* css.c: Functions for DVD authentification and unscrambling
*****************************************************************************
* Copyright (C) 1999-2001 VideoLAN
- * $Id: css.c,v 1.1 2001/06/12 22:14:44 sam Exp $
+ * $Id: css.c,v 1.19 2002/01/04 14:01:34 sam Exp $
*
* Author: Stéphane Borel <stef@via.ecp.fr>
+ * Håkan Hjort <d95hjort@dtek.chalmers.se>
*
* based on:
* - css-auth by Derek Fawcus <derek@spider.com>
/*****************************************************************************
* Preamble
*****************************************************************************/
-#include "defs.h"
-
#include <stdio.h>
#include <stdlib.h>
-#ifdef HAVE_UNISTD_H
-# include <unistd.h>
-#elif defined( _MSC_VER ) && defined( _WIN32 )
-# include <io.h>
-#endif
-
#include <string.h>
-#include "config.h"
-#include "common.h"
+#include <videolan/vlc.h>
#include "videolan/dvdcss.h"
#include "libdvdcss.h"
-#ifdef HAVE_CSS
-# include "csstables.h"
-#endif /* HAVE_CSS */
+#include "csstables.h"
#include "ioctl.h"
+#ifdef HAVE_CSSKEYS
+# include "csskeys.h"
+#endif
+
+
/*****************************************************************************
* Local prototypes
*****************************************************************************/
-#ifdef HAVE_CSS
static int CSSGetASF ( dvdcss_handle dvdcss );
static void CSSCryptKey ( int i_key_type, int i_varient,
- u8 const * pi_challenge, u8* pi_key );
-static int CSSCracker ( int i_start, unsigned char * p_crypted,
+ u8 const * p_challenge, u8* p_key );
+static void CSSDecryptKey( u8* p_crypted, u8* p_key, u8 );
+static int CSSDiscCrack ( dvdcss_handle dvdcss, u8 * p_disc_key );
+static int CSSTitleCrack( int i_start, unsigned char * p_crypted,
unsigned char * p_decrypted,
dvd_key_t * p_sector_key, dvd_key_t * p_key );
-#endif /* HAVE_CSS */
/*****************************************************************************
* CSSTest : check if the disc is encrypted or not
{
/* Since it's the first ioctl we try to issue, we add a notice */
_dvdcss_error( dvdcss, "css error: ioctl_ReadCopyright failed, "
- "make sure DVD ioctls were compiled in" );
+ "make sure there is a DVD in the drive, and that "
+ "DVD ioctls were compiled in this libdvdcss version" );
return i_ret;
}
}
/*****************************************************************************
- * CSSInit : CSS Structure initialisation and DVD authentication.
+ * CSSAuth : CSS Structure initialisation and DVD authentication.
*****************************************************************************
* It simulates the mutual authentication between logical unit and host.
* Since we don't need the disc key to find the title key, we just run the
* basic unavoidable commands to authenticate device and disc.
*****************************************************************************/
-int CSSInit( dvdcss_handle dvdcss )
+int CSSAuth( dvdcss_handle dvdcss )
{
-#ifdef HAVE_CSS
/* structures defined in cdrom.h or dvdio.h */
- char p_buffer[2048 + 4 + 1];
- char psz_warning[32];
- int i_agid = 0;
+ unsigned char p_buffer[10];
+ char psz_warning[48];
int i_ret = -1;
int i;
+ dvdcss->css.i_agid = 0;
+
/* Test authentication success */
switch( CSSGetASF( dvdcss ) )
{
case 1:
_dvdcss_debug( dvdcss, "already authenticated" );
- return 0;
+ break;
case 0:
_dvdcss_debug( dvdcss, "need to authenticate" );
+ break;
}
/* Init sequence, request AGID */
for( i = 1; i < 4 ; ++i )
{
- sprintf( psz_warning, "requesting AGID %d", i );
+ snprintf( psz_warning, sizeof(psz_warning), "requesting AGID %d", i );
_dvdcss_debug( dvdcss, psz_warning );
- i_ret = ioctl_ReportAgid( dvdcss->i_fd, &i_agid );
+ i_ret = ioctl_ReportAgid( dvdcss->i_fd, &dvdcss->css.i_agid );
if( i_ret != -1 )
{
_dvdcss_error( dvdcss, "ioctl_ReportAgid failed, invalidating" );
- i_agid = 0;
- ioctl_InvalidateAgid( dvdcss->i_fd, &i_agid );
+ dvdcss->css.i_agid = 0;
+ ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid );
}
/* Unable to authenticate without AGID */
for( i = 0 ; i < 10; ++i )
{
- dvdcss->css.disc.pi_challenge[i] = i;
+ dvdcss->css.disc.p_challenge[i] = i;
}
/* Get challenge from host */
for( i = 0 ; i < 10 ; ++i )
{
- p_buffer[9-i] = dvdcss->css.disc.pi_challenge[i];
+ p_buffer[9-i] = dvdcss->css.disc.p_challenge[i];
}
/* Send challenge to LU */
- if( ioctl_SendChallenge( dvdcss->i_fd, &i_agid, p_buffer ) < 0 )
+ if( ioctl_SendChallenge( dvdcss->i_fd, &dvdcss->css.i_agid, p_buffer ) < 0 )
{
_dvdcss_error( dvdcss, "ioctl_SendChallenge failed" );
return -1;
}
/* Get key1 from LU */
- if( ioctl_ReportKey1( dvdcss->i_fd, &i_agid, p_buffer ) < 0)
+ if( ioctl_ReportKey1( dvdcss->i_fd, &dvdcss->css.i_agid, p_buffer ) < 0)
{
_dvdcss_error( dvdcss, "ioctl_ReportKey1 failed" );
return -1;
/* Send key1 to host */
for( i = 0 ; i < KEY_SIZE ; i++ )
{
- dvdcss->css.disc.pi_key1[i] = p_buffer[4-i];
+ dvdcss->css.disc.p_key1[i] = p_buffer[4-i];
}
for( i = 0 ; i < 32 ; ++i )
{
- CSSCryptKey( 0, i, dvdcss->css.disc.pi_challenge,
- dvdcss->css.disc.pi_key_check );
+ CSSCryptKey( 0, i, dvdcss->css.disc.p_challenge,
+ dvdcss->css.disc.p_key_check );
- if( memcmp( dvdcss->css.disc.pi_key_check,
- dvdcss->css.disc.pi_key1, KEY_SIZE ) == 0 )
+ if( memcmp( dvdcss->css.disc.p_key_check,
