DES加密C语言实现源代码

void *memcpy( void *dest, const void *src, unsigned char count )

{

// ASSERT((dest != NULL)&&(src != NULL));

unsigned char *temp_dest = (unsigned char *)dest;

unsigned char *temp_src = (unsigned char *)src;

while(count--) // 不对是否存在重叠区域进行判断

{

*temp_dest++ = *temp_src++;

}

return dest;

}

unsigned char *memset(unsigned char *dst,unsigned char value,unsigned char count) {

unsigned char *start = dst;

while (count--)

*dst++ = value;

return(start);

}

// 初始置换表IP

unsigned char IP_Table[64] = { 57,49,41,33,25,17,9,1,

59,51,43,35,27,19,11,3,

61,53,45,37,29,21,13,5,

63,55,47,39,31,23,15,7,

56,48,40,32,24,16,8,0,

58,50,42,34,26,18,10,2,

60,52,44,36,28,20,12,4,

62,54,46,38,30,22,14,6};

//逆初始置换表IP^-1

unsigned char IP_1_Table[64] = {39,7,47,15,55,23,63,31,

38,6,46,14,54,22,62,30,

37,5,45,13,53,21,61,29,

36,4,44,12,52,20,60,28,

35,3,43,11,51,19,59,27,

34,2,42,10,50,18,58,26,

33,1,41,9,49,17,57,25,

32,0,40,8,48,16,56,24}; //扩充置换表E

unsigned char E_Table[48] = {31, 0, 1, 2, 3, 4,

3, 4, 5, 6, 7, 8,

7, 8,9,10,11,12,

11,12,13,14,15,16,

15,16,17,18,19,20,

19,20,21,22,23,24,

23,24,25,26,27,28,

27,28,29,30,31, 0};

//置换函数P

unsigned char P_Table[32] = {15,6,19,20,28,11,27,16,

0,14,22,25,4,17,30,9,

1,7,23,13,31,26,2,8,

18,12,29,5,21,10,3,24};

//S盒

unsigned char S[8][4][16] =// S1 {{{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}}, // S2

{{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}}, //S3

{{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}}, // S4

{{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}}, //S5

{{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}},

//S6

{{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}},

// S7

{{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}},

//S8

{{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}}};

//置换选择1

unsigned char PC_1[56] = {56,48,40,32,24,16,8,

0,57,49,41,33,25,17,

9,1,58,50,42,34,26,

18,10,2,59,51,43,35,

62,54,46,38,30,22,14,

6,61,53,45,37,29,21,

13,5,60,52,44,36,28,

20,12,4,27,19,11,3};

//置换选择2

unsigned char PC_2[48] = {13,16,10,23,0,4,2,27,

14,5,20,9,22,18,11,3,

25,7,15,6,26,19,12,1,

40,51,30,36,46,54,29,39,

50,44,32,46,43,48,38,55,

33,52,45,41,49,35,28,31};

// 对左移次数的规定

unsigned char MOVE_TIMES[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1}; //字节转换成二进制

unsigned char ByteToBit(unsigned char ch, unsigned char bit[8]) {

unsigned char cnt;

for(cnt = 0;cnt < 8; cnt++)

{

*(bit+cnt) = (ch>>cnt)&1;

}

return 0;

}

// 二进制转换成字节

unsigned char BitToByte(unsigned char bit[8],unsigned char *ch)

{

unsigned char cnt;

for(cnt = 0;cnt < 8; cnt++)

{

*ch |= *(bit + cnt)<

}

return 0;

}

// 将长度为8的字符串转为二进制位串

unsigned char Char8ToBit64(unsigned char ch[8],unsigned char bit[64])

{

unsigned char cnt;

for(cnt = 0; cnt < 8; cnt++)

{

ByteToBit(*(ch+cnt),bit+(cnt<<3));

}

return 0;

}

// 将二进制位串转为长度为8的字符串

unsigned char Bit64ToChar8(unsigned char bit[64],unsigned char ch[8])

{

unsigned char cnt;

memset(ch,0,8);

for(cnt = 0; cnt < 8; cnt++)

{

BitToByte(bit+(cnt<<3),ch+cnt);

}

return 0;

}

// 密钥置换1

unsigned char DES_PC1_Transform(unsigned char key[64], unsigned char tempbts[56]) {

unsigned char cnt;

for(cnt = 0; cnt < 56; cnt++)

