| package android.nfc.cardemulation; |
| |
| import android.annotation.SdkConstant; |
| import android.annotation.SdkConstant.SdkConstantType; |
| import android.app.Service; |
| import android.content.Intent; |
| import android.os.Bundle; |
| import android.os.Handler; |
| import android.os.IBinder; |
| import android.os.Message; |
| import android.os.Messenger; |
| import android.os.RemoteException; |
| import android.util.Log; |
| |
| /** |
| * <p>A convenience class that can be extended to implement |
| * a service that processes ISO7816-4 commands on top of |
| * the ISO14443-4 / IsoDep protocol (T=CL). |
| * |
| * <p>To tell the platform which ISO7816 application ID (AIDs) |
| * are implemented by this service, a {@link #SERVICE_META_DATA} |
| * entry must be included in the declaration of the service. An |
| * example of such a service declaration is shown below: |
| * <pre> <service android:name=".MyHostApduService"> |
| * <intent-filter> |
| * <action android:name="android.nfc.HostApduService"/> |
| * </intent-filter> |
| * <meta-data android:name="android.nfc.HostApduService" android:resource="@xml/apduservice.xml"/> |
| * </service></pre> |
| * <p>For more details refer to {@link #SERVICE_META_DATA}, |
| * <code><{@link android.R.styleable#HostApduService host-apdu-service}></code>, |
| * <code><{@link android.R.styleable#AidGroup aid-group}></code> and |
| * <code><{@link android.R.styleable#AidFilter aid-filter}></code>. |
| * <p class="note">The Android platform currently only supports a single |
| * logical channel. |
| */ |
| public abstract class HostApduService extends Service { |
| /** |
| * The {@link Intent} that must be declared as handled by the service. |
| */ |
| @SdkConstant(SdkConstantType.SERVICE_ACTION) |
| public static final String SERVICE_INTERFACE = |
| "android.nfc.cardemulation.action.HOST_APDU_SERVICE"; |
| |
| /** |
| * The name of the meta-data element that contains |
| * more information about this service. |
| */ |
| public static final String SERVICE_META_DATA = |
| "android.nfc.cardemulation.host_apdu_service"; |
| |
| /** |
| * The {@link Intent} that must be declared as handled by the service. |
| * TODO Remove |
| * @hide |
| */ |
| public static final String OLD_SERVICE_INTERFACE = |
| "android.nfc.HostApduService"; |
| |
| /** |
| * The name of the meta-data element that contains |
| * more information about this service. |
| * |
| * TODO Remove |
| * @hide |
| */ |
| public static final String OLD_SERVICE_META_DATA = "android.nfc.HostApduService"; |
| |
| /** |
| * Reason for {@link #onDeactivated(int)}. |
| * Indicates deactivation was due to the NFC link |
| * being lost. |
| */ |
| public static final int DEACTIVATION_LINK_LOSS = 0; |
| |
| /** |
| * Reason for {@link #onDeactivated(int)}. |
| * |
| * <p>Indicates deactivation was due to a different AID |
| * being selected (which implicitly deselects the AID |
| * currently active on the logical channel). |
| * |
| * <p>Note that this next AID may still be resolved to this |
| * service, in which case {@link #processCommandApdu(byte[], Bundle)} |
| * will be called again. |
| */ |
| public static final int DEACTIVATION_DESELECTED = 1; |
| |
| static final String TAG = "ApduService"; |
| |
| /** |
| * MSG_COMMAND_APDU is sent by NfcService when |
| * a 7816-4 command APDU has been received. |
| * |
| * @hide |
| */ |
| public static final int MSG_COMMAND_APDU = 0; |
| |
| /** |
| * MSG_RESPONSE_APDU is sent to NfcService to send |
| * a response APDU back to the remote device. |
| * |
| * @hide |
| */ |
| public static final int MSG_RESPONSE_APDU = 1; |
| |
| /** |
| * MSG_DEACTIVATED is sent by NfcService when |
| * the current session is finished; either because |
| * another AID was selected that resolved to |
| * another service, or because the NFC link |
| * was deactivated. |
| * |
| * @hide |
| */ |
| public static final int MSG_DEACTIVATED = 2; |
| |
| /** |
| * |
| * @hide |
| */ |
| public static final int MSG_UNHANDLED = 3; |
| |
| /** |
| * @hide |
| */ |
| public static final String KEY_DATA = "data"; |
| |
| /** |
| * Messenger interface to NfcService for sending responses. |
| * Only accessed on main thread by the message handler. |
| * |
| * @hide |
| */ |
| Messenger mNfcService = null; |
| |
| final Messenger mMessenger = new Messenger(new MsgHandler()); |
| |
| final class MsgHandler extends Handler { |
| @Override |
| public void handleMessage(Message msg) { |
| switch (msg.what) { |
| case MSG_COMMAND_APDU: |
| Bundle dataBundle = msg.getData(); |
| if (dataBundle == null) { |
| return; |
| } |
| if (mNfcService == null) mNfcService = msg.replyTo; |
| |
| byte[] apdu = dataBundle.getByteArray(KEY_DATA); |
| if (apdu != null) { |
| byte[] responseApdu = processCommandApdu(apdu, null); |
| if (responseApdu != null) { |
| if (mNfcService == null) { |
| Log.e(TAG, "Response not sent; service was deactivated."); |
| return; |
| } |
| Message responseMsg = Message.obtain(null, MSG_RESPONSE_APDU); |
| Bundle responseBundle = new Bundle(); |
| responseBundle.putByteArray(KEY_DATA, responseApdu); |
| responseMsg.setData(responseBundle); |
| responseMsg.replyTo = mMessenger; |
| try { |
| mNfcService.send(responseMsg); |
| } catch (RemoteException e) { |
| Log.e("TAG", "Response not sent; RemoteException calling into " + |
| "NfcService."); |
| } |
| } |
| } else { |
| Log.e(TAG, "Received MSG_COMMAND_APDU without data."); |
| } |
| break; |
| case MSG_RESPONSE_APDU: |
| if (mNfcService == null) { |
| Log.e(TAG, "Response not sent; service was deactivated."); |
