#include "../include/blowfish.h"

#define BF_PTR2

/* This is actually a big endian algorithm, the most significant byte
 * is used to lookup array 0 */

#if defined(BF_PTR2)

/*
 * This is basically a special Intel version. Point is that Intel
 * doesn't have many registers, but offers a reach choice of addressing
 * modes. So we spare some registers by directly traversing BF_KEY
 * structure and hiring the most decorated addressing mode. The code
 * generated by EGCS is *perfectly* competitive with assembler
 * implementation!
 */
#define BF_ENC(LL,R,KEY,Pi) (\
	LL^=KEY[Pi], \
	t=  KEY[BF_ROUNDS+2 +   0 + ((R>>24)&0xFF)], \
	t+= KEY[BF_ROUNDS+2 + 256 + ((R>>16)&0xFF)], \
	t^= KEY[BF_ROUNDS+2 + 512 + ((R>>8 )&0xFF)], \
	t+= KEY[BF_ROUNDS+2 + 768 + ((R    )&0xFF)], \
	LL^=t \
	)

#elif defined(BF_PTR)

#ifndef BF_LONG_LOG2
#define BF_LONG_LOG2  2       /* default to BF_LONG being 32 bits */
#endif
#define BF_M  (0xFF<<BF_LONG_LOG2)
#define BF_0  (24-BF_LONG_LOG2)
#define BF_1  (16-BF_LONG_LOG2)
#define BF_2  ( 8-BF_LONG_LOG2)
#define BF_3  BF_LONG_LOG2 /* left shift */

/*
 * This is normally very good on RISC platforms where normally you
 * have to explicitly "multiply" array index by sizeof(BF_LONG)
 * in order to calculate the effective address. This implementation
 * excuses CPU from this extra work. Power[PC] uses should have most
 * fun as (R>>BF_i)&BF_M gets folded into a single instruction, namely
 * rlwinm. So let'em double-check if their compiler does it.
 */

#define BF_ENC(LL,R,S,P) ( \
	LL^=P, \
	LL^= (((*(BF_LONG *)((unsigned char *)&(S[  0])+((R>>BF_0)&BF_M))+ \
		*(BF_LONG *)((unsigned char *)&(S[256])+((R>>BF_1)&BF_M)))^ \
		*(BF_LONG *)((unsigned char *)&(S[512])+((R>>BF_2)&BF_M)))+ \
		*(BF_LONG *)((unsigned char *)&(S[768])+((R<<BF_3)&BF_M))) \
	)
#else

/*
 * This is a *generic* version. Seem to perform best on platforms that
 * offer explicit support for extraction of 8-bit nibbles preferably
 * complemented with "multiplying" of array index by sizeof(BF_LONG).
 * For the moment of this writing the list comprises Alpha CPU featuring
 * extbl and s[48]addq instructions.
 */

#define BF_ENC(LL,R,S,P) ( \
	LL^=P, \
	LL^=(((	S[       ((int)(R>>24)&0xff)] + \
		S[0x0100+((int)(R>>16)&0xff)])^ \
		S[0x0200+((int)(R>> 8)&0xff)])+ \
		S[0x0300+((int)(R    )&0xff)])&0xffffffffL \
	)
#endif


void BF_encrypt(BF_LONG *data, const BF_KEY *key)
	{
#ifndef BF_PTR2
	register BF_LONG l,r;
    const register BF_LONG *p,*s;

	p=key->P;
	s= &(key->S[0]);
	l=data[0];
	r=data[1];

	l^=p[0];
	BF_ENC(r,l,s,p[ 1]);
	BF_ENC(l,r,s,p[ 2]);
	BF_ENC(r,l,s,p[ 3]);
	BF_ENC(l,r,s,p[ 4]);
	BF_ENC(r,l,s,p[ 5]);
	BF_ENC(l,r,s,p[ 6]);
	BF_ENC(r,l,s,p[ 7]);
	BF_ENC(l,r,s,p[ 8]);
	BF_ENC(r,l,s,p[ 9]);
	BF_ENC(l,r,s,p[10]);
	BF_ENC(r,l,s,p[11]);
	BF_ENC(l,r,s,p[12]);
	BF_ENC(r,l,s,p[13]);
	BF_ENC(l,r,s,p[14]);
	BF_ENC(r,l,s,p[15]);
	BF_ENC(l,r,s,p[16]);
#if BF_ROUNDS == 20
	BF_ENC(r,l,s,p[17]);
	BF_ENC(l,r,s,p[18]);
	BF_ENC(r,l,s,p[19]);
	BF_ENC(l,r,s,p[20]);
#endif
	r^=p[BF_ROUNDS+1];

