*
* This code may be used under the terms of Version 2 of the GPL,
* read the file COPYING for details.
*
*/
/*
* These routines do some reordering of the supplied data before
* calling engine() to do the main work.
*
* The reordering seems similar to that done by the initial stages of
* the DES algorithm, in that it looks like it's just been done to
* try and make software decoding slower. I'm not sure that it
* actually adds anything to the security.
*
* The nature of the shuffling is that the bits of the supplied
* parameter 'varient' are reorganised (and some inverted), and
* the bytes of the parameter 'challenge' are reorganised.
*
* The reorganisation in each routine is different, and the first
* (CryptKey1) does not bother of play with the 'varient' parameter.
*
* Since this code is only run once per disk change, I've made the
* code table driven in order to improve readability.
*
* Since these routines are so similar to each other, one could even
* abstract them all to one routine supplied a parameter determining
* the nature of the reordering it has to do.
*/
for (i = 9; i >= 0; --i)
scratch[i] = challenge[perm_challenge[i]];
engine(perm_varient[varient], scratch, key);
}
/*
* We use two LFSR's (seeded from some of the input data bytes) to
* generate two streams of pseudo-random bits. These two bit streams
* are then combined by simply adding with carry to generate a final
* sequence of pseudo-random bits which is stored in the buffer that
* 'output' points to the end of - len is the size of this buffer.
*
* The first LFSR is of degree 25, and has a polynomial of:
* x^13 + x^5 + x^4 + x^1 + 1
*
* The second LSFR is of degree 17, and has a (primitive) polynomial of:
* x^15 + x^1 + 1
*
* I don't know if these polynomials are primitive modulo 2, and thus
* represent maximal-period LFSR's.
*
*
* Note that we take the output of each LFSR from the new shifted in
* bit, not the old shifted out bit. Thus for ease of use the LFSR's
* are implemented in bit reversed order.
*
*/
static void generate_bits(byte *output, int len, struct block const *s)
{
u32 lfsr0, lfsr1;
byte carry;
/* In order to ensure that the LFSR works we need to ensure that the
* initial values are non-zero. Thus when we initialise them from
* the seed, we ensure that a bit is set.
*/
lfsr0 = (s->b[0] b[1] b[2] & ~7) b[2] & 7);
lfsr1 = (s->b[3] b[4];
/*
* This encryption engine implements one of 32 variations
* one the same theme depending upon the choice in the
* varient parameter (0 - 31).
*
* The algorithm itself manipulates a 40 bit input into
* a 40 bit output.
* The parameter 'input' is 80 bits. It consists of
* the 40 bit input value that is to be encrypted followed
* by a 40 bit seed value for the pseudo random number
* generators.
*/
static void engine(int varient, byte const *input, struct block *output)
{
byte cse, term, index;
struct block temp1;
struct block temp2;
byte bits[30];
int i;
/* Feed the secret into the input values such that
* we alter the seed to the LFSR's used above, then
* generate the bits to play with.
*/
for (i = 5; --i >= 0; )
temp1.b[i] = input[5 + i] ^ Secret[i] ^ Table2[i];
generate_bits(&bits[29], sizeof bits, &temp1);
/* This term is used throughout the following to
* select one of 32 different variations on the
* algorithm.
*/
cse = Varients[varient] ^ Table2[varient];
/* Now the actual blocks doing the encryption. Each
* of these works on 40 bits at a time and are quite
* similar.
*/
for (i = 5, term = 0; --i >= 0; term = input[i]) {
index = bits[25 + i] ^ input[i];
index = Table1[index] ^ ~Table2[index] ^ cse;
for (i = 5, term = 0; --i >= 0; term = temp2.b[i]) {
index = bits[15 + i] ^ temp2.b[i];
index = Table1[index] ^ ~Table2[index] ^ cse;
index = Table2[index] ^ Table3[index] ^ term;
/*
*
* this function is only used internally when decrypting title key
