Define initial trust agent API

Adds the minimal API needed to define a useful trust agent.

Bug: 13723878
Change-Id: Ib24440bab7b16d0b656bde8b059e7d42cab2c7dc

Android.mk

@@ -190,6 +190,8 @@ LOCAL_SRC_FILES += \
 	core/java/android/service/dreams/IDozeHardware.aidl \
 	core/java/android/service/dreams/IDreamManager.aidl \
 	core/java/android/service/dreams/IDreamService.aidl \
+	core/java/android/service/trust/ITrustAgentService.aidl \
+	core/java/android/service/trust/ITrustAgentServiceCallback.aidl \
 	core/java/android/service/wallpaper/IWallpaperConnection.aidl \
 	core/java/android/service/wallpaper/IWallpaperEngine.aidl \
 	core/java/android/service/wallpaper/IWallpaperService.aidl \

api/current.txt

@@ -28,6 +28,7 @@ package android {
     field public static final java.lang.String BIND_PRINT_SERVICE = "android.permission.BIND_PRINT_SERVICE";
     field public static final java.lang.String BIND_REMOTEVIEWS = "android.permission.BIND_REMOTEVIEWS";
     field public static final java.lang.String BIND_TEXT_SERVICE = "android.permission.BIND_TEXT_SERVICE";
+    field public static final java.lang.String BIND_TRUST_AGENT_SERVICE = "android.permission.BIND_TRUST_AGENT_SERVICE";
     field public static final java.lang.String BIND_VPN_SERVICE = "android.permission.BIND_VPN_SERVICE";
     field public static final java.lang.String BIND_WALLPAPER = "android.permission.BIND_WALLPAPER";
     field public static final java.lang.String BLUETOOTH = "android.permission.BLUETOOTH";
@@ -24387,6 +24388,20 @@ package android.service.textservice {
 
 }
 
+package android.service.trust {
+
+  public class TrustAgentService extends android.app.Service {
+    ctor public TrustAgentService();
+    method protected final void enableTrust(java.lang.String, long, boolean);
+    method public final android.os.IBinder onBind(android.content.Intent);
+    method protected void onUnlockAttempt(boolean);
+    method protected final void revokeTrust();
+    field public static final java.lang.String SERVICE_INTERFACE = "android.service.trust.TrustAgentService";
+    field public static final java.lang.String TRUST_AGENT_META_DATA = "android.service.trust.trustagent";
+  }
+
+}
+
 package android.service.wallpaper {
 
   public abstract class WallpaperService extends android.app.Service {

core/java/android/service/trust/ITrustAgentService.aidl

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.service.trust;
+
+import android.os.Bundle;
+import android.service.trust.ITrustAgentServiceCallback;
+
+/**
+ * Communication channel from TrustManagerService to the TrustAgent.
+ * @hide
+ */
+oneway interface ITrustAgentService {
+    void onUnlockAttempt(boolean successful);
+    void setCallback(ITrustAgentServiceCallback callback);
+}

core/java/android/service/trust/ITrustAgentServiceCallback.aidl

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.service.trust;
+
+import android.os.Bundle;
+import android.os.UserHandle;
+
+/**
+ * Communication channel from the TrustAgentService back to TrustManagerService.
+ * @hide
+ */
+oneway interface ITrustAgentServiceCallback {
+    void enableTrust(String message, long durationMs, boolean initiatedByUser);
+    void revokeTrust();
+}

