4轮des算法的差分分析的c语言代码

以下是一个基本的4轮DES算法的差分分析C语言代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* 4轮DES算法的S盒 */
int SBox[8][4][16] = {
    {
        {14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7},
        {0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8},
        {4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0},
        {15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13}
    },
    {
        {15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10},
        {3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5},
        {0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15},
        {13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9}
    },
    {
        {10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8},
        {13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1},
        {13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7},
        {1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12}
    },
    {
        {7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15},
        {13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9},
        {10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4},
        {3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14}
    },
    {
        {2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9},
        {14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6},
        {4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14},
        {11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3}
    },
    {
        {12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11},
        {10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8},
        {9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6},
        {4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13}
    },
    {
        {4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1},
        {13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6},
        {1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2},
        {6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12}
    },
    {
        {13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7},
        {1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2},
        {7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8},
        {2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11}
    }
};

/* 4轮DES算法的P盒 */
int PBox[32] = {16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10,
                2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25};

/* 差分分析函数 */
void differential_analysis(int diff_in, int diff_out, int keys[])
{
    int i, j;
    int count[64] = {0};  /* 统计每个密钥出现的次数 */

    /* 遍历所有可能的第1轮子密钥 */
    for (i = 0; i < 64; i++) {
        int key1 = i << 1;  /* 将6位密钥扩展为8位 */
        int key2 = key1 | (key1 >> 5);  /* 循环左移1位 */
        int subkey1 = key2 & 0x3f;  /* 取低6位作为第1轮子密钥 */
        int subkey2 = (key2 >> 6) & 0x3f;  /* 取高6位作为第2轮子密钥 */

        /* 遍历所有可能的第2轮子密钥 */
        for (j = 0; j < 64; j++) {
            int subkey3 = j & 0x3f;  /* 取低6位作为第3轮子密钥 */
            int subkey4 = (j >> 6) & 0x3f;  /* 取高6位作为第4轮子密钥 */

            int k;
            int cnt = 0;

            /* 遍历所有可能的64位密钥 */
            for (k = 0; k < 64; k++) {
                int key = k;

                /* 进行4轮加密 */
                key = (key ^ subkey1) & 0x3f;
                key = SBox[0][key >> 4][key & 0x0f];
                key = (key ^ subkey2) & 0x3f;
                key = SBox[1][key >> 4][key & 0x0f];
                key = (key ^ subkey3) & 0x3f;
                key = SBox[2][key >> 4][key & 0x0f];
                key = (key ^ subkey4) & 0x3f;
                key = SBox[3][key >> 4][key & 0x0f];
                key = (key << 1) | (key >> 5);
                key = key ^ subkey1;

                /* 判断差分是否满足要求 */
                if (((key ^ (key ^ diff_in)) & 0x3f) == diff_in) {
                    /* 进行P盒置换 */
                    int out = 0;
                    int x;
                    for (x = 0; x < 32; x++) {
                        out |= ((key >> (32 - PBox[x])) & 0x01) << (31 - x);
                    }

                    /* 统计密钥出现的次数 */
                    count[(out ^ (out ^ diff_out)) >> 26]++;
                    cnt++;
                }
            }

            /* 输出当前轮的结果 */
            printf("subkey1=%02x, subkey2=%02x, subkey3=%02x, subkey4=%02x, count=%d\n",
                   subkey1, subkey2, subkey3, subkey4, cnt);
        }
    }

    /* 输出结果 */
    printf("Key\tCount\n");
    for (i = 0; i < 64; i++) {
        printf("%02x\t%d\n", keys[i], count[i]);
    }
}

int main()
{
    int diff_in = 0x00000001;  /* 明文差分 */
    int diff_out = 0x08000000;  /* 密文差分 */
    int keys[64] = {0};  /* 所有可能的密钥 */

    int i;
    for (i = 0; i < 64; i++) {
        keys[i] = i;
    }

    differential_analysis(diff_in, diff_out, keys);

    return 0;
}

这个代码实现了4轮DES算法的差分分析，其中包含了S盒和P盒的定义。您可以根据需要修改输入输出差分和密钥长度，并根据需要输出统计结果。