#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include "DeCSS.h"

unsigned int CSStab0[11]={5,0,1,2,3,4,0,1,2,3,4};

unsigned char CSStab1[256]=
{
	0x33,0x73,0x3b,0x26,0x63,0x23,0x6b,0x76,0x3e,0x7e,0x36,0x2b,0x6e,0x2e,0x66,0x7b,
	0xd3,0x93,0xdb,0x06,0x43,0x03,0x4b,0x96,0xde,0x9e,0xd6,0x0b,0x4e,0x0e,0x46,0x9b,
	0x57,0x17,0x5f,0x82,0xc7,0x87,0xcf,0x12,0x5a,0x1a,0x52,0x8f,0xca,0x8a,0xc2,0x1f,
	0xd9,0x99,0xd1,0x00,0x49,0x09,0x41,0x90,0xd8,0x98,0xd0,0x01,0x48,0x08,0x40,0x91,

	0x3d,0x7d,0x35,0x24,0x6d,0x2d,0x65,0x74,0x3c,0x7c,0x34,0x25,0x6c,0x2c,0x64,0x75,
	0xdd,0x9d,0xd5,0x04,0x4d,0x0d,0x45,0x94,0xdc,0x9c,0xd4,0x05,0x4c,0x0c,0x44,0x95,
	0x59,0x19,0x51,0x80,0xc9,0x89,0xc1,0x10,0x58,0x18,0x50,0x81,0xc8,0x88,0xc0,0x11,
	0xd7,0x97,0xdf,0x02,0x47,0x07,0x4f,0x92,0xda,0x9a,0xd2,0x0f,0x4a,0x0a,0x42,0x9f,

	0x53,0x13,0x5b,0x86,0xc3,0x83,0xcb,0x16,0x5e,0x1e,0x56,0x8b,0xce,0x8e,0xc6,0x1b,
	0xb3,0xf3,0xbb,0xa6,0xe3,0xa3,0xeb,0xf6,0xbe,0xfe,0xb6,0xab,0xee,0xae,0xe6,0xfb,
	0x37,0x77,0x3f,0x22,0x67,0x27,0x6f,0x72,0x3a,0x7a,0x32,0x2f,0x6a,0x2a,0x62,0x7f,
	0xb9,0xf9,0xb1,0xa0,0xe9,0xa9,0xe1,0xf0,0xb8,0xf8,0xb0,0xa1,0xe8,0xa8,0xe0,0xf1,

	0x5d,0x1d,0x55,0x84,0xcd,0x8d,0xc5,0x14,0x5c,0x1c,0x54,0x85,0xcc,0x8c,0xc4,0x15,
	0xbd,0xfd,0xb5,0xa4,0xed,0xad,0xe5,0xf4,0xbc,0xfc,0xb4,0xa5,0xec,0xac,0xe4,0xf5,
	0x39,0x79,0x31,0x20,0x69,0x29,0x61,0x70,0x38,0x78,0x30,0x21,0x68,0x28,0x60,0x71,
	0xb7,0xf7,0xbf,0xa2,0xe7,0xa7,0xef,0xf2,0xba,0xfa,0xb2,0xaf,0xea,0xaa,0xe2,0xff
};

