libnfc/libnfc/iso14443-subr.c
Romain Tartiere 10baef235f (libnfc-less-bitutils-more-ponies) Get rid of bitutils.[hc] (part 1).
- New API function append_iso14443a_crc();
  - Add a PRINT_HEX macro for driver debugging (replaces print_hex function from bitutils.c);
  - Move bit-mirroring related functions to libnfc/mirror-subr.[hc];
  - Move iso14443 related functions to libnfc/iso14443-subr.c;
  - Move libnfc/bitutils.c hex-dumping code to examples/nfc-utils.c;
  - Replace calls to swap_endian32() and swap_endian64() functions with calls to bswap32() and bswap64 provided by endian.h.

And while I am here:
  - Fix the DBG macro so that it does not throw warning at compile time.
2010-04-16 16:38:57 +00:00

52 lines
1.4 KiB
C

/*-
* Public platform independent Near Field Communication (NFC) library
*
* Copyright (C) 2009, Roel Verdult
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file iso14443-subr.c
* @brief
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif // HAVE_CONFIG_H
#include <stdio.h>
#include <nfc/nfc.h>
void iso14443a_crc(byte_t* pbtData, size_t szLen, byte_t* pbtCrc)
{
byte_t bt;
uint32_t wCrc = 0x6363;
do {
bt = *pbtData++;
bt = (bt^(byte_t)(wCrc & 0x00FF));
bt = (bt^(bt<<4));
wCrc = (wCrc >> 8)^((uint32_t)bt << 8)^((uint32_t)bt<<3)^((uint32_t)bt>>4);
} while (--szLen);
*pbtCrc++ = (byte_t) (wCrc & 0xFF);
*pbtCrc = (byte_t) ((wCrc >> 8) & 0xFF);
}
void append_iso14443a_crc(byte_t* pbtData, size_t szLen)
{
iso14443a_crc(pbtData, szLen, pbtData + szLen);
}