+ dvdcss->css.disc.p_key1, KEY_SIZE ) == 0 )
{
- sprintf( psz_warning, "drive authentic, using variant %d", i );
+ snprintf( psz_warning, sizeof(psz_warning),
+ "drive authentic, using variant %d", i );
_dvdcss_debug( dvdcss, psz_warning );
dvdcss->css.disc.i_varient = i;
break;
}
/* Get challenge from LU */
- if( ioctl_ReportChallenge( dvdcss->i_fd, &i_agid, p_buffer ) < 0 )
+ if( ioctl_ReportChallenge( dvdcss->i_fd, &dvdcss->css.i_agid, p_buffer ) < 0 )
{
_dvdcss_error( dvdcss, "ioctl_ReportKeyChallenge failed" );
return -1;
/* Send challenge to host */
for( i = 0 ; i < 10 ; ++i )
{
- dvdcss->css.disc.pi_challenge[i] = p_buffer[9-i];
+ dvdcss->css.disc.p_challenge[i] = p_buffer[9-i];
}
CSSCryptKey( 1, dvdcss->css.disc.i_varient,
- dvdcss->css.disc.pi_challenge,
- dvdcss->css.disc.pi_key2 );
+ dvdcss->css.disc.p_challenge,
+ dvdcss->css.disc.p_key2 );
/* Get key2 from host */
for( i = 0 ; i < KEY_SIZE ; ++i )
{
- p_buffer[4-i] = dvdcss->css.disc.pi_key2[i];
+ p_buffer[4-i] = dvdcss->css.disc.p_key2[i];
}
/* Send key2 to LU */
- if( ioctl_SendKey2( dvdcss->i_fd, &i_agid, p_buffer ) < 0 )
+ if( ioctl_SendKey2( dvdcss->i_fd, &dvdcss->css.i_agid, p_buffer ) < 0 )
{
_dvdcss_error( dvdcss, "ioctl_SendKey2 failed" );
return -1;
_dvdcss_debug( dvdcss, "authentication established" );
- memcpy( dvdcss->css.disc.pi_challenge,
- dvdcss->css.disc.pi_key1, KEY_SIZE );
- memcpy( dvdcss->css.disc.pi_challenge+KEY_SIZE,
- dvdcss->css.disc.pi_key2, KEY_SIZE );
+ memcpy( dvdcss->css.disc.p_challenge,
+ dvdcss->css.disc.p_key1, KEY_SIZE );
+ memcpy( dvdcss->css.disc.p_challenge+KEY_SIZE,
+ dvdcss->css.disc.p_key2, KEY_SIZE );
CSSCryptKey( 2, dvdcss->css.disc.i_varient,
- dvdcss->css.disc.pi_challenge,
- dvdcss->css.disc.pi_key_check );
+ dvdcss->css.disc.p_challenge,
+ dvdcss->css.disc.p_key_check );
_dvdcss_debug( dvdcss, "received session key" );
- if( i_agid < 0 )
+ if( dvdcss->css.i_agid < 0 )
{
return -1;
}
case 0:
_dvdcss_debug( dvdcss, "need to get disc key" );
+ return 0;
+ }
+
+ return -1;
+}
+
+/*****************************************************************************
+ * CSSGetDiscKey : get disc key and optionnaly decrypts it.
+ *****************************************************************************
+ * This function should only be called if DVD ioctls are present.
+ * Two decryption methods are then offered:
+ * -disc key hash crack,
+ * -decryption with player keys if they are available.
+ *****************************************************************************/
+int CSSGetDiscKey( dvdcss_handle dvdcss )
+{
+ unsigned char p_buffer[2048 + 4 + 1];
+#ifdef HAVE_CSSKEYS
+ dvd_key_t disc_key;
+ dvd_key_t test_key;
+#endif
+ int i;
+
+ if( CSSAuth( dvdcss ) )
+ {
+ return -1;
}
/* Get encrypted disc key */
- if( ioctl_ReadKey( dvdcss->i_fd, &i_agid, p_buffer ) < 0 )
+ if( ioctl_ReadDiscKey( dvdcss->i_fd, &dvdcss->css.i_agid, p_buffer ) < 0 )
{
- _dvdcss_error( dvdcss, "ioctl_ReadKey failed" );
+ _dvdcss_error( dvdcss, "ioctl_ReadDiscKey failed" );
return -1;
}
/* Unencrypt disc key using bus key */
for( i = 0 ; i < 2048 ; i++ )
{
- p_buffer[ i ] ^= dvdcss->css.disc.pi_key_check[ 4 - (i % KEY_SIZE) ];
+ p_buffer[ i ] ^= dvdcss->css.disc.p_key_check[ 4 - (i % KEY_SIZE) ];
}
- memcpy( dvdcss->css.disc.pi_key_check, p_buffer, 2048 );
+ memcpy( dvdcss->css.disc.p_disc_key, p_buffer, 2048 );
- /* initialize title key to know it empty */
- for( i = 0 ; i < KEY_SIZE ; i++ )
+ switch( dvdcss->i_method )
{
- dvdcss->css.pi_title_key[i] = 0;
- }
+ case DVDCSS_METHOD_KEY:
+#ifdef HAVE_CSSKEYS
+ /* Decrypt disc key with player keys from csskeys.h */
+ _dvdcss_debug( dvdcss, "decrypting disc key with player keys" );
+ i = 0;
+ do
+ {
+ /* Take encrypted disc key and decrypt it */
+ memcpy( disc_key,
+ dvdcss->css.disc.p_disc_key
+ + playerkeys[i].i_offset,
+ KEY_SIZE );
+ CSSDecryptKey( disc_key, playerkeys[i].p_key, 0 );
- /* Test authentication success */
- switch( CSSGetASF( dvdcss ) )
- {
- case -1:
- return -1;
+ /* Encrypt disc key hash with disc key to
+ * check we have disc key */
+ memcpy( test_key, dvdcss->css.disc.p_disc_key, KEY_SIZE );
+ CSSDecryptKey( test_key, disc_key, 0);
- case 1:
- _dvdcss_debug( dvdcss, "successfully authenticated" );
- return 0;
+ i++;
- case 0:
- _dvdcss_error( dvdcss, "no way to authenticate" );
- return -1;
- }
+ } while( ( playerkeys[i].i_offset != -1 ) &&
+ ( memcmp( test_key, disc_key, KEY_SIZE ) ) );
-#else /* HAVE_CSS */
- _dvdcss_error( dvdcss, "CSS decryption is disabled in this module" );
+ /* The decrypted disk key will replace the disk key hash */
+ memcpy( dvdcss->css.disc.p_disc_key, disc_key, KEY_SIZE );
+ break;
+#else
+ dvdcss->i_method = DVDCSS_METHOD_DISC;
+#endif
+ case DVDCSS_METHOD_DISC:
+ /* Crack Disc key to be able to use it */
+ _dvdcss_debug( dvdcss, "cracking disc key with key hash" );
+ _dvdcss_debug( dvdcss, "building 64MB table ... this will take some time" );
+ CSSDiscCrack( dvdcss, dvdcss->css.disc.p_disc_key );
+ break;
-#endif /* HAVE_CSS */
- return -1;
+ default:
+ _dvdcss_debug( dvdcss, "disc key won't be decrypted" );
+ }
+ return 0;
}
+
/*****************************************************************************
- * CSSGetKey : get title key.
