wsutil/crc8.c

   1 /* crc8.c
   2  * Implementation CRC-8 declarations and routines
   3  *
   4  * 2011 Roland Knall <rknall@gmail.com>
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * SPDX-License-Identifier: GPL-2.0-or-later
  11  */
  12
  13
  14 #include "config.h"
  15
  16 #include <wsutil/crc8.h>
  17
  18 /* @brief Precompiled table for CRC8 values for the polynom 0x2F */
  19 static const uint8_t crc8_precompiled_2F[256] =
  20 {
  21     0x00, 0x2F, 0x5E, 0x71, 0xBC, 0x93, 0xE2, 0xCD,
  22     0x57, 0x78, 0x09, 0x26, 0xEB, 0xC4, 0xB5, 0x9A,
  23     0xAE, 0x81, 0xF0, 0xDF, 0x12, 0x3D, 0x4C, 0x63,
  24     0xF9, 0xD6, 0xA7, 0x88, 0x45, 0x6A, 0x1B, 0x34,
  25     0x73, 0x5C, 0x2D, 0x02, 0xCF, 0xE0, 0x91, 0xBE,
  26     0x24, 0x0B, 0x7A, 0x55, 0x98, 0xB7, 0xC6, 0xE9,
  27     0xDD, 0xF2, 0x83, 0xAC, 0x61, 0x4E, 0x3F, 0x10,
  28     0x8A, 0xA5, 0xD4, 0xFB, 0x36, 0x19, 0x68, 0x47,
  29     0xE6, 0xC9, 0xB8, 0x97, 0x5A, 0x75, 0x04, 0x2B,
  30     0xB1, 0x9E, 0xEF, 0xC0, 0x0D, 0x22, 0x53, 0x7C,
  31     0x48, 0x67, 0x16, 0x39, 0xF4, 0xDB, 0xAA, 0x85,
  32     0x1F, 0x30, 0x41, 0x6E, 0xA3, 0x8C, 0xFD, 0xD2,
  33     0x95, 0xBA, 0xCB, 0xE4, 0x29, 0x06, 0x77, 0x58,
  34     0xC2, 0xED, 0x9C, 0xB3, 0x7E, 0x51, 0x20, 0x0F,
  35     0x3B, 0x14, 0x65, 0x4A, 0x87, 0xA8, 0xD9, 0xF6,
  36     0x6C, 0x43, 0x32, 0x1D, 0xD0, 0xFF, 0x8E, 0xA1,
  37     0xE3, 0xCC, 0xBD, 0x92, 0x5F, 0x70, 0x01, 0x2E,
  38     0xB4, 0x9B, 0xEA, 0xC5, 0x08, 0x27, 0x56, 0x79,
  39     0x4D, 0x62, 0x13, 0x3C, 0xF1, 0xDE, 0xAF, 0x80,
  40     0x1A, 0x35, 0x44, 0x6B, 0xA6, 0x89, 0xF8, 0xD7,
  41     0x90, 0xBF, 0xCE, 0xE1, 0x2C, 0x03, 0x72, 0x5D,
  42     0xC7, 0xE8, 0x99, 0xB6, 0x7B, 0x54, 0x25, 0x0A,
  43     0x3E, 0x11, 0x60, 0x4F, 0x82, 0xAD, 0xDC, 0xF3,
  44     0x69, 0x46, 0x37, 0x18, 0xD5, 0xFA, 0x8B, 0xA4,
  45     0x05, 0x2A, 0x5B, 0x74, 0xB9, 0x96, 0xE7, 0xC8,
  46     0x52, 0x7D, 0x0C, 0x23, 0xEE, 0xC1, 0xB0, 0x9F,
  47     0xAB, 0x84, 0xF5, 0xDA, 0x17, 0x38, 0x49, 0x66,
  48     0xFC, 0xD3, 0xA2, 0x8D, 0x40, 0x6F, 0x1E, 0x31,
  49     0x76, 0x59, 0x28, 0x07, 0xCA, 0xE5, 0x94, 0xBB,
  50     0x21, 0x0E, 0x7F, 0x50, 0x9D, 0xB2, 0xC3, 0xEC,
  51     0xD8, 0xF7, 0x86, 0xA9, 0x64, 0x4B, 0x3A, 0x15,
  52     0x8F, 0xA0, 0xD1, 0xFE, 0x33, 0x1C, 0x6D, 0x42
  53 };
  54
  55 /* @brief Precompiled table for CRC8 values for the polynom 0x37 */
  56 static const unsigned char crc8_precompiled_37[256] =
  57 {
  58     0x00, 0x37, 0x6e, 0x59, 0xdc, 0xeb, 0xb2, 0x85,
  59     0x8f, 0xb8, 0xe1, 0xd6, 0x53, 0x64, 0x3d, 0x0a,
  60     0x29, 0x1e, 0x47, 0x70, 0xf5, 0xc2, 0x9b, 0xac,
  61     0xa6, 0x91, 0xc8, 0xff, 0x7a, 0x4d, 0x14, 0x23,
  62     0x52, 0x65, 0x3c, 0x0b, 0x8e, 0xb9, 0xe0, 0xd7,
  63     0xdd, 0xea, 0xb3, 0x84, 0x01, 0x36, 0x6f, 0x58,
  64     0x7b, 0x4c, 0x15, 0x22, 0xa7, 0x90, 0xc9, 0xfe,
  65     0xf4, 0xc3, 0x9a, 0xad, 0x28, 0x1f, 0x46, 0x71,
  66     0xa4, 0x93, 0xca, 0xfd, 0x78, 0x4f, 0x16, 0x21,