*
*/
static void css_titlekey(byte *key, byte *im, byte invert)
{
unsigned int lfsr1_lo,lfsr1_hi,lfsr0,combined;
byte o_lfsr0, o_lfsr1;
byte k[5];
int i;
lfsr1_lo = im[0] | 0x100;
lfsr1_hi = im[1];
lfsr0 = ((im[4] >8)&0xff] >16)&0xff]>24)&0xff];
combined = 0;
for (i = 0; i >1;
lfsr1_lo = ((lfsr1_lo&1)>7)^(lfsr0>>10)^(lfsr0>>11)^(lfsr0>>1 9);*/
o_lfsr0 = (((((((lfsr0>>8)^lfsr0)>>1)^lfsr0)>>3)^lfsr0)>>7); lfsr0 = (lfsr0>>8)|(o_lfsr0>= 8;
}
/*
*
* this function decrypts a title key with the specified disk key
*
* tkey: the unobfuscated title key (XORed with BusKey)
* dkey: the unobfuscated disk key (XORed with BusKey)
* 2048 bytes in length (though only 5 bytes are needed, see below)
* pkey: array of pointers to player keys and disk key offsets
*
*
* use the result returned in tkey with css_descramble
*
*/
int css_decrypttitlekey(byte *tkey, byte *dkey, struct playkey **pkey)
{
byte test[5], pretkey[5];
int i = 0;
unsigned int CSStab0[11]={5,0,1,2,3,4,0,1,2,3,4};
, 0x36,0x2b,0x6e,0x2e,0x66,0x7b,
, 0xd6,0x0b,0x4e,0x0e,0x46,0x9b,
, 0x52,0x8f,0xca,0x8a,0xc2,0x1f,
, 0xd0,0x01,0x48,0x08,0x40,0x91,
, 0x34,0x25,0x6c,0x2c,0x64,0x75,
, 0xd4,0x05,0x4c,0x0c,0x44,0x95,
, 0x50,0x81,0xc8,0x88,0xc0,0x11,
, 0xd2,0x0f,0x4a,0x0a,0x42,0x9f,
, 0x56,0x8b,0xce,0x8e,0xc6,0x1b,
, 0xb6,0xab,0xee,0xae,0xe6,0xfb,
, 0x32,0x2f,0x6a,0x2a,0x62,0x7f,
, 0xb0,0xa1,0xe8,0xa8,0xe0,0xf1,
, 0x54,0x85,0xcc,0x8c,0xc4,0x15,
, 0xb4,0xa5,0xec,0xac,0xe4,0xf5,
, 0x30,0x21,0x68,0x28,0x60,0x71,
, 0xb2,0xaf,0xea,0xaa,0xe2,0xff
, 0x0b,0x0a,0x0d,0x0c,0x0f,0x0e,
, 0x19,0x18,0x1f,0x1e,0x1d,0x1c,
, 0x2f,0x2e,0x29,0x28,0x2b,0x2a,
, 0x3d,0x3c,0x3b,0x3a,0x39,0x38,
, 0x42,0x43,0x44,0x45,0x46,0x47,
, 0x50,0x51,0x56,0x57,0x54,0x55,
, 0x66,0x67,0x60,0x61,0x62,0x63,
, 0x74,0x75,0x72,0x73,0x70,0x71,
, 0x99,0x98,0x9f,0x9e,0x9d,0x9c,
, 0x8b,0x8a,0x8d,0x8c,0x8f,0x8e,
, 0xbd,0xbc,0xbb,0xba,0xb9,0xb8,
, 0xaf,0xae,0xa9,0xa8,0xab,0xaa,
, 0xd0,0xd1,0xd6,0xd7,0xd4,0xd5,
, 0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,
, 0xf4,0xf5,0xf2,0xf3,0xf0,0xf1,
, 0xe6,0xe7,0xe0,0xe1,0xe2,0xe3
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff,
, 0x49,0x6d,0x92,0xb6,0xdb,0xff
, 0x50,0xd0,0x30,0xb0,0x70,0xf0,
, 0x58,0xd8,0x38,0xb8,0x78,0xf8,
, 0x54,0xd4,0x34,0xb4,0x74,0xf4,
, 0x5c,0xdc,0x3c,0xbc,0x7c,0xfc,
, 0x52,0xd2,0x32,0xb2,0x72,0xf2,
, 0x5a,0xda,0x3a,0xba,0x7a,0xfa,
, 0x56,0xd6,0x36,0xb6,0x76,0xf6,
, 0x5e,0xde,0x3e,0xbe,0x7e,0xfe,
, 0x51,0xd1,0x31,0xb1,0x71,0xf1,
, 0x59,0xd9,0x39,0xb9,0x79,0xf9,
, 0x55,0xd5,0x35,0xb5,0x75,0xf5,
, 0x5d,0xdd,0x3d,0xbd,0x7d,0xfd,
, 0x53,0xd3,0x33,0xb3,0x73,0xf3,
, 0x5b,0xdb,0x3b,0xbb,0x7b,0xfb,
, 0x57,0xd7,0x37,0xb7,0x77,0xf7,
, 0x5f,0xdf,0x3f,0xbf,0x7f,0xff
, 0xaf,0x2f,0xcf,0x4f,0x8f,0x0f,
, 0xa7,0x27,0xc7,0x47,0x87,0x07,
, 0xab,0x2b,0xcb,0x4b,0x8b,0x0b,
, 0xa3,0x23,0xc3,0x43,0x83,0x03,
, 0xad,0x2d,0xcd,0x4d,0x8d,0x0d,
, 0xa5,0x25,0xc5,0x45,0x85,0x05,
, 0xa9,0x29,0xc9,0x49,0x89,0x09,
, 0xa1,0x21,0xc1,0x41,0x81,0x01,
, 0xae,0x2e,0xce,0x4e,0x8e,0x0e,
, 0xa6,0x26,0xc6,0x46,0x86,0x06,
, 0xaa,0x2a,0xca,0x4a,0x8a,0x0a,
, 0xa2,0x22,0xc2,0x42,0x82,0x02,
, 0xac,0x2c,0xcc,0x4c,0x8c,0x0c,
, 0xa4,0x24,0xc4,0x44,0x84,0x04,
, 0xa8,0x28,0xc8,0x48,0x88,0x08,
, 0xa0,0x20,0xc0,0x40,0x80,0x00
t ab0[i+1]]]^key[CSStab0[i]];
t ab0[i+1]]]^key[CSStab0[i]];
unsigned char CSStab1[256]=
{
0x33,0x73,0x3b,0x26,0x63,0x23,0x6b,0x76,0x3e,0x7e
0xd3,0x93,0xdb,0x06,0x43,0x03,0x4b,0x96,0xde,0x9e
0x57,0x17,0x5f,0x82,0xc7,0x87,0xcf,0x12,0x5a,0x1a
0xd9,0x99,0xd1,0x00,0x49,0x09,0x41,0x90,0xd8,0x98
0x3d,0x7d,0x35,0x24,0x6d,0x2d,0x65,0x74,0x3c,0x7c
0xdd,0x9d,0xd5,0x04,0x4d,0x0d,0x45,0x94,0xdc,0x9c
0x59,0x19,0x51,0x80,0xc9,0x89,0xc1,0x10,0x58,0x18
0xd7,0x97,0xdf,0x02,0x47,0x07,0x4f,0x92,0xda,0x9a
0x53,0x13,0x5b,0x86,0xc3,0x83,0xcb,0x16,0x5e,0x1e
0xb3,0xf3,0xbb,0xa6,0xe3,0xa3,0xeb,0xf6,0xbe,0xfe
0x37,0x77,0x3f,0x22,0x67,0x27,0x6f,0x72,0x3a,0x7a