- *****************************************************************************
- * The DVD should have been opened and authenticated before.
+ * CSSGetTitleKey : get title key.
*****************************************************************************/
-int CSSGetKey( dvdcss_handle dvdcss )
+int CSSGetTitleKey( dvdcss_handle dvdcss, int i_pos )
{
-#ifdef HAVE_CSS
- /*
- * Title key cracking method from Ethan Hawke,
- * with Frank A. Stevenson algorithm.
- * Does not use any player key table and ioctls.
- */
- u8 pi_buf[0x800];
- dvd_key_t pi_key;
- off_t i_pos;
- boolean_t b_encrypted;
- boolean_t b_stop_scanning;
- int i_bytes_read;
- int i_best_plen;
- int i_best_p;
+ dvd_key_t p_key;
int i,j;
- for( i = 0 ; i < KEY_SIZE ; i++ )
+ if( ( dvdcss->i_method == DVDCSS_METHOD_TITLE )
+ || ( dvdcss->b_ioctls == 0 ) )
{
- pi_key[i] = 0;
- }
-
- b_encrypted = 0;
- b_stop_scanning = 0;
+ /*
+ * Title key cracking method from Ethan Hawke,
+ * with Frank A. Stevenson algorithm.
+ * Does not use any player key table and ioctls.
+ */
+ u8 p_buf[0x800];
+ u8 p_packstart[4] = { 0x00, 0x00, 0x01, 0xba };
+ boolean_t b_encrypted;
+ boolean_t b_stop_scanning;
+ int i_blocks_read;
+ int i_best_plen;
+ int i_best_p;
+
+ _dvdcss_debug( dvdcss, "cracking title key ... this may take some time" );
+
+ for( i = 0 ; i < KEY_SIZE ; i++ )
+ {
+ p_key[i] = 0;
+ }
- /* Position of the title on the disc */
- i_pos = (off_t)DVDCSS_BLOCK_SIZE * (off_t)dvdcss->css.i_title_pos;
+ b_encrypted = 0;
+ b_stop_scanning = 0;
+ i_blocks_read = 0;
- do {
-#if !defined( WIN32 )
- i_pos = lseek( dvdcss->i_fd, i_pos, SEEK_SET );
- i_bytes_read = read( dvdcss->i_fd, pi_buf, 0x800 );
-#else
- i_pos = SetFilePointer( (HANDLE) dvdcss->i_fd, i_pos, 0, FILE_BEGIN );
- ReadFile( (HANDLE) dvdcss->i_fd, pi_buf, 0x800, &i_bytes_read, NULL );
-#endif
+ do
+ {
+ i_pos = _dvdcss_seek( dvdcss, i_pos );
+ if( _dvdcss_read( dvdcss, p_buf, 1 ) != 1 ) break;
- /* PES_scrambling_control */
- if( pi_buf[0x14] & 0x30 )
- {
- b_encrypted = 1;
- i_best_plen = 0;
- i_best_p = 0;
+ /* Stop when we find a non MPEG stream block */
+ if( memcmp( p_buf, p_packstart, 4 ) )
+ {
+ /* The title is unencrypted */
+ if( !b_encrypted )
+ break;
+ /* dvdcss some times fail to find/crack the key,
+ hope that it's the same as the one in the next title
+ _dvdcss_debug( dvdcss, "no key found at end of title" );
+ */
+ }
- for( i = 2 ; i < 0x30 ; i++ )
- {
- for( j = i ; ( j < 0x80 ) &&
- ( pi_buf[0x7F - (j%i)] == pi_buf[0x7F-j] ) ; j++ );
+ /* PES_scrambling_control on and make sure that the packet type
+ is one that can be scrambled */
+ if( p_buf[0x14] & 0x30 && ! ( p_buf[0x11] == 0xbb
+ || p_buf[0x11] == 0xbe
+ || p_buf[0x11] == 0xbf ) )
{
- if( ( j > i_best_plen ) && ( j > i ) )
+ b_encrypted = 1;
+ i_best_plen = 0;
+ i_best_p = 0;
+
+ for( i = 2 ; i < 0x30 ; i++ )
{
- i_best_plen = j;
- i_best_p = i;
+ for( j = i+1 ;
+ j < 0x80 && ( p_buf[0x7F - (j%i)] == p_buf[0x7F-j] );
+ j++ );
+ {
+ if( j > i_best_plen )
+ {
+ i_best_plen = j;
+ i_best_p = i;
+ }
+ }
+ }
+
+ if( ( i_best_plen > 20 ) && ( i_best_plen / i_best_p >= 2) )
+ {
+ i = CSSTitleCrack( 0, &p_buf[0x80],
+ &p_buf[0x80 - ( i_best_plen / i_best_p) *i_best_p],
+ (dvd_key_t*)&p_buf[0x54],
+ &p_key );
+ b_stop_scanning = ( i >= 0 );
}
}
- }
- if( ( i_best_plen > 20 ) && ( i_best_plen / i_best_p >= 2) )
+ i_pos += 1;
+ i_blocks_read += 1;
+
+ /* If we haven't seen any encrypted ones after 3000 blocks stop */
+ if( !b_encrypted && i_blocks_read >= 1000 ) break;
+
+ } while( !b_stop_scanning );
+
+ if( b_stop_scanning )
{
- i = CSSCracker( 0, &pi_buf[0x80],
- &pi_buf[0x80 - ( i_best_plen / i_best_p) *i_best_p],
- (dvd_key_t*)&pi_buf[0x54],
- &pi_key );
- b_stop_scanning = ( i >= 0 );
+ memcpy( dvdcss->css.p_title_key, &p_key, sizeof(dvd_key_t) );
+ _dvdcss_debug( dvdcss, "vts key initialized" );
+ return 0;
}
- }
- i_pos += i_bytes_read;
- } while( i_bytes_read == 0x800 && !b_stop_scanning);
+ if( !b_encrypted )
+ {
+ _dvdcss_debug( dvdcss, "file was unscrambled" );
+ return 0;
+ }
- if( b_stop_scanning)
- {
- memcpy( dvdcss->css.pi_title_key,
- &pi_key, sizeof(dvd_key_t) );
- _dvdcss_debug( dvdcss, "vts key initialized" );
- return 0;
+ return -1;
}
-
- if( !b_encrypted )
+ else
{
- _dvdcss_debug( dvdcss, "this file was _NOT_ encrypted!" );
- return 0;
- }
+ /*
+ * if we are here we have a decrypted disc key and ioctls are available
+ * so we can read the title key and decrypt it.