	data[1]=l&0xffffffffL;
	data[0]=r&0xffffffffL;
#else
	register BF_LONG l,r,t,*k;

	l=data[0];
	r=data[1];
	k=(BF_LONG*)key;

	l^=k[0];
	BF_ENC(r,l,k, 1);
	BF_ENC(l,r,k, 2);
	BF_ENC(r,l,k, 3);
	BF_ENC(l,r,k, 4);
	BF_ENC(r,l,k, 5);
	BF_ENC(l,r,k, 6);
	BF_ENC(r,l,k, 7);
	BF_ENC(l,r,k, 8);
	BF_ENC(r,l,k, 9);
	BF_ENC(l,r,k,10);
	BF_ENC(r,l,k,11);
	BF_ENC(l,r,k,12);
	BF_ENC(r,l,k,13);
	BF_ENC(l,r,k,14);
	BF_ENC(r,l,k,15);
	BF_ENC(l,r,k,16);
#if BF_ROUNDS == 20
	BF_ENC(r,l,k,17);
	BF_ENC(l,r,k,18);
	BF_ENC(r,l,k,19);
	BF_ENC(l,r,k,20);
#endif
	r^=k[BF_ROUNDS+1];

	data[1]=l&0xffffffffL;
	data[0]=r&0xffffffffL;
#endif
	}

#ifndef BF_DEFAULT_OPTIONS

void BF_decrypt(BF_LONG *data, const BF_KEY *key)
	{
#ifndef BF_PTR2
	register BF_LONG l,r;
    const register BF_LONG *p,*s;

	p=key->P;
	s= &(key->S[0]);
	l=data[0];
	r=data[1];

	l^=p[BF_ROUNDS+1];
#if BF_ROUNDS == 20
	BF_ENC(r,l,s,p[20]);
	BF_ENC(l,r,s,p[19]);
	BF_ENC(r,l,s,p[18]);
	BF_ENC(l,r,s,p[17]);
#endif
	BF_ENC(r,l,s,p[16]);
	BF_ENC(l,r,s,p[15]);
	BF_ENC(r,l,s,p[14]);
	BF_ENC(l,r,s,p[13]);
	BF_ENC(r,l,s,p[12]);
	BF_ENC(l,r,s,p[11]);
	BF_ENC(r,l,s,p[10]);
	BF_ENC(l,r,s,p[ 9]);
	BF_ENC(r,l,s,p[ 8]);
	BF_ENC(l,r,s,p[ 7]);
	BF_ENC(r,l,s,p[ 6]);
	BF_ENC(l,r,s,p[ 5]);
	BF_ENC(r,l,s,p[ 4]);
	BF_ENC(l,r,s,p[ 3]);
	BF_ENC(r,l,s,p[ 2]);
	BF_ENC(l,r,s,p[ 1]);
	r^=p[0];

	data[1]=l&0xffffffffL;
	data[0]=r&0xffffffffL;
#else
	register BF_LONG l,r,t,*k;

	l=data[0];
	r=data[1];
	k=(BF_LONG *)key;

	l^=k[BF_ROUNDS+1];
#if BF_ROUNDS == 20
	BF_ENC(r,l,k,20);
	BF_ENC(l,r,k,19);
	BF_ENC(r,l,k,18);
	BF_ENC(l,r,k,17);
#endif
	BF_ENC(r,l,k,16);
	BF_ENC(l,r,k,15);
	BF_ENC(r,l,k,14);
	BF_ENC(l,r,k,13);
	BF_ENC(r,l,k,12);
	BF_ENC(l,r,k,11);
	BF_ENC(r,l,k,10);
	BF_ENC(l,r,k, 9);
	BF_ENC(r,l,k, 8);
	BF_ENC(l,r,k, 7);
	BF_ENC(r,l,k, 6);
	BF_ENC(l,r,k, 5);
	BF_ENC(r,l,k, 4);
	BF_ENC(l,r,k, 3);
	BF_ENC(r,l,k, 2);
	BF_ENC(l,r,k, 1);
	r^=k[0];

	data[1]=l&0xffffffffL;
	data[0]=r&0xffffffffL;
#endif
	}

#endif