unsigned char CSStab2[256]=
{
	0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x09,0x08,0x0b,0x0a,0x0d,0x0c,0x0f,0x0e,
	0x12,0x13,0x10,0x11,0x16,0x17,0x14,0x15,0x1b,0x1a,0x19,0x18,0x1f,0x1e,0x1d,0x1c,
	0x24,0x25,0x26,0x27,0x20,0x21,0x22,0x23,0x2d,0x2c,0x2f,0x2e,0x29,0x28,0x2b,0x2a,
	0x36,0x37,0x34,0x35,0x32,0x33,0x30,0x31,0x3f,0x3e,0x3d,0x3c,0x3b,0x3a,0x39,0x38,
	0x49,0x48,0x4b,0x4a,0x4d,0x4c,0x4f,0x4e,0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,
	0x5b,0x5a,0x59,0x58,0x5f,0x5e,0x5d,0x5c,0x52,0x53,0x50,0x51,0x56,0x57,0x54,0x55,
	0x6d,0x6c,0x6f,0x6e,0x69,0x68,0x6b,0x6a,0x64,0x65,0x66,0x67,0x60,0x61,0x62,0x63,
	0x7f,0x7e,0x7d,0x7c,0x7b,0x7a,0x79,0x78,0x76,0x77,0x74,0x75,0x72,0x73,0x70,0x71,
	0x92,0x93,0x90,0x91,0x96,0x97,0x94,0x95,0x9b,0x9a,0x99,0x98,0x9f,0x9e,0x9d,0x9c,
	0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x89,0x88,0x8b,0x8a,0x8d,0x8c,0x8f,0x8e,
	0xb6,0xb7,0xb4,0xb5,0xb2,0xb3,0xb0,0xb1,0xbf,0xbe,0xbd,0xbc,0xbb,0xba,0xb9,0xb8,
	0xa4,0xa5,0xa6,0xa7,0xa0,0xa1,0xa2,0xa3,0xad,0xac,0xaf,0xae,0xa9,0xa8,0xab,0xaa,
	0xdb,0xda,0xd9,0xd8,0xdf,0xde,0xdd,0xdc,0xd2,0xd3,0xd0,0xd1,0xd6,0xd7,0xd4,0xd5,
	0xc9,0xc8,0xcb,0xca,0xcd,0xcc,0xcf,0xce,0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,
	0xff,0xfe,0xfd,0xfc,0xfb,0xfa,0xf9,0xf8,0xf6,0xf7,0xf4,0xf5,0xf2,0xf3,0xf0,0xf1,
	0xed,0xec,0xef,0xee,0xe9,0xe8,0xeb,0xea,0xe4,0xe5,0xe6,0xe7,0xe0,0xe1,0xe2,0xe3
};

unsigned char CSStab3[512]=
{
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,
	0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff
};

unsigned char CSStab4[256]=
{
	0x00,0x80,0x40,0xc0,0x20,0xa0,0x60,0xe0,0x10,0x90,0x50,0xd0,0x30,0xb0,0x70,0xf0,
	0x08,0x88,0x48,0xc8,0x28,0xa8,0x68,0xe8,0x18,0x98,0x58,0xd8,0x38,0xb8,0x78,0xf8,
	0x04,0x84,0x44,0xc4,0x24,0xa4,0x64,0xe4,0x14,0x94,0x54,0xd4,0x34,0xb4,0x74,0xf4,
	0x0c,0x8c,0x4c,0xcc,0x2c,0xac,0x6c,0xec,0x1c,0x9c,0x5c,0xdc,0x3c,0xbc,0x7c,0xfc,
	0x02,0x82,0x42,0xc2,0x22,0xa2,0x62,0xe2,0x12,0x92,0x52,0xd2,0x32,0xb2,0x72,0xf2,
	0x0a,0x8a,0x4a,0xca,0x2a,0xaa,0x6a,0xea,0x1a,0x9a,0x5a,0xda,0x3a,0xba,0x7a,0xfa,
	0x06,0x86,0x46,0xc6,0x26,0xa6,0x66,0xe6,0x16,0x96,0x56,0xd6,0x36,0xb6,0x76,0xf6,
	0x0e,0x8e,0x4e,0xce,0x2e,0xae,0x6e,0xee,0x1e,0x9e,0x5e,0xde,0x3e,0xbe,0x7e,0xfe,
	0x01,0x81,0x41,0xc1,0x21,0xa1,0x61,0xe1,0x11,0x91,0x51,0xd1,0x31,0xb1,0x71,0xf1,
	0x09,0x89,0x49,0xc9,0x29,0xa9,0x69,0xe9,0x19,0x99,0x59,0xd9,0x39,0xb9,0x79,0xf9,
	0x05,0x85,0x45,0xc5,0x25,0xa5,0x65,0xe5,0x15,0x95,0x55,0xd5,0x35,0xb5,0x75,0xf5,
	0x0d,0x8d,0x4d,0xcd,0x2d,0xad,0x6d,0xed,0x1d,0x9d,0x5d,0xdd,0x3d,0xbd,0x7d,0xfd,
	0x03,0x83,0x43,0xc3,0x23,0xa3,0x63,0xe3,0x13,0x93,0x53,0xd3,0x33,0xb3,0x73,0xf3,
	0x0b,0x8b,0x4b,0xcb,0x2b,0xab,0x6b,0xeb,0x1b,0x9b,0x5b,0xdb,0x3b,0xbb,0x7b,0xfb,
	0x07,0x87,0x47,0xc7,0x27,0xa7,0x67,0xe7,0x17,0x97,0x57,0xd7,0x37,0xb7,0x77,0xf7,
	0x0f,0x8f,0x4f,0xcf,0x2f,0xaf,0x6f,0xef,0x1f,0x9f,0x5f,0xdf,0x3f,0xbf,0x7f,0xff
};

