1/*
2 * Copyright (C) 2014 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 com.android.settings;
18
19import android.content.ComponentName;
20import android.content.pm.PackageManager;
21import android.content.pm.ResolveInfo;
22import android.content.res.Resources;
23import android.content.res.TypedArray;
24import android.content.res.XmlResourceParser;
25import android.service.trust.TrustAgentService;
26import android.util.AttributeSet;
27import android.util.Log;
28import android.util.Slog;
29import android.util.Xml;
30
31import org.xmlpull.v1.XmlPullParser;
32import org.xmlpull.v1.XmlPullParserException;
33
34import java.io.IOException;
35
36public class TrustAgentUtils {
37    static final String TAG = "TrustAgentUtils";
38
39    private static final String TRUST_AGENT_META_DATA = TrustAgentService.TRUST_AGENT_META_DATA;
40    private static final String PERMISSION_PROVIDE_AGENT = android.Manifest.permission.PROVIDE_TRUST_AGENT;
41
42    /**
43     * @return true, if the service in resolveInfo has the permission to provide a trust agent.
44     */
45    public static boolean checkProvidePermission(ResolveInfo resolveInfo, PackageManager pm) {
46        String packageName = resolveInfo.serviceInfo.packageName;
47        if (pm.checkPermission(PERMISSION_PROVIDE_AGENT, packageName)
48                != PackageManager.PERMISSION_GRANTED) {
49            Log.w(TAG, "Skipping agent because package " + packageName
50                    + " does not have permission " + PERMISSION_PROVIDE_AGENT + ".");
51            return false;
52        }
53        return true;
54    }
55
56    public static class TrustAgentComponentInfo {
57        ComponentName componentName;
58        String title;
59        String summary;
60    }
61
62    public static ComponentName getComponentName(ResolveInfo resolveInfo) {
63        if (resolveInfo == null || resolveInfo.serviceInfo == null) return null;
64        return new ComponentName(resolveInfo.serviceInfo.packageName, resolveInfo.serviceInfo.name);
65    }
66
67    public static TrustAgentComponentInfo getSettingsComponent(
68            PackageManager pm, ResolveInfo resolveInfo) {
69        if (resolveInfo == null || resolveInfo.serviceInfo == null
70                || resolveInfo.serviceInfo.metaData == null) return null;
71        String cn = null;
72        TrustAgentComponentInfo trustAgentComponentInfo = new TrustAgentComponentInfo();
73        XmlResourceParser parser = null;
74        Exception caughtException = null;
75        try {
76            parser = resolveInfo.serviceInfo.loadXmlMetaData(pm, TRUST_AGENT_META_DATA);
77            if (parser == null) {
78                Slog.w(TAG, "Can't find " + TRUST_AGENT_META_DATA + " meta-data");
79                return null;
80            }
81            Resources res = pm.getResourcesForApplication(resolveInfo.serviceInfo.applicationInfo);
82            AttributeSet attrs = Xml.asAttributeSet(parser);
83            int type;
84            while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
85                    && type != XmlPullParser.START_TAG) {
86            }
87            String nodeName = parser.getName();
88            if (!"trust-agent".equals(nodeName)) {
89                Slog.w(TAG, "Meta-data does not start with trust-agent tag");
90                return null;
91            }
92            TypedArray sa =
93                    res.obtainAttributes(attrs, com.android.internal.R.styleable.TrustAgent);
94            trustAgentComponentInfo.summary =
95                    sa.getString(com.android.internal.R.styleable.TrustAgent_summary);
96            trustAgentComponentInfo.title =
97                    sa.getString(com.android.internal.R.styleable.TrustAgent_title);
98            cn = sa.getString(com.android.internal.R.styleable.TrustAgent_settingsActivity);
99            sa.recycle();
100        } catch (PackageManager.NameNotFoundException e) {
101            caughtException = e;
102        } catch (IOException e) {
103            caughtException = e;
104        } catch (XmlPullParserException e) {
105            caughtException = e;
106        } finally {
107            if (parser != null) parser.close();
108        }
109        if (caughtException != null) {
110            Slog.w(TAG, "Error parsing : " + resolveInfo.serviceInfo.packageName, caughtException);
111            return null;
112        }
113        if (cn != null && cn.indexOf('/') < 0) {
114            cn = resolveInfo.serviceInfo.packageName + "/" + cn;
115        }
116        trustAgentComponentInfo.componentName = (cn == null) ? null : ComponentName.unflattenFromString(cn);
117        return trustAgentComponentInfo;
118    }
119}
120