mfoc-always-skip-probes/src/mifare.c

/*-
 * Public platform independent Near Field Communication (NFC) library examples
 * 
 * Copyright (C) 2009, Roel Verdult
 * Copyright (C) 2010, Romuald Conty, Romain Tartière
 * 
 * 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
 *
 */

#include "mifare.h"

#include <string.h>

#include <nfc/nfc.h>

/**
 * @brief Execute a MIFARE Classic Command
 * @return Returns true if action was successfully performed; otherwise returns false.
 * @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. 
 * They are both used to initialize the internal cipher-state of the PN53X chip (http://libnfc.org/hardware/pn53x-chip).
 * After a successful authentication it will be possible to execute other commands (e.g. Read/Write). 
 * The MIFARE Classic Specification (http://www.nxp.com/acrobat/other/identification/M001053_MF1ICS50_rev5_3.pdf) explains more about this process.
 */
bool
nfc_initiator_mifare_cmd (nfc_device_t * pnd, const mifare_cmd mc, const uint8_t ui8Block, mifare_param * pmp)
{
  byte_t  abtRx[265];
  size_t  szRx = sizeof(abtRx);
  size_t  szParamLen;
  byte_t  abtCmd[265];
  bool    bEasyFraming;

  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 (mifare_param_auth);
    break;

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

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

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

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

  bEasyFraming = pnd->bEasyFraming;
  if (!nfc_configure (pnd, NDO_EASY_FRAMING, true)) {
    nfc_perror (pnd, "nfc_configure");
    return false;
  }
  // Fire the mifare command
  if (!nfc_initiator_transceive_bytes (pnd, abtCmd, 2 + szParamLen, abtRx, &szRx)) {
    if (pnd->iLastError == EINVRXFRAM) {
      // "Invalid received frame" AKA EINVRXFRAM,  usual means we are
      // authenticated on a sector but the requested MIFARE cmd (read, write)
      // is not permitted by current acces bytes;
      // So there is nothing to do here.
    } else if (pnd->iLastError == EMFAUTH) {
      // In MFOC, we have to hide authentication errors :)
    } else {
      nfc_perror (pnd, "nfc_initiator_transceive_bytes");
    }
    nfc_configure (pnd, NDO_EASY_FRAMING, bEasyFraming);
    return false;
  }
  if (!nfc_configure (pnd, NDO_EASY_FRAMING, bEasyFraming)) {
    nfc_perror (pnd, "nfc_configure");
    return false;
  }

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