  67     0x2b, 0x1c, 0x45, 0x72, 0xf7, 0xc0, 0x99, 0xae,
  68     0x8d, 0xba, 0xe3, 0xd4, 0x51, 0x66, 0x3f, 0x08,
  69     0x02, 0x35, 0x6c, 0x5b, 0xde, 0xe9, 0xb0, 0x87,
  70     0xf6, 0xc1, 0x98, 0xaf, 0x2a, 0x1d, 0x44, 0x73,
  71     0x79, 0x4e, 0x17, 0x20, 0xa5, 0x92, 0xcb, 0xfc,
  72     0xdf, 0xe8, 0xb1, 0x86, 0x03, 0x34, 0x6d, 0x5a,
  73     0x50, 0x67, 0x3e, 0x09, 0x8c, 0xbb, 0xe2, 0xd5,
  74     0x7f, 0x48, 0x11, 0x26, 0xa3, 0x94, 0xcd, 0xfa,
  75     0xf0, 0xc7, 0x9e, 0xa9, 0x2c, 0x1b, 0x42, 0x75,
  76     0x56, 0x61, 0x38, 0x0f, 0x8a, 0xbd, 0xe4, 0xd3,
  77     0xd9, 0xee, 0xb7, 0x80, 0x05, 0x32, 0x6b, 0x5c,
  78     0x2d, 0x1a, 0x43, 0x74, 0xf1, 0xc6, 0x9f, 0xa8,
  79     0xa2, 0x95, 0xcc, 0xfb, 0x7e, 0x49, 0x10, 0x27,
  80     0x04, 0x33, 0x6a, 0x5d, 0xd8, 0xef, 0xb6, 0x81,
  81     0x8b, 0xbc, 0xe5, 0xd2, 0x57, 0x60, 0x39, 0x0e,
  82     0xdb, 0xec, 0xb5, 0x82, 0x07, 0x30, 0x69, 0x5e,
  83     0x54, 0x63, 0x3a, 0x0d, 0x88, 0xbf, 0xe6, 0xd1,
  84     0xf2, 0xc5, 0x9c, 0xab, 0x2e, 0x19, 0x40, 0x77,
  85     0x7d, 0x4a, 0x13, 0x24, 0xa1, 0x96, 0xcf, 0xf8,
  86     0x89, 0xbe, 0xe7, 0xd0, 0x55, 0x62, 0x3b, 0x0c,
  87     0x06, 0x31, 0x68, 0x5f, 0xda, 0xed, 0xb4, 0x83,
  88     0xa0, 0x97, 0xce, 0xf9, 0x7c, 0x4b, 0x12, 0x25,
  89     0x2f, 0x18, 0x41, 0x76, 0xf3, 0xc4, 0x9d, 0xaa,
  90 };
  91
  92 /* @brief Precompiled table for CRC8 values for the polynom 0x3B */
  93 static const unsigned char crc8_precompiled_3b[256] =
  94 {
  95     0x00, 0x3b, 0x76, 0x4d, 0xec, 0xd7, 0x9a, 0xa1,
  96     0xe3, 0xd8, 0x95, 0xae, 0x0f, 0x34, 0x79, 0x42,
  97     0xfd, 0xc6, 0x8b, 0xb0, 0x11, 0x2a, 0x67, 0x5c,
  98     0x1e, 0x25, 0x68, 0x53, 0xf2, 0xc9, 0x84, 0xbf,
  99     0xc1, 0xfa, 0xb7, 0x8c, 0x2d, 0x16, 0x5b, 0x60,
 100     0x22, 0x19, 0x54, 0x6f, 0xce, 0xf5, 0xb8, 0x83,
 101     0x3c, 0x07, 0x4a, 0x71, 0xd0, 0xeb, 0xa6, 0x9d,
 102     0xdf, 0xe4, 0xa9, 0x92, 0x33, 0x08, 0x45, 0x7e,
 103     0xb9, 0x82, 0xcf, 0xf4, 0x55, 0x6e, 0x23, 0x18,
 104     0x5a, 0x61, 0x2c, 0x17, 0xb6, 0x8d, 0xc0, 0xfb,
 105     0x44, 0x7f, 0x32, 0x09, 0xa8, 0x93, 0xde, 0xe5,
 106     0xa7, 0x9c, 0xd1, 0xea, 0x4b, 0x70, 0x3d, 0x06,
 107     0x78, 0x43, 0x0e, 0x35, 0x94, 0xaf, 0xe2, 0xd9,
 108     0x9b, 0xa0, 0xed, 0xd6, 0x77, 0x4c, 0x01, 0x3a,
 109     0x85, 0xbe, 0xf3, 0xc8, 0x69, 0x52, 0x1f, 0x24,
 110     0x66, 0x5d, 0x10, 0x2b, 0x8a, 0xb1, 0xfc, 0xc7,
 111     0x49, 0x72, 0x3f, 0x04, 0xa5, 0x9e, 0xd3, 0xe8,
 112     0xaa, 0x91, 0xdc, 0xe7, 0x46, 0x7d, 0x30, 0x0b,
 113     0xb4, 0x8f, 0xc2, 0xf9, 0x58, 0x63, 0x2e, 0x15,
 114     0x57, 0x6c, 0x21, 0x1a, 0xbb, 0x80, 0xcd, 0xf6,
 115     0x88, 0xb3, 0xfe, 0xc5, 0x64, 0x5f, 0x12, 0x29,
 116     0x6b, 0x50, 0x1d, 0x26, 0x87, 0xbc, 0xf1, 0xca,
 117     0x75, 0x4e, 0x03, 0x38, 0x99, 0xa2, 0xef, 0xd4,
 118     0x96, 0xad, 0xe0, 0xdb, 0x7a, 0x41, 0x0c, 0x37,
 119     0xf0, 0xcb, 0x86, 0xbd, 0x1c, 0x27, 0x6a, 0x51,
 120     0x13, 0x28, 0x65, 0x5e, 0xff, 0xc4, 0x89, 0xb2,
