/**css_descramble.c**Releasedundertheversion2oftheGPL.**Copyright1999DerekFawcus**ThisfilecontainsfunctionstodescrambleCSSencryptedDVDconten
t**//**Stillinprogress:Removetheuseofthebit_reverse[]tablebyrecoding*thegenerationofLFSR1.Finishcombiningthiswith*
thecssauthenticationcode.**/#include(stdio.h)#include(string.h)#include"css-descramble.h"typedefunsignedcharbyte;/***sometables
usedfordescramblingsectorsand/ordecryptingtitlekeys**/staticbytecsstab1[256]={0x33,0x73,0x3b,0x26,0x63,0x23,0x6b,0x76,0x3e,0x7e,0x36,0x2b,0x6e,0x2e,0x66,0x7b,0x
d3,0x93,0xdb,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,0
x0c,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,0x53,0x13,0x5
b,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,0xc4,0x
15,0xbd,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};staticbytelfsr1_bits0[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,0x36,0x37,0x34,0x35,0x32,0x33,0x30,0x31,0
x3f,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,0x52,0x53,0x50,0x51,0x56,0x57,0x5
4,0x55,0x6d,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,0x
bd,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,0xe9,0xe8,0
xeb,0xea,0xe4,0xe5,0xe6,0xe7,0xe0,0xe1,0xe2,0xe3};staticbytelfsr1_bits1[512]={0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24,0x49,0
x6d,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,0x00,0x2
4,0x49,0x6d,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,0x92,0x
b6,0xdb,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,0x00,0
x24,0x49,0x6d,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,0xf
f,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,0x00,0x24,0x49,0x
6d,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,0x92,0xb
6,0xdb,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};
/*Reversetheorderofthebitswithinabyte.*/staticbytebit_reverse[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,0
x5c,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,
0x61,0xe1,0x11,0x91,0x51,0xd1,0x31,0xb1,0x71,0xf1,0x09,0x89,0x49,0xc9,0x29,0xa9,0x69,0xe9,0x19,0x99,0x59,0xd9,0x39,0xb9,0x79,0xf9,0x05,0x85,0x45,0xc5,0x25,0xa5,0x65,0xe5,0x15,0x95,0x55,0xd5,0x
35,0xb5,0x75,0xf5,0x0d,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,0
x1f,0x9f,0x5f,0xdf,0x3f,0xbf,0x7f,0xff};/***thisfunctionisonlyusedinternallywhendecryptingtitlekey**/staticvoidcss_titlekey(byte*key,byte*im,byteinve
rt){unsignedintlfsr1_lo,lfsr1_hi,lfsr0,combined;byteo_lfsr0,o_lfsr1;bytek[5];inti;lfsr1_lo=im[0]|0x100;lfsr1_hi=im[1];lfsr0=((im[4]((17)|
(im[3]((9)|(im[2]((1))+8-(im[2]&7);lfsr0=(bit_reverse[lfsr0&0xff]((24)|(bit_reverse[(lfsr0))8)&0xff]((16)|(bit_reverse[(lfsr0))16)&0xff]((8)|bit_reverse[(lfsr0))24)&0xff]
;combined=0;for(i=0;i(5;++i){o_lfsr1=lfsr1_bits0[lfsr1_hi]^lfsr1_bits1[lfsr1_lo];lfsr1_hi=lfsr1_lo))1;lfsr1_lo=((lfsr1_lo&1)((8)^o_lfsr1;o_
lfsr1=bit_reverse[o_lfsr1];/*o_lfsr0=(lfsr0))7)^(lfsr0))10)^(lfsr0))11)^(lfsr0))19);*/o_lfsr0=(((((((lfsr0))8)^lfsr0)))1)^lfsr0)))3)^lfsr0)))7);lfsr0=(lfsr0))8)|(o_lfsr0
((24);combined+=(o_lfsr0^invert)+o_lfsr1;k[i]=combined&0xff;combined))=8;}key[4]=k[4]^csstab1[key[4]]^key[3];key[3]=k[3]^csstab1[key[3]]^key[2];
key[2]=k[2]^csstab1[key[2]]^key[1];key[1]=k[1]^csstab1[key[1]]^key[0];key[0]=k[0]^csstab1[key[0]]^key[4];key[4]=k[4]^csstab1[key[4]]^key[3];key[3]=k[3]^csstab1[key[3]]^key[2];
key[2]=k[2]^csstab1[key[2]]^key[1];key[1]=k[1]^csstab1[key[1]]^key[0];key[0]=k[0]^csstab1[key[0]];}/***thisfunctiondecryptsatitlekeywiththespecifieddiskkey
**tkey:theunobfuscatedtitlekey(XORedwithBusKey)*dkey:theunobfuscateddiskkey(XORedwithBusKey)*2048bytesinlength(thoughonly5bytesareneeded,seebelow)
*pkey:arrayofpointerstoplayerkeysanddiskkeyoffsets***usetheresultreturnedintkeywithcss_descramble**/intcss_decrypttitlekey(byte*tkey,byte*dkey,s
tructplaykey**pkey){bytetest[5],pretkey[5];inti=0;for(;*pkey;++pkey,++i){memcpy(pretkey,dkey+(*pkey)-)offset,5);css_titlekey(pretkey,(*pkey)-)key,0);
memcpy(test,dkey,5);css_titlekey(test,pretkey,0);if(memcmp(test,pretkey,5)==0){fprintf(stderr,"UsingKey%d\n",i+1);break;}}if(!*
pkey){fprintf(stderr,"Shit-NeedKey%d\n",i+1);return0;}css_titlekey(tkey,pretkey,0xff);return1;}/***thisfunctiondoestheactualdesc
rambling**sec:encryptedsector(2048bytes)*key:decryptedtitlekeyobtainedfromcss_decrypttitlekey**/voidcss_descramble(byte*sec,byte*key){unsignedintlf
sr1_lo,lfsr1_hi,lfsr0,combined;unsignedcharo_lfsr0,o_lfsr1;unsignedchar*end=sec+0x800;#defineSALTED(i)(key[i]^sec[0x54+(i)])lfsr1_lo=SALTED(0)|0x100;lfsr1_
hi=SALTED(1);lfsr0=((SALTED(4)((17)|(SALTED(3)((9)|(SALTED(2)((1))+8-(SALTED(2)&7);lfsr0=(bit_reverse[lfsr0&0xff]((24)|(bit_reverse[(lfsr0))8)&0xff]((16)|(
bit_reverse[(lfsr0))16)&0xff]((8)|bit_reverse[(lfsr0))24)&0xff];sec+=0x80;combined=0;while(sec!=end){o_lfsr1=lfsr1_bits0[lfsr1_hi]^lfsr1_bits1[lfsr1_lo];lfs
r1_hi=lfsr1_lo))1;lfsr1_lo=((lfsr1_lo&1)((8)^o_lfsr1;o_lfsr1=bit_reverse[o_lfsr1];/*o_lfsr0=(lfsr0))7)^(lfsr0))10)^(lfsr0))11)^(lfsr0))19);*/o_lfsr0=(((((((lfs
r0))8)^lfsr0)))1)^lfsr0)))3)^lfsr0)))7);lfsr0=(lfsr0))8)|(o_lfsr0((24);combined+=o_lfsr0+(byte)~o_lfsr1;*sec++=csstab1[*sec]^(combined&0xff);combined))=8;}
}/*###############################################################################################################################################################################################*/