+ */
+
+ _dvdcss_debug( dvdcss, "decrypting title key with disc key" );
+
+ /* We need to authenticate again for every key
+ * (to get a new session key ?) */
+ CSSAuth( dvdcss );
+
+ /* Get encrypted title key */
+ if( ioctl_ReadTitleKey( dvdcss->i_fd, &dvdcss->css.i_agid,
+ i_pos, p_key ) < 0 )
+ {
+ _dvdcss_error( dvdcss, "ioctl_ReadTitleKey failed" );
+ return -1;
+ }
+ /* Unencrypt title key using bus key */
+ for( i = 0 ; i < KEY_SIZE ; i++ )
+ {
+ p_key[ i ] ^= dvdcss->css.disc.p_key_check[ 4 - (i % KEY_SIZE) ];
+ }
- return -1;
+ /* Title key decryption needs one inversion 0xff */
+ CSSDecryptKey( p_key, dvdcss->css.disc.p_disc_key, 0xff );
-#else /* HAVE_CSS */
- _dvdcss_error( dvdcss, "css decryption unavailable" );
- return -1;
+ memcpy( dvdcss->css.p_title_key, p_key, sizeof(dvd_key_t) );
-#endif /* HAVE_CSS */
+ return 0;
+ } // (dvdcss->i_method == DVDCSS_METHOD_TITLE) || (dvdcss->b_ioctls == 0)
}
/*****************************************************************************
- * CSSDescrambleSector
+ * CSSDescrambleSector: does the actual descrambling of data
*****************************************************************************
* sec : sector to descramble
* key : title key for this sector
*****************************************************************************/
-int CSSDescrambleSector( dvd_key_t pi_key, u8* pi_sec )
+int CSSDescrambleSector( dvd_key_t p_key, u8* p_sec )
{
-#ifdef HAVE_CSS
unsigned int i_t1, i_t2, i_t3, i_t4, i_t5, i_t6;
- u8* pi_end = pi_sec + 0x800;
+ u8* p_end = p_sec + 0x800;
/* PES_scrambling_control */
- if( pi_sec[0x14] & 0x30)
+ if( p_sec[0x14] & 0x30)
{
- i_t1 = ((pi_key)[0] ^ pi_sec[0x54]) | 0x100;
- i_t2 = (pi_key)[1] ^ pi_sec[0x55];
- i_t3 = (((pi_key)[2]) | ((pi_key)[3] << 8) |
- ((pi_key)[4] << 16)) ^ ((pi_sec[0x56]) |
- (pi_sec[0x57] << 8) | (pi_sec[0x58] << 16));
+ i_t1 = ((p_key)[0] ^ p_sec[0x54]) | 0x100;
+ i_t2 = (p_key)[1] ^ p_sec[0x55];
+ i_t3 = (((p_key)[2]) | ((p_key)[3] << 8) |
+ ((p_key)[4] << 16)) ^ ((p_sec[0x56]) |
+ (p_sec[0x57] << 8) | (p_sec[0x58] << 16));
i_t4 = i_t3 & 7;
i_t3 = i_t3 * 2 + 8 - i_t4;
- pi_sec += 0x80;
+ p_sec += 0x80;
i_t5 = 0;
- while( pi_sec != pi_end )
+ while( p_sec != p_end )
{
- i_t4 = pi_css_tab2[i_t2] ^ pi_css_tab3[i_t1];
+ i_t4 = p_css_tab2[i_t2] ^ p_css_tab3[i_t1];
i_t2 = i_t1>>1;
i_t1 = ( ( i_t1 & 1 ) << 8 ) ^ i_t4;
- i_t4 = pi_css_tab5[i_t4];
+ i_t4 = p_css_tab5[i_t4];
i_t6 = ((((((( i_t3 >> 3 ) ^ i_t3 ) >> 1 ) ^
- i_t3 ) >> 8 ) ^ i_t3 ) >> 5) & 0xff;
+ i_t3 ) >> 8 ) ^ i_t3 ) >> 5 ) & 0xff;
i_t3 = (i_t3 << 8 ) | i_t6;
- i_t6 = pi_css_tab4[i_t6];
+ i_t6 = p_css_tab4[i_t6];
i_t5 += i_t6 + i_t4;
- *pi_sec = pi_css_tab1[*pi_sec] ^( i_t5 & 0xff );
- pi_sec++;
+ *p_sec = p_css_tab1[*p_sec] ^( i_t5 & 0xff );
+ p_sec++;
i_t5 >>= 8;
}
}
return 0;
-
-#else /* HAVE_CSS */
- return 1;
-
-#endif /* HAVE_CSS */
}
-#ifdef HAVE_CSS
-
/* Following functions are local */
/*****************************************************************************
/*****************************************************************************
* CSSCryptKey : shuffles bits and unencrypt keys.
*****************************************************************************
- * Used during authentication and disc key negociation in CSSInit.
+ * Used during authentication and disc key negociation in CSSAuth.
* i_key_type : 0->key1, 1->key2, 2->buskey.
* i_varient : between 0 and 31.