| return; |
| } |
| try { |
| msg.replyTo = mMessenger; |
| mNfcService.send(msg); |
| } catch (RemoteException e) { |
| Log.e(TAG, "RemoteException calling into NfcService."); |
| } |
| break; |
| case MSG_DEACTIVATED: |
| // Make sure we won't call into NfcService again |
| mNfcService = null; |
| onDeactivated(msg.arg1); |
| break; |
| case MSG_UNHANDLED: |
| if (mNfcService == null) { |
| Log.e(TAG, "notifyUnhandled not sent; service was deactivated."); |
| return; |
| } |
| try { |
| msg.replyTo = mMessenger; |
| mNfcService.send(msg); |
| } catch (RemoteException e) { |
| Log.e(TAG, "RemoteException calling into NfcService."); |
| } |
| break; |
| default: |
| super.handleMessage(msg); |
| } |
| } |
| } |
| |
| @Override |
| public final IBinder onBind(Intent intent) { |
| return mMessenger.getBinder(); |
| } |
| |
| /** |
| * Sends a response APDU back to the remote device. |
| * |
| * <p>Note: this method may be called from any thread and will not block. |
| * @param responseApdu A byte-array containing the reponse APDU. |
| */ |
| public final void sendResponseApdu(byte[] responseApdu) { |
| Message responseMsg = Message.obtain(null, MSG_RESPONSE_APDU); |
| Bundle dataBundle = new Bundle(); |
| dataBundle.putByteArray(KEY_DATA, responseApdu); |
| responseMsg.setData(dataBundle); |
| try { |
| mMessenger.send(responseMsg); |
| } catch (RemoteException e) { |
| Log.e("TAG", "Local messenger has died."); |
| } |
| } |
| |
| /** |
| * Calling this method allows the service to tell the OS |
| * that it won't be able to complete this transaction - |
| * for example, because it requires data connectivity |
| * that is not present at that moment. |
| * |
| * The OS may use this indication to give the user a list |
| * of alternative applications that can handle the last |
| * AID that was selected. If the user would select an |
| * application from the list, that action by itself |
| * will not cause the default to be changed; the selected |
| * application will be invoked for the next tap only. |
| * |
| * If there are no other applications that can handle |
| * this transaction, the OS will show an error dialog |
| * indicating your service could not complete the |
| * transaction. |
| * |
| * <p>Note: this method may be called anywhere between |
| * the first {@link #processCommandApdu(byte[], Bundle)} |
| * call and a {@link #onDeactivated(int)} call. |
| */ |
| public final void notifyUnhandled() { |
| Message unhandledMsg = Message.obtain(null, MSG_UNHANDLED); |
| try { |
| mMessenger.send(unhandledMsg); |
| } catch (RemoteException e) { |
| Log.e("TAG", "Local messenger has died."); |
| } |
| } |
| |
| |
| /** |
| * <p>This method will be called when a command APDU has been received |
| * from a remote device. A response APDU can be provided directly |
| * by returning a byte-array in this method. Note that in general |
| * response APDUs must be sent as quickly as possible, given the fact |
| * that the user is likely holding his device over an NFC reader |
| * when this method is called. |
| * |
| * <p class="note">If there are multiple services that have registered for the same |
| * AIDs in their meta-data entry, you will only get called if the user has |
| * explicitly selected your service, either as a default or just for the next tap. |
| * |
| * <p class="note">This method is running on the main thread of your application. |
| * If you cannot return a response APDU immediately, return null |
| * and use the {@link #sendResponseApdu(byte[])} method later. |
| * |
| * @param commandApdu The APDU that received from the remote device |
| * @param extras A bundle containing extra data. May be null. |
| * @return a byte-array containing the response APDU, or null if no |
| * response APDU can be sent at this point. |
| */ |
| public byte[] processCommandApdu(byte[] commandApdu, Bundle extras) { |
| // TODO make this abstract |
| return processCommandApdu(commandApdu, 0); |
| } |
| |
| /** |
| * <p>This method will be called when a command APDU has been received |
| * from a remote device. A response APDU can be provided directly |
| * by returning a byte-array in this method. Note that in general |
| * response APDUs must be sent as quickly as possible, given the fact |
| * that the user is likely holding his device over an NFC reader |
| * when this method is called. |
| * |
| * <p class="note">If there are multiple services that have registered for the same |
| * AIDs in their meta-data entry, you will only get called if the user has |
| * explicitly selected your service, either as a default or just for the next tap. |
| * |
| * <p class="note">This method is running on the main thread of your application. |
| * If you cannot return a response APDU immediately, return null |
| * and use the {@link #sendResponseApdu(byte[])} method later. |
| * |
| * @deprecated use {@link #processCommandApdu(byte[], Bundle)} |
| * @param commandApdu |
| * @param flags |
| * @return a byte-array containing the response APDU, or null if no |
| * response APDU can be sent at this point. |
| * @hide |
| */ |
| public byte[] processCommandApdu(byte[] commandApdu, int flags) { |
| return null; |
| } |
| |
| /** |
| * This method will be called in two possible scenarios: |
| * <li>The NFC link has been deactivated or lost |
| * <li>A different AID has been selected and was resolved to a different |
| * service component |
| * @param reason Either {@link #DEACTIVATION_LINK_LOSS} or {@link #DEACTIVATION_DESELECTED} |
| */ |
| public abstract void onDeactivated(int reason); |
| } |
