diff options
Diffstat (limited to 'libmpdvdkit2/css.c')
-rw-r--r-- | libmpdvdkit2/css.c | 1695 |
1 files changed, 0 insertions, 1695 deletions
diff --git a/libmpdvdkit2/css.c b/libmpdvdkit2/css.c deleted file mode 100644 index a704a3fcf9..0000000000 --- a/libmpdvdkit2/css.c +++ /dev/null @@ -1,1695 +0,0 @@ -/***************************************************************************** - * css.c: Functions for DVD authentication and descrambling - ***************************************************************************** - * Copyright (C) 1999-2003 VideoLAN - * $Id$ - * - * Authors: Stéphane Borel <stef@via.ecp.fr> - * Håkan Hjort <d95hjort@dtek.chalmers.se> - * - * based on: - * - css-auth by Derek Fawcus <derek@spider.com> - * - DVD CSS ioctls example program by Andrew T. Veliath <andrewtv@usa.net> - * - The Divide and conquer attack by Frank A. Stevenson <frank@funcom.com> - * (see http://www-2.cs.cmu.edu/~dst/DeCSS/FrankStevenson/index.html) - * - DeCSSPlus by Ethan Hawke - * - DecVOB - * see http://www.lemuria.org/DeCSS/ by Tom Vogt for more information. - * - * 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. - *****************************************************************************/ - -/***************************************************************************** - * Preamble - *****************************************************************************/ -#include "config.h" - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <sys/types.h> -#include <sys/stat.h> -#ifdef HAVE_SYS_PARAM_H -# include <sys/param.h> -#endif -#ifdef HAVE_UNISTD_H -# include <unistd.h> -#endif -#include <fcntl.h> - -#ifdef HAVE_LIMITS_H -# include <limits.h> -#endif - -#include "dvdcss/dvdcss.h" - -#include "common.h" -#include "css.h" -#include "libdvdcss.h" -#include "csstables.h" -#include "ioctl.h" -#include "device.h" - -/***************************************************************************** - * Local prototypes - *****************************************************************************/ -static void PrintKey ( dvdcss_t, char *, uint8_t const * ); - -static int GetBusKey ( dvdcss_t ); -static int GetASF ( dvdcss_t ); - -static void CryptKey ( int, int, uint8_t const *, uint8_t * ); -static void DecryptKey ( uint8_t, - uint8_t const *, uint8_t const *, uint8_t * ); - -static int DecryptDiscKey ( dvdcss_t, uint8_t const *, dvd_key_t ); -static int CrackDiscKey ( dvdcss_t, uint8_t * ); - -static void DecryptTitleKey ( dvd_key_t, dvd_key_t ); -static int RecoverTitleKey ( int, uint8_t const *, - uint8_t const *, uint8_t const *, uint8_t * ); -static int CrackTitleKey ( dvdcss_t, int, int, dvd_key_t ); - -static int AttackPattern ( uint8_t const[], int, uint8_t * ); -#if 0 -static int AttackPadding ( uint8_t const[], int, uint8_t * ); -#endif - -/***************************************************************************** - * _dvdcss_test: check if the disc is encrypted or not - *****************************************************************************/ -int _dvdcss_test( dvdcss_t dvdcss ) -{ - int i_ret, i_copyright; - - i_ret = ioctl_ReadCopyright( dvdcss->i_fd, 0 /* i_layer */, &i_copyright ); - -#ifdef WIN32 - if( i_ret < 0 ) - { - /* Maybe we didn't have enough privileges to read the copyright - * (see ioctl_ReadCopyright comments). - * Apparently, on unencrypted DVDs _dvdcss_disckey() always fails, so - * we can check this as a workaround. */ - i_ret = 0; - i_copyright = 1; - if( _dvdcss_disckey( dvdcss ) < 0 ) - { - i_copyright = 0; - } - } -#endif - - if( i_ret < 0 ) - { - /* Since it's the first ioctl we try to issue, we add a notice */ - print_error( dvdcss, "css error: ioctl_ReadCopyright failed, " - "make sure there is a DVD in the drive, and that " - "you have used the correct device