4.4.1.4 创建/使用内部服务

内部服务是除了内部应用以外的应用禁止使用的服务。 它们用于内部开发的应用，以便安全地共享信息和功能。 以下是使用Messenger绑定类型服务的示例。

要点（创建服务）：

  1. 定义内部签名权限。

  2. 需要内部签名权限。

  3. 不要定义意图过滤器，并将导出属性显式设置为true。

  4. 确认内部签名权限是由内部应用定义的。

  5. 尽管意图是从内部应用发送的，但要小心并安全地处理接收到的意图。

  6. 由于请求应用是内部的，因此可以返回敏感信息。

  7. 导出 APK 时，请使用与请求应用相同的开发人员密钥对 APK 进行签名。

AndroidManifest.xml

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <manifest xmlns:android="http://schemas.android.com/apk/res/android"
  3.     package="org.jssec.android.service.inhouseservice.messenger" >
  4.     <!-- *** POINT 1 *** Define an in-house signature permission -->
  5.     <permission
  6.     android:name="org.jssec.android.service.inhouseservice.messenger.MY_PERMISSION"
  7.     android:protectionLevel="signature" />
  8.     <application
  9.         android:icon="@drawable/ic_launcher"
  10.         android:label="@string/app_name"
  11.         android:allowBackup="false" >
  12.         <!-- Service using Messenger -->
  13.         <!-- *** POINT 2 *** Require the in-house signature permission -->
  14.         <!-- *** POINT 3 *** Do not define the intent filter and explicitly set the exported attribute to true. -->
  15.         <service
  16.             android:name="org.jssec.android.service.inhouseservice.messenger.InhouseMessengerService"
  17.             android:exported="true"
  18.             android:permission="org.jssec.android.service.inhouseservice.messenger.MY_PERMISSION" />
  19.     </application>
  20. </manifest>

InhouseMessengerService.java

  1. package org.jssec.android.service.inhouseservice.messenger;
  3. import org.jssec.android.shared.SigPerm;
  4. import org.jssec.android.shared.Utils;
  5. import java.lang.reflect.Array;
  6. import java.util.ArrayList;
  7. import java.util.Iterator;
  8. import android.app.Service;
  9. import android.content.Context;
  10. import android.content.Intent;
  11. import android.os.Bundle;
  12. import android.os.Handler;
  13. import android.os.IBinder;
  14. import android.os.Message;
  15. import android.os.Messenger;
  16. import android.os.RemoteException;
  17. import android.widget.Toast;
  19. public class InhouseMessengerService extends Service{
  21.     // In-house signature permission
  22.     private static final String MY_PERMISSION = "org.jssec.android.service.inhouseservice.messenger.MY_PERMISSION";
  23.     // In-house certificate hash value
  24.     private static String sMyCertHash = null;
  26.     private static String myCertHash(Context context) {
  27.         if (sMyCertHash == null) {
  28.             if (Utils.isDebuggable(context)) {
  29.                 // Certificate hash value of debug.keystore "androiddebugkey"
  30.                 sMyCertHash = "0EFB7236 328348A9 89718BAD DF57F544 D5CCB4AE B9DB34BC 1E29DD26 F77C8255";
  31.             } else {
  32.                 // Certificate hash value of keystore "my company key"
  33.                 sMyCertHash = "D397D343 A5CBC10F 4EDDEB7C A10062DE 5690984F 1FB9E88B D7B3A7C2 42E142CA";
  34.             }
  35.         }
  36.         return sMyCertHash;
  37.     }
  39.     // Manage clients(destinations of sending data) in a list
  40.     private ArrayList<Messenger> mClients = new ArrayList<Messenger>();
  41.     // Messenger used when service receive data from client
  42.     private final Messenger mMessenger = new Messenger(new ServiceSideHandler(mClients));
  44.     // Handler which handles message received from client
  45.     private static class ServiceSideHandler extends Handler{
  46.         private ArrayList<Messenger> mClients;
  48.         public ServiceSideHandler(ArrayList<Messenger> clients){
  49.             mClients = clients;
  50.         }
  52.         @Override
  53.         public void handleMessage(Message msg){
  54.             switch(msg.what){
  55.                 case CommonValue.MSG_REGISTER_CLIENT:
  56.                     // Add messenger received from client
  57.                     mClients.add(msg.replyTo);
  58.                     break;
  59.                 case CommonValue.MSG_UNREGISTER_CLIENT:
  60.                     mClients.remove(msg.replyTo);
  61.                     break;
  62.                 case CommonValue.MSG_SET_VALUE:
  63.                     // Send data to client
  64.                     sendMessageToClients(mClients);
  65.                     break;
  66.                 default:
  67.                     super.handleMessage(msg);
  68.                     break;
  69.             }
  70.         }
  71.     }
  73.     /**
  74.     * Send data to client
  75.     */
  76.     private static void sendMessageToClients(ArrayList<Messenger> mClients){
  77.         // *** POINT 6 *** Sensitive information can be returned since the requesting application is inhouse.
  78.         String sendValue = "Sensitive information (from Service)";
  79.         // Send data to the registered client one by one.
  80.         // Use iterator to send all clients even though clients are removed in the loop process.
  81.         Iterator<Messenger> ite = mClients.iterator();
  82.         while(ite.hasNext()){
  83.             try {
  84.                 Message sendMsg = Message.obtain(null, CommonValue.MSG_SET_VALUE, null);
  85.                 Bundle data = new Bundle();
  86.                 data.putString("key", sendValue);
  87.                 sendMsg.setData(data);
  88.                 Messenger next = ite.next();
  89.                 next.send(sendMsg);
  90.             } catch (RemoteException e) {
  91.                 // If client does not exits, remove it from a list.
  92.                 ite.remove();
  93.             }
  94.         }
  95.     }
  97.     public IBinder onBind(Intent intent) {
  98.         // *** POINT 4 *** Verify that the in-house signature permission is defined by an in-house application.
  99.         if (!SigPerm.test(this, MY_PERMISSION, myCertHash(this))) {
  100.             Toast.makeText(this, "In-house defined signature permission is not defined by in-house application.", Toast.LENGTH_LONG).show();
  101.             return null;
  102.         }
  103.         // *** POINT 5 *** Handle the received intent carefully and securely,
  104.         // even though the intent was sent from an in-house application.
  105.         // Omitted, since this is a sample. Please refer to "3.2 Handling Input Data Carefully and Securely."
  106.         String param = intent.getStringExtra("PARAM");
  107.         Toast.makeText(this, String.format("Received parameter ¥"%s¥".", param), Toast.LENGTH_LONG).show();
  108.         return mMessenger.getBinder();
  109.     }
  111.     @Override
  112.     public void onCreate() {
  113.         Toast.makeText(this, "Service - onCreate()", Toast.LENGTH_SHORT).show();
  114.     }
  116.     @Override
  117.     public void onDestroy() {
  118.         Toast.makeText(this, "Service - onDestroy()", Toast.LENGTH_SHORT).show();
  119.     }
  120. }

