mifare.c

/*-
 * Public platform independent Near Field Communication (NFC) library examples
 *
 * Copyright (C) 2009 Roel Verdult
 * Copyright (C) 2010 Romain Tartière
 * Copyright (C) 2010, 2011, 2013 Romuald Conty
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *  1) Redistributions of source code must retain the above copyright notice,
 *  this list of conditions and the following disclaimer.
 *  2 )Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in the
 *  documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Note that this license only applies on the examples, NFC library itself is under LGPL
 *
 */

/**
 * @file mifare.c
 * @brief provide samples structs and functions to manipulate MIFARE Classic and Ultralight tags using libnfc
 */

/*
 * This implementation was written based on information provided by the
 * following document:
 *
 * MIFARE Classic Specification
 *  MF1ICS50
 *  Functional specification
 *  Rev. 5.3 - 29 January 2008
 *  http://www.nxp.com/acrobat/other/identification/M001053_MF1ICS50_rev5_3.pdf
 */

#include "mifare.h"

#include <string.h>

#include <nfc/nfc.h>

/**
 * @brief Execute a MIFARE Classic command
 * @return Returns NFC_SUCCESS if action was successfully performed; otherwise returns error code (negative value).
 * @param pmp Some commands need additional information. This information should be supplied in the mifare_param union.
 *
 * The specified MIFARE command will be executed on the tag. There are
 * different commands possible, they all require the destination block number.
 *
 * @note There are three different types of information (Authenticate, Data and Value).
 *
 * First an authentication must take place using Key A or B. It requires a 48 bit Key (6 bytes) and the UID.
 * After a successful authentication it will be possible to execute other commands (e.g. Read/Write).
 *
 * Like libnfc's functions, this one returns negative value on error (libnfc's
 * error code) but two of them need a special attention in this context (MIFARE
 * Classic):
 *  - NFC_EMFCAUTHFAIL, "MIFARE authentication failed", means key is not valid
 *  on specified sector.
 *  - NFC_ERFTRANS, "Invalid received frame", when occurs on MIFARE command
 *  read or write after a successful authentication, means permissions allowed
 *  by current acces bytes are not sufficient to process the command.
 */
int
nfc_initiator_mifare_cmd(nfc_device *pnd, const mifare_cmd mc, const uint8_t ui8Block, mifare_param *pmp)
{
  uint8_t  abtRx[265];
  size_t  szParamLen;
  uint8_t  abtCmd[265];

  abtCmd[0] = mc;               // The MIFARE Classic command
  abtCmd[1] = ui8Block;         // The block address (1K=0x00..0x39, 4K=0x00..0xff)

  switch (mc) {
      // Read and store command have no parameter
    case MC_READ:
    case MC_STORE:
      szParamLen = 0;
      break;

      // Authenticate command
    case MC_AUTH_A:
    case MC_AUTH_B:
      szParamLen = sizeof(struct mifare_param_auth);
      break;

      // Data command
    case MC_WRITE:
      szParamLen = sizeof(struct mifare_param_data);
      break;

      // Value command
    case MC_DECREMENT:
    case MC_INCREMENT:
    case MC_TRANSFER:
      szParamLen = sizeof(struct mifare_param_value);
      break;

      // Please fix your code, you never should reach this statement
    default:
      return NFC_EINVARG;
      break;
  }

  // When available, copy the parameter bytes
  if (szParamLen)
    memcpy(abtCmd + 2, (uint8_t *) pmp, szParamLen);

  // FIXME: Save and restore bEasyFraming
  int res;
  if ((res = nfc_device_set_property_bool(pnd, NP_EASY_FRAMING, true)) < 0) {
    return res;
  }
  // Fire the mifare command
  if ((res = nfc_initiator_transceive_bytes(pnd, abtCmd, 2 + szParamLen, abtRx, sizeof(abtRx), -1))  < 0) {
    return res;
  }

  // When we have executed a read command, copy the received bytes into the param
  if (mc == MC_READ) {
    if (res == 16) {
      memcpy(pmp->mpd.abtData, abtRx, 16);
    } else {
      return NFC_EINVARG;
    }
  }
  // Command succesfully executed
  return NFC_SUCCESS;
}