1 /* 2 * Copyright (C) 2016 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.security.trustagent; 18 19 import static android.service.trust.TrustAgentService.TRUST_AGENT_META_DATA; 20 21 import android.app.admin.DevicePolicyManager; 22 import android.content.ComponentName; 23 import android.content.Context; 24 import android.content.Intent; 25 import android.content.pm.PackageManager; 26 import android.content.pm.ResolveInfo; 27 import android.content.res.Resources; 28 import android.content.res.TypedArray; 29 import android.content.res.XmlResourceParser; 30 import android.os.UserHandle; 31 import android.service.trust.TrustAgentService; 32 import android.text.TextUtils; 33 import android.util.AttributeSet; 34 import android.util.Log; 35 import android.util.Slog; 36 import android.util.Xml; 37 38 import androidx.annotation.VisibleForTesting; 39 40 import com.android.internal.widget.LockPatternUtils; 41 import com.android.settingslib.RestrictedLockUtils; 42 import com.android.settingslib.RestrictedLockUtilsInternal; 43 44 import org.xmlpull.v1.XmlPullParser; 45 import org.xmlpull.v1.XmlPullParserException; 46 47 import java.io.IOException; 48 import java.util.ArrayList; 49 import java.util.List; 50 51 52 /** A manager for trust agent state. */ 53 public class TrustAgentManager { 54 55 // Only allow one trust agent on the platform. 56 private static final boolean ONLY_ONE_TRUST_AGENT = false; 57 58 public static class TrustAgentComponentInfo { 59 public ComponentName componentName; 60 public String title; 61 public String summary; 62 public RestrictedLockUtils.EnforcedAdmin admin = null; 63 } 64 65 private static final String TAG = "TrustAgentManager"; 66 private static final Intent TRUST_AGENT_INTENT = 67 new Intent(TrustAgentService.SERVICE_INTERFACE); 68 69 @VisibleForTesting 70 static final String PERMISSION_PROVIDE_AGENT = 71 android.Manifest.permission.PROVIDE_TRUST_AGENT; 72 73 /** 74 * Determines if the service associated with a resolved trust agent intent is allowed to provide 75 * trust on this device. 76 * 77 * @param resolveInfo The entry corresponding to the matched trust agent intent. 78 * @param pm The package manager to be used to check for permissions. 79 * @return {@code true} if the associated service is allowed to provide a trust agent, and 80 * {@code false} if otherwise. 81 */ shouldProvideTrust(ResolveInfo resolveInfo, PackageManager pm)82 public boolean shouldProvideTrust(ResolveInfo resolveInfo, PackageManager pm) { 83 final String packageName = resolveInfo.serviceInfo.packageName; 84 if (pm.checkPermission(PERMISSION_PROVIDE_AGENT, packageName) 85 != PackageManager.PERMISSION_GRANTED) { 86 Log.w(TAG, "Skipping agent because package " + packageName 87 + " does not have permission " + PERMISSION_PROVIDE_AGENT + "."); 88 return false; 89 } 90 return true; 91 } 92 93 /** 94 * Return the display label for active trust agent. 95 */ getActiveTrustAgentLabel(Context context, LockPatternUtils utils)96 public CharSequence getActiveTrustAgentLabel(Context context, LockPatternUtils utils) { 97 final List<TrustAgentComponentInfo> agents = getActiveTrustAgents(context, utils); 98 return agents.isEmpty() ? null : agents.get(0).title; 99 } 100 101 /** 102 * Returns a list of trust agents. 103 * 104 * If {@link #ONLY_ONE_TRUST_AGENT} is set, the list will contain up to 1 agent instead of all 105 * available agents on device. 