SigPerm.java

  1. package org.jssec.android.shared;
  3. import android.content.Context;
  4. import android.content.pm.PackageManager;
  5. import android.content.pm.PackageManager.NameNotFoundException;
  6. import android.content.pm.PermissionInfo;
  8. public class SigPerm {
  10.     public static boolean test(Context ctx, String sigPermName, String correctHash) {
  11.         if (correctHash == null) return false;
  12.         correctHash = correctHash.replaceAll(" ", "");
  13.         return correctHash.equals(hash(ctx, sigPermName));
  14.     }
  16.     public static String hash(Context ctx, String sigPermName) {
  17.         if (sigPermName == null) return null;
  18.         try {
  19.             // Get the package name of the application which declares a permission named sigPermName.
  20.             PackageManager pm = ctx.getPackageManager();
  21.             PermissionInfo pi;
  22.             pi = pm.getPermissionInfo(sigPermName, PackageManager.GET_META_DATA);
  23.             String pkgname = pi.packageName;
  24.             // Fail if the permission named sigPermName is not a Signature Permission
  25.             if (pi.protectionLevel != PermissionInfo.PROTECTION_SIGNATURE) return null;
  26.             // Return the certificate hash value of the application which declares a permission named sigPermName.
  27.             return PkgCert.hash(ctx, pkgname);
  28.         } catch (NameNotFoundException e) {
  29.             return null;
  30.         }
  31.     }
  32. }