unsigned char CSStab5[256]=
{
	0xff,0x7f,0xbf,0x3f,0xdf,0x5f,0x9f,0x1f,0xef,0x6f,0xaf,0x2f,0xcf,0x4f,0x8f,0x0f,
	0xf7,0x77,0xb7,0x37,0xd7,0x57,0x97,0x17,0xe7,0x67,0xa7,0x27,0xc7,0x47,0x87,0x07,
	0xfb,0x7b,0xbb,0x3b,0xdb,0x5b,0x9b,0x1b,0xeb,0x6b,0xab,0x2b,0xcb,0x4b,0x8b,0x0b,
	0xf3,0x73,0xb3,0x33,0xd3,0x53,0x93,0x13,0xe3,0x63,0xa3,0x23,0xc3,0x43,0x83,0x03,
	0xfd,0x7d,0xbd,0x3d,0xdd,0x5d,0x9d,0x1d,0xed,0x6d,0xad,0x2d,0xcd,0x4d,0x8d,0x0d,
	0xf5,0x75,0xb5,0x35,0xd5,0x55,0x95,0x15,0xe5,0x65,0xa5,0x25,0xc5,0x45,0x85,0x05,
	0xf9,0x79,0xb9,0x39,0xd9,0x59,0x99,0x19,0xe9,0x69,0xa9,0x29,0xc9,0x49,0x89,0x09,
	0xf1,0x71,0xb1,0x31,0xd1,0x51,0x91,0x11,0xe1,0x61,0xa1,0x21,0xc1,0x41,0x81,0x01,
	0xfe,0x7e,0xbe,0x3e,0xde,0x5e,0x9e,0x1e,0xee,0x6e,0xae,0x2e,0xce,0x4e,0x8e,0x0e,
	0xf6,0x76,0xb6,0x36,0xd6,0x56,0x96,0x16,0xe6,0x66,0xa6,0x26,0xc6,0x46,0x86,0x06,
	0xfa,0x7a,0xba,0x3a,0xda,0x5a,0x9a,0x1a,0xea,0x6a,0xaa,0x2a,0xca,0x4a,0x8a,0x0a,
	0xf2,0x72,0xb2,0x32,0xd2,0x52,0x92,0x12,0xe2,0x62,0xa2,0x22,0xc2,0x42,0x82,0x02,
	0xfc,0x7c,0xbc,0x3c,0xdc,0x5c,0x9c,0x1c,0xec,0x6c,0xac,0x2c,0xcc,0x4c,0x8c,0x0c,
	0xf4,0x74,0xb4,0x34,0xd4,0x54,0x94,0x14,0xe4,0x64,0xa4,0x24,0xc4,0x44,0x84,0x04,
	0xf8,0x78,0xb8,0x38,0xd8,0x58,0x98,0x18,0xe8,0x68,0xa8,0x28,0xc8,0x48,0x88,0x08,
	0xf0,0x70,0xb0,0x30,0xd0,0x50,0x90,0x10,0xe0,0x60,0xa0,0x20,0xc0,0x40,0x80,0x00
};

/***********************************************
 *
 * The basic CSS cipher code
 *
 *
 * With reduced mangling in the key setup
 *
 *
 ***********************************************/

void CSSdescramble( DVD40bitKey *key )
{
	unsigned int t1,t2,t3,t4,t5,t6;
	unsigned int i;

	t1= (*key)[0] ^ 0x100;
	t2= (*key)[1];
	t3= ((*key)[2]) | ((*key)[3]<<8) | ((*key)[4]<<16);
	t4=t3&7;
	t3=t3*2+8-t4;
	t5=0;

	printf( "Keystate at start: %03x %02x %08x\n", t1, t2, t3 );
	printf( "output: " );
	for( i=0 ; i < 10 ; i++ )
	{
		t4=CSStab2[t2]^CSStab3[t1];
		t2=t1>>1;
		t1=((t1&1)<<8)^t4;
		t4=CSStab5[t4];
		t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff;
		t3=(t3<<8)|t6;
		t6=CSStab4[t6];
		t5+=t6+t4;
		printf( "%02x ",t5&0xff);
		t5>>=8;
	}
	printf( "\n" );
}