0xb9,0xf9,0xb1,0xa0,0xe9,0xa9,0xe1,0xf0,0xb8,0xf8
0x5d,0x1d,0x55,0x84,0xcd,0x8d,0xc5,0x14,0x5c,0x1c
0xbd,0xfd,0xb5,0xa4,0xed,0xad,0xe5,0xf4,0xbc,0xfc
0x39,0x79,0x31,0x20,0x69,0x29,0x61,0x70,0x38,0x78
0xb7,0xf7,0xbf,0xa2,0xe7,0xa7,0xef,0xf2,0xba,0xfa
};
unsigned char CSStab2[256]=
{
0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x09,0x08
0x12,0x13,0x10,0x11,0x16,0x17,0x14,0x15,0x1b,0x1a
0x24,0x25,0x26,0x27,0x20,0x21,0x22,0x23,0x2d,0x2c
0x36,0x37,0x34,0x35,0x32,0x33,0x30,0x31,0x3f,0x3e
0x49,0x48,0x4b,0x4a,0x4d,0x4c,0x4f,0x4e,0x40,0x41
0x5b,0x5a,0x59,0x58,0x5f,0x5e,0x5d,0x5c,0x52,0x53
0x6d,0x6c,0x6f,0x6e,0x69,0x68,0x6b,0x6a,0x64,0x65
0x7f,0x7e,0x7d,0x7c,0x7b,0x7a,0x79,0x78,0x76,0x77
0x92,0x93,0x90,0x91,0x96,0x97,0x94,0x95,0x9b,0x9a
0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x89,0x88
0xb6,0xb7,0xb4,0xb5,0xb2,0xb3,0xb0,0xb1,0xbf,0xbe
0xa4,0xa5,0xa6,0xa7,0xa0,0xa1,0xa2,0xa3,0xad,0xac
0xdb,0xda,0xd9,0xd8,0xdf,0xde,0xdd,0xdc,0xd2,0xd3
0xc9,0xc8,0xcb,0xca,0xcd,0xcc,0xcf,0xce,0xc0,0xc1
0xff,0xfe,0xfd,0xfc,0xfb,0xfa,0xf9,0xf8,0xf6,0xf7
0xed,0xec,0xef,0xee,0xe9,0xe8,0xeb,0xea,0xe4,0xe5
};
unsigned char CSStab3[512]=
{
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff,0x00,0x24
};
unsigned char CSStab4[256]=
{
0x00,0x80,0x40,0xc0,0x20,0xa0,0x60,0xe0,0x10,0x90
0x08,0x88,0x48,0xc8,0x28,0xa8,0x68,0xe8,0x18,0x98
0x04,0x84,0x44,0xc4,0x24,0xa4,0x64,0xe4,0x14,0x94
0x0c,0x8c,0x4c,0xcc,0x2c,0xac,0x6c,0xec,0x1c,0x9c
0x02,0x82,0x42,0xc2,0x22,0xa2,0x62,0xe2,0x12,0x92
0x0a,0x8a,0x4a,0xca,0x2a,0xaa,0x6a,0xea,0x1a,0x9a
0x06,0x86,0x46,0xc6,0x26,0xa6,0x66,0xe6,0x16,0x96
0x0e,0x8e,0x4e,0xce,0x2e,0xae,0x6e,0xee,0x1e,0x9e
0x01,0x81,0x41,0xc1,0x21,0xa1,0x61,0xe1,0x11,0x91
0x09,0x89,0x49,0xc9,0x29,0xa9,0x69,0xe9,0x19,0x99
0x05,0x85,0x45,0xc5,0x25,0xa5,0x65,0xe5,0x15,0x95
0x0d,0x8d,0x4d,0xcd,0x2d,0xad,0x6d,0xed,0x1d,0x9d
0x03,0x83,0x43,0xc3,0x23,0xa3,0x63,0xe3,0x13,0x93
0x0b,0x8b,0x4b,0xcb,0x2b,0xab,0x6b,0xeb,0x1b,0x9b
0x07,0x87,0x47,0xc7,0x27,0xa7,0x67,0xe7,0x17,0x97
0x0f,0x8f,0x4f,0xcf,0x2f,0xaf,0x6f,0xef,0x1f,0x9f
};
unsigned char CSStab5[256]=
{
0xff,0x7f,0xbf,0x3f,0xdf,0x5f,0x9f,0x1f,0xef,0x6f
0xf7,0x77,0xb7,0x37,0xd7,0x57,0x97,0x17,0xe7,0x67
0xfb,0x7b,0xbb,0x3b,0xdb,0x5b,0x9b,0x1b,0xeb,0x6b
0xf3,0x73,0xb3,0x33,0xd3,0x53,0x93,0x13,0xe3,0x63
0xfd,0x7d,0xbd,0x3d,0xdd,0x5d,0x9d,0x1d,0xed,0x6d
0xf5,0x75,0xb5,0x35,0xd5,0x55,0x95,0x15,0xe5,0x65
0xf9,0x79,0xb9,0x39,0xd9,0x59,0x99,0x19,0xe9,0x69
0xf1,0x71,0xb1,0x31,0xd1,0x51,0x91,0x11,0xe1,0x61
0xfe,0x7e,0xbe,0x3e,0xde,0x5e,0x9e,0x1e,0xee,0x6e
0xf6,0x76,0xb6,0x36,0xd6,0x56,0x96,0x16,0xe6,0x66
0xfa,0x7a,0xba,0x3a,0xda,0x5a,0x9a,0x1a,0xea,0x6a
0xf2,0x72,0xb2,0x32,0xd2,0x52,0x92,0x12,0xe2,0x62
0xfc,0x7c,0xbc,0x3c,0xdc,0x5c,0x9c,0x1c,0xec,0x6c
0xf4,0x74,0xb4,0x34,0xd4,0x54,0x94,0x14,0xe4,0x64
0xf8,0x78,0xb8,0x38,0xd8,0x58,0x98,0x18,0xe8,0x68
0xf0,0x70,0xb0,0x30,0xd0,0x50,0x90,0x10,0xe0,0x60
};
void CSSdescramble(unsigned char *sec,unsigned char *key)
{
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=(*((unsigned int *)(key+2)))^(*((unsigned int *)(sec+0x56)));
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(unsigned char *key,unsigned char *im)
{
unsigned int t1,t2,t3,t4,t5,t6;
unsigned char k[5];
int i;
t1=im[0]|0x100;
t2=im[1];
t3=*((unsigned int *)(im+2));
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[CSS
}
void CSStitlekey2(unsigned char *key,unsigned char *im)
{
unsigned int t1,t2,t3,t4,t5,t6;
unsigned char k[5];
int i;
t1=im[0]|0x100;
t2=im[1];
t3=*((unsigned int *)(im+2));
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[CSS
}
void CSSdecrypttitlekey(unsigned char *tkey,unsigned char *dkey)
{
int i;
unsigned char im1[6];
unsigned char im2[6]={0x51,0x67,0x67,0xc5,0xe0,0x00};
for(i=0;i<6;i++)
im1[i]=dkey[i];
CSStitlekey1(im1,im2);
CSStitlekey2(tkey,im1);
}
DeCSS must live! Mirror a copy today!
