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CRC32 calculation code written (or copied?) by me long ago, doing a backup here.
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#include <stdint.h> | |
#include <stdbool.h> | |
#include <stdlib.h> | |
#include <stdio.h> | |
const static uint32_t crc32_table[256] = | |
{ | |
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 | |
}; | |
typedef struct crc32_state_t | |
{ | |
uint32_t reg; | |
} crc32_state; | |
void crc32_init(crc32_state *s) | |
{ | |
s->reg = 0xFFFFFFFF; | |
} | |
void crc32_end(crc32_state *s) | |
{ | |
s->reg = ~(s->reg); | |
} | |
inline void crc32_step(crc32_state *s, uint8_t newByte) | |
{ | |
s->reg = crc32_table[(s->reg & 0xFF) ^ newByte] ^ (s->reg >> 8); | |
} | |
int32_t memcrc32(const void *begin, const void *end) | |
{ | |
uint8_t *p; | |
crc32_state s; | |
crc32_init(&s); | |
for(p = (uint8_t *)begin; p < (uint8_t *)end; ++p) | |
{ | |
crc32_step(&s, *p); | |
} | |
crc32_end(&s); | |
return s.reg; | |
} | |
int32_t strcrc32(const char *str) | |
{ | |
uint8_t *p; | |
crc32_state s; | |
crc32_init(&s); | |
for(p = (uint8_t *)str; *p != '\0'; ++p) | |
{ | |
crc32_step(&s, *p); | |
} | |
crc32_end(&s); | |
return s.reg; | |
} | |
int main(void) | |
{ | |
unsigned char raw[] = { 0x49, 0x48, 0x44, 0x52, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x80, 0x08, 0x02, 0x00, 0x00, 0x00 }; | |
printf("%x\n", memcrc32(raw, raw + sizeof(raw))); | |
return 0; | |
} |
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