des.c

在原作者Jim Gillogly代码的基础上修改优化

   0x08000008L, 0x00000200L, 0x00000000L, 0x08020008L, 
   0x08000208L, 0x00020000L, 0x08000000L, 0x08020208L, 
   0x00000008L, 0x00020208L, 0x00020200L, 0x08000008L, 
   0x08020000L, 0x08000208L, 0x00000208L, 0x08020000L, 
   0x00020208L, 0x00000008L, 0x08020008L, 0x00020200L 
}; 

static unsigned long SP4[64] = 
{
   0x00802001L, 0x00002081L, 0x00002081L, 0x00000080L, 
   0x00802080L, 0x00800081L, 0x00800001L, 0x00002001L,
   0x00000000L, 0x00802000L, 0x00802000L, 0x00802081L,
   0x00000081L, 0x00000000L, 0x00800080L, 0x00800001L,
   0x00000001L, 0x00002000L, 0x00800000L, 0x00802001L,
   0x00000080L, 0x00800000L, 0x00002001L, 0x00002080L,
   0x00800081L, 0x00000001L, 0x00002080L, 0x00800080L,
   0x00002000L, 0x00802080L, 0x00802081L, 0x00000081L,
   0x00800080L, 0x00800001L, 0x00802000L, 0x00802081L, 
   0x00000081L, 0x00000000L, 0x00000000L, 0x00802000L, 
   0x00002080L, 0x00800080L, 0x00800081L, 0x00000001L,
   0x00802001L, 0x00002081L, 0x00002081L, 0x00000080L,
   0x00802081L, 0x00000081L, 0x00000001L, 0x00002000L,
   0x00800001L, 0x00002001L, 0x00802080L, 0x00800081L, 
   0x00002001L, 0x00002080L, 0x00800000L, 0x00802001L, 
   0x00000080L, 0x00800000L, 0x00002000L, 0x00802080L 
};

static unsigned long SP5[64] =  
{  
   0x00000100L, 0x02080100L, 0x02080000L, 0x42000100L, 
   0x00080000L, 0x00000100L, 0x40000000L, 0x02080000L,
   0x40080100L, 0x00080000L, 0x02000100L, 0x40080100L,
   0x42000100L, 0x42080000L, 0x00080100L, 0x40000000L, 
   0x02000000L, 0x40080000L, 0x40080000L, 0x00000000L, 
   0x40000100L, 0x42080100L, 0x42080100L, 0x02000100L, 
   0x42080000L, 0x40000100L, 0x00000000L, 0x42000000L, 
   0x02080100L, 0x02000000L, 0x42000000L, 0x00080100L,
   0x00080000L, 0x42000100L, 0x00000100L, 0x02000000L, 
   0x40000000L, 0x02080000L, 0x42000100L, 0x40080100L, 
   0x02000100L, 0x40000000L, 0x42080000L, 0x02080100L, 
   0x40080100L, 0x00000100L, 0x02000000L, 0x42080000L, 
   0x42080100L, 0x00080100L, 0x42000000L, 0x42080100L, 
   0x02080000L, 0x00000000L, 0x40080000L, 0x42000000L, 
   0x00080100L, 0x02000100L, 0x40000100L, 0x00080000L, 
   0x00000000L, 0x40080000L, 0x02080100L, 0x40000100L   
};  

static unsigned long SP6[64] = 
{ 
   0x20000010L, 0x20400000L, 0x00004000L, 0x20404010L, 
   0x20400000L, 0x00000010L, 0x20404010L, 0x00400000L, 
   0x20004000L, 0x00404010L, 0x00400000L, 0x20000010L, 
   0x00400010L, 0x20004000L, 0x20000000L, 0x00004010L, 
   0x00000000L, 0x00400010L, 0x20004010L, 0x00004000L, 
   0x00404000L, 0x20004010L, 0x00000010L, 0x20400010L, 
   0x20400010L, 0x00000000L, 0x00404010L, 0x20404000L, 
   0x00004010L, 0x00404000L, 0x20404000L, 0x20000000L,
   0x20004000L, 0x00000010L, 0x20400010L, 0x00404000L, 
   0x20404010L, 0x00400000L, 0x00004010L, 0x20000010L, 
   0x00400000L, 0x20004000L, 0x20000000L, 0x00004010L, 
   0x20000010L, 0x20404010L, 0x00404000L, 0x20400000L, 
   0x00404010L, 0x20404000L, 0x00000000L, 0x20400010L, 
   0x00000010L, 0x00004000L, 0x20400000L, 0x00404010L, 
   0x00004000L, 0x00400010L, 0x20004010L, 0x00000000L, 
   0x20404000L, 0x20000000L, 0x00400010L, 0x20004010L 
};