*****************************************************************************/
static void CSSCryptKey( int i_key_type, int i_varient,
- u8 const * pi_challenge, u8* pi_key )
+ u8 const * p_challenge, u8* p_key )
{
/* Permutation table for challenge */
- u8 ppi_perm_challenge[3][10] =
+ u8 pp_perm_challenge[3][10] =
{ { 1, 3, 0, 7, 5, 2, 9, 6, 4, 8 },
{ 6, 1, 9, 3, 8, 5, 7, 4, 0, 2 },
{ 4, 0, 3, 5, 7, 2, 8, 6, 1, 9 } };
/* Permutation table for varient table for key2 and buskey */
- u8 ppi_perm_varient[2][32] =
+ u8 pp_perm_varient[2][32] =
{ { 0x0a, 0x08, 0x0e, 0x0c, 0x0b, 0x09, 0x0f, 0x0d,
0x1a, 0x18, 0x1e, 0x1c, 0x1b, 0x19, 0x1f, 0x1d,
0x02, 0x00, 0x06, 0x04, 0x03, 0x01, 0x07, 0x05,
0x13, 0x1b, 0x17, 0x1f, 0x03, 0x0b, 0x07, 0x0f,
0x11, 0x19, 0x15, 0x1d, 0x01, 0x09, 0x05, 0x0d } };
- u8 pi_varients[32] =
+ u8 p_varients[32] =
{ 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 };
/* The "secret" key */
- u8 pi_secret[5] = { 0x55, 0xD6, 0xC4, 0xC5, 0x28 };
+ u8 p_secret[5] = { 0x55, 0xD6, 0xC4, 0xC5, 0x28 };
- u8 pi_bits[30];
- u8 pi_scratch[10];
- u8 pi_tmp1[5];
- u8 pi_tmp2[5];
+ u8 p_bits[30];
+ u8 p_scratch[10];
+ u8 p_tmp1[5];
+ u8 p_tmp2[5];
u8 i_lfsr0_o; /* 1 bit used */
u8 i_lfsr1_o; /* 1 bit used */
u32 i_lfsr0;
int i;
for (i = 9; i >= 0; --i)
- pi_scratch[i] = pi_challenge[ppi_perm_challenge[i_key_type][i]];
+ p_scratch[i] = p_challenge[pp_perm_challenge[i_key_type][i]];
i_css_varient = ( i_key_type == 0 ) ? i_varient :
- ppi_perm_varient[i_key_type-1][i_varient];
+ pp_perm_varient[i_key_type-1][i_varient];
/*
* This encryption engine implements one of 32 variations
*/
for( i = 5 ; --i >= 0 ; )
{
- pi_tmp1[i] = pi_scratch[5 + i] ^ pi_secret[i] ^ pi_crypt_tab2[i];
+ p_tmp1[i] = p_scratch[5 + i] ^ p_secret[i] ^ p_crypt_tab2[i];
}
/*
* initial values are non-zero. Thus when we initialise them from
* the seed, we ensure that a bit is set.
*/
- i_lfsr0 = ( pi_tmp1[0] << 17 ) | ( pi_tmp1[1] << 9 ) |
- (( pi_tmp1[2] & ~7 ) << 1 ) | 8 | ( pi_tmp1[2] & 7 );
- i_lfsr1 = ( pi_tmp1[3] << 9 ) | 0x100 | pi_tmp1[4];
+ i_lfsr0 = ( p_tmp1[0] << 17 ) | ( p_tmp1[1] << 9 ) |
+ (( p_tmp1[2] & ~7 ) << 1 ) | 8 | ( p_tmp1[2] & 7 );
+ i_lfsr1 = ( p_tmp1[3] << 9 ) | 0x100 | p_tmp1[4];
- i_index = sizeof(pi_bits);
+ i_index = sizeof(p_bits);
i_carry = 0;
do
i_val |= ( i_combined & 1 ) << i_bit;
}
- pi_bits[--i_index] = i_val;
+ p_bits[--i_index] = i_val;
} while( i_index > 0 );
/* This term is used throughout the following to
* select one of 32 different variations on the
* algorithm.
*/
- i_cse = pi_varients[i_css_varient] ^ pi_crypt_tab2[i_css_varient];
+ i_cse = p_varients[i_css_varient] ^ p_crypt_tab2[i_css_varient];
/* Now the actual blocks doing the encryption. Each
* of these works on 40 bits at a time and are quite
* similar.
*/
i_index = 0;
- for( i = 5, i_term = 0 ; --i >= 0 ; i_term = pi_scratch[i] )
+ for( i = 5, i_term = 0 ; --i >= 0 ; i_term = p_scratch[i] )
{
- i_index = pi_bits[25 + i] ^ pi_scratch[i];
- i_index = pi_crypt_tab1[i_index] ^ ~pi_crypt_tab2[i_index] ^ i_cse;
+ i_index = p_bits[25 + i] ^ p_scratch[i];
+ i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse;
- pi_tmp1[i] = pi_crypt_tab2[i_index] ^ pi_crypt_tab3[i_index] ^ i_term;
+ p_tmp1[i] = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term;
}
- pi_tmp1[4] ^= pi_tmp1[0];
+ p_tmp1[4] ^= p_tmp1[0];
- for( i = 5, i_term = 0 ; --i >= 0 ; i_term = pi_tmp1[i] )
+ for( i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp1[i] )
{
- i_index = pi_bits[20 + i] ^ pi_tmp1[i];
- i_index = pi_crypt_tab1[i_index] ^ ~pi_crypt_tab2[i_index] ^ i_cse;
+ i_index = p_bits[20 + i] ^ p_tmp1[i];
+ i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse;
- pi_tmp2[i] = pi_crypt_tab2[i_index] ^ pi_crypt_tab3[i_index] ^ i_term;
+ p_tmp2[i] = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term;
}
- pi_tmp2[4] ^= pi_tmp2[0];
+ p_tmp2[4] ^= p_tmp2[0];
- for( i = 5, i_term = 0 ; --i >= 0 ; i_term = pi_tmp2[i] )
+ for( i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp2[i] )
{
- i_index = pi_bits[15 + i] ^ pi_tmp2[i];
- i_index = pi_crypt_tab1[i_index] ^ ~pi_crypt_tab2[i_index] ^ i_cse;
- i_index = pi_crypt_tab2[i_index] ^ pi_crypt_tab3[i_index] ^ i_term;
+ i_index = p_bits[15 + i] ^ p_tmp2[i];
+ i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse;
+ i_index = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term;
- pi_tmp1[i] = pi_crypt_tab0[i_index] ^ pi_crypt_tab2[i_index];
