des.c

最传统得加密解密方法des,此源代码需在嵌入式linux下编译运行

/*=================================================================
此程序由张长青改写于2007年5月28日
并在windows,linux及嵌入式uclinux环境下编译通过
参考http://itedu.xuhy.com/中
IT学院 >> IT学院 >> 系统编程 >> VC语言 >> 经典算法 栏目中
关于des算法的讲解
=================================================================*/
#include <stdio.h>
#include <string.h>
/* ================================================================ 
void des(unsigned char *source,unsigned char * dest,unsigned char * inkey, int flg) 
参数说明：
source--原文数据缓冲区指针（8bytes）
dest  --密文数据缓冲区指针（8bytes）
inkey --加密密钥指针
flg   --加密解密标识（1为加密，0为解密）		  
================================================================ */ 
void des(unsigned char *source,unsigned char * dest,unsigned char * inkey, int flg) 
{ 
/*
buffer[64]：临时缓冲区
bufout[64]：存放转置后64位原文
kwork[56]：存放初始化64位密钥
worka[48]：存放右半部分48位数据
kn[48]：存放每一轮子密钥
*/
	unsigned char bufout[64], 
	kwork[56], worka[48], kn[48], buffer[64], key[64], 
	nbrofshift, temp1, temp2; 
	int valindex; 
	register i, j, k, iter; 

/* 初始化s盒矩阵 */ 
/* 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 }; 


/* 循环左移数组 */ 
	static unsigned char shift[16] = { 
	1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 }; 
/* Binary比对表 */ 
	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 }; 

/* 加密或解密算法入口 */ 
/* 64位密钥转换 */ 
	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; 
	} 

/* 64位密文转换 */ 
	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; 
	} 

/* 初始换位IP */ 
	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]; 

/* 经过PC-1去掉64位密钥奇偶效验位，产生56位密钥 */ 
	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次迭代过程 */ 
	for (iter = 1; iter < 17; iter++) { 
/* 将64位分为左右各32位 */
		for (i = 0; i < 32; i++) 
			buffer[i] = bufout[32+i]; 

/* 实现函数F(R, K) 32位输入，32位输出 */ 
/* 经过扩充函数E，通过循环抄录将8个4位二进制块扩充为8个6位二进制块 */ 
		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];