{

tempbts[cnt] = key[PC_1[cnt]];

}

return 0;

}

//密钥置换2

unsigned char DES_PC2_Transform(unsigned char key[56], unsigned char tempbts[48]) {

unsigned char cnt;

for(cnt = 0; cnt < 48; cnt++)

{

tempbts[cnt] = key[PC_2[cnt]];

}

return 0;

}

//循环左移

unsigned char DES_ROL(unsigned char data[56], unsigned char time)

{

unsigned char temp[56];

//保存将要循环移动到右边的位

memcpy(temp,data,time);

memcpy(temp+time,data+28,time);

//前28位移动

memcpy(data,data+time,28-time);

memcpy(data+28-time,temp,time);

//后28位移动

memcpy(data+28,data+28+time,28-time);

memcpy(data+56-time,temp+time,time);

return 0;

}

//IP置换

unsigned char DES_IP_Transform(unsigned char data[64])

{

unsigned char cnt;

unsigned char temp[64];

for(cnt = 0; cnt < 64; cnt++)

{

temp[cnt] = data[IP_Table[cnt]];

}

memcpy(data,temp,64);

return 0;

}

// IP逆置换

unsigned char DES_IP_1_Transform(unsigned char data[64]) {

unsigned char cnt;

unsigned char temp[64];

for(cnt = 0; cnt < 64; cnt++)

{

temp[cnt] = data[IP_1_Table[cnt]];

}

memcpy(data,temp,64);

return 0;

}

//扩展置换

unsigned char DES_E_Transform(unsigned char data[48]) {

unsigned char cnt;

unsigned char temp[48];

for(cnt = 0; cnt < 48; cnt++)

{

temp[cnt] = data[E_Table[cnt]];

}

memcpy(data,temp,48);

return 0;

}

//P置换

unsigned char DES_P_Transform(unsigned char data[32]) {

unsigned char cnt;

unsigned char temp[32];

for(cnt = 0; cnt < 32; cnt++)

{

temp[cnt] = data[P_Table[cnt]];

}

memcpy(data,temp,32);

return 0;

}

// 异或

unsigned char DES_XOR(unsigned char R[48], unsigned char L[48] ,unsigned char count) {

unsigned char cnt;

for(cnt = 0; cnt < count; cnt++)

{

R[cnt] ^= L[cnt];

}

return 0;

}

// S盒置换

unsigned char DES_SBOX(unsigned char data[48])

{

unsigned char cnt;

unsigned char line,row,output;

unsigned char cur1,cur2;

for(cnt = 0; cnt < 8; cnt++)

{

cur1 = cnt*6;

cur2 = cnt<<2;

// 计算在S盒中的行与列

line = (data[cur1]<<1) + data[cur1+5];

row = (data[cur1+1]<<3) + (data[cur1+2]<<2)

+ (data[cur1+3]<<1) + data[cur1+4];

output = S[cnt][line][row];

// 化为2进制

data[cur2] = (output&0X08)>>3;

data[cur2+1] = (output&0X04)>>2;

data[cur2+2] = (output&0X02)>>1;

data[cur2+3] = output&0x01;

}

return 0;

}

//交换

unsigned char DES_Swap(unsigned char left[32], unsigned char right[32])

{

unsigned char temp[32];

memcpy(temp,left,32);

memcpy(left,right,32);

memcpy(right,temp,32);

return 0;

}

//生成子密钥

unsigned char DES_MakeSubKeys(unsigned char key[64],unsigned char subKeys[16][48])

{

unsigned char temp[56];

unsigned char cnt;

DES_PC1_Transform(key,temp);// PC1置换

for(cnt = 0; cnt < 16; cnt++) //16轮跌代，产生16个子密钥

{

DES_ROL(temp,MOVE_TIMES[cnt]);// 循环左移

DES_PC2_Transform(temp,subKeys[cnt]);//PC2置换，产生子密钥}

return 0;

}

//加密单个分组

unsigned char DES_EncryptBlock(unsigned char plainBlock[8], unsigned char subKeys[16][48], unsigned char cipherBlock[8])

{

unsigned char plainBits[64];

unsigned char copyRight[48];

unsigned char cnt;

Char8ToBit64(plainBlock,plainBits);

//初始置换（IP置换）

DES_IP_Transform(plainBits);

// 16轮迭代

for(cnt = 0; cnt < 16; cnt++)

{

memcpy(copyRight,plainBits+32,32);