*
* This code may be used under the terms of Version 2 of the GPL,
* read the file COPYING for details.
*
*/
/*
* These routines do some reordering of the supplied data before
* calling engine() to do the main work.
*
* The reordering seems similar to that done by the initial stages of
* the DES algorithm, in that it looks like it's just been done to
* try and make software decoding slower. I'm not sure that it
* actually adds anything to the security.
*
* The nature of the shuffling is that the bits of the supplied
* parameter 'varient' are reorganised (and some inverted), and
* the bytes of the parameter 'challenge' are reorganised.
*
* The reorganisation in each routine is different, and the first
* (CryptKey1) does not bother of play with the 'varient' parameter.
*
* Since this code is only run once per disk change, I've made the
* code table driven in order to improve readability.
*
* Since these routines are so similar to each other, one could even
* abstract them all to one routine supplied a parameter determining
* the nature of the reordering it has to do.
*/
#include "css-auth.h"
typedef unsigned long u32;
static void engine(int varient, byte const *input, struct block *output);
void CryptKey1(int varient, byte const *challenge, struct block *key)
{
static byte perm_challenge[] = {1,3,0,7,5, 2,9,6,4,8};
byte scratch[10];
int i;
for (i = 9; i >= 0; --i)
scratch[i] = challenge[perm_challenge[i]];
engine(varient, scratch, key);
}
/* This shuffles the bits in varient to make perm_varient such that
* 4 -> !3
* 3 -> 4
* varient bits: 2 -> 0 perm_varient bits
* 1 -> 2
* 0 -> !1
*/
void CryptKey2(int varient, byte const *challenge, struct block *key)
{
static byte perm_challenge[] = {6,1,9,3,8, 5,7,4,0,2};
static byte perm_varient[] = {
0x0a, 0x08, 0x0e, 0x0c, 0x0b, 0x09, 0x0f, 0x0d,
0x1a, 0x18, 0x1e, 0x1c, 0x1b, 0x19, 0x1f, 0x1d,
0x02, 0x00, 0x06, 0x04, 0x03, 0x01, 0x07, 0x05,
0x12, 0x10, 0x16, 0x14, 0x13, 0x11, 0x17, 0x15};
byte scratch[10];
int i;
for (i = 9; i >= 0; --i)
scratch[i] = challenge[perm_challenge[i]];
engine(perm_varient[varient], scratch, key);
}
/* This shuffles the bits in varient to make perm_varient such that
* 4 -> 0
* 3 -> !1
* varient bits: 2 -> !4 perm_varient bits
* 1 -> 2
* 0 -> 3
*/
void CryptBusKey(int varient, byte const *challenge, struct block *key)
{
static byte perm_challenge[] = {4,0,3,5,7, 2,8,6,1,9};
static byte perm_varient[] = {
0x12, 0x1a, 0x16, 0x1e, 0x02, 0x0a, 0x06, 0x0e,
0x10, 0x18, 0x14, 0x1c, 0x00, 0x08, 0x04, 0x0c,
0x13, 0x1b, 0x17, 0x1f, 0x03, 0x0b, 0x07, 0x0f,
0x11, 0x19, 0x15, 0x1d, 0x01, 0x09, 0x05, 0x0d};
byte scratch[10];
int i;
for (i = 9; i >= 0; --i)
scratch[i] = challenge[perm_challenge[i]];
engine(perm_varient[varient], scratch, key);
}
/*
* We use two LFSR's (seeded from some of the input data bytes) to
* generate two streams of pseudo-random bits. These two bit streams
* are then combined by simply adding with carry to generate a final
* sequence of pseudo-random bits which is stored in the buffer that
* 'output' points to the end of - len is the size of this buffer.
*
* The first LFSR is of degree 25, and has a polynomial of:
* x^13 + x^5 + x^4 + x^1 + 1
*
* The second LSFR is of degree 17, and has a (primitive) polynomial of:
* x^15 + x^1 + 1
*
* I don't know if these polynomials are primitive modulo 2, and thus
* represent maximal-period LFSR's.
*
*
* Note that we take the output of each LFSR from the new shifted in
* bit, not the old shifted out bit. Thus for ease of use the LFSR's
* are implemented in bit reversed order.
