TrustAgentService.java revision ff2144ccb4215acf4587fc628493b3d49dca6043
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 android.service.trust; 18 19import android.annotation.SdkConstant; 20import android.app.Service; 21import android.content.Intent; 22import android.os.Handler; 23import android.os.IBinder; 24import android.os.RemoteException; 25import android.util.Slog; 26 27/** 28 * A service that notifies the system about whether it believes the environment of the device 29 * to be trusted. 30 * 31 * <p>To extend this class, you must declare the service in your manifest file with 32 * the {@link android.Manifest.permission#BIND_TRUST_AGENT_SERVICE} permission 33 * and include an intent filter with the {@link #SERVICE_INTERFACE} action. For example:</p> 34 * <pre> 35 * <service android:name=".TrustAgent" 36 * android:label="@string/service_name" 37 * android:permission="android.permission.BIND_TRUST_AGENT_SERVICE"> 38 * <intent-filter> 39 * <action android:name="android.service.trust.TrustAgentService" /> 40 * </intent-filter> 41 * <meta-data android:name="android.service.trust.trustagent" 42 * android:value="@xml/trust_agent" /> 43 * </service></pre> 44 * 45 * <p>The associated meta-data file can specify an activity that is accessible through Settings 46 * and should allow configuring the trust agent, as defined in 47 * {@link android.R.styleable#TrustAgent}. For example:</p> 48 * 49 * <pre> 50 * <trust_agent xmlns:android="http://schemas.android.com/apk/res/android" 51 * android:settingsActivity=".TrustAgentSettings" /></pre> 52 */ 53public class TrustAgentService extends Service { 54 private final String TAG = TrustAgentService.class.getSimpleName() + 55 "[" + getClass().getSimpleName() + "]"; 56 57 /** 58 * The {@link Intent} that must be declared as handled by the service. 59 */ 60 @SdkConstant(SdkConstant.SdkConstantType.SERVICE_ACTION) 61 public static final String SERVICE_INTERFACE 62 = "android.service.trust.TrustAgentService"; 63 64 /** 65 * The name of the {@code meta-data} tag pointing to additional configuration of the trust 66 * agent. 67 */ 68 public static final String TRUST_AGENT_META_DATA = "android.service.trust.trustagent"; 69 70 private static final int MSG_UNLOCK_ATTEMPT = 1; 71 72 private static final boolean DEBUG = false; 73 74 private ITrustAgentServiceCallback mCallback; 75 76 private Handler mHandler = new Handler() { 77 public void handleMessage(android.os.Message msg) { 78 switch (msg.what) { 79 case MSG_UNLOCK_ATTEMPT: 80 onUnlockAttempt(msg.arg1 != 0); 81 break; 82 } 83 }; 84 }; 85 86 /** 87 * Called when the user attempted to authenticate on the device. 88 * 89 * @param successful true if the attempt succeeded 90 */ 91 protected void onUnlockAttempt(boolean successful) { 92 } 93 94 private void onError(String msg) { 95 Slog.v(TAG, "Remote exception while " + msg); 96 } 97 98 /** 99 * Call to enable trust on the device. 100 * 101 * @param message describes why the device is trusted, e.g. "Trusted by location". 102 * @param durationMs amount of time in milliseconds to keep the device in a trusted state. Trust 103 * for this agent will automatically be revoked when the timeout expires. 104 * @param initiatedByUser indicates that the user has explicitly initiated an action that proves 105 * the user is about to use the device. 106 */ 107 protected final void enableTrust(String message, long durationMs, boolean initiatedByUser) { 108 if (mCallback != null) { 109 try { 110 mCallback.enableTrust(message, durationMs, initiatedByUser); 111 } catch (RemoteException e) { 112 onError("calling enableTrust()"); 113 } 114 } 115 } 116 117 /** 118 * Call to revoke trust on the device. 119 */ 120 protected final void revokeTrust() { 121 if (mCallback != null) { 122 try { 123 mCallback.revokeTrust(); 124 } catch (RemoteException e) { 125 onError("calling revokeTrust()"); 126 } 127 } 128 } 129 130 @Override 131 public final IBinder onBind(Intent intent) { 132 if (DEBUG) Slog.v(TAG, "onBind() intent = " + intent); 133 return new TrustAgentServiceWrapper(); 134 } 135 136 private final class TrustAgentServiceWrapper extends ITrustAgentService.Stub { 137 @Override 138 public void onUnlockAttempt(boolean successful) { 139 mHandler.obtainMessage(MSG_UNLOCK_ATTEMPT, successful ? 1 : 0, 0) 140 .sendToTarget(); 141 } 142 143 public void setCallback(ITrustAgentServiceCallback callback) { 144 mCallback = callback; 145 } 146 } 147 148} 149