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[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 "common.h" //stdint, stddef, stdbool
13 #include "util.h" // reflect, bswap_16
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 int topbit;
23 bool refin; /* Parameter: Reflect input bytes? */
24 bool refout; /* Parameter: Reflect output CRC? */
25 } crc_t;
26
27 /* Initialize a crc structure. order is the order of the polynom, e.g. 32 for a CRC-32
28 * polynom is the CRC polynom. initial_value is the initial value of a clean state.
29 * final_xor is XORed onto the state before returning it from crc_result().
30 * refin is the setting for reversing (bitwise) the bytes during crc
31 * refot is the setting for reversing (bitwise) the crc byte before returning it.
32 */
33 extern void crc_init_ref(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor, bool refin, bool refout);
34
35 /* Initialize a crc structure. order is the order of the polynom, e.g. 32 for a CRC-32
36 * polynom is the CRC polynom. initial_value is the initial value of a clean state.
37 * final_xor is XORed onto the state before returning it from crc_result(). */
38 extern void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor);
39
40
41 /* Update the crc state. data is the data of length data_width bits (only the
42 * data_width lower-most bits are used).
43 */
44 extern void crc_update(crc_t *crc, uint32_t data, int data_width);
45 extern void crc_update2(crc_t *crc, uint32_t data, int data_width);
46
47 /* Clean the crc state, e.g. reset it to initial_value */
48 extern void crc_clear(crc_t *crc);
49
50 /* Get the result of the crc calculation */
51 extern uint32_t crc_finish(crc_t *crc);
52
53 // Calculate CRC-8/Maxim checksum
54 uint32_t CRC8Maxim(uint8_t *buff, size_t size);
55
56 // Calculate CRC-4/Legic checksum
57 uint32_t CRC4Legic(uint8_t *buff, size_t size);
58
59 // Calculate CRC-8/Legic checksum
60 uint32_t CRC8Legic(uint8_t *buff, size_t size);
61
62 // Calculate CRC-16/Legic checksum
63 // the initial_value is based on the previous legic_Crc8 of the UID.
64 // ie: uidcrc = 0x78 then initial_value == 0x7878
65 uint32_t CRC16Legic(uint8_t *buff, size_t size, uint8_t uidcrc);
66
67 // test crc 16.
68 uint32_t CRC16_DNP(uint8_t *buff, size_t size);
69 uint32_t CRC16_CCITT(uint8_t *buff, size_t size);
70 uint32_t CRC16_Iso15693(uint8_t *buff, size_t size);
71 uint32_t CRC16_ICLASS(uint8_t *buff, size_t size);
72
73 /* Static initialization of a crc structure */
74 #define CRC_INITIALIZER(_order, _polynom, _initial_value, _final_xor) { \
75 .state = ((_initial_value) & ((1L<<(_order))-1)), \
76 .order = (_order), \
77 .polynom = (_polynom), \
78 .initial_value = (_initial_value), \
79 .final_xor = (_final_xor), \
80 .mask = ((1L<<(_order))-1) \
81 .refin = FALSE, \
82 .refout = FALSE \
83 }
84
85 #endif /* __CRC_H */
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