PkgCert.java

  1. package org.jssec.android.shared;
  3. import java.security.MessageDigest;
  4. import java.security.NoSuchAlgorithmException;
  5. import android.content.Context;
  6. import android.content.pm.PackageInfo;
  7. import android.content.pm.PackageManager;
  8. import android.content.pm.PackageManager.NameNotFoundException;
  9. import android.content.pm.Signature;
  11. public class PkgCert {
  13.     public static boolean test(Context ctx, String pkgname, String correctHash) {
  14.         if (correctHash == null) return false;
  15.         correctHash = correctHash.replaceAll(" ", "");
  16.         return correctHash.equals(hash(ctx, pkgname));
  17.     }
  19.     public static String hash(Context ctx, String pkgname) {
  20.         if (pkgname == null) return null;
  21.         try {
  22.             PackageManager pm = ctx.getPackageManager();
  23.             PackageInfo pkginfo = pm.getPackageInfo(pkgname, PackageManager.GET_SIGNATURES);
  24.             if (pkginfo.signatures.length != 1) return null; // Will not handle multiple signatures.
  25.             Signature sig = pkginfo.signatures[0];
  26.             byte[] cert = sig.toByteArray();
  27.             byte[] sha256 = computeSha256(cert);
  28.             return byte2hex(sha256);
  29.         } catch (NameNotFoundException e) {
  30.             return null;
  31.         }
  32.     }
  34.     private static byte[] computeSha256(byte[] data) {
  35.         try {
  36.             return MessageDigest.getInstance("SHA-256").digest(data);
  37.         } catch (NoSuchAlgorithmException e) {
  38.             return null;
  39.         }
  40.     }
  42.     private static String byte2hex(byte[] data) {
  43.         if (data == null) return null;
  44.         final StringBuilder hexadecimal = new StringBuilder();
  45.         for (final byte b : data) {
  46.             hexadecimal.append(String.format("%02X", b));
  47.         }
  48.         return hexadecimal.toString();
  49.     }
  50. }

要点 7：导出 APK 时，请使用与请求应用相同的开发人员密钥对 APK 进行签名。

4.4.1.4.md - 图1

下面是使用内部服务的活动代码：

要点（使用服务）：

  1. 声明使用内部签名权限。

  2. 确认内部签名权限是由内部应用定义的。

  3. 验证目标应用是否使用内部证书签名。

  4. 由于目标应用是内部的，因此可以发送敏感信息。

  5. 使用显式意图调用内部服务。

  6. 即使数据来自内部应用，也要小心并安全地处理收到的结果数据。

  7. 导出 APK 时，请使用与目标应用相同的开发人员密钥对 APK 进行签名。

AndroidManifest.xml

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <manifest xmlns:android="http://schemas.android.com/apk/res/android"
  3.     package="org.jssec.android.service.inhouseservice.messengeruser" >
  4.     <!-- *** POINT 8 *** Declare to use the in-house signature permission. -->
  5.     <uses-permission
  6.     android:name="org.jssec.android.service.inhouseservice.messenger.MY_PERMISSION" />
  7.     <application
  8.         android:icon="@drawable/ic_launcher"
  9.         android:label="@string/app_name"
  10.         android:allowBackup="false" >
  11.         <activity
  12.             android:name="org.jssec.android.service.inhouseservice.messengeruser.InhouseMessengerUserActivity"
  13.             android:label="@string/app_name"
  14.             android:exported="true" >
  15.             <intent-filter>
  16.                 <action android:name="android.intent.action.MAIN" />
  17.                 <category android:name="android.intent.category.LAUNCHER" />
  18.             </intent-filter>
  19.         </activity>
  20.     </application>
  21. </manifest>