static unsigned long SP7[64] = 
{ 
   0x00200000L, 0x04200002L, 0x04000802L, 0x00000000L, 
   0x00000800L, 0x04000802L, 0x00200802L, 0x04200800L,
   0x04200802L, 0x00200000L, 0x00000000L, 0x04000002L, 
   0x00000002L, 0x04000000L, 0x04200002L, 0x00000802L, 
   0x04000800L, 0x00200802L, 0x00200002L, 0x04000800L, 
   0x04000002L, 0x04200000L, 0x04200800L, 0x00200002L, 
   0x04200000L, 0x00000800L, 0x00000802L, 0x04200802L, 
   0x00200800L, 0x00000002L, 0x04000000L, 0x00200800L, 
   0x04000000L, 0x00200800L, 0x00200000L, 0x04000802L, 
   0x04000802L, 0x04200002L, 0x04200002L, 0x00000002L, 
   0x00200002L, 0x04000000L, 0x04000800L, 0x00200000L, 
   0x04200800L, 0x00000802L, 0x00200802L, 0x04200800L, 
   0x00000802L, 0x04000002L, 0x04200802L, 0x04200000L, 
   0x00200800L, 0x00000000L, 0x00000002L, 0x04200802L, 
   0x00000000L, 0x00200802L, 0x04200000L, 0x00000800L, 
   0x04000002L, 0x04000800L, 0x00000800L, 0x00200002L 
};  

static unsigned long SP8[64] = 
{ 
   0x10001040L, 0x00001000L, 0x00040000L, 0x10041040L, 
   0x10000000L, 0x10001040L, 0x00000040L, 0x10000000L, 
   0x00040040L, 0x10040000L, 0x10041040L, 0x00041000L, 
   0x10041000L, 0x00041040L, 0x00001000L, 0x00000040L, 
   0x10040000L, 0x10000040L, 0x10001000L, 0x00001040L, 
   0x00041000L, 0x00040040L, 0x10040040L, 0x10041000L, 
   0x00001040L, 0x00000000L, 0x00000000L, 0x10040040L, 
   0x10000040L, 0x10001000L, 0x00041040L, 0x00040000L,  
   0x00041040L, 0x00040000L, 0x10041000L, 0x00001000L, 
   0x00000040L, 0x10040040L, 0x00001000L, 0x00041040L, 
   0x10001000L, 0x00000040L, 0x10000040L, 0x10040000L, 
   0x10040040L, 0x10000000L, 0x00040000L, 0x10001040L,
   0x00000000L, 0x10041040L, 0x00040040L, 0x10000040L, 
   0x10040000L, 0x10001000L, 0x10001040L, 0x00000000L, 
   0x10041040L, 0x00041000L, 0x00041000L, 0x00001040L, 
   0x00001040L, 0x00040040L, 0x10000000L, 0x10041000L 
};

static void desfunc(register unsigned long *block,register unsigned long *keys)
{
	register unsigned long fval,work,right,leftt;
	register int round;
	leftt = block[0];
	right = block[1];
	work = ((leftt >> 4) ^ right) & 0x0f0f0f0fL;
	right ^= work;
	leftt ^= (work << 4);
	work = ((leftt >> 16) ^ right) & 0x0000ffffL;
	right ^= work;
	leftt ^= (work<<16);
	work = ((right >> 2) ^ leftt) & 0x33333333L;
	leftt ^= work;
	right ^=(work << 2);
	work = ((right >> 8) ^ leftt) & 0x00ff00ffL;
	leftt ^= work;
	right ^= (work << 8);
	right = ((right << 1) | ((right >> 31) & 1L)) & 0xffffffffL;
	work = (leftt ^ right) & 0xaaaaaaaaL;
	leftt ^= work;
	right ^= work;
	leftt = ((leftt << 1) | ((leftt >> 31) & 1L)) & 0xffffffffL;