node." ); - - return i_ret; - } - - return i_copyright; -} - -/***************************************************************************** - * _dvdcss_title: crack or decrypt the current title key if needed - ***************************************************************************** - * This function should only be called by dvdcss->pf_seek and should eventually - * not be external if possible. - *****************************************************************************/ -int _dvdcss_title ( dvdcss_t dvdcss, int i_block ) -{ - dvd_title_t *p_title; - dvd_title_t *p_newtitle; - dvd_key_t p_title_key; - int i_fd, i_ret = -1, b_cache = 0; - - if( ! dvdcss->b_scrambled ) - { - return 0; - } - - /* Check if we've already cracked this key */ - p_title = dvdcss->p_titles; - while( p_title != NULL - && p_title->p_next != NULL - && p_title->p_next->i_startlb <= i_block ) - { - p_title = p_title->p_next; - } - - if( p_title != NULL - && p_title->i_startlb == i_block ) - { - /* We've already cracked this key, nothing to do */ - memcpy( dvdcss->css.p_title_key, p_title->p_key, sizeof(dvd_key_t) ); - return 0; - } - - /* Check whether the key is in our disk cache */ - if( dvdcss->psz_cachefile[0] ) - { - /* XXX: be careful, we use sprintf and not snprintf */ - sprintf( dvdcss->psz_block, "%.10x", i_block ); - i_fd = open( dvdcss->psz_cachefile, O_RDONLY ); - b_cache = 1; - - if( i_fd >= 0 ) - { - char psz_key[KEY_SIZE * 3]; - unsigned int k0, k1, k2, k3, k4; - - psz_key[KEY_SIZE * 3 - 1] = '\0'; - - if( read( i_fd, psz_key, KEY_SIZE * 3 - 1 ) == KEY_SIZE * 3 - 1 - && sscanf( psz_key, "%x:%x:%x:%x:%x", - &k0, &k1, &k2, &k3, &k4 ) == 5 ) - { - p_title_key[0] = k0; - p_title_key[1] = k1; - p_title_key[2] = k2; - p_title_key[3] = k3; - p_title_key[4] = k4; - PrintKey( dvdcss, "title key found in cache ", p_title_key ); - - /* Don't try to save it again */ - b_cache = 0; - i_ret = 1; - } - - close( i_fd ); - } - } - - /* Crack or decrypt CSS title key for current VTS */ - if( i_ret < 0 ) - { - i_ret = _dvdcss_titlekey( dvdcss, i_block, p_title_key ); - - if( i_ret < 0 ) - { - print_error( dvdcss, "fatal error in vts css key" ); - return i_ret; - } - - if( i_ret == 0 ) - { - print_debug( dvdcss, "unencrypted title" ); - /* We cache this anyway, so we don't need to check again. */ - } - } - - /* Key is valid, we store it on disk. */ - if( dvdcss->psz_cachefile[0] && b_cache ) - { - i_fd = open( dvdcss->psz_cachefile, O_RDWR|O_CREAT, 0644 ); - if( i_fd >= 0 ) - { - char psz_key[KEY_SIZE * 3 + 2]; - - sprintf( psz_key, "%02x:%02x:%02x:%02x:%02x\r\n", - p_title_key[0], p_title_key[1], p_title_key[2], - p_title_key[3], p_title_key[4] ); - - write( i_fd, psz_key, KEY_SIZE * 3 + 1 ); - close( i_fd ); - } - } - - /* Find our spot in the list */ - p_newtitle = NULL; - p_title = dvdcss->p_titles; - while( ( p_title != NULL ) && ( p_title->i_startlb < i_block ) ) - { - p_newtitle = p_title; - p_title = p_title->p_next; - } - - /* Save the found title */ - p_title = p_newtitle; - - /* Write in the new title and its key */ - p_newtitle = malloc( sizeof( dvd_title_t ) ); - p_newtitle->i_startlb = i_block; - memcpy( p_newtitle->p_key, p_title_key, KEY_SIZE ); - - /* Link it at the head of the (possibly empty) list */ - if( p_title == NULL ) - { - p_newtitle->p_next = dvdcss->p_titles; - dvdcss->p_titles = p_newtitle; - } - /* Link the new title inside the list */ - else - { - p_newtitle->p_next = p_title->p_next; - p_title->p_next = p_newtitle; - } - - memcpy( dvdcss->css.p_title_key, p_title_key, KEY_SIZE ); - return 0; -} - -/***************************************************************************** - * _dvdcss_disckey: get disc key. - ***************************************************************************** - * This function should only be called