core/java/android/service/trust/TrustAgentService.java

@@ -0,0 +1,148 @@
+/**
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.service.trust;
+
+import android.annotation.SdkConstant;
+import android.app.Service;
+import android.content.Intent;
+import android.os.Handler;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.util.Slog;
+
+/**
+ * A service that notifies the system about whether it believes the environment of the device
+ * to be trusted.
+ *
+ * <p>To extend this class, you must declare the service in your manifest file with
+ * the {@link android.Manifest.permission#BIND_TRUST_AGENT_SERVICE} permission
+ * and include an intent filter with the {@link #SERVICE_INTERFACE} action. For example:</p>
+ * <pre>
+ * &lt;service android:name=".TrustAgent"
+ *          android:label="&#64;string/service_name"
+ *          android:permission="android.permission.BIND_TRUST_AGENT_SERVICE">
+ *     &lt;intent-filter>
+ *         &lt;action android:name="android.service.trust.TrustAgentService" />
+ *     &lt;/intent-filter>
+ *     &lt;meta-data android:name="android.service.trust.trustagent"
+ *          android:value="&#64;xml/trust_agent" />
+ * &lt;/service></pre>
+ *
+ * <p>The associated meta-data file can specify an activity that is accessible through Settings
+ * and should allow configuring the trust agent, as defined in
+ * {@link android.R.styleable#TrustAgent}. For example:</p>
+ *
+ * <pre>
+ * &lt;trust_agent xmlns:android="http://schemas.android.com/apk/res/android"
+ *          android:settingsActivity=".TrustAgentSettings" /></pre>
+ */
+public class TrustAgentService extends Service {
+    private final String TAG = TrustAgentService.class.getSimpleName() +
+            "[" + getClass().getSimpleName() + "]";
+
+    /**
+     * The {@link Intent} that must be declared as handled by the service.
+     */
+    @SdkConstant(SdkConstant.SdkConstantType.SERVICE_ACTION)
+    public static final String SERVICE_INTERFACE
+            = "android.service.trust.TrustAgentService";
+
+    /**
+     * The name of the {@code meta-data} tag pointing to additional configuration of the trust
+     * agent.
+     */
+    public static final String TRUST_AGENT_META_DATA = "android.service.trust.trustagent";
+
+    private static final int MSG_UNLOCK_ATTEMPT = 1;
+
+    private static final boolean DEBUG = false;
+
+    private ITrustAgentServiceCallback mCallback;
+
+    private Handler mHandler = new Handler() {
+        public void handleMessage(android.os.Message msg) {
+            switch (msg.what) {
+                case MSG_UNLOCK_ATTEMPT:
+                    onUnlockAttempt(msg.arg1 != 0);
+                    break;
+            }
+        };
+    };
+
+    /**
+     * Called when the user attempted to authenticate on the device.
+     *
+     * @param successful true if the attempt succeeded
+     */
+    protected void onUnlockAttempt(boolean successful) {
+    }
+
+    private void onError(String msg) {
+        Slog.v(TAG, "Remote exception while " + msg);
+    }
+
+    /**
+     * Call to enable trust on the device.
+     *
+     * @param message describes why the device is trusted, e.g. "Trusted by location".
+     * @param durationMs amount of time in milliseconds to keep the device in a trusted state. Trust
+     *                   for this agent will automatically be revoked when the timeout expires.
+     * @param initiatedByUser indicates that the user has explicitly initiated an action that proves
+     *                        the user is about to use the device.
+     */
+    protected final void enableTrust(String message, long durationMs, boolean initiatedByUser) {
+        if (mCallback != null) {
+            try {
+                mCallback.enableTrust(message, durationMs, initiatedByUser);
+            } catch (RemoteException e) {
+                onError("calling enableTrust()");
+            }
+        }
+    }
+
+    /**
+     * Call to revoke trust on the device.
+     */
+    protected final void revokeTrust() {
+        if (mCallback != null) {
+            try {
+                mCallback.revokeTrust();
+            } catch (RemoteException e) {
+                onError("calling revokeTrust()");
+            }
+        }
+    }
+
+    @Override
+    public final IBinder onBind(Intent intent) {
+        if (DEBUG) Slog.v(TAG, "onBind() intent = " + intent);
+        return new TrustAgentServiceWrapper();
+    }
+
+    private final class TrustAgentServiceWrapper extends ITrustAgentService.Stub {
+        @Override
+        public void onUnlockAttempt(boolean successful) {
+            mHandler.obtainMessage(MSG_UNLOCK_ATTEMPT, successful ? 1 : 0, 0)
+                    .sendToTarget();
+        }
+
+        public void setCallback(ITrustAgentServiceCallback callback) {
+            mCallback = callback;
+        }
+    }
+
+}

core/res/AndroidManifest.xml

@@ -2547,6 +2547,14 @@
         android:label="@string/permlab_control_keyguard"
         android:description="@string/permdesc_control_keyguard" />
 
+    <!-- Must be required by an {@link
+         android.service.trust.TrustAgentService},
+         to ensure that only the system can bind to it. -->
+    <permission android:name="android.permission.BIND_TRUST_AGENT_SERVICE"
+                android:protectionLevel="signature"
+                android:label="@string/permlab_bind_trust_agent_service"
+                android:description="@string/permdesc_bind_trust_agent_service" />
+
     <!-- Must be required by an {@link
          android.service.notification.NotificationListenerService},
          to ensure that only the system can bind to it. -->

core/res/res/values/attrs.xml

@@ -5925,6 +5925,16 @@
         <attr name="settingsActivity" />
     </declare-styleable>
 
+    <!-- Use <code>trust_agent</code> as the root tag of the XML resource that
+         describes an {@link android.service.trust.TrustAgentService}, which is
+         referenced from its {@link android.service.trust.TrustAgentService#TRUST_AGENT_META_DATA}
+         meta-data entry.  Described here are the attributes that can be included in that tag. -->
+    <declare-styleable name="TrustAgent">
+        <!-- Component name of an activity that allows the user to modify
+             the settings for this TrustAgent. -->
+        <attr name="settingsActivity" />
+    </declare-styleable>
+
     <!-- =============================== -->
     <!-- Accounts package class attributes -->
     <!-- =============================== -->

core/res/res/values/strings.xml

@@ -3651,6 +3651,11 @@
     <!-- Description of an application permission that lets it control keyguard. -->
     <string name="permdesc_control_keyguard">Allows an application to control keguard.</string>
 
+    <!-- Title of an application permission that lets it bind to a trust agent service. -->
+    <string name="permlab_bind_trust_agent_service">Bind to a trust agent service</string>
+    <!-- Description of an application permission that lets it bind to a trust agent service. -->
+    <string name="permdesc_bind_trust_agent_service">Allows an application to bind to a trust agent service.</string>
+
     <!-- Title of an application permission that lets it interact with recovery. -->
     <string name="permlab_recovery">Interact with update and recovery system</string>
     <!-- Description of an application permission that lets it control keyguard. -->