用C语言实现DES算法

用C语言实现DES算法

本DES算法，使用了效率很高的C完成。目前，国内知名企业的POS终端中，单DES算法，均是采用这个函数完成。函数经本站验证过，可以放心使用。

#include "stdafx.h"

int des(unsigned char *source,unsigned char * dest,unsigned char * inkey, int flg);

int _tmain(int argc, _TCHAR* argv[])

{

unsigned char s[65]="DES算法是这样工作的：如Mode为加密，则用Key 去把数据Data进行加abc";

unsigned char d[65]={0};

unsigned char k[11]="adsss";

unsigned char m[65]={0};

for(int i =0;i<8;i++)

{

des(&s[8*i],&d[8*i],k,0);

}

for(int i =0;i<8;i++)

{

des(&d[8*i],&m[8*i],k,1);

}

//des(s,d,k,0);

//des(d,m,k2,1);

//printf(d);

char i;

scanf("%c",&i);

return 0;

}

/* ============================================================

des()

Description: DES algorithm,do encript or descript.

============================================================ */

int des(unsigned char *source,unsigned char * dest,unsigned char * inkey, int flg)

{

unsigned char bufout[64],

kwork[56], worka[48], kn[48], buffer[64], key[64],

nbrofshift, temp1, temp2;

int valindex;

register i, j, k, iter;

/* INITIALIZE THE TABLES */

/* Table - s1 */

static unsigned char s1[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 };

/* Table - s2 */

static unsigned char s2[4][16] = {

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 };

/* Table - s3 */

static unsigned char s3[4][16] = {

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 };

/* Table - s4 */

static unsigned char s4[4][16] = {

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 };

/* Table - s5 */

static unsigned char s5[4][16] = {

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 };

/* Table - s6 */

static unsigned char s6[4][16] = {

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 };

/* Table - s7 */

static unsigned char s7[4][16] = {

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 };

/* Table - s8 */

static unsigned char s8[4][16] = {

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 };

/* Table - Shift */

static unsigned char shift[16] = {

1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 };

/* Table - Binary */

static unsigned char binary[64] = {

0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1,

0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1,

1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1,

1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1 };

/* MAIN PROCESS */

/* Convert from 64-bit key into 64-byte key */

for (i = 0; i < 8; i++) {

key[8*i] = ((j = *(inkey + i)) / 128) % 2;

key[8*i+1] = (j / 64) % 2;

key[8*i+2] = (j / 32) % 2;

key[8*i+3] = (j / 16) % 2;

key[8*i+4] = (j / 8) % 2;

key[8*i+5] = (j / 4) % 2;

key[8*i+6] = (j / 2) % 2;

key[8*i+7] = j % 2;

}

/* Convert from 64-bit data into 64-byte data */

for (i = 0; i < 8; i++) {

buffer[8*i] = ((j = *(source + i)) / 128) % 2;

buffer[8*i+1] = (j / 64) % 2;

buffer[8*i+2] = (j / 32) % 2;

buffer[8*i+3] = (j / 16) % 2;

buffer[8*i+4] = (j / 8) % 2;

buffer[8*i+5] = (j / 4) % 2;

buffer[8*i+6] = (j / 2) % 2;

buffer[8*i+7] = j % 2;

}

/* Initial Permutation of Data */

bufout[ 0] = buffer[57];

bufout[ 1] = buffer[49];

bufout[ 2] = buffer[41];

bufout[ 3] = buffer[33];

bufout[ 4] = buffer[25];

bufout[ 5] = buffer[17];

bufout[ 6] = buffer[ 9];

bufout[ 7] = buffer[ 1];

bufout[ 8] = buffer[59];

bufout[ 9] = buffer[51];

bufout[10] = buffer[43];

bufout[11] = buffer[35];

bufout[12] = buffer[27];

bufout[13] = buffer[19];

bufout[14] = buffer[11];

bufout[15] = buffer[ 3];

bufout[16] = buffer[61];

bufout[17] = buffer[53];

bufout[18] = buffer[45];

bufout[19] = buffer[37];

bufout[20] = buffer[29];

bufout[21] = buffer[21];

bufout[22] = buffer[13];

bufout[23] = buffer[ 5];

bufout[24] = buffer[63];

bufout[25] = buffer[55];

bufout[26] = buffer[47];

bufout[27] = buffer[39];

bufout[28] = buffer[31];

bufout[29] = buffer[23];

bufout[30] = buffer[15];

bufout[31] = buffer[ 7];

bufout[32] = buffer[56];

bufout[33] = buffer[48];

bufout[34] = buffer[40];

bufout[35] = buffer[32];

bufout[36] = buffer[24];

bufout[37] = buffer[16];

bufout[38] = buffer[ 8];

