android.media.MediaCodec.CryptoInfo#key} field.
82     * @param sessionId the MediaDrm sessionId to associate with this
83     * MediaCrypto instance
84     * @throws MediaCryptoException on failure to set the sessionId
85     */
86    public final native void setMediaDrmSession(@NonNull byte[] sessionId)
87        throws MediaCryptoException;
88
89    @Override
90    protected void finalize() {
91        native_finalize();
92    }
93
94    public native final void release();
95    private static native final void native_init();
96
97    private native final void native_setup(@NonNull byte[] uuid, @NonNull byte[] initData)
98        throws MediaCryptoException;
99
100    private native final void native_finalize();
101
102    static {
103        System.loadLibrary("media_jni");
104        native_init();
105    }
106
107    private long mNativeContext;
108}
109