if DVD ioctls are present. - * It will set dvdcss->i_method = DVDCSS_METHOD_TITLE if it fails to find - * a valid disc key. - * Two decryption methods are offered: - * -disc key hash crack, - * -decryption with player keys if they are available. - *****************************************************************************/ -int _dvdcss_disckey( dvdcss_t dvdcss ) -{ - unsigned char p_buffer[ DVD_DISCKEY_SIZE ]; - dvd_key_t p_disc_key; - int i; - - if( GetBusKey( dvdcss ) < 0 ) - { - return -1; - } - - /* Get encrypted disc key */ - if( ioctl_ReadDiscKey( dvdcss->i_fd, &dvdcss->css.i_agid, p_buffer ) < 0 ) - { - print_error( dvdcss, "ioctl ReadDiscKey failed" ); - return -1; - } - - /* This should have invaidated the AGID and got us ASF=1. */ - if( GetASF( dvdcss ) != 1 ) - { - /* Region mismatch (or region not set) is the most likely source. */ - print_error( dvdcss, - "ASF not 1 after reading disc key (region mismatch?)" ); - ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - return -1; - } - - /* Shuffle disc key using bus key */ - for( i = 0 ; i < DVD_DISCKEY_SIZE ; i++ ) - { - p_buffer[ i ] ^= dvdcss->css.p_bus_key[ 4 - (i % KEY_SIZE) ]; - } - - /* Decrypt disc key */ - switch( dvdcss->i_method ) - { - case DVDCSS_METHOD_KEY: - - /* Decrypt disc key with player key. */ - PrintKey( dvdcss, "decrypting disc key ", p_buffer ); - if( ! DecryptDiscKey( dvdcss, p_buffer, p_disc_key ) ) - { - PrintKey( dvdcss, "decrypted disc key is ", p_disc_key ); - break; - } - print_debug( dvdcss, "failed to decrypt the disc key, " - "faulty drive/kernel? " - "cracking title keys instead" ); - - /* Fallback, but not to DISC as the disc key might be faulty */ - dvdcss->i_method = DVDCSS_METHOD_TITLE; - break; - - case DVDCSS_METHOD_DISC: - - /* Crack Disc key to be able to use it */ - memcpy( p_disc_key, p_buffer, KEY_SIZE ); - PrintKey( dvdcss, "cracking disc key ", p_disc_key ); - if( ! CrackDiscKey( dvdcss, p_disc_key ) ) - { - PrintKey( dvdcss, "cracked disc key is ", p_disc_key ); - break; - } - print_debug( dvdcss, "failed to crack the disc key" ); - memset( p_disc_key, 0, KEY_SIZE ); - dvdcss->i_method = DVDCSS_METHOD_TITLE; - break; - - default: - - print_debug( dvdcss, "disc key needs not be decrypted" ); - memset( p_disc_key, 0, KEY_SIZE ); - break; - } - - memcpy( dvdcss->css.p_disc_key, p_disc_key, KEY_SIZE ); - - return 0; -} - - -/***************************************************************************** - * _dvdcss_titlekey: get title key. - *****************************************************************************/ -int _dvdcss_titlekey( dvdcss_t dvdcss, int i_pos, dvd_key_t p_title_key ) -{ - static uint8_t p_garbage[ DVDCSS_BLOCK_SIZE ]; /* we never read it back */ - uint8_t p_key[ KEY_SIZE ]; - int i, i_ret = 0; - - if( dvdcss->b_ioctls && ( dvdcss->i_method == DVDCSS_METHOD_KEY || - dvdcss->i_method == DVDCSS_METHOD_DISC ) ) - { - /* We have a decrypted Disc key and the ioctls are available, - * read the title key and decrypt it. - */ - - print_debug( dvdcss, "getting title key at block %i the classic way", - i_pos ); - - /* We need to authenticate again every time to get a new session key */ - if( GetBusKey( dvdcss ) < 0 ) - { - return -1; - } - - /* Get encrypted title key */ - if( ioctl_ReadTitleKey( dvdcss->i_fd, &dvdcss->css.i_agid, - i_pos, p_key ) < 0 ) - { - print_debug( dvdcss, - "ioctl ReadTitleKey failed (region mismatch?)" ); - i_ret = -1; - } - - /* Test ASF, it will be reset to 0 if we got a Region error */ - switch( GetASF( dvdcss ) ) - { - case -1: - /* An error getting the ASF status, something must be wrong. */ - print_debug( dvdcss, "lost ASF requesting title key" ); - ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - i_ret = -1; - break; - - case 0: - /* This might either be a title that has no key, - * or we encountered a region error. */ - print_debug( dvdcss, "lost ASF requesting title key" ); - break; - - case 1: - /* Drive status is ok. */ - /* If the title key request failed, but we did not loose ASF, - * we might stil have the AGID. Other code assume that we - * will not after this so invalidate it(?). */ - if( i_ret < 0 ) - { - ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - } - break; - } - - if( !