 121     0x0d, 0x36, 0x7b, 0x40, 0xe1, 0xda, 0x97, 0xac,
 122     0xee, 0xd5, 0x98, 0xa3, 0x02, 0x39, 0x74, 0x4f,
 123     0x31, 0x0a, 0x47, 0x7c, 0xdd, 0xe6, 0xab, 0x90,
 124     0xd2, 0xe9, 0xa4, 0x9f, 0x3e, 0x05, 0x48, 0x73,
 125     0xcc, 0xf7, 0xba, 0x81, 0x20, 0x1b, 0x56, 0x6d,
 126     0x2f, 0x14, 0x59, 0x62, 0xc3, 0xf8, 0xb5, 0x8e,
 127 };
 128 /** Calculates a CRC8 checksum for the given buffer with the polynom
 129  *  stored in the crc_table
 130  * @param buf a pointer to a buffer of the given length
 131  * @param len the length of the given buffer
 132  * @param seed The seed to use.
 133  * @param crc_table a table storing 256 entries for crc8 checksums
 134  * @return the CRC8 checksum for the buffer
 135  */
 136 static uint8_t crc8_precompiled(const uint8_t *buf, uint32_t len, uint8_t seed, const uint8_t crc_table[])
 137 {
 138     uint8_t crc;
 139
 140     crc = seed;
 141     while(len-- > 0)
 142         crc = crc_table[(uint8_t)(*buf++) ^ crc];
 143
 144     return crc;
 145 }
 146
 147 /** Calculates a CRC8 checksum for the given buffer with the polynom
 148  *  0x2F using the precompiled CRC table
 149  * @param buf a pointer to a buffer of the given length
 150  * @param len the length of the given buffer
 151  * @param seed The seed to use.
 152  * @return the CRC8 checksum for the buffer
 153  */
 154 uint8_t crc8_0x2F(const uint8_t *buf, uint32_t len, uint8_t seed)
 155 {
 156     return crc8_precompiled(buf, len, seed, crc8_precompiled_2F);
 157 }
 158
 159 /** Calculates a CRC8 checksum for the given buffer with the polynom
 160  *  0x37 using the precompiled CRC table
 161  * @param buf a pointer to a buffer of the given length
 162  * @param len the length of the given buffer
 163  * @param seed The seed to use.
 164  * @return the CRC8 checksum for the buffer
 165  */
 166 uint8_t crc8_0x37(const uint8_t *buf, uint32_t len, uint8_t seed)
 167 {
 168     uint8_t crc = seed;
 169     while (len-- > 0)
 170     {
 171         crc = crc8_precompiled_37[(crc ^ *buf++)];
 172     }
 173     return (crc);
 174 }
 175
 176 /** Calculates a CRC8 checksum for the given buffer with the polynom
 177  *  0x3B using the precompiled CRC table
 178  * @param buf a pointer to a buffer of the given length
 179  * @param len the length of the given buffer
 180  * @param seed The seed to use.
 181  * @return the CRC8 checksum for the buffer
 182  */
 183 uint8_t crc8_0x3B(const uint8_t *buf, uint32_t len, uint8_t seed)
 184 {
 185     uint8_t crc = seed;
 186     while (len-- > 0)
 187     {
 188         crc = crc8_precompiled_3b[(crc ^ *buf++)];
 189     }
 190     return (crc);
 191 }
 192
 193 /*
 194  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 195  *
 196  * Local variables:
 197  * c-basic-offset: 4
 198  * tab-width: 8
 199  * indent-tabs-mode: nil
 200  * End:
 201  *
 202  * vi: set shiftwidth=4 tabstop=8 expandtab:
 203  * :indentSize=4:tabSize=8:noTabs=true:
 204  */