CRC-CCITT CRC-16

CRC分为以下几种标准：

• CRC-12码
• CRC-16码
• CRC-CCITT码
• CRC-32码

在线CRC计算器

https://www.lammertbies.nl/comm/info/crc-calculation.html



CRC计算器

http://www.pc6.com/softview/SoftView_100981.html



CRC16

const uint16_t Table[256] =
{
   0x0000U, 0x1021U, 0x2042U, 0x3063U, 0x4084U, 0x50A5U, 0x60C6U, 0x70E7U,
   0x8108U, 0x9129U, 0xA14AU, 0xB16BU, 0xC18CU, 0xD1ADU, 0xE1CEU, 0xF1EFU,
   0x1231U, 0x0210U, 0x3273U, 0x2252U, 0x52B5U, 0x4294U, 0x72F7U, 0x62D6U,
   0x9339U, 0x8318U, 0xB37BU, 0xA35AU, 0xD3BDU, 0xC39CU, 0xF3FFU, 0xE3DEU,
   0x2462U, 0x3443U, 0x0420U, 0x1401U, 0x64E6U, 0x74C7U, 0x44A4U, 0x5485U,
   0xA56AU, 0xB54BU, 0x8528U, 0x9509U, 0xE5EEU, 0xF5CFU, 0xC5ACU, 0xD58DU,
   0x3653U, 0x2672U, 0x1611U, 0x0630U, 0x76D7U, 0x66F6U, 0x5695U, 0x46B4U,
   0xB75BU, 0xA77AU, 0x9719U, 0x8738U, 0xF7DFU, 0xE7FEU, 0xD79DU, 0xC7BCU,
   0x48C4U, 0x58E5U, 0x6886U, 0x78A7U, 0x0840U, 0x1861U, 0x2802U, 0x3823U,
   0xC9CCU, 0xD9EDU, 0xE98EU, 0xF9AFU, 0x8948U, 0x9969U, 0xA90AU, 0xB92BU,
   0x5AF5U, 0x4AD4U, 0x7AB7U, 0x6A96U, 0x1A71U, 0x0A50U, 0x3A33U, 0x2A12U,
   0xDBFDU, 0xCBDCU, 0xFBBFU, 0xEB9EU, 0x9B79U, 0x8B58U, 0xBB3BU, 0xAB1AU,
   0x6CA6U, 0x7C87U, 0x4CE4U, 0x5CC5U, 0x2C22U, 0x3C03U, 0x0C60U, 0x1C41U,
   0xEDAEU, 0xFD8FU, 0xCDECU, 0xDDCDU, 0xAD2AU, 0xBD0BU, 0x8D68U, 0x9D49U,
   0x7E97U, 0x6EB6U, 0x5ED5U, 0x4EF4U, 0x3E13U, 0x2E32U, 0x1E51U, 0x0E70U,
   0xFF9FU, 0xEFBEU, 0xDFDDU, 0xCFFCU, 0xBF1BU, 0xAF3AU, 0x9F59U, 0x8F78U,
   0x9188U, 0x81A9U, 0xB1CAU, 0xA1EBU, 0xD10CU, 0xC12DU, 0xF14EU, 0xE16FU,
   0x1080U, 0x00A1U, 0x30C2U, 0x20E3U, 0x5004U, 0x4025U, 0x7046U, 0x6067U,
   0x83B9U, 0x9398U, 0xA3FBU, 0xB3DAU, 0xC33DU, 0xD31CU, 0xE37FU, 0xF35EU,
   0x02B1U, 0x1290U, 0x22F3U, 0x32D2U, 0x4235U, 0x5214U, 0x6277U, 0x7256U,
   0xB5EAU, 0xA5CBU, 0x95A8U, 0x8589U, 0xF56EU, 0xE54FU, 0xD52CU, 0xC50DU,
   0x34E2U, 0x24C3U, 0x14A0U, 0x0481U, 0x7466U, 0x6447U, 0x5424U, 0x4405U,
   0xA7DBU, 0xB7FAU, 0x8799U, 0x97B8U, 0xE75FU, 0xF77EU, 0xC71DU, 0xD73CU,
   0x26D3U, 0x36F2U, 0x0691U, 0x16B0U, 0x6657U, 0x7676U, 0x4615U, 0x5634U,
   0xD94CU, 0xC96DU, 0xF90EU, 0xE92FU, 0x99C8U, 0x89E9U, 0xB98AU, 0xA9ABU,
   0x5844U, 0x4865U, 0x7806U, 0x6827U, 0x18C0U, 0x08E1U, 0x3882U, 0x28A3U,
   0xCB7DU, 0xDB5CU, 0xEB3FU, 0xFB1EU, 0x8BF9U, 0x9BD8U, 0xABBBU, 0xBB9AU,
   0x4A75U, 0x5A54U, 0x6A37U, 0x7A16U, 0x0AF1U, 0x1AD0U, 0x2AB3U, 0x3A92U,
   0xFD2EU, 0xED0FU, 0xDD6CU, 0xCD4DU, 0xBDAAU, 0xAD8BU, 0x9DE8U, 0x8DC9U,
   0x7C26U, 0x6C07U, 0x5C64U, 0x4C45U, 0x3CA2U, 0x2C83U, 0x1CE0U, 0x0CC1U,
   0xEF1FU, 0xFF3EU, 0xCF5DU, 0xDF7CU, 0xAF9BU, 0xBFBAU, 0x8FD9U, 0x9FF8U,
   0x6E17U, 0x7E36U, 0x4E55U, 0x5E74U, 0x2E93U, 0x3EB2U, 0x0ED1U, 0x1EF0U
};

uint16_t add(const uint8_t *bytes, unsigned len)
{
   uint16_t value_ = 0xa635; //初始值，根据CRC类型设定

   while(len--)
   {
      value_ = ((value_ << 8) ^ Table[(uint16_t)((value_ >> 8) ^ *bytes) & 0xFFU]) & 0xFFFFU;

      bytes++;
   }

   return value_;
}

CRC32

static const uint32_t crc32_tab[] =
{
  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
  0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
  0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
  0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
  0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
  0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
  0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
  0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
  0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
  0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
  0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
  0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
  0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
  0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
  0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
  0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
  0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
  0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
  0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
  0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
  0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
  0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
  0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
  0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
  0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
  0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
  0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
  0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
  0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
  0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
  0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
  0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};

uint32_t crc32part(const uint8_t *src, size_t len, uint32_t crc32val)
{
    size_t i;

    for (i = 0;  i < len;  i++)
    {
        crc32val = crc32_tab[(crc32val ^ src[i]) & 0xff] ^ (crc32val >> 8);
    }

    return crc32val;
}