*
*/
static void generate_bits(byte *output, int len, struct block const *s)
{
u32 lfsr0, lfsr1;
byte carry;
* initial values are non-zero. Thus when we initialise them from
* the seed, we ensure that a bit is set.
*/
lfsr0 = (s->b[0] b[1] b[2] & ~7) b[2] & 7);
lfsr1 = (s->b[3] b[4];
++output;
carry = 0;
do {
int bit;
byte val;
for (bit = 0, val = 0; bit > 24) ^ (lfsr0 >> 21) ^ (lfsr0 >> 20) ^ (lfsr0 >> 12)) & 1;
lfsr0 = (lfsr0 > 16) ^ (lfsr1 >> 2)) & 1;
lfsr1 = (lfsr1 > 1) & 1)
combined = !o_lfsr1 + carry + !o_lfsr0;
carry = BIT1(combined);
val |= BIT0(combined) 0);
}
static byte Secret[];
static byte Varients[];
static byte Table0[];
static byte Table1[];
static byte Table2[];
static byte Table3[];
/*
* This encryption engine implements one of 32 variations
* one the same theme depending upon the choice in the
* varient parameter (0 - 31).
*
* The algorithm itself manipulates a 40 bit input into
* a 40 bit output.
* The parameter 'input' is 80 bits. It consists of
* the 40 bit input value that is to be encrypted followed
* by a 40 bit seed value for the pseudo random number
* generators.
*/
static void engine(int varient, byte const *input, struct block *output)
{
byte cse, term, index;
struct block temp1;
struct block temp2;
byte bits[30];
int i;
* we alter the seed to the LFSR's used above, then
* generate the bits to play with.
*/
for (i = 5; --i >= 0; )
temp1.b[i] = input[5 + i] ^ Secret[i] ^ Table2[i];
generate_bits(&bits[29], sizeof bits, &temp1);
* select one of 32 different variations on the
* algorithm.
*/
cse = Varients[varient] ^ Table2[varient];
* of these works on 40 bits at a time and are quite
* similar.
*/
for (i = 5, term = 0; --i >= 0; term = input[i]) {
index = bits[25 + i] ^ input[i];
index = Table1[index] ^ ~Table2[index] ^ cse;
temp1.b[i] = Table2[index] ^ Table3[index] ^ term;
}
temp1.b[4] ^= temp1.b[0];
for (i = 5, term = 0; --i >= 0; term = temp1.b[i]) {
index = bits[20 + i] ^ temp1.b[i];
index = Table1[index] ^ ~Table2[index] ^ cse;
temp2.b[i] = Table2[index] ^ Table3[index] ^ term;
}
temp2.b[4] ^= temp2.b[0];
for (i = 5, term = 0; --i >= 0; term = temp2.b[i]) {
index = bits[15 + i] ^ temp2.b[i];
index = Table1[index] ^ ~Table2[index] ^ cse;
index = Table2[index] ^ Table3[index] ^ term;
temp1.b[i] = Table0[index] ^ Table2[index];
}
temp1.b[4] ^= temp1.b[0];
for (i = 5, term = 0; --i >= 0; term = temp1.b[i]) {
index = bits[10 + i] ^ temp1.b[i];
index = Table1[index] ^ ~Table2[index] ^ cse;
index = Table2[index] ^ Table3[index] ^ term;
temp2.b[i] = Table0[index] ^ Table2[index];
}
temp2.b[4] ^= temp2.b[0];
for (i = 5, term = 0; --i >= 0; term = temp2.b[i]) {
index = bits[5 + i] ^ temp2.b[i];
index = Table1[index] ^ ~Table2[index] ^ cse;
temp1.b[i] = Table2[index] ^ Table3[index] ^ term;
}
temp1.b[4] ^= temp1.b[0];
for (i = 5, term = 0; --i >= 0; term = temp1.b[i]) {
index = bits[i] ^ temp1.b[i];
index = Table1[index] ^ ~Table2[index] ^ cse;
output->b[i] = Table2[index] ^ Table3[index] ^ term;
}
}
static byte Varients[] = {
0xB7, 0x74, 0x85, 0xD0, 0xCC, 0xDB, 0xCA, 0x73,
