adbfb237c8cd3671dc26db260833af94c6188640
[proxmark3-svn] / common / crc.h
1 //-----------------------------------------------------------------------------
2 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
3 // at your option, any later version. See the LICENSE.txt file for the text of
4 // the license.
5 //-----------------------------------------------------------------------------
6 // Generic CRC calculation code.
7 //-----------------------------------------------------------------------------
8
9 #ifndef __CRC_H
10 #define __CRC_H
11
12 #include <stdint.h>
13 #include <stddef.h>
14
15 typedef struct crc {
16 uint32_t state;
17 int order;
18 uint32_t polynom;
19 uint32_t initial_value;
20 uint32_t final_xor;
21 uint32_t mask;
22 } crc_t;
23
24 /* Initialize a crc structure. order is the order of the polynom, e.g. 32 for a CRC-32
25 * polynom is the CRC polynom. initial_value is the initial value of a clean state.
26 * final_xor is XORed onto the state before returning it from crc_result(). */
27 extern void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor);
28
29 /* Update the crc state. data is the data of length data_width bits (only the the
30 * data_width lower-most bits are used).
31 */
32 extern void crc_update(crc_t *crc, uint32_t data, int data_width);
33
34 /* Clean the crc state, e.g. reset it to initial_value */
35 extern void crc_clear(crc_t *crc);
36
37 /* Get the result of the crc calculation */
38 extern uint32_t crc_finish(crc_t *crc);
39
40 // Calculate CRC-8/Maxim checksum
41 uint32_t CRC8Maxim(uint8_t *buff, size_t size );
42 /* Static initialization of a crc structure */
43 #define CRC_INITIALIZER(_order, _polynom, _initial_value, _final_xor) { \
44 .state = ((_initial_value) & ((1L<<(_order))-1)), \
45 .order = (_order), \
46 .polynom = (_polynom), \
47 .initial_value = (_initial_value), \
48 .final_xor = (_final_xor), \
49 .mask = ((1L<<(_order))-1) }
50
51 #endif /* __CRC_H */
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