src/org/average/nfcauthcr/YkNeo.java

   1 package org.average.nfcauthcr;
   2
   3 import java.lang.String;
   4 import java.io.IOException;
   5 import java.util.Arrays;
   6
   7 import android.nfc.NfcAdapter;
   8 import android.nfc.Tag;
   9 import android.nfc.TagLostException;
  10 import android.nfc.tech.IsoDep;
  11
  12 import org.average.nfcauthcr.CRException;
  13
  14 public class YkNeo {
  15
  16         // This is a CCID APDU, ISO 7816-4.
  17         // 00 A4 04 00 xx AID - GlobalPlatform - SELECT
  18         // Lc, send data = 07: A0 00 00 05 27 20 01
  19         // Le, recv data = 00
  20         private static final byte[] selectApdu =
  21                 {0x00, (byte) 0xA4, 0x04, 0x00, 0x07, (byte) 0xA0,
  22                  0x00, 0x00, 0x05, 0x27, 0x20, 0x01, 0x00};
  23
  24         private static final byte SLOT_CHAL_HMAC1 = 0x30;
  25         private static final byte SLOT_CHAL_HMAC2 = 0x38;
  26
  27         public static byte[] doChalResp(IsoDep isoTag, int slot,
  28                                         byte[] challenge) throws CRException {
  29                 try {
  30                         isoTag.connect();
  31                         byte[] resp = isoTag.transceive(selectApdu);
  32                         int length = resp.length;
  33                         if (resp[length - 2] != (byte)0x90 ||
  34                             resp[length - 1] != 0x00) {
  35                                 throw new CRException(String.format(
  36                                 "NFC select error code: %02x:%02x",
  37                                 resp[length - 2], resp[length - 1]));
  38                         }
  39                         byte[] crApdu = new byte[69];
  40                         crApdu[0] = 0x00; // CLA
  41                         crApdu[1] = 0x01; // INS
  42                         switch (slot) {
  43                         case 1: crApdu[2] = SLOT_CHAL_HMAC1; break; // P1
  44                         case 2: crApdu[2] = SLOT_CHAL_HMAC2; break; // P1
  45                         }
  46                         crApdu[3] = 0x00; // P2
  47                         crApdu[4] = 63;   // Lc
  48                         System.arraycopy(challenge, 0, crApdu, 5,
  49                                                 challenge.length); // Payload
  50                         crApdu[crApdu.length-1] = 22; // Le
  51                         resp = isoTag.transceive(crApdu);
  52                         length = resp.length;
  53                         if (resp[length - 2] != (byte)0x90 ||
  54                             resp[length - 1] != 0x00) {
  55                                 throw new CRException(String.format(
  56                                 "NFC CR error code: %02x:%02x",
  57                                 resp[length - 2], resp[length - 1]));
  58                         }
  59                         if (length != 22) {
  60                                 throw new CRException(String.format(
  61                                 "NFC wrong response size: got %d, need 20",
  62                                 length-2));
  63                         }
  64                         return Arrays.copyOf(resp, length-2);
  65                 } catch (TagLostException e) {
  66                         throw new CRException("NFC connection lost", e);
  67                 } catch (IOException e) {
  68                         throw new CRException("NFC I/O: " + e.getMessage(), e);
  69                 }
  70         }
  71 }