bufout[39] = buffer[ 0];

bufout[40] = buffer[58];

bufout[41] = buffer[50];

bufout[42] = buffer[42];

bufout[43] = buffer[34];

bufout[44] = buffer[26];

bufout[45] = buffer[18];

bufout[46] = buffer[10];

bufout[47] = buffer[ 2];

bufout[48] = buffer[60];

bufout[49] = buffer[52];

bufout[50] = buffer[44];

bufout[51] = buffer[36];

bufout[52] = buffer[28];

bufout[53] = buffer[20];

bufout[54] = buffer[12];

bufout[55] = buffer[ 4];

bufout[56] = buffer[62];

bufout[57] = buffer[54];

bufout[58] = buffer[46];

bufout[59] = buffer[38];

bufout[60] = buffer[30];

bufout[61] = buffer[22];

bufout[62] = buffer[14];

bufout[63] = buffer[ 6];

/* Initial Permutation of Key */

kwork[ 0] = key[56];

kwork[ 1] = key[48];

kwork[ 2] = key[40];

kwork[ 3] = key[32];

kwork[ 4] = key[24];

kwork[ 5] = key[16];

kwork[ 6] = key[ 8];

kwork[ 7] = key[ 0];

kwork[ 8] = key[57];

kwork[ 9] = key[49];

kwork[10] = key[41];

kwork[11] = key[33];

kwork[12] = key[25];

kwork[13] = key[17];

kwork[14] = key[ 9];

kwork[15] = key[ 1];

kwork[16] = key[58];

kwork[17] = key[50];

kwork[18] = key[42];

kwork[19] = key[34];

kwork[20] = key[26];

kwork[21] = key[18];

kwork[22] = key[10];

kwork[23] = key[ 2];

kwork[24] = key[59];

kwork[25] = key[51];

kwork[26] = key[43];

kwork[27] = key[35];

kwork[28] = key[62];

kwork[29] = key[54];

kwork[30] = key[46];

kwork[31] = key[38];

kwork[32] = key[30];

kwork[33] = key[22];

kwork[34] = key[14];

kwork[35] = key[ 6];

kwork[36] = key[61];

kwork[37] = key[53];

kwork[38] = key[45];

kwork[39] = key[37];

kwork[40] = key[29];

kwork[41] = key[21];

kwork[42] = key[13];

kwork[43] = key[ 5];

kwork[44] = key[60];

kwork[45] = key[52];

kwork[46] = key[44];

kwork[47] = key[36];

kwork[48] = key[28];

kwork[49] = key[20];

kwork[50] = key[12];

kwork[51] = key[ 4];

kwork[52] = key[27];

kwork[53] = key[19];

kwork[54] = key[11];

kwork[55] = key[ 3];

/* 16 Iterations */

for (iter = 1; iter < 17; iter++) {

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

{

buffer= bufout[32+i];

}

/* Calculation of F(R, K) */

/* Permute - E */

worka[ 0] = buffer[31];

worka[ 1] = buffer[ 0];

worka[ 2] = buffer[ 1];

worka[ 3] = buffer[ 2];

worka[ 4] = buffer[ 3];

worka[ 5] = buffer[ 4];

worka[ 6] = buffer[ 3];

worka[ 7] = buffer[ 4];

worka[ 8] = buffer[ 5];

worka[ 9] = buffer[ 6];

worka[10] = buffer[ 7];

worka[11] = buffer[ 8];

worka[12] = buffer[ 7];

worka[13] = buffer[ 8];

worka[14] = buffer[ 9];

worka[15] = buffer[10];

worka[16] = buffer[11];

worka[17] = buffer[12];

worka[18] = buffer[11];

worka[19] = buffer[12];

worka[20] = buffer[13];

worka[21] = buffer[14];

worka[22] = buffer[15];

worka[23] = buffer[16];

worka[24] = buffer[15];

worka[25] = buffer[16];

worka[26] = buffer[17];

worka[27] = buffer[18];

worka[28] = buffer[19];

worka[29] = buffer[20];

worka[30] = buffer[19];

worka[31] = buffer[20];

worka[32] = buffer[21];

worka[33] = buffer[22];

worka[34] = buffer[23];

worka[35] = buffer[24];

worka[36] = buffer[23];

worka[37] = buffer[24];

worka[38] = buffer[25];

worka[39] = buffer[26];

worka[40] = buffer[27];

worka[41] = buffer[28];

worka[42] = buffer[27];

worka[43] = buffer[28];

worka[44] = buffer[29];

worka[45] = buffer[30];

worka[46] = buffer[31];

worka[47] = buffer[ 0];

