ref: 068c36acd9849d770f1a263f06b6aa3d88fa176d
dir: /src/libdvdcss.c/
/*****************************************************************************
* libdvdcss.c: DVD reading library.
*****************************************************************************
* Copyright (C) 1998-2001 VideoLAN
* $Id: libdvdcss.c,v 1.14 2002/08/09 14:10:43 sam Exp $
*
* Authors: St�phane Borel <stef@via.ecp.fr>
* Samuel Hocevar <sam@zoy.org>
* H�kan Hjort <d95hjort@dtek.chalmers.se>
*
* 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>
#include <fcntl.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include "dvdcss/dvdcss.h"
#include "common.h"
#include "css.h"
#include "libdvdcss.h"
#include "ioctl.h"
#include "device.h"
/*****************************************************************************
* dvdcss_interface_?: the current libdvdcss version and interface version
*****************************************************************************/
char * dvdcss_interface_2 = VERSION;
/*****************************************************************************
* dvdcss_open: initialize library, open a DVD device, crack CSS key
*****************************************************************************/
extern dvdcss_handle dvdcss_open ( char *psz_target )
{
int i_ret;
char *psz_method = getenv( "DVDCSS_METHOD" );
char *psz_verbose = getenv( "DVDCSS_VERBOSE" );
#ifndef WIN32
char *psz_raw_device = getenv( "DVDCSS_RAW_DEVICE" );
#endif
dvdcss_handle dvdcss;
/*
* Allocate the library structure
*/
dvdcss = malloc( sizeof( struct dvdcss_s ) );
if( dvdcss == NULL )
{
return NULL;
}
/*
* Initialize structure with default values
*/
#ifndef WIN32
dvdcss->i_raw_fd = -1;
#endif
dvdcss->p_titles = NULL;
dvdcss->psz_device = (char *)strdup( psz_target );
dvdcss->psz_error = "no error";
dvdcss->i_method = DVDCSS_METHOD_KEY;
dvdcss->b_debug = 0;
dvdcss->b_errors = 0;
/*
* Find verbosity from DVDCSS_VERBOSE environment variable
*/
if( psz_verbose != NULL )
{
switch( atoi( psz_verbose ) )
{
case 2:
dvdcss->b_debug = 1;
case 1:
dvdcss->b_errors = 1;
case 0:
break;
}
}
/*
* Find method from DVDCSS_METHOD environment variable
*/
if( psz_method != NULL )
{
if( !strncmp( psz_method, "key", 4 ) )
{
dvdcss->i_method = DVDCSS_METHOD_KEY;
}
else if( !strncmp( psz_method, "disc", 5 ) )
{
dvdcss->i_method = DVDCSS_METHOD_DISC;
}
else if( !strncmp( psz_method, "title", 5 ) )
{
dvdcss->i_method = DVDCSS_METHOD_TITLE;
}
else
{
_dvdcss_error( dvdcss, "unknown decrypt method, please choose "
"from 'title', 'key' or 'disc'" );
free( dvdcss->psz_device );
free( dvdcss );
return NULL;
}
}
/*
* Open device
*/
i_ret = _dvdcss_open( dvdcss );
if( i_ret < 0 )
{
free( dvdcss->psz_device );
free( dvdcss );
return NULL;
}
dvdcss->b_scrambled = 1; /* Assume the worst */
dvdcss->b_ioctls = _dvdcss_use_ioctls( dvdcss );
if( dvdcss->b_ioctls )
{
i_ret = _dvdcss_test( dvdcss );
if( i_ret < 0 )
{
/* Disable the CSS ioctls and hope that it works? */
_dvdcss_debug( dvdcss,
"could not check whether the disc was scrambled" );
dvdcss->b_ioctls = 0;
}
else
{
_dvdcss_debug( dvdcss, i_ret ? "disc is scrambled"
: "disc is unscrambled" );
dvdcss->b_scrambled = i_ret;
}
}
/* If disc is CSS protected and the ioctls work, authenticate the drive */
if( dvdcss->b_scrambled && dvdcss->b_ioctls )
{
i_ret = _dvdcss_disckey( dvdcss );
if( i_ret < 0 )
{
_dvdcss_close( dvdcss );