InhouseMessengerUserActivity.java

  1. package org.jssec.android.service.inhouseservice.messengeruser;
  3. import org.jssec.android.shared.PkgCert;
  4. import org.jssec.android.shared.SigPerm;
  5. import org.jssec.android.shared.Utils;
  6. import android.app.Activity;
  7. import android.content.ComponentName;
  8. import android.content.Context;
  9. import android.content.Intent;
  10. import android.content.ServiceConnection;
  11. import android.os.Bundle;
  12. import android.os.Handler;
  13. import android.os.IBinder;
  14. import android.os.Message;
  15. import android.os.Messenger;
  16. import android.os.RemoteException;
  17. import android.view.View;
  18. import android.widget.Toast;
  20. public class InhouseMessengerUserActivity extends Activity {
  22.     private boolean mIsBound;
  23.     private Context mContext;
  24.     // Destination (Requested) service application information
  25.     private static final String TARGET_PACKAGE = "org.jssec.android.service.inhouseservice.messenger";
  26.     private static final String TARGET_CLASS = "org.jssec.android.service.inhouseservice.messenger.InhouseMessengerService";
  27.     // In-house signature permission
  28.     private static final String MY_PERMISSION = "org.jssec.android.service.inhouseservice.messenger.MY_PERMISSION";
  29.     // In-house certificate hash value
  30.     private static String sMyCertHash = null;
  32.     private static String myCertHash(Context context) {
  33.         if (sMyCertHash == null) {
  34.             if (Utils.isDebuggable(context)) {
  35.                 // Certificate hash value of debug.keystore "androiddebugkey"
  36.                 sMyCertHash = "0EFB7236 328348A9 89718BAD DF57F544 D5CCB4AE B9DB34BC 1E29DD26 F77C8255";
  37.             } else {
  38.                 // Certificate hash value of keystore "my company key"
  39.                 sMyCertHash = "D397D343 A5CBC10F 4EDDEB7C A10062DE 5690984F 1FB9E88B D7B3A7C2 42E142CA";
  40.             }
  41.         }
  42.         return sMyCertHash;
  43.     }
  45.     // Messenger used when this application receives data from service.
  46.     private Messenger mServiceMessenger = null;
  47.     // Messenger used when this application sends data to service.
  48.     private final Messenger mActivityMessenger = new Messenger(new ActivitySideHandler());
  50.     // Handler which handles message received from service
  51.     private class ActivitySideHandler extends Handler {
  53.         @Override
  54.         public void handleMessage(Message msg) {
  55.             switch (msg.what) {
  56.                 case CommonValue.MSG_SET_VALUE:
  57.                     Bundle data = msg.getData();
  58.                     String info = data.getString("key");
  59.                     // *** POINT 13 *** Handle the received result data carefully and securely,
  60.                     // even though the data came from an in-house application
  61.                     // Omitted, since this is a sample. Please refer to "3.2 Handling Input Data Carefully and Securely."
  62.                     Toast.makeText(mContext, String.format("Received ¥"%s¥" from service.", info),
  63.                     Toast.LENGTH_SHORT).show();
  64.                     break;
  65.                 default:
  66.                     super.handleMessage(msg);
  67.             }
  68.         }
  70.     }
  72.     // Connection used to connect with service. This is necessary when service is implemented with bindSrvice().
  73.     private ServiceConnection mConnection = new ServiceConnection() {
  75.         // This is called when the connection with the service has been established.
  76.         @Override
  77.         public void onServiceConnected(ComponentName className, IBinder service) {
  78.             mServiceMessenger = new Messenger(service);
  79.             Toast.makeText(mContext, "Connect to service", Toast.LENGTH_SHORT).show();
  80.             try {
  81.                 // Send own messenger to service
  82.                 Message msg = Message.obtain(null, CommonValue.MSG_REGISTER_CLIENT);
  83.                 msg.replyTo = mActivityMessenger;
  84.                 mServiceMessenger.send(msg);
  85.             } catch (RemoteException e) {
  86.                 // Service stopped abnormally
  87.             }
  88.         }
  90.         // This is called when the service stopped abnormally and connection is disconnected.
  91.         @Override
  92.         public void onServiceDisconnected(ComponentName className) {
  93.             mServiceMessenger = null;
  94.             Toast.makeText(mContext, "Disconnected from service", Toast.LENGTH_SHORT).show();
  95.         }
  96.     };
  98.     @Override
  99.     public void onCreate(Bundle savedInstanceState) {
  100.         super.onCreate(savedInstanceState);
  101.         setContentView(R.layout.inhouseservice_activity);
  102.         mContext = this;
  103.     }
  105.     // --- StartService control ---
  106.     public void onStartServiceClick(View v) {
  107.         // Start bindService
  108.         doBindService();
  109.     }
  111.     public void onGetInfoClick(View v) {
  112.         getServiceinfo();
  113.     }
  115.     public void onStopServiceClick(View v) {
  116.         doUnbindService();
  117.     }
  119.     @Override
  120.     protected void onDestroy() {
  121.         super.onDestroy();
  122.         doUnbindService();
  123.     }
  125.     /**
  126.     * Connect to service
  127.     */
  128.     void doBindService() {
  129.         if (!mIsBound){
  130.             // *** POINT 9 *** Verify that the in-house signature permission is defined by an in-house application.
  131.             if (!SigPerm.test(this, MY_PERMISSION, myCertHash(this))) {
  132.                 Toast.makeText(this, "In-house defined signature permission is not defined by in-house application.", Toast.LENGTH_LONG).show();
  133.                 return;
  134.             }
  135.             // *** POINT 10 *** Verify that the destination application is signed with the in-house certificate.
  136.             if (!PkgCert.test(this, TARGET_PACKAGE, myCertHash(this))) {
  137.                 Toast.makeText(this, "Destination(Requested) service application is not in-house application.", Toast.LENGTH_LONG).show();
  138.                 return;
  139.             }
  140.             Intent intent = new Intent();
  141.             // *** POINT 11 *** Sensitive information can be sent since the destination application is in-house one.
  142.             intent.putExtra("PARAM", "Sensitive information");
  143.             // *** POINT 12 *** Use the explicit intent to call an in-house service.
  144.             intent.setClassName(TARGET_PACKAGE, TARGET_CLASS);
  145.             bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
  146.             mIsBound = true;
  147.         }
  148.     }
  150.     /**
  151.     * Disconnect service
  152.     */
  153.     void doUnbindService() {
  154.         if (mIsBound) {
  155.             unbindService(mConnection);
  156.             mIsBound = false;
  157.         }
  158.     }
  160.     /**
  161.     * Get information from service
  162.     */
  163.     void getServiceinfo() {
  164.         if (mServiceMessenger != null) {
  165.             try {
  166.                 // Request sending information
  167.                 Message msg = Message.obtain(null, CommonValue.MSG_SET_VALUE);
  168.                 mServiceMessenger.send(msg);
  169.             } catch (RemoteException e) {
  170.                 // Service stopped abnormally
  171.             }
  172.         }
  173.     }
  174. }

