1/*
2 * Copyright (C) 2011 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
18package com.android.providers.downloads;
19
20import android.content.Context;
21import android.drm.DrmManagerClient;
22
23import java.io.File;
24
25public class DownloadDrmHelper {
26
27    /** The MIME type of special DRM files */
28    public static final String MIMETYPE_DRM_MESSAGE = "application/vnd.oma.drm.message";
29
30    /** The extensions of special DRM files */
31    public static final String EXTENSION_DRM_MESSAGE = ".dm";
32
33    public static final String EXTENSION_INTERNAL_FWDL = ".fl";
34
35    /**
36     * Checks if the Media Type needs to be DRM converted
37     *
38     * @param mimetype Media type of the content
39     * @return True if convert is needed else false
40     */
41    public static boolean isDrmConvertNeeded(String mimetype) {
42        return MIMETYPE_DRM_MESSAGE.equals(mimetype);
43    }
44
45    /**
46     * Modifies the file extension for a DRM Forward Lock file NOTE: This
47     * function shouldn't be called if the file shouldn't be DRM converted
48     */
49    public static String modifyDrmFwLockFileExtension(String filename) {
50        if (filename != null) {
51            int extensionIndex;
52            extensionIndex = filename.lastIndexOf(".");
53            if (extensionIndex != -1) {
54                filename = filename.substring(0, extensionIndex);
55            }
56            filename = filename.concat(EXTENSION_INTERNAL_FWDL);
57        }
58        return filename;
59    }
60
61    /**
62     * Return the original MIME type of the given file, using the DRM framework
63     * if the file is protected content.
64     */
65    public static String getOriginalMimeType(Context context, File file, String currentMime) {
66        final DrmManagerClient client = new DrmManagerClient(context);
67        try {
68            final String rawFile = file.toString();
69            if (client.canHandle(rawFile, null)) {
70                return client.getOriginalMimeType(rawFile);
71            } else {
72                return currentMime;
73            }
74        } finally {
75            client.release();
76        }
77    }
78}
79