proxmark3/common/crc16.h

//-----------------------------------------------------------------------------
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// CRC16
//-----------------------------------------------------------------------------
#ifndef __CRC16_H
#define __CRC16_H

#include <stdint.h>
#include <stdio.h>
#include "util.h"

#define CRC16_POLY_CCITT  0x1021
#define CRC16_POLY_LEGIC  0xc6c6 //0x6363
#define CRC16_POLY_DNP	  0x3d65

#define X25_CRC_CHECK		((uint16_t)(~0xF0B8 & 0xFFFF)) 	// use this for checking of a correct crc

typedef enum {
	CRC_NONE,
	CRC_14443_A,
	CRC_14443_B,
	CRC_15693,
	CRC_ICLASS,
	CRC_FELICA,
	CRC_LEGIC,
	CRC_CCITT,
	CRC_KERMIT,
} CrcType_t;

uint16_t update_crc16_ex( uint16_t crc, uint8_t c, uint16_t polynomial );
uint16_t update_crc16(uint16_t crc, uint8_t c);
uint16_t crc16(uint8_t const *message, size_t length, uint16_t remainder, uint16_t polynomial, bool refin, bool refout);

uint16_t crc(CrcType_t ct, const uint8_t *d, size_t n);
void compute_crc(CrcType_t ct, const uint8_t *d, size_t n, uint8_t *first, uint8_t *second);
bool check_crc(CrcType_t ct, const uint8_t *d, size_t n);

// Calculate CRC-16/CCITT-FALSE
uint16_t crc16_ccitt(uint8_t const *d, size_t n);

// Calculate CRC-16/KERMIT (FDX-B ISO11784/85)  LF
uint16_t crc16_kermit(uint8_t const *d, size_t n);

// Calculate CRC-16/XMODEM (FeliCa)
uint16_t crc16_xmodem(uint8_t const *d, size_t n);

// Calculate CRC-16/X25 (ISO15693, ISO14443 CRC-B,ISO/IEC 13239) 
uint16_t crc16_x25(uint8_t const *d, size_t n);

// Calculate CRC-16/CRC-A (ISO14443 CRC-A)
uint16_t crc16_a(uint8_t const *d, size_t n);

// Calculate CRC-16/iCLASS
uint16_t crc16_iclass(uint8_t const *d, size_t n);

// Calculate CRC-16/Legic
// the initial_value is based on the previous legic_Crc8 of the UID.
// ie:  uidcrc = 0x78  then initial_value == 0x7878
uint16_t crc16_legic(uint8_t const *d, size_t n, uint8_t uidcrc);

// table implementation
void init_table(CrcType_t crctype);
void reset_table(void);
void generate_table(uint16_t polynomial, bool refin);
uint16_t crc16_fast(uint8_t const *d, size_t n, uint16_t initval, bool refin, bool refout);

#endif