	for(round = 0; round < 8; round++)
	{
		work = (right << 28) | (right >> 4);
		work ^= *keys++;
		fval  = SP7[(work & 0x3fL)];
		fval |= SP5[(work >>  8) & 0x3fL];
		fval |= SP3[(work >> 16) & 0x3fL];
		fval |= SP1[(work >> 24) & 0x3fL];
		work = right ^ *keys++;
		fval |= SP8[(work & 0x3fL)];
		fval |= SP6[(work >>  8) & 0x3fL];
		fval |= SP4[(work >> 16) & 0x3fL];
		fval |= SP2[(work >> 24) & 0x3fL];
		leftt ^= fval;
		work = (leftt << 28) | (leftt >> 4);
		work ^= *keys++;
		fval  = SP7[(work & 0x3fL)];
		fval |= SP5[(work >>  8) & 0x3fL];
		fval |= SP3[(work >> 16) & 0x3fL];
		fval |= SP1[(work >> 24) & 0x3fL];
		work = leftt ^ *keys++;
		fval |= SP8[(work & 0x3fL)];
		fval |= SP6[(work >>  8) & 0x3fL];
		fval |= SP4[(work >> 16) & 0x3fL];
		fval |= SP2[(work >> 24) & 0x3fL];
		right ^= fval;		
	}
	right = (right << 31) | (right >> 1);
	work = (leftt ^ right) & 0xaaaaaaaaL;
	leftt ^= work;
	right ^= work;
	leftt = (leftt << 31) | (leftt >> 1);
	work = ((leftt >> 8) ^ right) & 0x00ff00ffL;
	right ^= work;
	leftt ^= (work << 8);
	work = ((leftt >> 2) ^ right) & 0x33333333L;
	right ^= work;
	leftt ^= (work << 2);
	work = ((right >> 16) ^ leftt) & 0x0000ffffL;
	leftt ^= work;
	right ^= (work << 16);
	work = ((right >> 4) ^ leftt) & 0x0f0f0f0fL;
	leftt ^= work;
	right ^= (work << 4);
	*block++ = right;
	*block = leftt;
	return;
}

void des_key(des_ctx *dc,unsigned char *key)
{
	deskey(key,EN0);
	cpkey(dc->ek);
	deskey(key,DE1);
	cpkey(dc->dk);
}

void des_enc(des_ctx *dc,unsigned char *data,int blocks)
{
	unsigned long work[2];
	int i;
	unsigned char *cp;
	
	cp = data;
	for(i=0;i<blocks;i++)
	{
		scrunch(cp,work);
		desfunc(work,dc->ek);
		unscrun(work,cp);
		cp += 8;
	}
}

void des_dec(des_ctx *dc,unsigned char *data,int blocks)
{
	unsigned long work[2];
	int i;
	unsigned char *cp;
	
	cp = data;
	for(i=0;i<blocks;i++)
	{
		scrunch(cp,work);
		desfunc(work,dc->dk);
		unscrun(work,cp);
		cp += 8;
	}
}


void main(void)
{
 	des_ctx dc;
 	int i;
 	unsigned long data[10];
 	unsigned char *cp,key[8] = {0x01,0x23,0x45,0x67,0x89,0xab,0xcd,0xef};
	unsigned char x[8] = {0x01,0x23,0x45,0x67,0x89,0xab,0xcd,0xe7};

	cp = x;

	des_key(&dc,key);
	des_enc(&dc,cp,1);
	printf("Enc(0..7,0..7) = ");
	for(i=0;i<8;i++)	printf("%02x ",((unsigned int) cp[i]) & 0x00ff);
	printf("\n");

	des_dec(&dc,cp,1);

	printf("Dec(above,0..7) = ");
	for(i=0;i<8;i++)	printf("%02x ",((unsigned int) cp[i]) & 0x00ff);
	printf("\n");

	cp = (unsigned char *)data;

	for(i=0;i<10;i++)	data[i] = i;
	
	des_enc(&dc,cp,5);
	for(i=0;i<10;i+=2)	printf("Block %01d = %08lx %08lx.\n",i/2,data[i],data[i+1]);

	des_enc(&dc,cp,1);
	des_enc(&dc,cp+8,4);
	for(i=0;i<10;i+=2)	printf("Block %01d = %08lx %08lx.\n",i/2,data[i],data[i+1]);

}