SigPerm.java

  1. package org.jssec.android.shared;
  3. import android.content.Context;
  4. import android.content.pm.PackageManager;
  5. import android.content.pm.PackageManager.NameNotFoundException;
  6. import android.content.pm.PermissionInfo;
  8. public class SigPerm {
  10.     public static boolean test(Context ctx, String sigPermName, String correctHash) {
  11.         if (correctHash == null) return false;
  12.         correctHash = correctHash.replaceAll(" ", "");
  13.         return correctHash.equals(hash(ctx, sigPermName));
  14.     }
  16.     public static String hash(Context ctx, String sigPermName) {
  17.         if (sigPermName == null) return null;
  18.         try {
  19.             // Get the package name of the application which declares a permission named sigPermName.
  20.             PackageManager pm = ctx.getPackageManager();
  21.             PermissionInfo pi;
  22.             pi = pm.getPermissionInfo(sigPermName, PackageManager.GET_META_DATA);
  23.             String pkgname = pi.packageName;
  24.             // Fail if the permission named sigPermName is not a Signature Permission
  25.             if (pi.protectionLevel != PermissionInfo.PROTECTION_SIGNATURE) return null;
  26.             // Return the certificate hash value of the application which declares a permission named sigPermName.
  27.             return PkgCert.hash(ctx, pkgname);
  28.         } catch (NameNotFoundException e) {
  29.             return null;
  30.         }
  31.     }
  32. }

PkgCert.java

  1. package org.jssec.android.shared;
  3. import java.security.MessageDigest;
  4. import java.security.NoSuchAlgorithmException;
  5. import android.content.Context;
  6. import android.content.pm.PackageInfo;
  7. import android.content.pm.PackageManager;
  8. import android.content.pm.PackageManager.NameNotFoundException;
  9. import android.content.pm.Signature;
  11. public class PkgCert {
  13.     public static boolean test(Context ctx, String pkgname, String correctHash) {
  14.         if (correctHash == null) return false;
  15.         correctHash = correctHash.replaceAll(" ", "");
  16.         return correctHash.equals(hash(ctx, pkgname));
  17.     }
  19.     public static String hash(Context ctx, String pkgname) {
  20.         if (pkgname == null) return null;
  21.         try {
  22.             PackageManager pm = ctx.getPackageManager();
  23.             PackageInfo pkginfo = pm.getPackageInfo(pkgname, PackageManager.GET_SIGNATURES);
  24.             if (pkginfo.signatures.length != 1) return null; // Will not handle multiple signatures.
  25.             Signature sig = pkginfo.signatures[0];
  26.             byte[] cert = sig.toByteArray();
  27.             byte[] sha256 = computeSha256(cert);
  28.             return byte2hex(sha256);
  29.         } catch (NameNotFoundException e) {
  30.             return null;
  31.         }
  32.     }
  34.     private static byte[] computeSha256(byte[] data) {
  35.         try {
  36.             return MessageDigest.getInstance("SHA-256").digest(data);
  37.         } catch (NoSuchAlgorithmException e) {
  38.             return null;
  39.         }
  40.     }
  42.     private static String byte2hex(byte[] data) {
  43.         if (data == null) return null;
  44.         final StringBuilder hexadecimal = new StringBuilder();
  45.         for (final byte b : data) {
  46.             hexadecimal.append(String.format("%02X", b));
  47.         }
  48.         return hexadecimal.toString();
  49.     }
  50. }

要点 14：导出 APK 时，请使用与目标应用相同的开发人员密钥对 APK 进行签名。

4.4.1.4.md - 图2