DES_E_Transform(copyRight); // 将右半部分进行扩展置换，从32位扩

展到48位

DES_XOR(copyRight,subKeys[cnt],48); // 将右半部分与子密钥进行异或操作

DES_SBOX(copyRight); // 异或结果进入S盒，输出32位结果

DES_P_Transform(copyRight); // P置换

DES_XOR(plainBits,copyRight,32); //将明文左半部分与右半部分进行异或

if(cnt != 15)

{

DES_Swap(plainBits,plainBits+32);//最终完成左右部的交换

}

}

DES_IP_1_Transform(plainBits); //逆初始置换（IP^1置换）

Bit64ToChar8(plainBits,cipherBlock);

return 0;

}

// 解密单个分组

unsigned char DES_DecryptBlock(unsigned char cipherBlock[8], unsigned char subKeys[16][48],unsigned char plainBlock[8])

{

unsigned char cipherBits[64];

unsigned char copyRight[48];

short cnt;

Char8ToBit64(cipherBlock,cipherBits);

//初始置换（IP置换）

DES_IP_Transform(cipherBits);

// 16轮迭代

for(cnt = 15; cnt >= 0; cnt--)

{

memcpy(copyRight,cipherBits+32,32);

//将右半部分进行扩展置换，从32位扩展到48位

DES_E_Transform(copyRight);

// 将右半部分与子密钥进行异或操作

DES_XOR(copyRight,subKeys[cnt],48);

//异或结果进入S盒，输出32位结果

DES_SBOX(copyRight);

// P置换

DES_P_Transform(copyRight);

//将明文左半部分与右半部分进行异或

DES_XOR(cipherBits,copyRight,32);

if(cnt != 0)

{

// 最终完成左右部的交换

DES_Swap(cipherBits,cipherBits+32);

}

}

// 逆初始置换（IP^1置换）

DES_IP_1_Transform(cipherBits);

Bit64ToChar8(cipherBits,plainBlock);

return 0;

}

//加密文件

unsigned char DES_Encrypt(unsigned char *keyStr,unsigned char *plainFile,unsigned char *cipherFile)

{

unsigned char keyBlock[8],bKey[64],subKeys[16][48];

memcpy(keyBlock,keyStr,8); //设置密钥

Char8ToBit64(keyBlock,bKey); //将密钥转换为二进制流

DES_MakeSubKeys(bKey,subKeys); //生成子密钥

DES_EncryptBlock(plainFile,subKeys,cipherFile);

return 1;

}

//解密文件

unsigned char DES_Decrypt(unsigned char *keyStr,unsigned char *cipherFile,unsigned char *plainFile)

{

// unsigned char plainBlock[8],cipherBlock[8],

unsigned char bKey[64],keyBlock[8],subKeys[16][48];

memcpy(keyBlock,keyStr,8); //设置密钥

Char8ToBit64(keyBlock,bKey); //将密钥转换为二进制流

DES_MakeSubKeys(bKey,subKeys); //生成子密钥

DES_DecryptBlock(cipherFile,subKeys,plainFile);

return 1;

}

/****************************************************************************** *****************

* 作者：win2kddk

* 说明：3重DES是使用16字节密钥将8字节明文数据块进行3次DES加密和解密。******************************************************************************* ****************/

unsigned char DES_key[16];

void DEC3_Encrypt(unsigned char *in_buf, unsigned char *miwen)

{

unsigned char buf1[8],buf2[8];

DES_Encrypt(&DES_key[0],in_buf,buf1);

DES_Decrypt(&DES_key[8],buf1,buf2);

DES_Encrypt(&DES_key[0],buf2,miwen);

}

void DEC3_Decrypt(unsigned char *miwen, unsigned char *out_buf)

{

unsigned char buf1[8],buf2[8];

DES_Decrypt(&DES_key[0],miwen,buf1);

DES_Encrypt(&DES_key[8],buf1,buf2);

DES_Decrypt(&DES_key[0],buf2,out_buf);

}

void DES3_Test(void)

{

unsigned char in_buf[8] = "ABCDEFGH";

unsigned char miwen[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};

unsigned char out_buf[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};

memcpy(DES_key,"0123456789abcdef",16);//3DES的密钥是128位的，这里只是设置密钥的DEMO。

DEC3_Encrypt(in_buf,miwen); //3DES加密

DEC3_Decrypt(miwen,out_buf); //3DES解密

}