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C語言實作SM4加解密

簡介:sm4也是一種對稱加密算法,使用16位元組秘鑰加解密16位元組資料。先生成32個32位子秘鑰,資料再配合秘鑰疊代計算資料32次,取最後四次生成的32位資料,倒序組合成128位結果。使用到3張表,系統參數表,固定參數表,和sbox表。128位秘鑰拆分成4段32位,分别異或4個系統參數得到k1到k4,k5到k6分别依賴前4組秘鑰使用固定算法所得.....  過程可根據代碼了解,流程比較簡單。

tables.h

#ifndef _SM4_H_
#define _SM4_H_

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

const unsigned long TBL_SYS_PARAMS[4] = {
    0xa3b1bac6,
    0x56aa3350,
    0x677d9197,
    0xb27022dc
};

const unsigned long TBL_FIX_PARAMS[32] = {
    0x00070e15,0x1c232a31,0x383f464d,0x545b6269,
    0x70777e85,0x8c939aa1,0xa8afb6bd,0xc4cbd2d9,
    0xe0e7eef5,0xfc030a11,0x181f262d,0x343b4249,
    0x50575e65,0x6c737a81,0x888f969d,0xa4abb2b9,
    0xc0c7ced5,0xdce3eaf1,0xf8ff060d,0x141b2229,
    0x30373e45,0x4c535a61,0x686f767d,0x848b9299,
    0xa0a7aeb5,0xbcc3cad1,0xd8dfe6ed,0xf4fb0209,
    0x10171e25,0x2c333a41,0x484f565d,0x646b7279
};

const unsigned char TBL_SBOX[256] = {
    0xd6,0x90,0xe9,0xfe,0xcc,0xe1,0x3d,0xb7,0x16,0xb6,0x14,0xc2,0x28,0xfb,0x2c,0x05,
    0x2b,0x67,0x9a,0x76,0x2a,0xbe,0x04,0xc3,0xaa,0x44,0x13,0x26,0x49,0x86,0x06,0x99,
    0x9c,0x42,0x50,0xf4,0x91,0xef,0x98,0x7a,0x33,0x54,0x0b,0x43,0xed,0xcf,0xac,0x62,
    0xe4,0xb3,0x1c,0xa9,0xc9,0x08,0xe8,0x95,0x80,0xdf,0x94,0xfa,0x75,0x8f,0x3f,0xa6,
    0x47,0x07,0xa7,0xfc,0xf3,0x73,0x17,0xba,0x83,0x59,0x3c,0x19,0xe6,0x85,0x4f,0xa8,
    0x68,0x6b,0x81,0xb2,0x71,0x64,0xda,0x8b,0xf8,0xeb,0x0f,0x4b,0x70,0x56,0x9d,0x35,
    0x1e,0x24,0x0e,0x5e,0x63,0x58,0xd1,0xa2,0x25,0x22,0x7c,0x3b,0x01,0x21,0x78,0x87,
    0xd4,0x00,0x46,0x57,0x9f,0xd3,0x27,0x52,0x4c,0x36,0x02,0xe7,0xa0,0xc4,0xc8,0x9e,
    0xea,0xbf,0x8a,0xd2,0x40,0xc7,0x38,0xb5,0xa3,0xf7,0xf2,0xce,0xf9,0x61,0x15,0xa1,
    0xe0,0xae,0x5d,0xa4,0x9b,0x34,0x1a,0x55,0xad,0x93,0x32,0x30,0xf5,0x8c,0xb1,0xe3,
    0x1d,0xf6,0xe2,0x2e,0x82,0x66,0xca,0x60,0xc0,0x29,0x23,0xab,0x0d,0x53,0x4e,0x6f,
    0xd5,0xdb,0x37,0x45,0xde,0xfd,0x8e,0x2f,0x03,0xff,0x6a,0x72,0x6d,0x6c,0x5b,0x51,
    0x8d,0x1b,0xaf,0x92,0xbb,0xdd,0xbc,0x7f,0x11,0xd9,0x5c,0x41,0x1f,0x10,0x5a,0xd8,
    0x0a,0xc1,0x31,0x88,0xa5,0xcd,0x7b,0xbd,0x2d,0x74,0xd0,0x12,0xb8,0xe5,0xb4,0xb0,
    0x89,0x69,0x97,0x4a,0x0c,0x96,0x77,0x7e,0x65,0xb9,0xf1,0x09,0xc5,0x6e,0xc6,0x84,
    0x18,0xf0,0x7d,0xec,0x3a,0xdc,0x4d,0x20,0x79,0xee,0x5f,0x3e,0xd7,0xcb,0x39,0x48
};


