1 /*
2  * Copyright (C) 2011 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 
17 package com.android.nfc_extras;
18 
19 import android.annotation.SdkConstant;
20 import android.annotation.SdkConstant.SdkConstantType;
21 import android.os.Binder;
22 import android.os.Bundle;
23 import android.os.RemoteException;
24 
25 import java.io.IOException;
26 
27 public class NfcExecutionEnvironment {
28     private final NfcAdapterExtras mExtras;
29     private final Binder mToken;
30 
31     // Exception types that can be thrown by NfcService
32     // 1:1 mapped to EE_ERROR_ types in NfcService
33     private static final int EE_ERROR_IO = -1;
34     private static final int EE_ERROR_ALREADY_OPEN = -2;
35     private static final int EE_ERROR_INIT = -3;
36     private static final int EE_ERROR_LISTEN_MODE = -4;
37     private static final int EE_ERROR_EXT_FIELD = -5;
38     private static final int EE_ERROR_NFC_DISABLED = -6;
39 
40     /**
41      * Broadcast Action: An ISO-DEP AID was selected.
42      *
43      * <p>This happens as the result of a 'SELECT AID' command from an
44      * external NFC reader/writer.
45      *
46      * <p>Always contains the extra field {@link #EXTRA_AID}
47      *
48      * <p class="note">
49      * Requires the {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission
50      * to receive.
51      */
52     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
53     public static final String ACTION_AID_SELECTED =
54         "com.android.nfc_extras.action.AID_SELECTED";
55 
56     /**
57      * Mandatory byte array extra field in {@link #ACTION_AID_SELECTED}.
58      *
59      * <p>Contains the AID selected.
60      * @hide
61      */
62     public static final String EXTRA_AID = "com.android.nfc_extras.extra.AID";
63 
64     /**
65      * Broadcast action: A filtered APDU was received.
66      *
67      * <p>This happens when an APDU of interest was matched by the Nfc adapter,
68      * for instance as the result of matching an externally-configured filter.
69      *
70      * <p>The filter configuration mechanism is not currently defined.
71      *
72      * <p>Always contains the extra field {@link EXTRA_APDU_BYTES}.
73      *
74      * @hide
75      */
76     public static final String ACTION_APDU_RECEIVED =
77         "com.android.nfc_extras.action.APDU_RECEIVED";
78 
79     /**
80      * Mandatory byte array extra field in {@link #ACTION_APDU_RECEIVED}.
81      *
82      * <p>Contains the bytes of the received APDU.
83      *
84      * @hide
85      */
86     public static final String EXTRA_APDU_BYTES =
87         "com.android.nfc_extras.extra.APDU_BYTES";
88 
89     /**
90      * Broadcast action: An EMV card removal event was detected.
91      *
92      * @hide
93      */
94     public static final String ACTION_EMV_CARD_REMOVAL =
95         "com.android.nfc_extras.action.EMV_CARD_REMOVAL";
96 
97     /**
98      * Broadcast action: An adapter implementing MIFARE Classic via card
99      * emulation detected that a block has been accessed.
100      *
101      * <p>This may only be issued for the first block that the reader
102      * authenticates to.
103      *
104      * <p>May contain the extra field {@link #EXTRA_MIFARE_BLOCK}.
105      *
106      * @hide
107      */
108     public static final String ACTION_MIFARE_ACCESS_DETECTED =
109         "com.android.nfc_extras.action.MIFARE_ACCESS_DETECTED";
110 
111     /**
112      * Optional integer extra field in {@link #ACTION_MIFARE_ACCESS_DETECTED}.
113      *
114      * <p>Provides the block number being accessed.  If not set, the block
115      * number being accessed is unknown.
116      *
117      * @hide
118      */
119     public static final String EXTRA_MIFARE_BLOCK =
120         "com.android.nfc_extras.extra.MIFARE_BLOCK";
121 
NfcExecutionEnvironment(NfcAdapterExtras extras)122     NfcExecutionEnvironment(NfcAdapterExtras extras) {
123         mExtras = extras;
124         mToken = new Binder();
125     }
126 
127     /**
128      * Open the NFC Execution Environment on its contact interface.
