CRC-512算法输出64字节

1. 逐位计算法（最容易理解）

c 复制代码

#include <stdint.h>
#include <string.h>

// CRC-512 结果 = 64字节
typedef uint8_t crc512_t[64];

// 标准 CRC-512 多项式
static const uint8_t CRC512_POLY[64] = {
    0x02,0xDC,0x76,0x25,0x32,0x83,0x8E,0x69,
    0x84,0x22,0x3E,0xAC,0x3E,0x86,0x91,0x19,
    0x27,0x5C,0x59,0x4C,0xB7,0x61,0x0B,0x74,
    0xA9,0x4B,0x68,0xF4,0xF9,0xAE,0x81,0xA1,
    0x7E,0x16,0x8D,0xE1,0x4A,0x10,0xE8,0x1D,
    0x52,0x5D,0x27,0x9D,0x6B,0xB1,0x7F,0x12,
    0x74,0xFE,0x64,0x00,0x8F,0x3E,0x67,0xF9,
    0xF9,0xB6,0xE5,0x40,0xE1,0x44,0x17,0x05
};

// 工具：512位数左移1位
static void crc512_shift_left_1(uint8_t *crc) {
    int carry = 0;
    for (int i = 63; i >= 0; i--) {
        int new_carry = crc[i] >> 7;
        crc[i] = (crc[i] << 1) | carry;
        carry = new_carry;
    }
}

// 工具：512位异或
static void crc512_xor(uint8_t *a, const uint8_t *b) {
    for (int i = 0; i < 64; i++) a[i] ^= b[i];
}

// ==============================
// CRC-512 逐位计算法
// ==============================
void crc512_bitwise(crc512_t out, const uint8_t *data, size_t len) {
    // 初始化为 0
    memset(out, 0, 64);

    // 逐字节
    for (size_t i = 0; i < len; i++) {
        uint8_t b = data[i];

        // 逐位
        for (int bit = 7; bit >= 0; bit--) {
            int carry = !!(out[0] & 0x80); // 取最高位

            crc512_shift_left_1(out);

            if (b & (1 << bit))
                out[63] |= 1; // 当前位为1，移入CRC

            if (carry)
                crc512_xor(out, CRC512_POLY);
        }
    }
}

2. 查表法（高速工程版）

c 复制代码

// 256项表，每项64字节
static uint8_t crc512_table[256][64];

// 工具：左移8位
static void crc512_shift_left_8(uint8_t *crc) {
    for (int i = 0; i < 63; i++) crc[i] = crc[i+1];
    crc[63] = 0;
}

// 初始化表（必须调用一次）
void crc512_init_table(void) {
    for (int b = 0; b < 256; b++) {
        uint8_t rem[64] = {0};
        rem[0] = b;

        for (int i = 0; i < 8; i++) {
            int carry = !!(rem[0] & 0x80);
            crc512_shift_left_1(rem);
            if (carry) crc512_xor(rem, CRC512_POLY);
        }
        memcpy(crc512_table[b], rem, 64);
    }
}

// ==============================
// CRC-512 查表法（超快）
// ==============================
void crc512_lookup(crc512_t out, const uint8_t *data, size_t len) {
    memset(out, 0, 64);

    for (size_t i = 0; i < len; i++) {
        uint8_t index = out[0] ^ data[i];
        crc512_shift_left_8(out);
        crc512_xor(out, crc512_table[index]);
    }
}

3. 测试代码（验证）

c 复制代码

#include <stdio.h>

int main() {
    uint8_t test[] = "123456789";
    crc512_t result;

    // 方法1：逐位计算
    crc512_bitwise(result, test, 9);

    // 方法2：查表计算（先初始化）
    // crc512_init_table();
    // crc512_lookup(result, test, 9);

    printf("CRC-512 (64字节):\n");
    for (int i = 0; i < 64; i++) {
        printf("%02X ", result[i]);
        if ((i + 1) % 16 == 0) printf("\n");
    }
    return 0;
}