106 */ getActiveTrustAgents(Context context, LockPatternUtils utils)107 public List<TrustAgentComponentInfo> getActiveTrustAgents(Context context, 108 LockPatternUtils utils) { 109 final int myUserId = UserHandle.myUserId(); 110 final DevicePolicyManager dpm = context.getSystemService(DevicePolicyManager.class); 111 final PackageManager pm = context.getPackageManager(); 112 final List<TrustAgentComponentInfo> result = new ArrayList<>(); 113 114 final List<ResolveInfo> resolveInfos = pm.queryIntentServices(TRUST_AGENT_INTENT, 115 PackageManager.GET_META_DATA); 116 final List<ComponentName> enabledTrustAgents = utils.getEnabledTrustAgents(myUserId); 117 final RestrictedLockUtils.EnforcedAdmin admin = RestrictedLockUtilsInternal 118 .checkIfKeyguardFeaturesDisabled( 119 context, DevicePolicyManager.KEYGUARD_DISABLE_TRUST_AGENTS, myUserId); 120 121 if (enabledTrustAgents != null && !enabledTrustAgents.isEmpty()) { 122 for (ResolveInfo resolveInfo : resolveInfos) { 123 if (resolveInfo.serviceInfo == null || !shouldProvideTrust(resolveInfo, pm)) { 124 continue; 125 } 126 final TrustAgentComponentInfo trustAgentComponentInfo = 127 getSettingsComponent(pm, resolveInfo); 128 if (trustAgentComponentInfo.componentName == null || 129 !enabledTrustAgents.contains(getComponentName(resolveInfo)) || 130 TextUtils.isEmpty(trustAgentComponentInfo.title)) { 131 continue; 132 } 133 if (admin != null && dpm.getTrustAgentConfiguration( 134 null, getComponentName(resolveInfo)) == null) { 135 trustAgentComponentInfo.admin = admin; 136 } 137 result.add(trustAgentComponentInfo); 138 if (ONLY_ONE_TRUST_AGENT) { 139 break; 140 } 141 } 142 } 143 return result; 144 } 145 getComponentName(ResolveInfo resolveInfo)146 public ComponentName getComponentName(ResolveInfo resolveInfo) { 147 if (resolveInfo == null || resolveInfo.serviceInfo == null) return null; 148 return new ComponentName(resolveInfo.serviceInfo.packageName, resolveInfo.serviceInfo.name); 149 } 150 getSettingsComponent(PackageManager pm, ResolveInfo resolveInfo)151 private TrustAgentComponentInfo getSettingsComponent(PackageManager pm, 152 ResolveInfo resolveInfo) { 153 if (resolveInfo == null || resolveInfo.serviceInfo == null 154 || resolveInfo.serviceInfo.metaData == null) { 155 return null; 156 } 157 String cn = null; 158 TrustAgentComponentInfo trustAgentComponentInfo = new TrustAgentComponentInfo(); 159 XmlResourceParser parser = null; 160 Exception caughtException = null; 161 try { 162 parser = resolveInfo.serviceInfo.loadXmlMetaData(pm, TRUST_AGENT_META_DATA); 163 if (parser == null) { 164 Slog.w(TAG, "Can't find " + TRUST_AGENT_META_DATA + " meta-data"); 165 return null; 166 } 167 Resources res = pm.getResourcesForApplication(resolveInfo.serviceInfo.applicationInfo); 168 AttributeSet attrs = Xml.asAttributeSet(parser); 169 int type; 170 while ((type = parser.next()) != XmlPullParser.END_DOCUMENT 171 && type != XmlPullParser.START_TAG) { 172 } 173 String nodeName = parser.getName(); 174 if (!"trust-agent".equals(nodeName)) { 175 Slog.w(TAG, "Meta-data does not start with trust-agent tag"); 176 return null; 177 } 178 TypedArray sa = 179 res.obtainAttributes(attrs, com.android.internal.R.styleable.TrustAgent); 180 trustAgentComponentInfo.summary = 181 sa.getString(com.android.internal.R.styleable.TrustAgent_summary); 182 trustAgentComponentInfo.title = 183 sa.getString(com.android.internal.R.styleable.TrustAgent_title); 184 cn = sa.getString(com.android.internal.R.styleable.TrustAgent_settingsActivity); 185 sa.recycle(); 186 } catch (PackageManager.NameNotFoundException e) { 187 caughtException = e; 188 } catch (IOException e) { 189 caughtException = e; 190 } catch (XmlPullParserException e) { 191 caughtException = e; 192 } finally { 193 if (parser != null) parser.close(); 194 } 195 if (caughtException != null) { 196 Slog.w(TAG, "Error parsing : " + resolveInfo.serviceInfo.packageName, caughtException); 197 return null; 198 } 199 if (cn != null && cn.indexOf('/') < 0) { 200 cn = resolveInfo.serviceInfo.packageName + "/" + cn; 201 } 202 trustAgentComponentInfo.componentName = 203 (cn == null) ? null : ComponentName.unflattenFromString(cn); 204 return trustAgentComponentInfo; 205 } 206 } 207