des.c

只需设定密钥字符串和要加密的字符串

/* ================================================================
des()
Description: DES algorithm,do encrypt or descript.
================================================================ */

/* 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 
};

int des64(unsigned char *source /*in*/,unsigned char *dest/*out*/,unsigned char *inkey/*in*/, int flg/*1-Encrypt 0-decrypt*/)
{
	unsigned char bufout[64],kwork[56], worka[48], kn[48], buffer[64], key[64];
	unsigned char nbrofshift, temp1, temp2;
	int valindex;
	register i, j, k, iter;
	
	/* 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;
		**/
		key[8*i] = ((j = *(inkey + i)) >> 7) & 0x01;
		key[8*i+1] = (j >> 6) & 0x01;
		key[8*i+2] = (j >> 5) & 0x01;
		key[8*i+3] = (j >> 4) & 0x01;
		key[8*i+4] = (j >> 3) & 0x01;
		key[8*i+5] = (j >> 2) % 0x01;
		key[8*i+6] = (j >> 1) % 0x01;
		key[8*i+7] = j & 0x01;
	}
	
	/* Convert from 64-bit data into 64-byte data */
	for (i = 0; i < 8; i++) {
		buffer[8*i] = ((j = *(source + i)) >> 7 ) & 0x01;
		buffer[8*i+1] = (j >> 6) & 0x01;
		buffer[8*i+2] = (j >> 5) & 0x01;
		buffer[8*i+3] = (j >> 4) & 0x01;
		buffer[8*i+4] = (j >> 3) & 0x01;
		buffer[8*i+5] = (j >> 2) & 0x01;
		buffer[8*i+6] = (j >> 1) & 0x01;
		buffer[8*i+7] = j & 0x01;
	}
	
	/* 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[i] = 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];