des加密.c

DES加密算法模块

/*=================================*
 *         DES加密模块             *
 *                                 *
 *  其中crypt()函数描述的DES算法   *
 *  取自GNU/Linux中加密的源码      *
 *                                 *
 *  desplus()函数用于对长于8位     *
 *  的密码进行循环DES加密          *
 *=================================*/

#include<string.h>

static const char IP[]={58, 50, 42, 34, 26, 18, 10, 2,60, 52, 44, 36, 28, 20, 12, 4,62, 54, 46, 38, 30, 22, 14, 6,64, 56, 48, 40, 32, 24, 16, 8,57, 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,};
static const char FP[]={40, 8, 48, 16, 56, 24, 64, 32,39, 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,};
static const char PC1_C[]={57, 49, 41, 33, 25, 17,  9,1, 58, 50, 42, 34, 26, 18,10,  2, 59, 51, 43, 35, 27,19, 11,  3, 60, 52, 44, 36,};
static const char PC1_D[]={63, 55, 47, 39, 31, 23, 15,7, 62, 54, 46, 38, 30, 22,14,  6, 61, 53, 45, 37, 29,21, 13,  5, 28, 20, 12,  4,};
static const char shifts[]={1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1};
static const char PC2_C[]={14, 17, 11, 24,  1,  5,3, 28, 15,  6, 21, 10,23, 19, 12,  4, 26,  8,16,  7, 27, 20, 13,  2,};
static const char PC2_D[]={41, 52, 31, 37, 47, 55,30, 40, 51, 45, 33, 48,44, 49, 39, 56, 34, 53,46, 42, 50, 36, 29, 32,};
static char C[28];
static char D[28];
static char KS[16][48];
static char E[48];
static const char e2[]={32,  1,  2,  3,  4,  5, 4,  5,  6,  7,  8,  9,8,  9, 10, 11, 12, 13,12, 13, 14, 15, 16, 17,16, 17, 18, 19, 20, 21,20, 21, 22, 23, 24, 25, 24, 25, 26, 27, 28, 29,28, 29, 30, 31, 32,  1,};
void setkey(char *key)
{
	int i, j, k, temp;
	for(i = 0; i < 28; i++)
	{
		C[i] = key[PC1_C[i] - 1];
		D[i] = key[PC1_D[i] - 1];
	}
	for(i = 0; i < 16; i++)
	{
		for(k = 0; k < shifts[i]; k++)
		{
			temp = C[0];
			for(j = 0; j < 28 - 1; j++)
				C[j] = C[j+1];
			C[27] = temp;
			temp = D[0];
			for(j = 0; j < 28 - 1; j++)
				D[j] = D[j+1];
			D[27] = temp;
        	}
		for(j = 0; j < 24; j++)
		{
			KS[i][j] = C[PC2_C[j] - 1];
			KS[i][j + 24] = D[PC2_D[j] - 28 -1];
		}
	}
	for(i=0; i < 48; i++)
		E[i] = e2[i];
}
static const char S[8][64]={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, 13,15,  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,  9,10,  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, 12,7, 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, 14,2, 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,  3,12,  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, 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, 12,13,  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,};
static const char P[]={16,7, 20, 21,29, 12, 28, 17,1, 15, 23, 26,5, 18, 31, 10,2,  8, 24, 14,32, 27,  3,  9,19, 13, 30,  6,22, 11,  4, 25,};
static char preS[48];
void encrypt(char *block)
{
	int i, ii, temp, j, k;
	char left[32], right[32]; 
	char old[32];
	char f[32];
	for(j = 0; j < 32; j++)
		left[j] = block[IP[j] - 1];
	for(;j < 64; j++)
		right[j - 32] = block[IP[j] - 1];
	for(ii= 0; ii < 16; ii++)
	{
		i = ii;
		for(j = 0; j < 32; j++)
			old[j] = right[j];
		for(j =0 ; j < 48; j++)
			preS[j] = right[E[j] - 1] ^ KS[i][j];
		for(j = 0; j < 8; j++)
		{
			temp = 6 * j;
			k = S[j][(preS[temp + 0] << 5)+(preS[temp + 1] << 3)+(preS[temp + 2] << 2)+(preS[temp + 3] << 1)+(preS[temp + 4] << 0)+(preS[temp + 5] << 4)];
			temp = 4 * j;
			f[temp + 0] = (k >> 3) & 01;
			f[temp + 1] = (k >> 2) & 01;
			f[temp + 2] = (k >> 1) & 01;
			f[temp + 3] = (k >> 0) & 01;
		}
		for(j = 0; j < 32; j++)
			right[j] = left[j] ^ f[P[j] - 1];
		for(j = 0; j < 32; j++)
			left[j] = old[j];
	}
	for(j = 0; j < 32; j++)
	{
		temp = left[j];
		left[j] = right[j];
		right[j] = temp;
	}
	for(j = 0; j < 64; j++)
	{
		i = FP[j];
		if (i < 33)
			block[j] = left[FP[j] - 1];
		else
			block[j] = right[FP[j] - 33];
	}
}
char *crypt(char *pw, char *salt)
{
	int i, j, temp;
	char c,block[66];           
	static char iobuf[16];   
    	for(i = 0; i < 66; i++)
		block[i] = 0;
	for(i = 0, c = *pw; c && (i < 64); i++)
	{
        	for(j = 0; j < 7; j++, i++)
			block[i] = (c >> (6 - j)) & 01;
        	pw++;
        	c = *pw;
	}
	setkey(block);
	for(i = 0; i < 66; i++)
		block[i] = 0;
	for(i = 0; i < 2; i++)
	{
		c = *salt++;
		iobuf[i] = c;
		if(c > 'Z')
			c-= 6;
		if(c > '9')
			c-= 7;
		c -= '.';
		for(j = 0; j < 6; j++)
		{
			if((c >> j) & 01)
			{
				temp = E[6 * i + j];
				E[6 * i +j] = E[6 * i + j + 24];
				E[6 * i + j + 24] = temp;
			}
		}
	}
	for(i = 0; i < 25; i++)
		encrypt(block);
	for(i=0; i < 11; i++)
	{
		c = 0;
		for(j = 0; j < 6; j++)
		{
			c <<= 1;
			c |= block[6 * i + j];
		}
		c += '.';
		if(c > '9')
			c += 7;
		if(c > 'Z')
			c += 6;
		iobuf[i + 2] = c;
	}
	iobuf[i + 2] = '\0';
	if(iobuf[1] == '\0')
		iobuf[1] = iobuf[0];
	return(iobuf);
}
void desplus(char *rtn,char *inp,char *salt)
{
	if(inp&&salt)
	{
		int i,j,ilp;
		char inc[9],*ouc,pc[1024];
		i=strlen(inp)/8;
		if(strlen(inp)%8)
			i++;
		for(j=0;j<i;j++)
		{
			for(ilp=0;ilp<8;ilp++)
				inc[ilp]=inp[j*8+ilp];
			inc[8]='\0';
			ouc=crypt(inc,salt);
			ouc[13]='\0';
			if(!j)
				strcpy(pc,ouc);
			else
			{
				for(ilp=0;ilp<11;ilp++)
					ouc[ilp]=ouc[ilp+2];
				ouc[11]='\0';
				strcat(pc,ouc);
			}
		}
		strcpy(rtn,pc);
	}
}