+ p_tmp1[i] = p_crypt_tab0[i_index] ^ p_crypt_tab2[i_index];
}
- pi_tmp1[4] ^= pi_tmp1[0];
+ p_tmp1[4] ^= p_tmp1[0];
- for( i = 5, i_term = 0 ; --i >= 0 ; i_term = pi_tmp1[i] )
+ for( i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp1[i] )
{
- i_index = pi_bits[10 + i] ^ pi_tmp1[i];
- i_index = pi_crypt_tab1[i_index] ^ ~pi_crypt_tab2[i_index] ^ i_cse;
+ i_index = p_bits[10 + i] ^ p_tmp1[i];
+ i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse;
- i_index = pi_crypt_tab2[i_index] ^ pi_crypt_tab3[i_index] ^ i_term;
+ i_index = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term;
- pi_tmp2[i] = pi_crypt_tab0[i_index] ^ pi_crypt_tab2[i_index];
+ p_tmp2[i] = p_crypt_tab0[i_index] ^ p_crypt_tab2[i_index];
}
- pi_tmp2[4] ^= pi_tmp2[0];
+ p_tmp2[4] ^= p_tmp2[0];
- for( i = 5, i_term = 0 ; --i >= 0 ; i_term = pi_tmp2[i] )
+ for( i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp2[i] )
{
- i_index = pi_bits[5 + i] ^ pi_tmp2[i];
- i_index = pi_crypt_tab1[i_index] ^ ~pi_crypt_tab2[i_index] ^ i_cse;
+ i_index = p_bits[5 + i] ^ p_tmp2[i];
+ i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse;
- pi_tmp1[i] = pi_crypt_tab2[i_index] ^ pi_crypt_tab3[i_index] ^ i_term;
+ p_tmp1[i] = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term;
}
- pi_tmp1[4] ^= pi_tmp1[0];
+ p_tmp1[4] ^= p_tmp1[0];
- for(i = 5, i_term = 0 ; --i >= 0 ; i_term = pi_tmp1[i] )
+ for(i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp1[i] )
{
- i_index = pi_bits[i] ^ pi_tmp1[i];
- i_index = pi_crypt_tab1[i_index] ^ ~pi_crypt_tab2[i_index] ^ i_cse;
+ i_index = p_bits[i] ^ p_tmp1[i];
+ i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse;
- pi_key[i] = pi_crypt_tab2[i_index] ^ pi_crypt_tab3[i_index] ^ i_term;
+ p_key[i] = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term;
}
return;
}
/*****************************************************************************
- * CSSCracker : title key decryption by cracking
+ * CSSDecryptKey: decrypt p_crypted with p_key.
+ *****************************************************************************
+ * Decryption is slightly dependant on the type of key:
+ * -for disc key, invert is 0x00,
+ * -for title key, invert if 0xff.
+ *****************************************************************************/
+static void CSSDecryptKey( u8* p_crypted, u8* p_key, u8 invert )
+{
+ unsigned int i_lfsr1_lo;
+ unsigned int i_lfsr1_hi;
+ unsigned int i_lfsr0;
+ unsigned int i_combined;
+ byte_t o_lfsr0;
+ byte_t o_lfsr1;
+ byte_t k[5];
+ int i;
+
+ i_lfsr1_lo = p_key[0] | 0x100;
+ i_lfsr1_hi = p_key[1];
+
+ i_lfsr0 = ( ( p_key[4] << 17 )
+ | ( p_key[3] << 9 )
+ | ( p_key[2] << 1 ) )
+ + 8 - ( p_key[2] & 7 );
+ i_lfsr0 = ( p_css_tab4[i_lfsr0 & 0xff] << 24 ) |
+ ( p_css_tab4[( i_lfsr0 >> 8 ) & 0xff] << 16 ) |
+ ( p_css_tab4[( i_lfsr0 >> 16 ) & 0xff] << 8 ) |
+ p_css_tab4[( i_lfsr0 >> 24 ) & 0xff];
+
+ i_combined = 0;
+ for( i = 0 ; i < KEY_SIZE ; ++i )
+ {
+ o_lfsr1 = p_css_tab2[i_lfsr1_hi] ^ p_css_tab3[i_lfsr1_lo];
+ i_lfsr1_hi = i_lfsr1_lo >> 1;
+ i_lfsr1_lo = ( ( i_lfsr1_lo & 1 ) << 8 ) ^ o_lfsr1;
+ o_lfsr1 = p_css_tab4[o_lfsr1];
+
+ o_lfsr0 = ((((((( i_lfsr0 >> 8 ) ^ i_lfsr0 ) >> 1 )
+ ^ i_lfsr0 ) >> 3 ) ^ i_lfsr0 ) >> 7 );
+ i_lfsr0 = ( i_lfsr0 >> 8 ) | ( o_lfsr0 << 24 );
+
+ i_combined += ( o_lfsr0 ^ invert ) + o_lfsr1;
+ k[i] = i_combined & 0xff;
+ i_combined >>= 8;
+ }
+
+ p_crypted[4] = k[4] ^ p_css_tab1[p_crypted[4]] ^ p_crypted[3];
+ p_crypted[3] = k[3] ^ p_css_tab1[p_crypted[3]] ^ p_crypted[2];
+ p_crypted[2] = k[2] ^ p_css_tab1[p_crypted[2]] ^ p_crypted[1];
+ p_crypted[1] = k[1] ^ p_css_tab1[p_crypted[1]] ^ p_crypted[0];
+ p_crypted[0] = k[0] ^ p_css_tab1[p_crypted[0]] ^ p_crypted[4];
+
+ p_crypted[4] = k[4] ^ p_css_tab1[p_crypted[4]] ^ p_crypted[3];
+ p_crypted[3] = k[3] ^ p_css_tab1[p_crypted[3]] ^ p_crypted[2];
+ p_crypted[2] = k[2] ^ p_css_tab1[p_crypted[2]] ^ p_crypted[1];
+ p_crypted[1] = k[1] ^ p_css_tab1[p_crypted[1]] ^ p_crypted[0];
+ p_crypted[0] = k[0] ^ p_css_tab1[p_crypted[0]];
+
+ return;
+}
+
+/*****************************************************************************
+ * CSSDiscCrack: brute force disc key
+ * CSS hash reversal function designed by Frank Stevenson
+ *****************************************************************************
+ * This function uses a big amount of memory to crack the disc key from the
+ * disc key hash, if player keys are not available.