0x03, 0xFE, 0x31, 0x03, 0x52, 0xE0, 0xB7, 0x42,
0x63, 0x16, 0xF2, 0x2A, 0x79, 0x52, 0xFF, 0x1B,
0x7A, 0x11, 0xCA, 0x1A, 0x9B, 0x40, 0xAD, 0x01};
static byte Secret[] = {0x55, 0xD6, 0xC4, 0xC5, 0x28};
static byte Table0[] = {
0xB7, 0xF4, 0x82, 0x57, 0xDA, 0x4D, 0xDB, 0xE2,
0x2F, 0x52, 0x1A, 0xA8, 0x68, 0x5A, 0x8A, 0xFF,
0xFB, 0x0E, 0x6D, 0x35, 0xF7, 0x5C, 0x76, 0x12,
0xCE, 0x25, 0x79, 0x29, 0x39, 0x62, 0x08, 0x24,
0xA5, 0x85, 0x7B, 0x56, 0x01, 0x23, 0x68, 0xCF,
0x0A, 0xE2, 0x5A, 0xED, 0x3D, 0x59, 0xB0, 0xA9,
0xB0, 0x2C, 0xF2, 0xB8, 0xEF, 0x32, 0xA9, 0x40,
0x80, 0x71, 0xAF, 0x1E, 0xDE, 0x8F, 0x58, 0x88,
0xB8, 0x3A, 0xD0, 0xFC, 0xC4, 0x1E, 0xB5, 0xA0,
0xBB, 0x3B, 0x0F, 0x01, 0x7E, 0x1F, 0x9F, 0xD9,
0xAA, 0xB8, 0x3D, 0x9D, 0x74, 0x1E, 0x25, 0xDB,
0x37, 0x56, 0x8F, 0x16, 0xBA, 0x49, 0x2B, 0xAC,
0xD0, 0xBD, 0x95, 0x20, 0xBE, 0x7A, 0x28, 0xD0,
0x51, 0x64, 0x63, 0x1C, 0x7F, 0x66, 0x10, 0xBB,
0xC4, 0x56, 0x1A, 0x04, 0x6E, 0x0A, 0xEC, 0x9C,
0xD6, 0xE8, 0x9A, 0x7A, 0xCF, 0x8C, 0xDB, 0xB1,
0xEF, 0x71, 0xDE, 0x31, 0xFF, 0x54, 0x3E, 0x5E,
0x07, 0x69, 0x96, 0xB0, 0xCF, 0xDD, 0x9E, 0x47,
0xC7, 0x96, 0x8F, 0xE4, 0x2B, 0x59, 0xC6, 0xEE,
0xB9, 0x86, 0x9A, 0x64, 0x84, 0x72, 0xE2, 0x5B,
0xA2, 0x96, 0x58, 0x99, 0x50, 0x03, 0xF5, 0x38,
0x4D, 0x02, 0x7D, 0xE7, 0x7D, 0x75, 0xA7, 0xB8,
0x67, 0x87, 0x84, 0x3F, 0x1D, 0x11, 0xE5, 0xFC,
0x1E, 0xD3, 0x83, 0x16, 0xA5, 0x29, 0xF6, 0xC7,
0x15, 0x61, 0x29, 0x1A, 0x43, 0x4F, 0x9B, 0xAF,
0xC5, 0x87, 0x34, 0x6C, 0x0F, 0x3B, 0xA8, 0x1D,
0x45, 0x58, 0x25, 0xDC, 0xA8, 0xA3, 0x3B, 0xD1,
0x79, 0x1B, 0x48, 0xF2, 0xE9, 0x93, 0x1F, 0xFC,
0xDB, 0x2A, 0x90, 0xA9, 0x8A, 0x3D, 0x39, 0x18,
0xA3, 0x8E, 0x58, 0x6C, 0xE0, 0x12, 0xBB, 0x25,
0xCD, 0x71, 0x22, 0xA2, 0x64, 0xC6, 0xE7, 0xFB,
0xAD, 0x94, 0x77, 0x04, 0x9A, 0x39, 0xCF, 0x7C};
static byte Table1[] = {
0x8C, 0x47, 0xB0, 0xE1, 0xEB, 0xFC, 0xEB, 0x56,
0x10, 0xE5, 0x2C, 0x1A, 0x5D, 0xEF, 0xBE, 0x4F,
0x08, 0x75, 0x97, 0x4B, 0x0E, 0x25, 0x8E, 0x6E,
0x39, 0x5A, 0x87, 0x53, 0xC4, 0x1F, 0xF4, 0x5C,
0x4E, 0xE6, 0x99, 0x30, 0xE0, 0x42, 0x88, 0xAB,
0xE5, 0x85, 0xBC, 0x8F, 0xD8, 0x3C, 0x54, 0xC9,
0x53, 0x47, 0x18, 0xD6, 0x06, 0x5B, 0x41, 0x2C,
0x67, 0x1E, 0x41, 0x74, 0x33, 0xE2, 0xB4, 0xE0,
0x23, 0x29, 0x42, 0xEA, 0x55, 0x0F, 0x25, 0xB4,
0x24, 0x2C, 0x99, 0x13, 0xEB, 0x0A, 0x0B, 0xC9,
0xF9, 0x63, 0x67, 0x43, 0x2D, 0xC7, 0x7D, 0x07,
0x60, 0x89, 0xD1, 0xCC, 0xE7, 0x94, 0x77, 0x74,
0x9B, 0x7E, 0xD7, 0xE6, 0xFF, 0xBB, 0x68, 0x14,
0x1E, 0xA3, 0x25, 0xDE, 0x3A, 0xA3, 0x54, 0x7B,
0x87, 0x9D, 0x50, 0xCA, 0x27, 0xC3, 0xA4, 0x50,
0x91, 0x27, 0xD4, 0xB0, 0x82, 0x41, 0x97, 0x79,
0x94, 0x82, 0xAC, 0xC7, 0x8E, 0xA5, 0x4E, 0xAA,
0x78, 0x9E, 0xE0, 0x42, 0xBA, 0x28, 0xEA, 0xB7,
0x74, 0xAD, 0x35, 0xDA, 0x92, 0x60, 0x7E, 0xD2,
0x0E, 0xB9, 0x24, 0x5E, 0x39, 0x4F, 0x5E, 0x63,
0x09, 0xB5, 0xFA, 0xBF, 0xF1, 0x22, 0x55, 0x1C,
0xE2, 0x25, 0xDB, 0xC5, 0xD8, 0x50, 0x03, 0x98,
0xC4, 0xAC, 0x2E, 0x11, 0xB4, 0x38, 0x4D, 0xD0,
0xB9, 0xFC, 0x2D, 0x3C, 0x08, 0x04, 0x5A, 0xEF,
0xCE, 0x32, 0xFB, 0x4C, 0x92, 0x1E, 0x4B, 0xFB,