#endif
           

sm4_tool.c

#include "tables.h"

void four_uCh2uLong(unsigned char *in , unsigned long *out);
void uLong2four_uCh(unsigned long in , unsigned char *out);
unsigned long move(unsigned long data , int length);
unsigned long func_key(unsigned long input);
unsigned long func_data(unsigned long input);
int proc_enc_dec(char *type , unsigned char *key , unsigned char *input , unsigned char *output);
void print_hex(unsigned char *data , int len);
int hex_str2bytes(unsigned char *in ,  unsigned char *out , int *outLen);

//4位元組無符号數組轉無符号long型
void four_uCh2uLong(unsigned char *in , unsigned long *out)
{
    int i = 0;
    *out = 0;
    for(i = 0 ; i < 4 ; i++)
        *out = ((unsigned long)in[i] << (24-i*8)) ^ *out;
}

//無符号long型轉4位元組無符号數組
void uLong2four_uCh(unsigned long in , unsigned char *out)
{
    int i = 0;
    //從32位unsigned long的高位開始取
    for(i = 0 ; i < 4 ; i++)
        *(out+i) = (unsigned char )(in >> (24-i*8));
}

//左移,保留丢棄位放置尾部
unsigned long move(unsigned long data , int length)
{
    unsigned long result = 0;
    result = (data << length) ^ (data >> (32-length));

    return result;
}

//秘鑰處理函數
unsigned long func_key(unsigned long input)
{
    int i = 0;
    unsigned long ulTmp = 0;
    unsigned char ucIndexList[4] = {0};
    unsigned char ucSboxValueList[4] = {0};
    uLong2four_uCh(input , ucIndexList);
    for(i = 0 ; i < 4 ; i++)
    {
        ucSboxValueList[i] = TBL_SBOX[ucIndexList[i]];
    }
    four_uCh2uLong(ucSboxValueList , &ulTmp);
    ulTmp = ulTmp ^ move(ulTmp , 13) ^ move(ulTmp , 23);

    return ulTmp;
}

//加解密資料處理函數
unsigned long func_data(unsigned long input)
{
    int i = 0;
    unsigned long ulTmp = 0;
    unsigned char ucIndexList[4] = {0};
    unsigned char ucSboxValueList[4] = {0};
    uLong2four_uCh(input , ucIndexList);
    for(i = 0 ; i < 4 ; i++)
    {
        ucSboxValueList[i] = TBL_SBOX[ucIndexList[i]];
    }
    four_uCh2uLong(ucSboxValueList , &ulTmp);
    ulTmp = ulTmp ^ move(ulTmp , 2) ^ move(ulTmp , 10) ^ move(ulTmp , 18) ^ move(ulTmp , 24);

    return ulTmp;
}

//加解密函數
int proc_enc_dec(char *type , unsigned char *key , unsigned char *input , unsigned char *output)
{
    int i = 0;
    unsigned long ulKeyTmpList[4] = {0};
    unsigned long ulKeyList[36] = {0};
    unsigned long ulDataList[36] = {0};

    /*開始生成子秘鑰*/
    four_uCh2uLong(key , &(ulKeyTmpList[0]));
    four_uCh2uLong(key+4 , &(ulKeyTmpList[1]));
    four_uCh2uLong(key+8 , &(ulKeyTmpList[2]));
    four_uCh2uLong(key+12 , &(ulKeyTmpList[3]));

    ulKeyList[0] = ulKeyTmpList[0] ^ TBL_SYS_PARAMS[0];
    ulKeyList[1] = ulKeyTmpList[1] ^ TBL_SYS_PARAMS[1];
    ulKeyList[2] = ulKeyTmpList[2] ^ TBL_SYS_PARAMS[2];
    ulKeyList[3] = ulKeyTmpList[3] ^ TBL_SYS_PARAMS[3];
    
    for(i = 0 ; i < 32 ; i++)
    {
		//5-36為32個子秘鑰
        ulKeyList[i+4] = ulKeyList[i] ^ func_key(ulKeyList[i+1] ^ ulKeyList[i+2] ^ ulKeyList[i+3] ^ TBL_FIX_PARAMS[i]);
    }
    /*生成32輪32位長子秘鑰結束*/