+ *****************************************************************************/
+#define K1TABLEWIDTH 10
+
+/*
+ * Simple function to test if a candidate key produces the given hash
+ */
+static int investigate( unsigned char* hash, unsigned char *ckey )
+{
+ unsigned char key[5];
+ unsigned char pkey[5];
+
+ memcpy( key, hash, 5 );
+ memcpy( pkey, ckey, 5 );
+
+ CSSDecryptKey( key, pkey, 0 );
+
+ return memcmp( key, pkey, 5 );
+}
+
+static int CSSDiscCrack( dvdcss_handle dvdcss, u8 * p_disc_key )
+{
+ unsigned char B[5] = { 0,0,0,0,0 }; /* Second Stage of mangle cipher */
+ unsigned char C[5] = { 0,0,0,0,0 }; /* Output Stage of mangle cipher
+ * IntermediateKey */
+ unsigned char k[5] = { 0,0,0,0,0 }; /* Mangling cipher key
+ * Also output from CSS( C ) */
+ unsigned char out1[5]; /* five first output bytes of LFSR1 */
+ unsigned char out2[5]; /* five first output bytes of LFSR2 */
+ unsigned int lfsr1a; /* upper 9 bits of LFSR1 */
+ unsigned int lfsr1b; /* lower 8 bits of LFSR1 */
+ unsigned int tmp, tmp2, tmp3, tmp4,tmp5;
+ int i,j;
+ unsigned int nStepA; /* iterator for LFSR1 start state */
+ unsigned int nStepB; /* iterator for possible B[0] */
+ unsigned int nTry; /* iterator for K[1] possibilities */
+ unsigned int nPossibleK1; /* #of possible K[1] values */
+ unsigned char* K1table; /* Lookup table for possible K[1] */
+ unsigned int* BigTable; /* LFSR2 startstate indexed by
+ * 1,2,5 output byte */
+
+ /*
+ * Prepare tables for hash reversal
+ */
+
+
+ /* initialize lookup tables for k[1] */
+ K1table = malloc( 65536 * K1TABLEWIDTH );
+ memset( K1table, 0 , 65536 * K1TABLEWIDTH );
+ if( K1table == NULL )
+ {
+ return -1;
+ }
+
+ tmp = p_disc_key[0] ^ p_css_tab1[ p_disc_key[1] ];
+ for( i = 0 ; i < 256 ; i++ ) /* k[1] */
+ {
+ tmp2 = p_css_tab1[ tmp ^ i ]; /* p_css_tab1[ B[1] ]*/
+
+ for( j = 0 ; j < 256 ; j++ ) /* B[0] */
+ {
+ tmp3 = j ^ tmp2 ^ i; /* C[1] */
+ tmp4 = K1table[ K1TABLEWIDTH * ( 256 * j + tmp3 ) ]; /* count of entries here */
+ tmp4++;
+/*
+ if( tmp4 == K1TABLEWIDTH )
+ {
+ _dvdcss_debug( dvdcss, "Table disaster %d", tmp4 );
+ }
+*/
+ if( tmp4 < K1TABLEWIDTH )
+ {
+ K1table[ K1TABLEWIDTH * ( 256 * j + tmp3 ) + tmp4 ] = i;
+ }
+ K1table[ K1TABLEWIDTH * ( 256 * j + tmp3 ) ] = tmp4;
+ }
+ }
+
+ /* Initing our Really big table */
+ BigTable = malloc( 16777216 * sizeof(int) );
+ memset( BigTable, 0 , 16777216 * sizeof(int) );
+ if( BigTable == NULL )
+ {
+ return -1;
+ }
+
+ tmp3 = 0;
+
+ _dvdcss_debug( dvdcss, "initializing the big table" );
+
+ for( i = 0 ; i < 16777216 ; i++ )
+ {
+/*
+ if( ( i & 0x07ffff ) == 0 )
+ {
+ fprintf( stderr, "#" );
+ }
+*/
+ tmp = (( i + i ) & 0x1fffff0 ) | 0x8 | ( i & 0x7 );
+
+ for( j = 0 ; j < 5 ; j++ )
+ {
+ tmp2=((((((( tmp >> 3 ) ^ tmp ) >> 1 ) ^ tmp ) >> 8 )
+ ^ tmp ) >> 5 ) & 0xff;
+ tmp = ( tmp << 8) | tmp2;
+ out2[j] = p_css_tab4[ tmp2 ];
+ }
+
+ j = ( out2[0] << 16 ) | ( out2[1] << 8 ) | out2[4];
+ BigTable[j] = i;
+ }
+
+/* fprintf( stderr, "\n" ); */
+
+ /*
+ * We are done initing, now reverse hash
+ */
+ tmp5 = p_disc_key[0] ^ p_css_tab1[ p_disc_key[1] ];
+
+ for( nStepA = 0 ; nStepA < 65536 ; nStepA ++ )
+ {
+ lfsr1a = 0x100 | ( nStepA >> 8 );
+ lfsr1b = nStepA & 0xff;
+
+ /* Generate 5 first output bytes from lfsr1 */
+ for( i = 0 ; i < 5 ; i++ )
+ {
+ tmp = p_css_tab2[ lfsr1b ] ^ p_css_tab3[ lfsr1a ];
+ lfsr1b = lfsr1a >> 1;
+ lfsr1a = ((lfsr1a&1)<<8) ^ tmp;
+ out1[ i ] = p_css_tab4[ tmp ];
+ }
+
+ /* cumpute and cache some variables */
+ C[0] = nStepA >> 8;
+ C[1] = nStepA & 0xff;
+ tmp = p_disc_key[3] ^ p_css_tab1[ p_disc_key[4] ];
+ tmp2 = p_css_tab1[ p_disc_key[0] ];
+
+ /* Search through all possible B[0] */
+ for( nStepB = 0 ; nStepB < 256 ; nStepB++ )
+ {
+ /* reverse parts of the mangling cipher */
+ B[0] = nStepB;
+ k[0] = p_css_tab1[ B[0] ] ^ C[0];
+ B[4] = B[0] ^ k[0] ^ tmp2;
+ k[4] = B[4] ^ tmp;
+ nPossibleK1 = K1table[ K1TABLEWIDTH * (256 * B[0] + C[1]) ];
+
+ /* Try out all possible values for k[1] */
+ for( nTry = 0 ; nTry < nPossibleK1 ; nTry++ )
+ {