0x1A, 0xD0, 0xE2, 0x3E, 0xDA, 0x6E, 0x7C, 0x4D,
0x56, 0xC3, 0x3F, 0x42, 0xB1, 0x3A, 0x23, 0x4D,
0x6E, 0x84, 0x56, 0x68, 0xF4, 0x0E, 0x03, 0x64,
0xD0, 0xA9, 0x92, 0x2F, 0x8B, 0xBC, 0x39, 0x9C,
0xAC, 0x09, 0x5E, 0xEE, 0xE5, 0x97, 0xBF, 0xA5,
0xCE, 0xFA, 0x28, 0x2C, 0x6D, 0x4F, 0xEF, 0x77,
0xAA, 0x1B, 0x79, 0x8E, 0x97, 0xB4, 0xC3, 0xF4};
static byte Table2[] = {
0xB7, 0x75, 0x81, 0xD5, 0xDC, 0xCA, 0xDE, 0x66,
0x23, 0xDF, 0x15, 0x26, 0x62, 0xD1, 0x83, 0x77,
0xE3, 0x97, 0x76, 0xAF, 0xE9, 0xC3, 0x6B, 0x8E,
0xDA, 0xB0, 0x6E, 0xBF, 0x2B, 0xF1, 0x19, 0xB4,
0x95, 0x34, 0x48, 0xE4, 0x37, 0x94, 0x5D, 0x7B,
0x36, 0x5F, 0x65, 0x53, 0x07, 0xE2, 0x89, 0x11,
0x98, 0x85, 0xD9, 0x12, 0xC1, 0x9D, 0x84, 0xEC,
0xA4, 0xD4, 0x88, 0xB8, 0xFC, 0x2C, 0x79, 0x28,
0xD8, 0xDB, 0xB3, 0x1E, 0xA2, 0xF9, 0xD0, 0x44,
0xD7, 0xD6, 0x60, 0xEF, 0x14, 0xF4, 0xF6, 0x31,
0xD2, 0x41, 0x46, 0x67, 0x0A, 0xE1, 0x58, 0x27,
0x43, 0xA3, 0xF8, 0xE0, 0xC8, 0xBA, 0x5A, 0x5C,
0x80, 0x6C, 0xC6, 0xF2, 0xE8, 0xAD, 0x7D, 0x04,
0x0D, 0xB9, 0x3C, 0xC2, 0x25, 0xBD, 0x49, 0x63,
0x8C, 0x9F, 0x51, 0xCE, 0x20, 0xC5, 0xA1, 0x50,
0x92, 0x2D, 0xDD, 0xBC, 0x8D, 0x4F, 0x9A, 0x71,
0x2F, 0x30, 0x1D, 0x73, 0x39, 0x13, 0xFB, 0x1A,
0xCB, 0x24, 0x59, 0xFE, 0x05, 0x96, 0x57, 0x0F,
0x1F, 0xCF, 0x54, 0xBE, 0xF5, 0x06, 0x1B, 0xB2,
0x6D, 0xD3, 0x4D, 0x32, 0x56, 0x21, 0x33, 0x0B,
0x52, 0xE7, 0xAB, 0xEB, 0xA6, 0x74, 0x00, 0x4C,
0xB1, 0x7F, 0x82, 0x99, 0x87, 0x0E, 0x5E, 0xC0,
0x8F, 0xEE, 0x6F, 0x55, 0xF3, 0x7E, 0x08, 0x90,
0xFA, 0xB6, 0x64, 0x70, 0x47, 0x4A, 0x17, 0xA7,
0xB5, 0x40, 0x8A, 0x38, 0xE5, 0x68, 0x3E, 0x8B,
0x69, 0xAA, 0x9B, 0x42, 0xA5, 0x10, 0x01, 0x35,
0xFD, 0x61, 0x9E, 0xE6, 0x16, 0x9C, 0x86, 0xED,
0xCD, 0x2E, 0xFF, 0xC4, 0x5B, 0xA0, 0xAE, 0xCC,
0x4B, 0x3B, 0x03, 0xBB, 0x1C, 0x2A, 0xAC, 0x0C,
0x3F, 0x93, 0xC7, 0x72, 0x7A, 0x09, 0x22, 0x3D,
0x45, 0x78, 0xA9, 0xA8, 0xEA, 0xC9, 0x6A, 0xF7,
0x29, 0x91, 0xF0, 0x02, 0x18, 0x3A, 0x4E, 0x7C};
static byte Table3[] = {
0x73, 0x51, 0x95, 0xE1, 0x12, 0xE4, 0xC0, 0x58,
0xEE, 0xF2, 0x08, 0x1B, 0xA9, 0xFA, 0x98, 0x4C,
0xA7, 0x33, 0xE2, 0x1B, 0xA7, 0x6D, 0xF5, 0x30,
0x97, 0x1D, 0xF3, 0x02, 0x60, 0x5A, 0x82, 0x0F,
0x91, 0xD0, 0x9C, 0x10, 0x39, 0x7A, 0x83, 0x85,
0x3B, 0xB2, 0xB8, 0xAE, 0x0C, 0x09, 0x52, 0xEA,
0x1C, 0xE1, 0x8D, 0x66, 0x4F, 0xF3, 0xDA, 0x92,
0x29, 0xB9, 0xD5, 0xC5, 0x77, 0x47, 0x22, 0x53,
0x14, 0xF7, 0xAF, 0x22, 0x64, 0xDF, 0xC6, 0x72,
0x12, 0xF3, 0x75, 0xDA, 0xD7, 0xD7, 0xE5, 0x02,
0x9E, 0xED, 0xDA, 0xDB, 0x4C, 0x47, 0xCE, 0x91,
0x06, 0x06, 0x6D, 0x55, 0x8B, 0x19, 0xC9, 0xEF,
0x8C, 0x80, 0x1A, 0x0E, 0xEE, 0x4B, 0xAB, 0xF2,
0x08, 0x5C, 0xE9, 0x37, 0x26, 0x5E, 0x9A, 0x90,
0x00, 0xF3, 0x0D, 0xB2, 0xA6, 0xA3, 0xF7, 0x26,
0x17, 0x48, 0x88, 0xC9, 0x0E, 0x2C, 0xC9, 0x02,
0xE7, 0x18, 0x05, 0x4B, 0xF3, 0x39, 0xE1, 0x20,
0x02, 0x0D, 0x40, 0xC7, 0xCA, 0xB9, 0x48, 0x30,
0x57, 0x67, 0xCC, 0x06, 0xBF, 0xAC, 0x81, 0x08,
0x24, 0x7A, 0xD4, 0x8B, 0x19, 0x8E, 0xAC, 0xB4,
0x5A, 0x0F, 0x73, 0x13, 0xAC, 0x9E, 0xDA, 0xB6,
0xB8, 0x96, 0x5B, 0x60, 0x88, 0xE1, 0x81, 0x3F,
0x07, 0x86, 0x37, 0x2D, 0x79, 0x14, 0x52, 0xEA,
