des.cpp

Example Dreambox CAM source code

		if (shifts2[i])
			{ c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
		else
			{ c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
		c&=0x0fffffffL;
		d&=0x0fffffffL;
		/* could be a few less shifts but I am to lazy at this
		 * point in time to investigate */
		s=	des_skb[0][ (c    )&0x3f                ]|
			des_skb[1][((c>> 6L)&0x03)|((c>> 7L)&0x3c)]|
			des_skb[2][((c>>13L)&0x0f)|((c>>14L)&0x30)]|
			des_skb[3][((c>>20L)&0x01)|((c>>21L)&0x06) |
						  ((c>>22L)&0x38)];
		t=	des_skb[4][ (d    )&0x3f                ]|
			des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
			des_skb[6][ (d>>15L)&0x3f                ]|
			des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];

		/* table contained 0213 4657 */
		t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
		*(k++)=i_ROTATE(t2,30)&0xffffffffL;

		t2=((s>>16L)|(t&0xffff0000L));
		*(k++)=i_ROTATE(t2,26)&0xffffffffL;
		}
}

void i_DES_encrypt3(i_DES_LONG *data, i_DES_key_schedule *ks1, i_DES_key_schedule *ks2, i_DES_key_schedule *ks3)
{
	register i_DES_LONG l, r;

	l = data[0];
	r = data[1];
	IP(l, r);
	data[0] = l;
	data[1] = r;
	i_DES_encrypt2((i_DES_LONG *)data, ks1, i_DES_ENCRYPT);
	i_DES_encrypt2((i_DES_LONG *)data, ks2, i_DES_DECRYPT);
	i_DES_encrypt2((i_DES_LONG *)data, ks3, i_DES_ENCRYPT);
	l = data[0];
	r = data[1];
	FP(r, l);
	data[0] = l;
	data[1] = r;
}

void i_DES_decrypt3(i_DES_LONG *data, i_DES_key_schedule *ks1, i_DES_key_schedule *ks2, i_DES_key_schedule *ks3)
{	
	register i_DES_LONG l, r;
	
	l = data[0];
	r = data[1];
	IP(l, r);
	data[0] = l;
	data[1] = r;
	i_DES_encrypt2((i_DES_LONG *)data, ks3, i_DES_DECRYPT);
	i_DES_encrypt2((i_DES_LONG *)data, ks2, i_DES_ENCRYPT);
	i_DES_encrypt2((i_DES_LONG *)data, ks1, i_DES_DECRYPT);
	l = data[0];
	r = data[1];
	FP(r, l);
	data[0] = l;
	data[1] = r;
}

void i_DES_encrypt2(i_DES_LONG *data, i_DES_key_schedule *ks, int enc)
{
	register i_DES_LONG l, r, t, u;
#ifndef i_DES_UNROLL
	register int i;
#endif
	register i_DES_LONG *s;

	r = data[0];
	l = data[1];

	/* Things have been modified so that the initial rotate is
	 * done outside the loop.  This required the
	 * DES_SPtrans values in sp.h to be rotated 1 bit to the right.
	 * One perl script later and things have a 5% speed up on a sparc2.
	 * Thanks to Richard Outerbridge <[e-mail]>
	 * for pointing this out. */
	/* clear the top bits on machines with 8byte longs */
	r = i_ROTATE(r, 29) & 0xffffffffL;
	l = i_ROTATE(l, 29) & 0xffffffffL;

	s = ks->ks->deslong;
	/* I don't know if it is worth the effort of loop unrolling the
	 * inner loop */
	if (enc)
	{
#ifdef i_DES_UNROLL
		D_ENCRYPT(l, r,  0); /*  1 */
		D_ENCRYPT(r, l,  2); /*  2 */
		D_ENCRYPT(l, r,  4); /*  3 */
		D_ENCRYPT(r, l,  6); /*  4 */
		D_ENCRYPT(l, r,  8); /*  5 */
		D_ENCRYPT(r, l, 10); /*  6 */
		D_ENCRYPT(l, r, 12); /*  7 */
		D_ENCRYPT(r, l, 14); /*  8 */
		D_ENCRYPT(l, r, 16); /*  9 */
		D_ENCRYPT(r, l, 18); /*  10 */
		D_ENCRYPT(l, r, 20); /*  11 */
		D_ENCRYPT(r, l, 22); /*  12 */
		D_ENCRYPT(l, r, 24); /*  13 */
		D_ENCRYPT(r, l, 26); /*  14 */
		D_ENCRYPT(l, r, 28); /*  15 */
		D_ENCRYPT(r, l, 30); /*  16 */
#else
		for (i = 0;i < 32; i += 8)
		{
			D_ENCRYPT(l, r, i + 0); /*  1 */
			D_ENCRYPT(r, l, i + 2); /*  2 */
			D_ENCRYPT(l, r, i + 4); /*  3 */
			D_ENCRYPT(r, l, i + 6); /*  4 */
		}
#endif
	}
	else
	{
#ifdef i_DES_UNROLL
		D_ENCRYPT(l, r, 30); /* 16 */
		D_ENCRYPT(r, l, 28); /* 15 */
		D_ENCRYPT(l, r, 26); /* 14 */
		D_ENCRYPT(r, l, 24); /* 13 */
		D_ENCRYPT(l, r, 22); /* 12 */
		D_ENCRYPT(r, l, 20); /* 11 */
		D_ENCRYPT(l, r, 18); /* 10 */
		D_ENCRYPT(r, l, 16); /*  9 */
		D_ENCRYPT(l, r, 14); /*  8 */
		D_ENCRYPT(r, l, 12); /*  7 */
		D_ENCRYPT(l, r, 10); /*  6 */
		D_ENCRYPT(r, l,  8); /*  5 */
		D_ENCRYPT(l, r,  6); /*  4 */
		D_ENCRYPT(r, l,  4); /*  3 */
		D_ENCRYPT(l, r,  2); /*  2 */
		D_ENCRYPT(r, l,  0); /*  1 */
#else
		for (i = 30;i > 0;i -= 8)
		{
			D_ENCRYPT(l, r, i - 0); /* 16 */
			D_ENCRYPT(r, l, i - 2); /* 15 */
			D_ENCRYPT(l, r, i - 4); /* 14 */
			D_ENCRYPT(r, l, i - 6); /* 13 */
		}
#endif
	}
	