void CSSdescrambleSector(DVD40bitKey *key,unsigned char *sec)
{
	unsigned int t1,t2,t3,t4,t5,t6;
	unsigned char *end=sec+0x800;

	t1=(*key)[0]^sec[0x54]|0x100;
	t2=(*key)[1]^sec[0x55];
	t3= (((*key)[2]) | ((*key)[3]<<8) | ((*key)[4]<<16)) ^ ((sec[0x56]) | (sec[0x57]<<8) | (sec[0x58]<<16));
	t4=t3&7;
	t3=t3*2+8-t4;
	sec+=0x80;
	t5=0;

	while(sec!=end)
	{
		t4=CSStab2[t2]^CSStab3[t1];
		t2=t1>>1;
		t1=((t1&1)<<8)^t4;
		t4=CSStab5[t4];
		t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff;
		t3=(t3<<8)|t6;
		t6=CSStab4[t6];
		t5+=t6+t4;
		*sec++=CSStab1[*sec]^(t5&0xff);
		t5>>=8;
	}
}

void CSStitlekey1(DVD40bitKey *key,DVD40bitKey *im)
{
	unsigned int t1,t2,t3,t4,t5,t6;
	unsigned char k[5];
	int i;

	t1=(*im)[0]|0x100;
	t2=(*im)[1];
	t3= ((*im)[2]) | ((*im)[3]<<8) | ((*im)[4]<<16);
	t4=t3&7;
	t3=t3*2+8-t4;
	t5=0;
	for(i=0;i<5;i++)
	{
		t4=CSStab2[t2]^CSStab3[t1];
		t2=t1>>1;
		t1=((t1&1)<<8)^t4;
		t4=CSStab4[t4];
		t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff;
		t3=(t3<<8)|t6;
		t6=CSStab4[t6];
		t5+=t6+t4;
		k[i]=t5&0xff;
		t5>>=8;
	}
	for(i=9;i>=0;i--)
		(*key)[CSStab0[i+1]]=k[CSStab0[i+1]]^CSStab1[(*key)[CSStab0[i+1]]]^(*key)[CSStab0[i]];
}

void CSStitlekey2(DVD40bitKey *key,DVD40bitKey *im)
{
	unsigned int t1,t2,t3,t4,t5,t6;
	unsigned char k[5];
	int i;

	t1=(*im)[0]|0x100;
	t2=(*im)[1];
	t3= ((*im)[2]) | ((*im)[3]<<8) | ((*im)[4]<<16);
	t4=t3&7;
	t3=t3*2+8-t4;
	t5=0;
	for(i=0;i<5;i++)
	{
		t4=CSStab2[t2]^CSStab3[t1];
		t2=t1>>1;
		t1=((t1&1)<<8)^t4;
		t4=CSStab4[t4];
		t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff;
		t3=(t3<<8)|t6;
		t6=CSStab5[t6];
		t5+=t6+t4;
		k[i]=t5&0xff;
		t5>>=8;
	}
	for(i=9;i>=0;i--)
		(*key)[CSStab0[i+1]]=k[CSStab0[i+1]]^CSStab1[(*key)[CSStab0[i+1]]]^(*key)[CSStab0[i]];
}

void CSSdecrypttitlekey(DVD40bitKey *tkey,DVD40bitKey *dkey)
{
	int i;
	DVD40bitKey im1,im2={0x51,0x67,0x67,0xc5,0xe0};
	
	for(i=0;i<6;i++)
		im1[i]=*dkey[i];

	CSStitlekey1(&im1,&im2);
	CSStitlekey2(tkey,&im1);
}


/********************************************************
 *
 *  The Divide and conquer attack
 *
 *  Deviced and written by Frank A. Stevenson 26 Oct 1999
 *
 *  ( frank@funcom.com )
 *  Released under the GPL license
 *
 ********************************************************/

#define KEYSTREAMBYTES 10

static unsigned char invtab4[256];

int CSScracker(int StartVal,unsigned char* pStream,DVD40bitKey *pkey)
{
	unsigned int t1,t2,t3,t4,t5,t6;
	unsigned int nTry;
	unsigned int vCandidate;
	int i;
	unsigned int j;