/* KS Function Begin */

if (flg) {

nbrofshift = shift[iter-1];

for (i = 0; i < (int) nbrofshift; i++) {

temp1 = kwork[0];

temp2 = kwork[28];

for (j = 0; j < 27; j++) {

kwork[j] = kwork[j+1];

kwork[j+28] = kwork[j+29];

}

kwork[27] = temp1;

kwork[55] = temp2;

}

} else if (iter > 1) {

nbrofshift = shift[17-iter];

for (i = 0; i < (int) nbrofshift; i++) {

temp1 = kwork[27];

temp2 = kwork[55];

for (j = 27; j > 0; j--) {

kwork[j] = kwork[j-1];

kwork[j+28] = kwork[j+27];

}

kwork[0] = temp1;

kwork[28] = temp2;

}

}

/* Permute kwork - PC2 */

kn[ 0] = kwork[13];

kn[ 1] = kwork[16];

kn[ 2] = kwork[10];

kn[ 3] = kwork[23];

kn[ 4] = kwork[ 0];

kn[ 5] = kwork[ 4];

kn[ 6] = kwork[ 2];

kn[ 7] = kwork[27];

kn[ 8] = kwork[14];

kn[ 9] = kwork[ 5];

kn[10] = kwork[20];

kn[11] = kwork[ 9];

kn[12] = kwork[22];

kn[13] = kwork[18];

kn[14] = kwork[11];

kn[15] = kwork[ 3];

kn[16] = kwork[25];

kn[17] = kwork[ 7];

kn[18] = kwork[15];

kn[19] = kwork[ 6];

kn[20] = kwork[26];

kn[21] = kwork[19];

kn[22] = kwork[12];

kn[23] = kwork[ 1];

kn[24] = kwork[40];

kn[25] = kwork[51];

kn[26] = kwork[30];

kn[27] = kwork[36];

kn[28] = kwork[46];

kn[29] = kwork[54];

kn[30] = kwork[29];

kn[31] = kwork[39];

kn[32] = kwork[50];

kn[33] = kwork[44];

kn[34] = kwork[32];

kn[35] = kwork[47];

kn[36] = kwork[43];

kn[37] = kwork[48];

kn[38] = kwork[38];

kn[39] = kwork[55];

kn[40] = kwork[33];

kn[41] = kwork[52];

kn[42] = kwork[45];

kn[43] = kwork[41];

kn[44] = kwork[49];

kn[45] = kwork[35];

kn[46] = kwork[28];

kn[47] = kwork[31];

/* KS Function End */

/* worka XOR kn */

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

worka= worka^ kn;

/* 8 s-functions */

valindex = s1[2*worka[ 0]+worka[ 5]]

[2*(2*(2*worka[ 1]+worka[ 2])+

worka[ 3])+worka[ 4]];

valindex = valindex * 4;

kn[ 0] = binary[0+valindex];

kn[ 1] = binary[1+valindex];

kn[ 2] = binary[2+valindex];

kn[ 3] = binary[3+valindex];

valindex = s2[2*worka[ 6]+worka[11]]

[2*(2*(2*worka[ 7]+worka[ 8])+

worka[ 9])+worka[10]];

valindex = valindex * 4;

kn[ 4] = binary[0+valindex];

kn[ 5] = binary[1+valindex];

kn[ 6] = binary[2+valindex];

kn[ 7] = binary[3+valindex];

valindex = s3[2*worka[12]+worka[17]]

[2*(2*(2*worka[13]+worka[14])+

worka[15])+worka[16]];

valindex = valindex * 4;

kn[ 8] = binary[0+valindex];

kn[ 9] = binary[1+valindex];

kn[10] = binary[2+valindex];

kn[11] = binary[3+valindex];

valindex = s4[2*worka[18]+worka[23]]

[2*(2*(2*worka[19]+worka[20])+

worka[21])+worka[22]];

valindex = valindex * 4;

kn[12] = binary[0+valindex];

kn[13] = binary[1+valindex];

kn[14] = binary[2+valindex];

kn[15] = binary[3+valindex];

valindex = s5[2*worka[24]+worka[29]]

[2*(2*(2*worka[25]+worka[26])+

worka[27])+worka[28]];

valindex = valindex * 4;

kn[16] = binary[0+valindex];

kn[17] = binary[1+valindex];

kn[18] = binary[2+valindex];

kn[19] = binary[3+valindex];

valindex = s6[2*worka[30]+worka[35]]

[2*(2*(2*worka[31]+worka[32])+

worka[33])+worka[34]];

valindex = valindex * 4;

kn[20] = binary[0+valindex];

kn[21] = binary[1+valindex];

kn[22] = binary[2+valindex];

kn[23] = binary[3+valindex];

valindex = s7[2*worka[36]+worka[41]]