0x73, 0xDF, 0x3D, 0x09, 0xC8, 0x25, 0x48, 0xD8,
0x75, 0x60, 0x9A, 0x08, 0x27, 0x4A, 0x2C, 0xB9,
0xA8, 0x8B, 0x8A, 0x73, 0x62, 0x37, 0x16, 0x02,
0xBD, 0xC1, 0x0E, 0x56, 0x54, 0x3E, 0x14, 0x5F,
0x8C, 0x8F, 0x6E, 0x75, 0x1C, 0x07, 0x39, 0x7B,
0x4B, 0xDB, 0xD3, 0x4B, 0x1E, 0xC8, 0x7E, 0xFE,
0x3E, 0x72, 0x16, 0x83, 0x7D, 0xEE, 0xF5, 0xCA,
0xC5, 0x18, 0xF9, 0xD8, 0x68, 0xAB, 0x38, 0x85,
0xA8, 0xF0, 0xA1, 0x73, 0x9F, 0x5D, 0x19, 0x0B,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x33, 0x72, 0x39, 0x25, 0x67, 0x26, 0x6D, 0x71,
0x36, 0x77, 0x3C, 0x20, 0x62, 0x23, 0x68, 0x74,
0xC3, 0x82, 0xC9, 0x15, 0x57, 0x16, 0x5D, 0x81};
3,
0x0b,0x8b,0x4b,0xcb,0x2b,0xab,0x6b,0xeb,0x1b,0x9b
0x07,0x87,0x47,0xc7,0x27,0xa7,0x67,0xe7,0x17,0x97
0x0f,0x8f,0x4f,0xcf,0x2f,0xaf,0x6f,0xef,0x1f,0x9f
};
/*
*
* this function is only used internally when decrypting title key
*
*/
static void css_titlekey(byte *key, byte *im, byte invert)
{
unsigned int lfsr1_lo,lfsr1_hi,lfsr0,combined;
byte o_lfsr0, o_lfsr1;
byte k[5];
int i;
lfsr1_lo = im[0] | 0x100;
lfsr1_hi = im[1];
lfsr0 = ((im[4] >8)&0xff] >16)&0xff]>24)&0xff];
combined = 0;
for (i = 0; i >1;
lfsr1_lo = ((lfsr1_lo&1)>7)^(lfsr0>>10)^(lfsr0>>11)^(lfsr0>>
o_lfsr0 = (((((((lfsr0>>8)^lfsr0)>>1)^lfsr0)>>3)^lfsr0)>>7)
lfsr0 = (lfsr0>>8)|(o_lfsr0>= 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]];
}
/*
*
* this function decrypts a title key with the specified disk key
*
* tkey: the unobfuscated title key (XORed with BusKey)
* dkey: the unobfuscated disk key (XORed with BusKey)
* 2048 bytes in length (though only 5 bytes are needed, see below)
* pkey: array of pointers to player keys and disk key offsets
*
*
* use the result returned in tkey with css_descramble
*
*/
int css_decrypttitlekey(byte *tkey, byte *dkey, struct playkey **pkey)
{
byte test[5], pretkey[5];
int i = 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, "Using Key %d\n", i+1);
break;
}
}
if (!*pkey) {
fprintf(stderr, "Shit - Need Key %d\n", i+1);
return 0;
}
css_titlekey(tkey, pretkey, 0xff);
return 1;
}
/*
*
* this function does the actual descrambling
*
* sec: encrypted sector (2048 bytes)
* key: decrypted title key obtained from css_decrypttitlekey
*
*/
void css_descramble(byte *sec,byte *key)
{
unsigned int lfsr1_lo,lfsr1_hi,lfsr0,combined;
unsigned char o_lfsr0, o_lfsr1;
unsigned char *end = sec + 0x800;
#define SALTED(i) (key[i] ^ sec[0x54 + (i)])
lfsr1_lo = SALTED(0) | 0x100;
lfsr1_hi = SALTED(1);
lfsr0 = ((SALTED(4) >8)&0xff] >16)&0xff]>24)&0xff];
sec+=0x80;
combined = 0;
while (sec != end) {
o_lfsr1 = lfsr1_bits0[lfsr1_hi] ^ lfsr1_bits1[lfsr1_lo];
lfsr1_hi = lfsr1_lo>>1;
lfsr1_lo = ((lfsr1_lo&1)>7)^(lfsr0>>10)^(lfsr0>>11)^(lfsr0>>
o_lfsr0 = (((((((lfsr0>>8)^lfsr0)>>1)^lfsr0)>>3)^lfsr0)>>7)
lfsr0 = (lfsr0>>8)|(o_lfsr0>= 8;
}
}
, &lba) != 0) {
perror("ioctl FIBMAP failed:");
close(fd);
return 0;
}
close(fd);
return lba;
}
int main(int ac, char **av)
{
char *device;
int fd, title = 0, lba = 0;
if (ac [title_path]\n");
exit (1);
}
device = av[1];
fd = open(device, O_RDONLY | O_NONBLOCK);
if (fd