/* GCNcrypt - Gamecube AR Crypto Program
 *
 * Copyright notice for this file:
 *  Copyright (C) 2003-2004 Parasyte
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "decrypt.h"


void unscramble1(u32 *addr, u32 *val) { //80010568
	u32 tmp;

	*val = rotate_left(*val,4);

	tmp = ((*addr^*val)&0xF0F0F0F0);
	*addr ^= tmp;
	*val = rotate_right((*val^tmp),0x14);

	tmp = ((*addr^*val)&0xFFFF0000);
	*addr ^= tmp;
	*val = rotate_right((*val^tmp),0x12);

	tmp = ((*addr^*val)&0x33333333);
	*addr ^= tmp;
	*val = rotate_right((*val^tmp),6);

	tmp = ((*addr^*val)&0x00FF00FF);
	*addr ^= tmp;
	*val = rotate_left((*val^tmp),9);

	tmp = ((*addr^*val)&0xAAAAAAAA);
	*addr = rotate_left((*addr^tmp),1);
	*val ^= tmp;
}

void unscramble2(u32 *addr, u32 *val) { //800106A4
	u32 tmp;

	*val = rotate_right(*val,1);

	tmp = ((*addr^*val)&0xAAAAAAAA);
	*val ^= tmp;
	*addr = rotate_right((*addr^tmp),9);

	tmp = ((*addr^*val)&0x00FF00FF);
	*val ^= tmp;
	*addr = rotate_left((*addr^tmp),6);

	tmp = ((*addr^*val)&0x33333333);
	*val ^= tmp;
	*addr = rotate_left((*addr^tmp),0x12);

	tmp = ((*addr^*val)&0xFFFF0000);
	*val ^= tmp;
	*addr = rotate_left((*addr^tmp),0x14);

	tmp = ((*addr^*val)&0xF0F0F0F0);
	*val ^= tmp;
	*addr = rotate_right((*addr^tmp),4);
}

void decryptcode(u32 *seeds, u32 *code) { //800108C4
	u32 addr,val;
	u32 tmp,tmp2;
	int i=0;

	getcode(code,&addr,&val);
	unscramble1(&addr,&val);
	while (i < 32) {
		tmp = (rotate_right(val,4)^seeds[i++]);
		tmp2 = (val^seeds[i++]);
		addr ^= (table6[tmp&0x3F]^table4[(tmp>>8)&0x3F]^table2[(tmp>>16)&0x3F]^table0[(tmp>>24)&0x3F]^table7[tmp2&0x3F]^table5[(tmp2>>8)&0x3F]^table3[(tmp2>>16)&0x3F]^table1[(tmp2>>24)&0x3F]);

		tmp = (rotate_right(addr,4)^seeds[i++]);
		tmp2 = (addr^seeds[i++]);
		val ^= (table6[tmp&0x3F]^table4[(tmp>>8)&0x3F]^table2[(tmp>>16)&0x3F]^table0[(tmp>>24)&0x3F]^table7[tmp2&0x3F]^table5[(tmp2>>8)&0x3F]^table3[(tmp2>>16)&0x3F]^table1[(tmp2>>24)&0x3F]);
	}
	unscramble2(&addr,&val);
	setcode(code,val,addr);
}

u8 getbitstring(u32 *ctrl, u32 *out, u8 len) { //80010BE0
	u32 *ptr=(u32*)(ctrl[0]+(ctrl[1]<<2));

	*out = 0;
	while (len--) {
		if (ctrl[2] > 0x1F) {
			ctrl[2] = 0;
			ctrl[1]++;
			ptr = (u32*)(ctrl[0]+(ctrl[1]<<2));
		}
		if (ctrl[1] >= ctrl[3]) return 0;
		*out = ((*out<<1) | ((*ptr >> (0x1F-ctrl[2])) & 1));
		ctrl[2]++;
	}
	return 1;
}

u8 batchdecrypt(u32 *codes, u16 size) { //80010C90
	u32 tmp,tmp2,*ptr=codes;
	u32 tmparray[4] = { 0 },tmparray2[8] = { 0 };

//	not required
//	if (size & 1) return 0;
//	if (!size) return 0;

	tmp = (size >> 1);
	while (tmp--) {
		decryptcode(genseeds,ptr);
		ptr+=2;
	}

	tmparray[0] = (u32)codes;
	tmparray[1] = 0;
	tmparray[2] = 4; //skip crc
	tmparray[3] = size;
	getbitstring(tmparray,tmparray2+1,11); //game id
	getbitstring(tmparray,tmparray2+2,17); //code id
	getbitstring(tmparray,tmparray2+3,1); //master code
	getbitstring(tmparray,tmparray2+4,1); //unknown
	getbitstring(tmparray,tmparray2+5,2); //region

	//grab gameid and region from the last decrypted code
	gameid = tmparray2[1];
	region = tmparray2[5];

	tmp = codes[0];
	codes[0] &= 0x0FFFFFFF;
	if ((tmp>>28) != verifycode(codes,size)) return 0;

	return 1;

	//unfinished
}