( i_ret < 0 ) ) - { - /* Decrypt title key using the bus key */ - for( i = 0 ; i < KEY_SIZE ; i++ ) - { - p_key[ i ] ^= dvdcss->css.p_bus_key[ 4 - (i % KEY_SIZE) ]; - } - - /* If p_key is all zero then there really wasn't any key present - * even though we got to read it without an error. */ - if( !( p_key[0] | p_key[1] | p_key[2] | p_key[3] | p_key[4] ) ) - { - i_ret = 0; - } - else - { - PrintKey( dvdcss, "initial disc key ", dvdcss->css.p_disc_key ); - DecryptTitleKey( dvdcss->css.p_disc_key, p_key ); - PrintKey( dvdcss, "decrypted title key ", p_key ); - i_ret = 1; - } - - /* All went well either there wasn't a key or we have it now. */ - memcpy( p_title_key, p_key, KEY_SIZE ); - PrintKey( dvdcss, "title key is ", p_title_key ); - - return i_ret; - } - - /* The title key request failed */ - print_debug( dvdcss, "resetting drive and cracking title key" ); - - /* Read an unscrambled sector and reset the drive */ - dvdcss->pf_seek( dvdcss, 0 ); - dvdcss->pf_read( dvdcss, p_garbage, 1 ); - dvdcss->pf_seek( dvdcss, 0 ); - _dvdcss_disckey( dvdcss ); - - /* Fallback */ - } - - /* METHOD is TITLE, we can't use the ioctls or requesting the title key - * failed above. For these cases we try to crack the key instead. */ - - /* For now, the read limit is 9Gb / 2048 = 4718592 sectors. */ - i_ret = CrackTitleKey( dvdcss, i_pos, 4718592, p_key ); - - memcpy( p_title_key, p_key, KEY_SIZE ); - PrintKey( dvdcss, "title key is ", p_title_key ); - - return i_ret; -} - -/***************************************************************************** - * _dvdcss_unscramble: does the actual descrambling of data - ***************************************************************************** - * sec : sector to unscramble - * key : title key for this sector - *****************************************************************************/ -int _dvdcss_unscramble( dvd_key_t p_key, uint8_t *p_sec ) -{ - unsigned int i_t1, i_t2, i_t3, i_t4, i_t5, i_t6; - uint8_t *p_end = p_sec + DVDCSS_BLOCK_SIZE; - - /* PES_scrambling_control */ - if( !(p_sec[0x14] & 0x30) ) - { - return 0; - } - - 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; - p_sec += 0x80; - i_t5 = 0; - - while( p_sec != p_end ) - { - 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 = 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 = p_css_tab4[i_t6]; - i_t5 += i_t6 + i_t4; - *p_sec = p_css_tab1[*p_sec] ^ ( i_t5 & 0xff ); - p_sec++; - i_t5 >>= 8; - } - - return 0; -} - -/* Following functions are local */ - -/***************************************************************************** - * GetBusKey : Go through the CSS Authentication process - ***************************************************************************** - * It simulates the mutual authentication between logical unit and host, - * and stops when a session key (called bus key) has been established. - * Always do the full auth sequence. Some drives seem to lie and always - * respond with ASF=1. For instance the old DVD roms on Compaq Armada says - * that ASF=1 from the start and then later fail with a 'read of scrambled - * block without authentication' error. - *****************************************************************************/ -static int GetBusKey( dvdcss_t dvdcss ) -{ - uint8_t p_buffer[10]; - uint8_t p_challenge[2*KEY_SIZE]; - dvd_key_t p_key1; - dvd_key_t