https://github.com/kubo/snzip/issues/25

crc32_test.c

/*
 * Copy this file to the root directory of snzip source tree and compile it as follows:
 *
 *   gcc -o crc32_test crc32_test.c crc32.c crc32_sse4_2.c -msse4.2
 */
#include <stdio.h>
#include "crc32.h"

/* See https://tools.ietf.org/html/rfc3720#appendix-B.4 */
typedef struct {
    const char *name;
    size_t data_len;
    const unsigned char *data;
    union {
        unsigned char crc_bytes[4];
        unsigned int crc;
    };
} crc_data_t;

static const crc_data_t crc_data[] = {
    {"32 bytes of zeroes",
     32,
     "\x00\x00\x00\x00"
     "\x00\x00\x00\x00"
     "\x00\x00\x00\x00"
     "\x00\x00\x00\x00"
     "\x00\x00\x00\x00"
     "\x00\x00\x00\x00"
     "\x00\x00\x00\x00"
     "\x00\x00\x00\x00",
     "\xaa\x36\x91\x8a"},
    {"32 bytes of ones",
     32,
     "\xff\xff\xff\xff"
     "\xff\xff\xff\xff"
     "\xff\xff\xff\xff"
     "\xff\xff\xff\xff"
     "\xff\xff\xff\xff"
     "\xff\xff\xff\xff"
     "\xff\xff\xff\xff"
     "\xff\xff\xff\xff",
     "\x43\xab\xa8\x62"},
    {"32 bytes of incrementing 00..1f",
     32,
     "\x00\x01\x02\x03"
     "\x04\x05\x06\x07"
     "\x08\x09\x0a\x0b"
     "\x0c\x0d\x0e\x0f"
     "\x10\x11\x12\x13"
     "\x14\x15\x16\x17"
     "\x18\x19\x1a\x1b"
     "\x1c\x1d\x1e\x1f",
     "\x4e\x79\xdd\x46"},
    {"32 bytes of decrementing 1f..00",
     32,
     "\x1f\x1e\x1d\x1c"
     "\x1b\x1a\x19\x18"
     "\x17\x16\x15\x14"
     "\x13\x12\x11\x10"
     "\x0f\x0e\x0d\x0c"
     "\x0b\x0a\x09\x08"
     "\x07\x06\x05\x04"
     "\x03\x02\x01\x00",
     "\x5c\xdb\x3f\x11"},
    {"An iSCSI - SCSI Read (10) Command PDU",
     48,
     "\x01\xc0\x00\x00"
     "\x00\x00\x00\x00"
     "\x00\x00\x00\x00"
     "\x00\x00\x00\x00"
     "\x14\x00\x00\x00"
     "\x00\x00\x04\x00"
     "\x00\x00\x00\x14"
     "\x00\x00\x00\x18"
     "\x28\x00\x00\x00"
     "\x00\x00\x00\x00"
     "\x02\x00\x00\x00"
     "\x00\x00\x00\x00",
     "\x56\x3a\x96\xd9"},
};
#define NUM_CRC_DATA (sizeof(crc_data)/sizeof(crc_data[0]))

int main()
{
    int i;
    for (i = 0; i < NUM_CRC_DATA; i++) {
        unsigned int crc = ~calculate_crc32c(~0, crc_data[i].data, crc_data[i].data_len);
        if (crc_data[i].crc == crc) {
            printf("%s: OK\n", crc_data[i].name);
        } else {
            printf("%s: expect 0x%x but 0x%x\n", crc_data[i].name, crc_data[i].crc, crc);
        }
    }
    return 0;
}