/*
unscrambler 0.4: unscramble not standard IVs scrambled DVDs thru 
bruteforce, intended for Gamecube/WII Optical Disks.

Copyright (C) 2006  Victor Muņoz (xt5@ingenieria-inversa.cl)

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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

#include "ecma-267.h"

/* EDC stuff */
unsigned int edc_table[256] = {
    0x00000000, 0x80000011, 0x80000033, 0x00000022, 0x80000077, 0x00000066, 0x00000044, 0x80000055,
    0x800000FF, 0x000000EE, 0x000000CC, 0x800000DD, 0x00000088, 0x80000099, 0x800000BB, 0x000000AA,
    0x800001EF, 0x000001FE, 0x000001DC, 0x800001CD, 0x00000198, 0x80000189, 0x800001AB, 0x000001BA,
    0x00000110, 0x80000101, 0x80000123, 0x00000132, 0x80000167, 0x00000176, 0x00000154, 0x80000145,
    0x800003CF, 0x000003DE, 0x000003FC, 0x800003ED, 0x000003B8, 0x800003A9, 0x8000038B, 0x0000039A,
    0x00000330, 0x80000321, 0x80000303, 0x00000312, 0x80000347, 0x00000356, 0x00000374, 0x80000365,
    0x00000220, 0x80000231, 0x80000213, 0x00000202, 0x80000257, 0x00000246, 0x00000264, 0x80000275,
    0x800002DF, 0x000002CE, 0x000002EC, 0x800002FD, 0x000002A8, 0x800002B9, 0x8000029B, 0x0000028A,
    0x8000078F, 0x0000079E, 0x000007BC, 0x800007AD, 0x000007F8, 0x800007E9, 0x800007CB, 0x000007DA,
    0x00000770, 0x80000761, 0x80000743, 0x00000752, 0x80000707, 0x00000716, 0x00000734, 0x80000725,
    0x00000660, 0x80000671, 0x80000653, 0x00000642, 0x80000617, 0x00000606, 0x00000624, 0x80000635,
    0x8000069F, 0x0000068E, 0x000006AC, 0x800006BD, 0x000006E8, 0x800006F9, 0x800006DB, 0x000006CA,
    0x00000440, 0x80000451, 0x80000473, 0x00000462, 0x80000437, 0x00000426, 0x00000404, 0x80000415,
    0x800004BF, 0x000004AE, 0x0000048C, 0x8000049D, 0x000004C8, 0x800004D9, 0x800004FB, 0x000004EA,
    0x800005AF, 0x000005BE, 0x0000059C, 0x8000058D, 0x000005D8, 0x800005C9, 0x800005EB, 0x000005FA,
    0x00000550, 0x80000541, 0x80000563, 0x00000572, 0x80000527, 0x00000536, 0x00000514, 0x80000505,
    0x80000F0F, 0x00000F1E, 0x00000F3C, 0x80000F2D, 0x00000F78, 0x80000F69, 0x80000F4B, 0x00000F5A,
    0x00000FF0, 0x80000FE1, 0x80000FC3, 0x00000FD2, 0x80000F87, 0x00000F96, 0x00000FB4, 0x80000FA5,
    0x00000EE0, 0x80000EF1, 0x80000ED3, 0x00000EC2, 0x80000E97, 0x00000E86, 0x00000EA4, 0x80000EB5,
    0x80000E1F, 0x00000E0E, 0x00000E2C, 0x80000E3D, 0x00000E68, 0x80000E79, 0x80000E5B, 0x00000E4A,
    0x00000CC0, 0x80000CD1, 0x80000CF3, 0x00000CE2, 0x80000CB7, 0x00000CA6, 0x00000C84, 0x80000C95,
    0x80000C3F, 0x00000C2E, 0x00000C0C, 0x80000C1D, 0x00000C48, 0x80000C59, 0x80000C7B, 0x00000C6A,
    0x80000D2F, 0x00000D3E, 0x00000D1C, 0x80000D0D, 0x00000D58, 0x80000D49, 0x80000D6B, 0x00000D7A,
    0x00000DD0, 0x80000DC1, 0x80000DE3, 0x00000DF2, 0x80000DA7, 0x00000DB6, 0x00000D94, 0x80000D85,
    0x00000880, 0x80000891, 0x800008B3, 0x000008A2, 0x800008F7, 0x000008E6, 0x000008C4, 0x800008D5,
    0x8000087F, 0x0000086E, 0x0000084C, 0x8000085D, 0x00000808, 0x80000819, 0x8000083B, 0x0000082A,
    0x8000096F, 0x0000097E, 0x0000095C, 0x8000094D, 0x00000918, 0x80000909, 0x8000092B, 0x0000093A,
    0x00000990, 0x80000981, 0x800009A3, 0x000009B2, 0x800009E7, 0x000009F6, 0x000009D4, 0x800009C5,
    0x80000B4F, 0x00000B5E, 0x00000B7C, 0x80000B6D, 0x00000B38, 0x80000B29, 0x80000B0B, 0x00000B1A,
    0x00000BB0, 0x80000BA1, 0x80000B83, 0x00000B92, 0x80000BC7, 0x00000BD6, 0x00000BF4, 0x80000BE5,
    0x00000AA0, 0x80000AB1, 0x80000A93, 0x00000A82, 0x80000AD7, 0x00000AC6, 0x00000AE4, 0x80000AF5,
    0x80000A5F, 0x00000A4E, 0x00000A6C, 0x80000A7D, 0x00000A28, 0x80000A39, 0x80000A1B, 0x00000A0AL
};

u32 edc_calc(u32 edc, u8 *ptr, u32  len) {
    while (len--) edc=edc_table[((edc>>24)^*ptr++)&0xFF]^(edc<<8);
    return edc;
}

/* end of EDC stuff */

/* LFSR stuff */

u16 ecma267_ivs[]= {
    0x0001, 0x5500, 0x0002, 0x2A00,
    0x0004, 0x5400, 0x0008, 0x2800,
    0x0010, 0x5000, 0x0020, 0x2001,
    0x0040, 0x4002, 0x0080, 0x0005
};


unsigned short LFSR;

void LFSR_ecma_init(int iv) {
     LFSR=ecma267_ivs[iv];
}

void LFSR_init(u16 seed) {
     LFSR=seed;
}

int LFSR_tick() {
    int ret;
    int n;
    
    ret=LFSR>>14;
    
    n=ret^((LFSR>>10)&1);
    LFSR=((LFSR<<1)|n)&0x7FFF;
    
    return ret;
}

unsigned char LFSR_byte() {
    u8 ret;
    int i;
    
    ret=0;
    for(i=0; i<8; i++) ret=(ret<<1)|LFSR_tick();
    
    return ret;
}

/* end of LFSR stuff */