p_key2; - dvd_key_t p_key_check; - uint8_t i_variant = 0; - int i_ret = -1; - int i; - - print_debug( dvdcss, "requesting AGID" ); - i_ret = ioctl_ReportAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - - /* We might have to reset hung authentication processes in the drive - * by invalidating the corresponding AGID'. As long as we haven't got - * an AGID, invalidate one (in sequence) and try again. */ - for( i = 0; i_ret == -1 && i < 4 ; ++i ) - { - print_debug( dvdcss, "ioctl ReportAgid failed, " - "invalidating AGID %d", i ); - - /* This is really _not good_, should be handled by the OS. - * Invalidating an AGID could make another process fail somewhere - * in its authentication process. */ - dvdcss->css.i_agid = i; - ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - - print_debug( dvdcss, "requesting AGID" ); - i_ret = ioctl_ReportAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - } - - /* Unable to authenticate without AGID */ - if( i_ret == -1 ) - { - print_error( dvdcss, "ioctl ReportAgid failed, fatal" ); - return -1; - } - - /* Setup a challenge, any values should work */ - for( i = 0 ; i < 10; ++i ) - { - p_challenge[i] = i; - } - - /* Get challenge from host */ - for( i = 0 ; i < 10 ; ++i ) - { - p_buffer[9-i] = p_challenge[i]; - } - - /* Send challenge to LU */ - if( ioctl_SendChallenge( dvdcss->i_fd, - &dvdcss->css.i_agid, p_buffer ) < 0 ) - { - print_error( dvdcss, "ioctl SendChallenge failed" ); - ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - return -1; - } - - /* Get key1 from LU */ - if( ioctl_ReportKey1( dvdcss->i_fd, &dvdcss->css.i_agid, p_buffer ) < 0) - { - print_error( dvdcss, "ioctl ReportKey1 failed" ); - ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - return -1; - } - - /* Send key1 to host */ - for( i = 0 ; i < KEY_SIZE ; i++ ) - { - p_key1[i] = p_buffer[4-i]; - } - - for( i = 0 ; i < 32 ; ++i ) - { - CryptKey( 0, i, p_challenge, p_key_check ); - - if( memcmp( p_key_check, p_key1, KEY_SIZE ) == 0 ) - { - print_debug( dvdcss, "drive authenticated, using variant %d", i ); - i_variant = i; - break; - } - } - - if( i == 32 ) - { - print_error( dvdcss, "drive would not authenticate" ); - ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - return -1; - } - - /* Get challenge from LU */ - if( ioctl_ReportChallenge( dvdcss->i_fd, - &dvdcss->css.i_agid, p_buffer ) < 0 ) - { - print_error( dvdcss, "ioctl ReportKeyChallenge failed" ); - ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - return -1; - } - - /* Send challenge to host */ - for( i = 0 ; i < 10 ; ++i ) - { - p_challenge[i] = p_buffer[9-i]; - } - - CryptKey( 1, i_variant, p_challenge, p_key2 ); - - /* Get key2 from host */ - for( i = 0 ; i < KEY_SIZE ; ++i ) - { - p_buffer[4-i] = p_key2[i]; - } - - /* Send key2 to LU */ - if( ioctl_SendKey2( dvdcss->i_fd, &dvdcss->css.i_agid, p_buffer ) < 0 ) - { - print_error( dvdcss, "ioctl SendKey2 failed" ); - ioctl_InvalidateAgid( dvdcss->i_fd, &dvdcss->css.i_agid ); - return -1; - } - - /* The drive has accepted us as authentic. */ - print_debug( dvdcss, "authentication established" ); - - memcpy( p_challenge, p_key1, KEY_SIZE ); - memcpy( p_challenge + KEY_SIZE, p_key2, KEY_SIZE ); - - CryptKey( 2, i_variant, p_challenge, dvdcss->css.p_bus_key ); - - return 0; -} - -/***************************************************************************** - * PrintKey : debug function that dumps a key value - *****************************************************************************/ -static void PrintKey( dvdcss_t dvdcss, char *prefix, uint8_t const *data ) -{ - print_debug( dvdcss, "%s%02x:%02x:%02x:%02x:%02x", prefix, - data[0], data[1], data[2], data[3], data[4] ); -} - -/***************************************************************************** - * GetASF : Get Authentication