	/* Test that CSStab4 is a permutation */
	memset( invtab4, 0, 256 );
	for( i = 0 ; i < 256 ; i++ )
		invtab4[ CSStab4[i] ] = 1; 
	for( i = 0 ; i < 256 ; i++ )
		if( invtab4[ i ] != 1 )
		{
			printf( "Permutation error\n" );
			exit( -1 );
		}

	/* initialize the inverse of table4 */
	for( i = 0 ; i < 256 ; i++ )
		invtab4[ CSStab4[i] ] = i;

	for( nTry = StartVal ; nTry < 65536 ; nTry++ )
	{
		t1 = nTry >> 8 | 0x100;
		t2 = nTry & 0xff;
		t3 = 0;   /* not needed */
		t5 = 0;

		/* iterate cipher 4 times to reconstruct LFSR2 */
		for( i = 0 ; i < 4 ; i++ )
		{
			/* advance LFSR1 normaly */
			t4=CSStab2[t2]^CSStab3[t1];
			t2=t1>>1;
			t1=((t1&1)<<8)^t4;
			t4=CSStab5[t4];
			/* deduce t6 & t5 */
			t6 = pStream[ i ];    
			if( t5 )
			  t6 = ( t6 + 0xff )&0x0ff;
			if( t6 < t4 )
			  t6 += 0x100;
			t6 -= t4;
			t5 += t6 + t4;
			t6 = invtab4[ t6 ];
			/* printf( "%02x/%02x ", t4, t6 ); */
			/* feed / advance t3 / t5 */
			t3 = (t3 << 8) | t6;
			t5 >>= 8;
		}

		vCandidate = t3;

		/* iterate 6 more times to validate candidate key */
		for( ; i < KEYSTREAMBYTES ; i++ )
		{
			t4=CSStab2[t2]^CSStab3[t1];
			t2=t1>>1;
			t1=((t1&1)<<8)^t4;
			t4=CSStab5[t4];
			t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff;
			t3=(t3<<8)|t6;
			t6=CSStab4[t6];
			t5+=t6+t4;
			if( (t5 & 0xff) != pStream[i] ) break;
			t5>>=8;
		}

		if( i == KEYSTREAMBYTES )
		{
			/* Do 4 backwards steps of iterating t3 to deduce initial state */
			t3 = vCandidate;
			for( i = 0 ; i < 4 ; i++ )
			{
				t1 = t3 & 0xff;
				t3 = ( t3 >> 8 );
				/* easy to code, and fast enough bruteforce search for byte shifted in */
				for( j=0 ; j < 256 ; j++ )
				{
					t3 = (t3 & 0x1ffff) | ( j << 17 );
					t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff;
					if( t6 == t1 ) break;  
				}
			}
//			printf( "Candidate: t1=%03x t2=%02x t3=%08x\n", 0x100|(nTry>>8),nTry&0x0ff, t3 );

			t4 = (t3>>1) - 4;
			for(t5=0;t5<8;t5++)
			{
				if ( ((t4+t5)*2 + 8 - ((t4+t5)&7))==t3 )
				{
					(*pkey)[0] = nTry>>8;
					(*pkey)[1] = nTry & 0xFF;
					(*pkey)[2] = ((t4+t5) >> 0) & 0xFF;
					(*pkey)[3] = ((t4+t5) >> 8) & 0xFF;
					(*pkey)[4] = ((t4+t5) >> 16) & 0xFF;
					return (nTry+1);
				}
			}
		}

	}
	return (-1);
}

int CSScrackerDVD(int StartVal,unsigned char* pCrypted,unsigned char* pDecrypted,DVD40bitKey *StreamKey,DVD40bitKey *pkey)
{
int i;
unsigned char MyBuf[10];

	for (i=0;i<10;i++)
		MyBuf[i] = CSStab1[pCrypted[i]] ^ pDecrypted[i]; 

	i = CSScracker(StartVal,(unsigned char*)&MyBuf,pkey);
	if (i>=0)
	{
		(*pkey)[0] ^= (*StreamKey)[0];
		(*pkey)[1] ^= (*StreamKey)[1];
		(*pkey)[2] ^= (*StreamKey)[2];
		(*pkey)[3] ^= (*StreamKey)[3];
		(*pkey)[4] ^= (*StreamKey)[4];
	}
	return i;
}