    /*開始處理加解密資料*/
    four_uCh2uLong(input , &(ulDataList[0]));
    four_uCh2uLong(input+4 , &(ulDataList[1]));
    four_uCh2uLong(input+8 , &(ulDataList[2]));
    four_uCh2uLong(input+12 , &(ulDataList[3]));

    if(strcmp(type , "1") == 0)
    {
		//加密
        for(i = 0 ; i < 32 ; i++)
        {
            ulDataList[i+4] = ulDataList[i] ^ func_data(ulDataList[i+1] ^ ulDataList[i+2] ^ ulDataList[i+3] ^ ulKeyList[i+4]);
        }
    }
    else if(strcmp(type , "2") == 0)
    {
		//解密
        for(i = 0 ; i < 32 ; i++)
        {
            ulDataList[i+4] = ulDataList[i] ^ func_data(ulDataList[i+1] ^ ulDataList[i+2] ^ ulDataList[i+3] ^ ulKeyList[35-i]);
        }
    }

    uLong2four_uCh(ulDataList[35] , output);
    uLong2four_uCh(ulDataList[34] , output+4);
    uLong2four_uCh(ulDataList[33] , output+8);
    uLong2four_uCh(ulDataList[32] , output+12);

    return 0;
}

//無符号字元數組轉16進制列印
void print_hex(unsigned char *data , int len)
{
    int i = 0;
    char alTmp[16] = {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
    for(i = 0 ; i < len ; i++)
    {
        printf("%c" , alTmp[data[i]/16]);
        printf("%c" , alTmp[data[i]%16]);
//        putchar(' ');
    }
    putchar('\n');
}

//16進制數組轉無符号字元數組
int hex_str2bytes(unsigned char *in ,  unsigned char *out , int *outLen)
{
    int i = 0 , j = 0;
    int num = 0;
    int tmp = 0;
    for (i = 0 ; i < strlen((char *)in) ; i++)
    {
        if(in[i] < 58 && in[i] > 47) //0-9
            tmp = in[i]-48;
        else if(in[i] < 71 && in[i] > 64) //A-F
            tmp = 10+in[i]-65;
        else if(in[i] < 103 && in[i] > 96) //a-f
            tmp = 10+in[i]-97;
        else
        {
            printf("Invalid arg!\n");
            return -1;
        }

        if(i%2 == 0)
            num = tmp*16;
        else
        {
            num += tmp;
            out[j++] = num;
        }
    }
    *outLen = j;
    return 0;
}

int main(int argc , char **argv)
{
    unsigned char alResult[16] = {0};
    unsigned char alKey[16] = {0};
    int ilKeyLen = 0;
    unsigned char alData[16] = {0};
    int ilDataLen = 0;

    if(argc != 4 || strlen(argv[2]) != 32 || strlen(argv[3]) != 32 || 
        (strcmp(argv[1] , "1") != 0 && strcmp(argv[1] , "2") != 0) )
    {
        printf("Usage: ./sm4_tool  [1/2]  hex32_key  hex32_data\n1:encrypt , 2:decrypt\n");
        return -1;
    }
    
    if(hex_str2bytes((unsigned char *)argv[2] , alKey , &ilKeyLen))
        return -1;
    if(hex_str2bytes((unsigned char *)argv[3] , alData, &ilDataLen))
        return -1;

    proc_enc_dec(argv[1] , alKey , alData , alResult);
    print_hex(alResult , 16);

    return 0;
}
           

Makefile:

TARGET = sm4_tool
DEPEND = sm4_tool.o
CC = gcc -g -Wall
RM = rm -f

.c.o :
	$(CC) -c $^ -o [email protected]

$(TARGET) : $(DEPEND)
	$(CC) $^ -o [email protected]

.PHONY : clean
clean :
	$(RM) $(TARGET) *.o
           

這裡main函數參數隻針對16位元組秘鑰和16位元組資料測試用。

加密:./sm4_tool  1  0123456789abcdeffedcba9876543210  0123456789abcdeffedcba9876543210

結果:681edf34d206965e86b3e94f536e4246

解密:./sm4_tool  2  0123456789abcdeffedcba9876543210  681edf34d206965e86b3e94f536e4246

結果:0123456789abcdeffedcba9876543210

sm4