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      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 
     17 package com.android.settings;
     18 
     19 import android.content.ComponentName;
     20 import android.content.pm.PackageManager;
     21 import android.content.pm.ResolveInfo;
     22 import android.content.res.Resources;
     23 import android.content.res.TypedArray;
     24 import android.content.res.XmlResourceParser;
     25 import android.service.trust.TrustAgentService;
     26 import android.util.AttributeSet;
     27 import android.util.Log;
     28 import android.util.Slog;
     29 import android.util.Xml;
     30 
     31 import org.xmlpull.v1.XmlPullParser;
     32 import org.xmlpull.v1.XmlPullParserException;
     33 
     34 import java.io.IOException;
     35 
     36 public 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