content: /*
   * Copyright (C) 2011 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 com.android.nfc_extras;
  
  import android.annotation.SdkConstant;
  import android.annotation.SdkConstant.SdkConstantType;
  import android.os.Binder;
  import android.os.Bundle;
  import android.os.RemoteException;
  
  import java.io.IOException;
  
  public class NfcExecutionEnvironment {
      private final NfcAdapterExtras mExtras;
      private final Binder mToken;
  
      // Exception types that can be thrown by NfcService
      // 1:1 mapped to EE_ERROR_ types in NfcService
      private static final int EE_ERROR_IO = -1;
      private static final int EE_ERROR_ALREADY_OPEN = -2;
      private static final int EE_ERROR_INIT = -3;
      private static final int EE_ERROR_LISTEN_MODE = -4;
      private static final int EE_ERROR_EXT_FIELD = -5;
      private static final int EE_ERROR_NFC_DISABLED = -6;
  
      /**
       * Broadcast Action: An ISO-DEP AID was selected.
       *
       * <p>This happens as the result of a 'SELECT AID' command from an
       * external NFC reader/writer.
       *
       * <p>Always contains the extra field {@link #EXTRA_AID}
       *
       * <p class="note">
       * Requires the {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission
       * to receive.
       */
      @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
      public static final String ACTION_AID_SELECTED =
          "com.android.nfc_extras.action.AID_SELECTED";
  
      /**
       * Mandatory byte array extra field in {@link #ACTION_AID_SELECTED}.
       *
       * <p>Contains the AID selected.
       * @hide
       */
      public static final String EXTRA_AID = "com.android.nfc_extras.extra.AID";
  
      /**
       * Broadcast action: A filtered APDU was received.
       *
       * <p>This happens when an APDU of interest was matched by the Nfc adapter,
       * for instance as the result of matching an externally-configured filter.
       *
       * <p>The filter configuration mechanism is not currently defined.
       *
       * <p>Always contains the extra field {@link EXTRA_APDU_BYTES}.
       *
       * @hide
       */
      public static final String ACTION_APDU_RECEIVED =
          "com.android.nfc_extras.action.APDU_RECEIVED";
  
      /**
       * Mandatory byte array extra field in {@link #ACTION_APDU_RECEIVED}.
       *
       * <p>Contains the bytes of the received APDU.
       *
       * @hide
       */
      public static final String EXTRA_APDU_BYTES =
          "com.android.nfc_extras.extra.APDU_BYTES";
  
      /**
       * Broadcast action: An EMV card removal event was detected.
       *
       * @hide
       */
      public static final String ACTION_EMV_CARD_REMOVAL =
          "com.android.nfc_extras.action.EMV_CARD_REMOVAL";
  
      /**
       * Broadcast action: An adapter implementing MIFARE Classic via card
       * emulation detected that a block has been accessed.
       *
       * <p>This may only be issued for the first block that the reader
       * authenticates to.
       *
       * <p>May contain the extra field {@link #EXTRA_MIFARE_BLOCK}.
       *
       * @hide
       */
      public static final String ACTION_MIFARE_ACCESS_DETECTED =
          "com.android.nfc_extras.action.MIFARE_ACCESS_DETECTED";
  
      /**
       * Optional integer extra field in {@link #ACTION_MIFARE_ACCESS_DETECTED}.
       *
       * <p>Provides the block number being accessed.  If not set, the block
       * number being accessed is unknown.
       *
       * @hide
       */
      public static final String EXTRA_MIFARE_BLOCK =
          "com.android.nfc_extras.extra.MIFARE_BLOCK";
  
      NfcExecutionEnvironment(NfcAdapterExtras extras) {
          mExtras = extras;
          mToken = new Binder();
      }
  
      /**
       * Open the NFC Execution Environment on its contact interface.
       *
       * <p>Opening a channel to the the secure element may fail
       * for a number of reasons:
       * <ul>
       * <li>NFC must be enabled for the connection to the SE to be opened.
       * If it is disabled at the time of this call, an {@link EeNfcDisabledException}
       * is thrown.
       *
       * <li>Only one process may open the secure element at a time. Additionally,
       * this method is not reentrant. If the secure element is already opened,
       * either by this process or by a different process, an {@link EeAlreadyOpenException}
       * is thrown.
       *
       * <li>If the connection to the secure element could not be initialized,
       * an {@link EeInitializationException} is thrown.
       *
       * <li>If the secure element or the NFC controller is activated in listen
       * mode - that is, it is talking over the contactless interface - an
       * {@link EeListenModeException} is thrown.
       *
       * <li>If the NFC controller is in a field powered by a remote device,
       * such as a payment terminal, an {@link EeExternalFieldException} is
       * thrown.
       * </ul>
       * <p>All other NFC functionality is disabled while the NFC-EE is open
       * on its contact interface, so make sure to call {@link #close} once complete.
       *
       * <p class="note">
       * Requires the {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission.
       *
       * @throws EeAlreadyOpenException if the NFC-EE is already open
       * @throws EeNfcDisabledException if NFC is disabled
       * @throws EeInitializationException if the Secure Element could not be initialized
       * @throws EeListenModeException if the NFCC or Secure Element is activated in listen mode
       * @throws EeExternalFieldException if the NFCC is in the presence of a remote-powered field
       * @throws EeIoException if an unknown error occurs
       */
      public void open() throws EeIOException {
          try {
              Bundle b = mExtras.getService().open(mExtras.mPackageName, mToken);
              throwBundle(b);
          } catch (RemoteException e) {
              mExtras.attemptDeadServiceRecovery(e);
              throw new EeIOException("NFC Service was dead, try again");
          }
      }
  
      /**
       * Close the NFC Execution Environment on its contact interface.
       *
       * <p class="note">
       * Requires the {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission.
       *
       * @throws IOException if the NFC-EE is already open, or some other error occurs
       */
      public void close() throws IOException {
          try {
              throwBundle(mExtras.getService().close(mExtras.mPackageName, mToken));
          } catch (RemoteException e) {
              mExtras.attemptDeadServiceRecovery(e);
              throw new IOException("NFC Service was dead");
          }
      }
  
      /**
       * Send raw commands to the NFC-EE and receive the response.
       *
       * <p class="note">
       * Requires the {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission.
       *
       * @throws IOException if the NFC-EE is not open, or some other error occurs
       */
      public byte[] transceive(byte[] in) throws IOException {
          Bundle b;
          try {
              b = mExtras.getService().transceive(mExtras.mPackageName, in);
          } catch (RemoteException e) {
              mExtras.attemptDeadServiceRecovery(e);
              throw new IOException("NFC Service was dead, need to re-open");
          }
          throwBundle(b);
          return b.getByteArray("out");
      }
  
      private static void throwBundle(Bundle b) throws EeIOException {
          switch (b.getInt("e")) {
              case EE_ERROR_NFC_DISABLED:
                  throw new EeNfcDisabledException(b.getString("m"));
              case EE_ERROR_IO:
                  throw new EeIOException(b.getString("m"));
              case EE_ERROR_INIT:
                  throw new EeInitializationException(b.getString("m"));
              case EE_ERROR_EXT_FIELD:
                  throw new EeExternalFieldException(b.getString("m"));
              case EE_ERROR_LISTEN_MODE:
                  throw new EeListenModeException(b.getString("m"));
              case EE_ERROR_ALREADY_OPEN:
                  throw new EeAlreadyOpenException(b.getString("m"));
          }
      }
  }
  