[2*(2*(2*worka[37]+worka[38])+

worka[39])+worka[40]];

valindex = valindex * 4;

kn[24] = binary[0+valindex];

kn[25] = binary[1+valindex];

kn[26] = binary[2+valindex];

kn[27] = binary[3+valindex];

valindex = s8[2*worka[42]+worka[47]]

[2*(2*(2*worka[43]+worka[44])+

worka[45])+worka[46]];

valindex = valindex * 4;

kn[28] = binary[0+valindex];

kn[29] = binary[1+valindex];

kn[30] = binary[2+valindex];

kn[31] = binary[3+valindex];

/* Permute - P */

worka[ 0] = kn[15];

worka[ 1] = kn[ 6];

worka[ 2] = kn[19];

worka[ 3] = kn[20];

worka[ 4] = kn[28];

worka[ 5] = kn[11];

worka[ 6] = kn[27];

worka[ 7] = kn[16];

worka[ 8] = kn[ 0];

worka[ 9] = kn[14];

worka[10] = kn[22];

worka[11] = kn[25];

worka[12] = kn[ 4];

worka[13] = kn[17];

worka[14] = kn[30];

worka[15] = kn[ 9];

worka[16] = kn[ 1];

worka[17] = kn[ 7];

worka[18] = kn[23];

worka[19] = kn[13];

worka[20] = kn[31];

worka[21] = kn[26];

worka[22] = kn[ 2];

worka[23] = kn[ 8];

worka[24] = kn[18];

worka[25] = kn[12];

worka[26] = kn[29];

worka[27] = kn[ 5];

worka[28] = kn[21];

worka[29] = kn[10];

worka[30] = kn[ 3];

worka[31] = kn[24];

/* bufout XOR worka */

for (i = 0; i < 32; i++) {

bufout[i+32] = bufout^ worka;

bufout= buffer;

}

} /* End of Iter */

/* Prepare Output */

for (i = 0; i < 32; i++) {

j = bufout;

bufout= bufout[32+i];

bufout[32+i] = j;

}

/* Inverse Initial Permutation */

buffer[ 0] = bufout[39];

buffer[ 1] = bufout[ 7];

buffer[ 2] = bufout[47];

buffer[ 3] = bufout[15];

buffer[ 4] = bufout[55];

buffer[ 5] = bufout[23];

buffer[ 6] = bufout[63];

buffer[ 7] = bufout[31];

buffer[ 8] = bufout[38];

buffer[ 9] = bufout[ 6];

buffer[10] = bufout[46];

buffer[11] = bufout[14];

buffer[12] = bufout[54];

buffer[13] = bufout[22];

buffer[14] = bufout[62];

buffer[15] = bufout[30];

buffer[16] = bufout[37];

buffer[17] = bufout[ 5];

buffer[18] = bufout[45];

buffer[19] = bufout[13];

buffer[20] = bufout[53];

buffer[21] = bufout[21];

buffer[22] = bufout[61];

buffer[23] = bufout[29];

buffer[24] = bufout[36];

buffer[25] = bufout[ 4];

buffer[26] = bufout[44];

buffer[27] = bufout[12];

buffer[28] = bufout[52];

buffer[29] = bufout[20];

buffer[30] = bufout[60];

buffer[31] = bufout[28];

buffer[32] = bufout[35];

buffer[33] = bufout[ 3];

buffer[34] = bufout[43];

buffer[35] = bufout[11];

buffer[36] = bufout[51];

buffer[37] = bufout[19];

buffer[38] = bufout[59];

buffer[39] = bufout[27];

buffer[40] = bufout[34];

buffer[41] = bufout[ 2];

buffer[42] = bufout[42];

buffer[43] = bufout[10];

buffer[44] = bufout[50];

buffer[45] = bufout[18];

buffer[46] = bufout[58];

buffer[47] = bufout[26];

buffer[48] = bufout[33];

buffer[49] = bufout[ 1];

buffer[50] = bufout[41];

buffer[51] = bufout[ 9];

buffer[52] = bufout[49];

buffer[53] = bufout[17];

buffer[54] = bufout[57];

buffer[55] = bufout[25];

buffer[56] = bufout[32];

buffer[57] = bufout[ 0];

buffer[58] = bufout[40];

buffer[59] = bufout[ 8];

buffer[60] = bufout[48];

buffer[61] = bufout[16];

buffer[62] = bufout[56];

buffer[63] = bufout[24];

j = 0;

for (i = 0; i < 8; i++) {

*(dest + i) = 0x00;

for (k = 0; k < 7; k++)

*(dest + i) = ((*(dest + i)) + buffer[j+k]) * 2;

*(dest + i) = *(dest + i) + buffer[j+7];

j += 8;

}

return 0;

}