success flag - ***************************************************************************** - * Returns : - * -1 on ioctl error, - * 0 if the device needs to be authenticated, - * 1 either. - *****************************************************************************/ -static int GetASF( dvdcss_t dvdcss ) -{ - int i_asf = 0; - - if( ioctl_ReportASF( dvdcss->i_fd, NULL, &i_asf ) != 0 ) - { - /* The ioctl process has failed */ - print_error( dvdcss, "GetASF fatal error" ); - return -1; - } - - if( i_asf ) - { - print_debug( dvdcss, "GetASF authenticated, ASF=1" ); - } - else - { - print_debug( dvdcss, "GetASF not authenticated, ASF=0" ); - } - - return i_asf; -} - -/***************************************************************************** - * CryptKey : shuffles bits and unencrypt keys. - ***************************************************************************** - * Used during authentication and disc key negociation in GetBusKey. - * i_key_type : 0->key1, 1->key2, 2->buskey. - * i_variant : between 0 and 31. - *****************************************************************************/ -static void CryptKey( int i_key_type, int i_variant, - uint8_t const *p_challenge, uint8_t *p_key ) -{ - /* Permutation table for challenge */ - uint8_t 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 variant table for key2 and buskey */ - uint8_t pp_perm_variant[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, - 0x12, 0x10, 0x16, 0x14, 0x13, 0x11, 0x17, 0x15 }, - { 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 } }; - - uint8_t p_variants[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 */ - uint8_t p_secret[5] = { 0x55, 0xD6, 0xC4, 0xC5, 0x28 }; - - uint8_t p_bits[30], p_scratch[10], p_tmp1[5], p_tmp2[5]; - uint8_t i_lfsr0_o; /* 1 bit used */ - uint8_t i_lfsr1_o; /* 1 bit used */ - uint8_t i_css_variant, i_cse, i_index, i_combined, i_carry; - uint8_t i_val = 0; - uint32_t i_lfsr0, i_lfsr1; - int i_term = 0; - int i_bit; - int i; - - for (i = 9; i >= 0; --i) - p_scratch[i] = p_challenge[pp_perm_challenge[i_key_type][i]]; - - i_css_variant = ( i_key_type == 0 ) ? i_variant : - pp_perm_variant[i_key_type-1][i_variant]; - - /* - * This encryption engine implements one of 32 variations - * one the same theme depending upon the choice in the - * variant 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. - */ - - /* 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 ; ) - { - p_tmp1[i] = p_scratch[5 + i] ^ p_secret[i] ^ p_crypt_tab2[i]; - } - - /* - * 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. - * - */ - - /* 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. - */ - 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(p_bits); - i_carry = 0; - - do - { - for( i_bit = 0, i_val = 0 ; i_bit < 8 ; ++i_bit ) - { - - i_lfsr0_o = ( ( i_lfsr0 >> 24 ) ^ ( i_lfsr0 >> 21 ) ^ - ( i_lfsr0 >> 20 ) ^ ( i_lfsr0 >> 12 ) ) & 1; - i_lfsr0 = ( i_lfsr0 << 1 ) | i_lfsr0_o; - - i_lfsr1_o = ( ( i_lfsr1 >> 16 ) ^ ( i_lfsr1 >> 2 ) ) & 1; - i_lfsr1 = ( i_lfsr1 << 1 ) | i_lfsr1_o; - - i_combined = !i_lfsr1_o + i_carry + !i_lfsr0_o; - /* taking bit 1 */ - i_carry = ( i_combined >> 1 ) & 1; - i_val |= ( i_combined & 1 ) << i_bit; - } - - 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 = p_variants[i_css_variant] ^ p_crypt_tab2[i_css_variant]; - - /* 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 = p_scratch[i] ) - { - i_index = p_bits[25 + i] ^ p_scratch[i]; - i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse; - - p_tmp1[i] = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term; - } - p_tmp1[4] ^= p_tmp1[0]; - - for( i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp1[i] ) - { - i_index = p_bits[20 + i] ^ p_tmp1[i]; - i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse; - - p_tmp2[i] = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term; - } - p_tmp2[4] ^= p_tmp2[0]; - - for( i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp2[i] ) - { - 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; - - p_tmp1[i] = p_crypt_tab0[i_index] ^ p_crypt_tab2[i_index]; - } - p_tmp1[4] ^= p_tmp1[0]; - - for( i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp1[i] ) - { - 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 = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term; - - p_tmp2[i] = p_crypt_tab0[i_index] ^ p_crypt_tab2[i_index]; - } - p_tmp2[4] ^= p_tmp2[0]; - - for( i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp2[i] ) - { - i_index = p_bits[5 + i] ^ p_tmp2[i]; - i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse; - - p_tmp1[i] = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term; - } - p_tmp1[4] ^= p_tmp1[0]; - - for(i = 5, i_term = 0 ; --i >= 0 ; i_term = p_tmp1[i] ) - { - i_index = p_bits[i] ^ p_tmp1[i]; - i_index = p_crypt_tab1[i_index] ^ ~p_crypt_tab2[i_index] ^ i_cse; - - p_key[i] = p_crypt_tab2[i_index] ^ p_crypt_tab3[i_index] ^ i_term; - } - - return; -} - -/***************************************************************************** - * DecryptKey: decrypt p_crypted with p_key. - ***************************************************************************** - * Used to decrypt the disc key, with a player key, after requesting it - * in _dvdcss_disckey and to decrypt title keys, with a disc key, requested - * in _dvdcss_titlekey. - * The player keys and the resulting disc key are only used as KEKs - * (key encryption keys). - * Decryption is slightly dependant on the type of key: - * -for disc key, invert is 0x00, - * -for title key, invert if 0xff. - *****************************************************************************/ -static void DecryptKey( uint8_t invert, uint8_t const *p_key, - uint8_t const *p_crypted, uint8_t *p_result ) -{ - unsigned int i_lfsr1_lo; - unsigned int i_lfsr1_hi; - unsigned int i_lfsr0; - unsigned int i_combined; - uint8_t o_lfsr0; - uint8_t o_lfsr1; - uint8_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_result[4] = k[4] ^ p_css_tab1[p_crypted[4]] ^ p_crypted[3]; - p_result[3] = k[3] ^ p_css_tab1[p_crypted[3]] ^ p_crypted[2]; - p_result[2] = k[2] ^ p_css_tab1[p_crypted[2]] ^ p_crypted[1]; - p_result[1] = k[1] ^ p_css_tab1[p_crypted[1]] ^ p_crypted[0]; - p_result[0] = k[0] ^ p_css_tab1[p_crypted[0]] ^ p_result[4]; - - p_result[4] = k[4] ^ p_css_tab1[p_result[4]] ^ p_result[3]; - p_result[3] = k[3] ^ p_css_tab1[p_result[3]] ^ p_result[2]; - p_result[2] = k[2] ^ p_css_tab1[p_result[2]] ^ p_result[1]; - p_result[1] = k[1] ^ p_css_tab1[p_result[1]] ^ p_result[0]; - p_result[0] = k[0] ^ p_css_tab1[p_result[0]]; - - return; -} - -/***************************************************************************** - * player_keys: alternate DVD player keys - ***************************************************************************** - * These player keys were generated using Frank A. Stevenson's PlayerKey - * cracker. A copy of his article can be found here: - * http://www-2.cs.cmu.edu/~dst/DeCSS/FrankStevenson/mail2.txt - *****************************************************************************/ -static const dvd_key_t player_keys[] = -{ - { 0x01, 0xaf, 0xe3, 0x12, 0x80 }, - { 0x12, 0x11, 0xca, 0x04, 0x3b }, - { 0x14, 0x0c, 0x9e, 0xd0, 0x09 }, - { 0x14, 0x71, 0x35, 0xba, 0xe2 }, - { 0x1a, 0xa4, 0x33, 0x21, 0xa6 }, - { 0x26, 0xec, 0xc4, 0xa7, 0x4e }, - { 0x2c, 0xb2, 0xc1, 0x09, 0xee }, - { 0x2f, 0x25, 0x9e, 0x96, 0xdd }, - { 0x33, 0x2f, 0x49, 0x6c, 0xe0 }, - { 0x35, 0x5b, 0xc1, 0x31, 0x0f }, - { 0x36, 0x67, 0xb2, 0xe3, 0x85 }, - { 0x39, 0x3d, 0xf1, 0xf1, 0xbd }, - { 0x3b, 0x31, 0x34, 0x0d, 0x91 }, - { 0x45, 0xed, 0x2 |