apdu_tag_test.c

/**
Modified from original example @ Libnfc:
http://nfc-tools.org/index.php?title=Libnfc:APDU_example
Allows testing of Host-based Card Emulatio Android example at
https://github.com/justinribeiro/android-hostcardemulation-sample
Requires Libnfc:
http://nfc-tools.org/index.php?title=Libnfc
To compile:
gcc -o apdu_tag_test apdu_tag_test.c -lnfc
*/
#include <stdlib.h>
#include <string.h>
#include <nfc/nfc.h>
#include <unistd.h>
int isReadySending = 0;
int
CardTransmit(nfc_device *pnd, uint8_t * capdu, size_t capdulen, uint8_t * rapdu, size_t * rapdulen)
{
  int res;
  size_t  szPos;
  //printf("=> ");
  for (szPos = 0; szPos < capdulen; szPos++) {
    //printf("%02x ", capdu[szPos]);
  }
  //printf("\n");
  if ((res = nfc_initiator_transceive_bytes(pnd, capdu, capdulen, rapdu, *rapdulen, 500)) < 0) {
    return -1;
  } else {
    *rapdulen = (size_t) res;
    //printf("<= ");
    if (isReadySending == 1) {
    for (szPos = 0; szPos < *rapdulen; szPos++) {
      printf("0x%02x ", rapdu[szPos]);
    }
    }
    isReadySending = 0;
    //printf("\n");
    return 0;
  }
}
void polling(int argc, const char *argv[]) {
  nfc_device *pnd;
  nfc_target nt;
  nfc_context *context;
  nfc_init(&context);
  
  //printf("\nRunning checks...\n");

  if (context == NULL) {
    //printf("Unable to init libnfc (malloc)\n");
    return;
  } 

  const char *acLibnfcVersion = nfc_version();
  (void)argc;
  //printf("%s uses libnfc %s\n", argv[0], acLibnfcVersion);

  pnd = nfc_open(context, NULL);

  if (pnd == NULL) {
    //printf("ERROR: %s", "Unable to open NFC device.");
    return;
  }
  if (nfc_initiator_init(pnd) < 0) {
    nfc_perror(pnd, "nfc_initiator_init");
    return;
  }

  //printf("NFC reader: %s opened\n", nfc_device_get_name(pnd));

  const nfc_modulation nmMifare = {
    .nmt = NMT_ISO14443A,
    .nbr = NBR_106,
  };
  // nfc_set_property_bool(pnd, NP_AUTO_ISO14443_4, true);
  while (nfc_initiator_select_passive_target(pnd, nmMifare, NULL, 0, &nt) <= 0);
  //printf("Target detected! Running command set...\n\n");
  uint8_t capdu[264];
  size_t capdulen;
  uint8_t rapdu[264];
  size_t rapdulen;
  // Select application
  memcpy(capdu, "\x00\xA4\x04\x00\x07\xFF\x39\x41\x48\x14\x81\x00\x00", 13);
  capdulen=13;
  rapdulen=sizeof(rapdu);

  //printf("Sending ADPU SELECT...\n");
  if (CardTransmit(pnd, capdu, capdulen, rapdu, &rapdulen) < 0) {
    return;
  }
  if (rapdulen < 2 || rapdu[rapdulen-2] != 0x90 || rapdu[rapdulen-1] != 0x00) {
    return;
  }
  //printf("Application selected!\n\n");

  // Select Capability Container
  memcpy(capdu, "\x00\xa4\x00\x0c\x02\xe1\x03", 7);  
  capdulen=7;
  rapdulen=sizeof(rapdu);
  
  //printf("Sending CC SELECT...\n");
  if (CardTransmit(pnd, capdu, capdulen, rapdu, &rapdulen) < 0)
    return;
  if (rapdulen < 2 || rapdu[rapdulen-2] != 0x90 || rapdu[rapdulen-1] != 0x00) {
    capdu[3]='\x00'; // Maybe an older Tag4 ?
    if (CardTransmit(pnd, capdu, capdulen, rapdu, &rapdulen) < 0)
      return;
  }
  //printf("Capability Container selected!\n\n");

  // Read Capability Container
  memcpy(capdu, "\x00\xb0\x00\x00\x0f", 5);  
  capdulen=5;
  rapdulen=sizeof(rapdu);
  
  //printf("Sending ReadBinary from CC...\n");
  if (CardTransmit(pnd, capdu, capdulen, rapdu, &rapdulen) < 0)
    return;
  if (rapdulen < 2 || rapdu[rapdulen-2] != 0x90 || rapdu[rapdulen-1] != 0x00)
    return;
  //printf("\nCapability Container header:\n");
  size_t  szPos;
  for (szPos = 0; szPos < rapdulen-2; szPos++) {
    //printf("%02x ", rapdu[szPos]);
  }
  //printf("\n\n");

  // NDEF Select
  memcpy(capdu, "\x00\xa4\x00\x0C\x02\xE1\x04", 7);
  capdulen=7;
  rapdulen=sizeof(rapdu);
  //printf("Sending NDEF Select...\n");
  if (CardTransmit(pnd, capdu, capdulen, rapdu, &rapdulen) < 0)
    return;
  if (rapdulen < 2 || rapdu[rapdulen-2] != 0x90 || rapdu[rapdulen-1] != 0x00)
    return;
  //printf("\n");

  // ReadBinary
  memcpy(capdu, "\x00\xb0\x00\x00\x02", 5);
  capdulen=5;
  rapdulen=sizeof(rapdu);
  //printf("Sending ReadBinary NLEN...\n");
  if (CardTransmit(pnd, capdu, capdulen, rapdu, &rapdulen) < 0)
    return;
  if (rapdulen < 2 || rapdu[rapdulen-2] != 0x90 || rapdu[rapdulen-1] != 0x00)
    return;
  //printf("\n");

  // ReadBinary - Get NDEF data
  memcpy(capdu, "\x00\xb0\x00\x00\x0f", 5);
  capdulen=5;
  rapdulen=sizeof(rapdu);
  //printf("Sending ReadBinary, get NDEF data...\n");
  isReadySending = 1;
  if (CardTransmit(pnd, capdu, capdulen, rapdu, &rapdulen) < 0)
    return;
  if (rapdulen < 2 || rapdu[rapdulen-2] != 0x90 || rapdu[rapdulen-1] != 0x00)
    return;
  //printf("\n");

  //printf("Wrapping up, closing session.\n\n");

  nfc_close(pnd);
  nfc_exit(context);
 
  return;
}

int
main(int argc, const char *argv[])
{
  while(1) {
    printf("O");
    polling(argc, argv);
    printf("X");
    usleep(2000*1000);
  }
  return 0;
}