+ k[1] = K1table[ K1TABLEWIDTH * (256 * B[0] + C[1]) + nTry + 1 ];
+ B[1] = tmp5 ^ k[1];
+
+ /* reconstruct output from LFSR2 */
+ tmp3 = ( 0x100 + k[0] - out1[0] );
+ out2[0] = tmp3 & 0xff;
+ tmp3 = tmp3 & 0x100 ? 0x100 : 0xff;
+ tmp3 = ( tmp3 + k[1] - out1[1] );
+ out2[1] = tmp3 & 0xff;
+ tmp3 = ( 0x100 + k[4] - out1[4] );
+ out2[4] = tmp3 & 0xff; /* Can be 1 off */
+
+ /* test first possible out2[4] */
+ tmp4 = ( out2[0] << 16 ) | ( out2[1] << 8 ) | out2[4];
+ tmp4 = BigTable[ tmp4 ];
+ C[2] = tmp4 & 0xff;
+ C[3] = ( tmp4 >> 8 ) & 0xff;
+ C[4] = ( tmp4 >> 16 ) & 0xff;
+ B[3] = p_css_tab1[ B[4] ] ^ k[4] ^ C[4];
+ k[3] = p_disc_key[2] ^ p_css_tab1[ p_disc_key[3] ] ^ B[3];
+ B[2] = p_css_tab1[ B[3] ] ^ k[3] ^ C[3];
+ k[2] = p_disc_key[1] ^ p_css_tab1[ p_disc_key[2] ] ^ B[2];
+
+ if( ( B[1] ^ p_css_tab1[ B[2] ] ^ k[ 2 ] ) == C[ 2 ] )
+ {
+ if( ! investigate( &p_disc_key[0] , &C[0] ) )
+ {
+ goto end;
+ }
+ }
+
+ /* Test second possible out2[4] */
+ out2[4] = ( out2[4] + 0xff ) & 0xff;
+ tmp4 = ( out2[0] << 16 ) | ( out2[1] << 8 ) | out2[4];
+ tmp4 = BigTable[ tmp4 ];
+ C[2] = tmp4 & 0xff;
+ C[3] = ( tmp4 >> 8 ) & 0xff;
+ C[4] = ( tmp4 >> 16 ) & 0xff;
+ B[3] = p_css_tab1[ B[4] ] ^ k[4] ^ C[4];
+ k[3] = p_disc_key[2] ^ p_css_tab1[ p_disc_key[3] ] ^ B[3];
+ B[2] = p_css_tab1[ B[3] ] ^ k[3] ^ C[3];
+ k[2] = p_disc_key[1] ^ p_css_tab1[ p_disc_key[2] ] ^ B[2];
+
+ if( ( B[1] ^ p_css_tab1[ B[2] ] ^ k[ 2 ] ) == C[ 2 ] )
+ {
+ if( ! investigate( &p_disc_key[0] , &C[0] ) )
+ {
+ goto end;
+ }
+ }
+ }
+ }
+ }
+
+end:
+
+ memcpy( p_disc_key, &C[0], KEY_SIZE );
+
+ free( K1table );
+ free( BigTable );
+
+ return( 0 );
+}
+
+/*****************************************************************************
+ * CSSTitleCrack : title key decryption by cracking
+ * Function designed by Frank Stevenson
*****************************************************************************
- * This function is called by CSSGetKeys to find a key
+ * This function is called by CSSGetTitleKey to find a title key, if we've
+ * chosen to crack title key instead of decrypting it with the disc key.
*****************************************************************************/
-static int CSSCracker( int i_start,
- unsigned char * p_crypted,
- unsigned char * p_decrypted,
- dvd_key_t * p_sector_key,
- dvd_key_t * p_key )
+static int CSSTitleCrack( int i_start,
+ unsigned char * p_crypted,
+ unsigned char * p_decrypted,
+ dvd_key_t * p_sector_key,
+ dvd_key_t * p_key )
{
- unsigned char pi_buffer[10];
+ unsigned char p_buffer[10];
unsigned int i_t1, i_t2, i_t3, i_t4, i_t5, i_t6;
unsigned int i_try;
unsigned int i_candidate;
for( i = 0 ; i < 10 ; i++ )
{
- pi_buffer[i] = pi_css_tab1[p_crypted[i]] ^ p_decrypted[i];
+ p_buffer[i] = p_css_tab1[p_crypted[i]] ^ p_decrypted[i];
}
for( i_try = i_start ; i_try < 0x10000 ; i_try++ )
for( i = 0 ; i < 4 ; i++ )
{
/* advance LFSR1 normaly */
- i_t4 = pi_css_tab2[i_t2] ^ pi_css_tab3[i_t1];
+ i_t4 = p_css_tab2[i_t2] ^ p_css_tab3[i_t1];
i_t2 = i_t1 >> 1;
i_t1 = ( ( i_t1 & 1 ) << 8 ) ^ i_t4;
- i_t4 = pi_css_tab5[i_t4];
+ i_t4 = p_css_tab5[i_t4];
/* deduce i_t6 & i_t5 */
- i_t6 = pi_buffer[i];
+ i_t6 = p_buffer[i];
if( i_t5 )
{
i_t6 = ( i_t6 + 0xff ) & 0x0ff;
}
i_t6 -= i_t4;
i_t5 += i_t6 + i_t4;
- i_t6 = pi_css_tab4[ i_t6 ];
+ i_t6 = p_css_tab4[ i_t6 ];
/* feed / advance i_t3 / i_t5 */
i_t3 = ( i_t3 << 8 ) | i_t6;
i_t5 >>= 8;
/* iterate 6 more times to validate candidate key */
for( ; i < 10 ; i++ )
{
- i_t4 = pi_css_tab2[i_t2] ^ pi_css_tab3[i_t1];
+ i_t4 = p_css_tab2[i_t2] ^ p_css_tab3[i_t1];
i_t2 = i_t1 >> 1;
i_t1 = ( ( i_t1 & 1 ) << 8 ) ^ i_t4;
- i_t4 = pi_css_tab5[i_t4];
+ i_t4 = p_css_tab5[i_t4];
i_t6 = ((((((( i_t3 >> 3 ) ^ i_t3 ) >> 1 ) ^
i_t3 ) >> 8 ) ^ i_t3 ) >> 5 ) & 0xff;
i_t3 = ( i_t3 << 8 ) | i_t6;
- i_t6 = pi_css_tab4[i_t6];
+ i_t6 = p_css_tab4[i_t6];
i_t5 += i_t6 + i_t4;
- if( ( i_t5 & 0xff ) != pi_buffer[i] )
+ if( ( i_t5 & 0xff ) != p_buffer[i] )
{
break;
}
return i_exit;
}
-
-#endif /* HAVE_CSS */
-
projects / vlc / blobdiff