src/org/average/nfcauthcr/NFCAuthCRCheck.java

   1 package org.average.nfcauthcr;
   2
   3 import java.io.IOException;
   4
   5 import android.app.Activity;
   6 import android.app.AlertDialog;
   7 import android.app.PendingIntent;
   8 import android.content.DialogInterface;
   9 import android.content.Intent;
  10 import android.content.IntentFilter;
  11 import android.nfc.NfcAdapter;
  12 import android.nfc.Tag;
  13 import android.nfc.TagLostException;
  14 import android.nfc.tech.IsoDep;
  15 import android.util.Log;
  16 import android.widget.Toast;
  17
  18 import org.average.nfcauthcr.NFCAuthCRYubiNeo;
  19
  20 public class NFCAuthCRCheck extends Activity {
  21
  22         private final String TAG = getClass().getName();
  23
  24         private static final byte[] selectCommand =
  25                 {0x00, (byte) 0xA4, 0x04, 0x00, 0x07, (byte) 0xA0,
  26                  0x00, 0x00, 0x05, 0x27, 0x20, 0x01, 0x00};
  27
  28         private AlertDialog swipeDialog;
  29         private PendingIntent tagIntent;
  30
  31         @Override
  32         protected void onResume() {
  33                 super.onResume();
  34                 Log.v(TAG, "Starting the work");
  35
  36                 Intent intent = getIntent();
  37                 setResult(RESULT_CANCELED);
  38                 if (swipeDialog != null) {
  39                         swipeDialog.dismiss();
  40                         swipeDialog = null;
  41                 }
  42                 int slot = intent.getIntExtra("slot", -1);
  43                 if (slot > 0) {
  44                         swipeDialog = makeDialog();
  45                         swipeDialog.show();
  46                         enableDispatch(slot);
  47                 }
  48         }
  49
  50         @Override
  51         protected void onPause() {
  52                 super.onPause();
  53                 Log.v(TAG, "Finished the work");
  54
  55                 if(swipeDialog != null) {
  56                         swipeDialog.dismiss();
  57                         swipeDialog = null;
  58                 }
  59                 disableDispatch();
  60         }
  61
  62         public void onNewIntent(Intent intent) {
  63                 Log.v(TAG, "NFC Intent arrived");
  64                 int slot = intent.getIntExtra("slot", -1);
  65                 byte[] challenge = intent.getByteArrayExtra("challenge");
  66                 if (slot <= 0) return;
  67                 Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
  68                 if (tag == null) return;
  69                 IsoDep isoTag = IsoDep.get(tag);
  70                 byte[] response = doChallengeYubiKey(isoTag, slot, challenge);
  71                 if (response != null) {
  72                         Intent data = getIntent();
  73                         data.putExtra("response", response);
  74                         setResult(RESULT_OK, data);
  75                 }
  76                 finish();
  77         }
  78
  79         private AlertDialog makeDialog() {
  80                 AlertDialog.Builder builder = new AlertDialog.Builder(this);
  81                 builder.setTitle(R.string.challenging);
  82                 builder.setMessage(R.string.swipe);
  83                 builder.setOnCancelListener(
  84                                 new DialogInterface.OnCancelListener() {
  85                         public void onCancel(DialogInterface dialog) {
  86                                 finish();
  87                         }
  88                 });
  89                 return builder.create();
  90         }
  91
  92         private void enableDispatch(int slot) {
  93                 Intent intent = getIntent();
  94                 intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
  95                 intent.putExtra("slot", slot);
  96                 tagIntent = PendingIntent.getActivity(this, 0, intent, 0);
  97                 IntentFilter iso =
  98                         new IntentFilter(NfcAdapter.ACTION_TECH_DISCOVERED);
  99                 NfcAdapter adapter = NfcAdapter.getDefaultAdapter(this);
 100                 if (adapter == null) {
 101                         Toast.makeText(this, R.string.no_nfc,
 102                                                 Toast.LENGTH_LONG).show();
 103                         finish();
 104                         return;
 105                 }
 106                 if (! adapter.isEnabled()) {
 107                         Toast.makeText(this, R.string.nfc_disabled,
 108                                                 Toast.LENGTH_LONG).show();
 109                         finish();
 110                         return;
 111                 }
 112                 adapter.enableForegroundDispatch(
 113                         this, tagIntent, new IntentFilter[] {iso},
 114                         new String[][] {new String[] {IsoDep.class.getName()}});
 115         }
 116
 117         private void disableDispatch() {
 118                 if (tagIntent != null) {
 119                         tagIntent.cancel();
 120                         tagIntent = null;
 121                 }
 122                 NfcAdapter adapter = NfcAdapter.getDefaultAdapter(this);
 123                 if (adapter != null) {
 124                         adapter.disableForegroundDispatch(this);
 125                 }
 126         }
 127
 128         private byte[] doChallengeYubiKey(IsoDep isoTag, int slot,
 129                                                 byte[] challenge) {
 130                 try {
 131                         isoTag.connect();
 132                         byte[] resp = isoTag.transceive(selectCommand);
 133                         int length = resp.length;
 134                         if (resp[length - 2] == (byte)0x90 &&
 135                             resp[length - 1] == 0x00) {
 136                                 return challenge;
 137                         } else {
 138                                 Toast.makeText(this, R.string.tag_error,
 139                                                 Toast.LENGTH_LONG).show();
 140                         }
 141                 } catch (TagLostException e) {
 142                         Toast.makeText(this,
 143                                 R.string.tag_lost, Toast.LENGTH_LONG).show();
 144                 } catch (IOException e) {
 145                         Toast.makeText(this,
 146                                 getText(R.string.tag_error) +
 147                                 e.getMessage(),
 148                                 Toast.LENGTH_LONG).show();
 149                 }
 150                 return null;
 151         }
 152 }