	/* rotate and clear the top bits on machines with 8byte longs */
	data[0] = i_ROTATE(l, 3) & 0xffffffffL;
	data[1] = i_ROTATE(r, 3) & 0xffffffffL;
	l = r = t = u = 0;
}

int i_DES_random_key(i_DES_cblock *ret)
{
	srand( time(NULL) );
	do
	{
		for(unsigned int i=0;i<sizeof(i_DES_cblock);i++) ((unsigned char *)ret)[i] = (unsigned char)rand();
	}
	while (i_DES_is_weak_key(ret));
	
	i_DES_set_odd_parity(ret);
	return 1;
}

void i_DES_set_odd_parity(i_DES_cblock *key)
{
	unsigned int i;

	for (i=0; i<i_DES_KEY_SZ; i++)
		(*key)[i] = odd_parity[(*key)[i]];
}

void i_DES_ecb3_encrypt(i_const_DES_cblock *input, i_DES_cblock *output, i_DES_key_schedule *ks1, i_DES_key_schedule *ks2, i_DES_key_schedule *ks3, int enc)
{
	register i_DES_LONG l0, l1;
	i_DES_LONG ll[2];
	const unsigned char *in = &(*input)[0];
	unsigned char *out = &(*output)[0];
	
	c2l(in,l0);
	c2l(in,l1);
	ll[0] = l0;
	ll[1] = l1;
	if( enc )
		i_DES_encrypt3(ll, ks1, ks2, ks3);
	else
		i_DES_decrypt3(ll, ks1, ks2, ks3);
	l0 = ll[0];
	l1 = ll[1];
	l2c(l0, out);
	l2c(l1, out);
}

void i_DES_ede3_cbc_encrypt(const unsigned char *input, unsigned char *output, long length, i_DES_key_schedule *ks1, i_DES_key_schedule *ks2, i_DES_key_schedule *ks3, i_DES_cblock *ivec, int enc)
{
	register i_DES_LONG tin0,tin1;
	register i_DES_LONG tout0,tout1,xor0,xor1;
	register const unsigned char *in;
	unsigned char *out;
	register long l=length;
	i_DES_LONG tin[2];
	unsigned char *iv;

	in=input;
	out=output;
	iv = &(*ivec)[0];

	if (enc)
	{
		c2l(iv,tout0);
		c2l(iv,tout1);
		for (l-=8; l>=0; l-=8)
		{
			c2l(in,tin0);
			c2l(in,tin1);
			tin0^=tout0;
			tin1^=tout1;

			tin[0]=tin0;
			tin[1]=tin1;
			i_DES_encrypt3((i_DES_LONG *)tin,ks1,ks2,ks3);
			tout0=tin[0];
			tout1=tin[1];

			l2c(tout0,out);
			l2c(tout1,out);
		}
		if (l != -8)
		{
			c2ln(in,tin0,tin1,l+8);
			tin0^=tout0;
			tin1^=tout1;

			tin[0]=tin0;
			tin[1]=tin1;
			i_DES_encrypt3((i_DES_LONG *)tin,ks1,ks2,ks3);
			tout0=tin[0];
			tout1=tin[1];

			l2c(tout0,out);
			l2c(tout1,out);
		}
		iv = &(*ivec)[0];
		l2c(tout0,iv);
		l2c(tout1,iv);
	}
	else
	{
		register i_DES_LONG t0,t1;

		c2l(iv,xor0);
		c2l(iv,xor1);
		for (l-=8; l>=0; l-=8)
		{
			c2l(in,tin0);
			c2l(in,tin1);

			t0=tin0;
			t1=tin1;

			tin[0]=tin0;
			tin[1]=tin1;
			i_DES_decrypt3((i_DES_LONG *)tin,ks1,ks2,ks3);
			tout0=tin[0];
			tout1=tin[1];

			tout0^=xor0;
			tout1^=xor1;
			l2c(tout0,out);
			l2c(tout1,out);
			xor0=t0;
			xor1=t1;
		}
		if (l != -8)
		{
			c2l(in,tin0);
			c2l(in,tin1);
			
			t0=tin0;
			t1=tin1;

			tin[0]=tin0;
			tin[1]=tin1;
			i_DES_decrypt3((i_DES_LONG *)tin,ks1,ks2,ks3);
			tout0=tin[0];
			tout1=tin[1];
		
			tout0^=xor0;
			tout1^=xor1;
			l2cn(tout0,tout1,out,l+8);
			xor0=t0;
			xor1=t1;
		}

		iv = &(*ivec)[0];
		l2c(xor0,iv);
		l2c(xor1,iv);
	}
	tin0=tin1=tout0=tout1=xor0=xor1=0;
	tin[0]=tin[1]=0;
}