129      *
130      * <p>Opening a channel to the the secure element may fail
131      * for a number of reasons:
132      * <ul>
133      * <li>NFC must be enabled for the connection to the SE to be opened.
134      * If it is disabled at the time of this call, an {@link EeNfcDisabledException}
135      * is thrown.
136      *
137      * <li>Only one process may open the secure element at a time. Additionally,
138      * this method is not reentrant. If the secure element is already opened,
139      * either by this process or by a different process, an {@link EeAlreadyOpenException}
140      * is thrown.
141      *
142      * <li>If the connection to the secure element could not be initialized,
143      * an {@link EeInitializationException} is thrown.
144      *
145      * <li>If the secure element or the NFC controller is activated in listen
146      * mode - that is, it is talking over the contactless interface - an
147      * {@link EeListenModeException} is thrown.
148      *
149      * <li>If the NFC controller is in a field powered by a remote device,
150      * such as a payment terminal, an {@link EeExternalFieldException} is
151      * thrown.
152      * </ul>
153      * <p>All other NFC functionality is disabled while the NFC-EE is open
154      * on its contact interface, so make sure to call {@link #close} once complete.
155      *
156      * <p class="note">
157      * Requires the {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission.
158      *
159      * @throws EeAlreadyOpenException if the NFC-EE is already open
160      * @throws EeNfcDisabledException if NFC is disabled
161      * @throws EeInitializationException if the Secure Element could not be initialized
162      * @throws EeListenModeException if the NFCC or Secure Element is activated in listen mode
163      * @throws EeExternalFieldException if the NFCC is in the presence of a remote-powered field
164      * @throws EeIoException if an unknown error occurs
165      */
open()166     public void open() throws EeIOException {
167         try {
168             Bundle b = mExtras.getService().open(mExtras.mPackageName, mToken);
169             throwBundle(b);
170         } catch (RemoteException e) {
171             mExtras.attemptDeadServiceRecovery(e);
172             throw new EeIOException("NFC Service was dead, try again");
173         }
174     }
175 
176     /**
177      * Close the NFC Execution Environment on its contact interface.
178      *
179      * <p class="note">
180      * Requires the {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission.
181      *
182      * @throws IOException if the NFC-EE is already open, or some other error occurs
183      */
close()184     public void close() throws IOException {
185         try {
186             throwBundle(mExtras.getService().close(mExtras.mPackageName, mToken));
187         } catch (RemoteException e) {
188             mExtras.attemptDeadServiceRecovery(e);
189             throw new IOException("NFC Service was dead");
190         }
191     }
192 
193     /**
194      * Send raw commands to the NFC-EE and receive the response.
195      *
196      * <p class="note">
197      * Requires the {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission.
198      *
199      * @throws IOException if the NFC-EE is not open, or some other error occurs
200      */
transceive(byte[] in)201     public byte[] transceive(byte[] in) throws IOException {
202         Bundle b;
203         try {
204             b = mExtras.getService().transceive(mExtras.mPackageName, in);
205         } catch (RemoteException e) {
206             mExtras.attemptDeadServiceRecovery(e);
207             throw new IOException("NFC Service was dead, need to re-open");
208         }
209         throwBundle(b);
210         return b.getByteArray("out");
211     }
212 
throwBundle(Bundle b)213     private static void throwBundle(Bundle b) throws EeIOException {
214         switch (b.getInt("e")) {
215             case EE_ERROR_NFC_DISABLED:
216                 throw new EeNfcDisabledException(b.getString("m"));
217             case EE_ERROR_IO:
218                 throw new EeIOException(b.getString("m"));
219             case EE_ERROR_INIT:
220                 throw new EeInitializationException(b.getString("m"));
221             case EE_ERROR_EXT_FIELD:
222                 throw new EeExternalFieldException(b.getString("m"));
223             case EE_ERROR_LISTEN_MODE:
224                 throw new EeListenModeException(b.getString("m"));
225             case EE_ERROR_ALREADY_OPEN:
226                 throw new EeAlreadyOpenException(b.getString("m"));
227         }
228     }
229 }
230