free( dvdcss->psz_device );
free( dvdcss );
return NULL;
}
}
#ifndef WIN32
if( psz_raw_device != NULL )
{
_dvdcss_raw_open( dvdcss, psz_raw_device );
}
#endif
return dvdcss;
}
/*****************************************************************************
* dvdcss_error: return the last libdvdcss error message
*****************************************************************************/
extern char * dvdcss_error ( dvdcss_handle dvdcss )
{
return dvdcss->psz_error;
}
/*****************************************************************************
* dvdcss_seek: seek into the device
*****************************************************************************/
extern int dvdcss_seek ( dvdcss_handle dvdcss, int i_blocks, int i_flags )
{
/* title cracking method is too slow to be used at each seek */
if( ( ( i_flags & DVDCSS_SEEK_MPEG )
&& ( dvdcss->i_method != DVDCSS_METHOD_TITLE ) )
|| ( i_flags & DVDCSS_SEEK_KEY ) )
{
/* check the title key */
if( _dvdcss_title( dvdcss, i_blocks ) )
{
return -1;
}
}
return _dvdcss_seek( dvdcss, i_blocks );
}
/*****************************************************************************
* dvdcss_title: crack or decrypt the current title key if needed
*****************************************************************************
* This function should only be called by dvdcss_seek and should eventually
* not be external if possible.
*****************************************************************************/
extern int dvdcss_title ( dvdcss_handle dvdcss, int i_block )
{
fprintf( stderr, "WARNING: dvdcss_title() is DEPRECATED\n" );
if( ! dvdcss->b_scrambled )
{
return 0;
}
return _dvdcss_title( dvdcss, i_block );
}
/*****************************************************************************
* dvdcss_read: read data from the device, decrypt if requested
*****************************************************************************/
extern int dvdcss_read ( dvdcss_handle dvdcss, void *p_buffer,
int i_blocks,
int i_flags )
{
int i_ret, i_index;
i_ret = _dvdcss_read( dvdcss, p_buffer, i_blocks );
if( i_ret <= 0
|| !dvdcss->b_scrambled
|| !(i_flags & DVDCSS_READ_DECRYPT) )
{
return i_ret;
}
if( ! memcmp( dvdcss->css.p_title_key, "\0\0\0\0\0", 5 ) )
{
/* For what we believe is an unencrypted title,
* check that there are no encrypted blocks */
for( i_index = i_ret; i_index; i_index-- )
{
if( ((u8*)p_buffer)[0x14] & 0x30 )
{
_dvdcss_error( dvdcss, "no key but found encrypted block" );
/* Only return the initial range of unscrambled blocks? */
/* or fail completely? return 0; */
break;
}
p_buffer = (void *) ((u8 *)p_buffer + DVDCSS_BLOCK_SIZE);
}
}
else
{
/* Decrypt the blocks we managed to read */
for( i_index = i_ret; i_index; i_index-- )
{
_dvdcss_unscramble( dvdcss->css.p_title_key, p_buffer );
((u8*)p_buffer)[0x14] &= 0x8f;
p_buffer = (void *) ((u8 *)p_buffer + DVDCSS_BLOCK_SIZE);
}
}
return i_ret;
}
/*****************************************************************************
* dvdcss_readv: read data to an iovec structure, decrypt if requested
*****************************************************************************/
extern int dvdcss_readv ( dvdcss_handle dvdcss, void *_p_iovec,
int i_blocks,
int i_flags )
{
struct iovec *p_iovec = (struct iovec *)_p_iovec;
int i_ret, i_index;
void *iov_base;
size_t iov_len;
i_ret = _dvdcss_readv( dvdcss, p_iovec, i_blocks );
if( i_ret <= 0
|| !dvdcss->b_scrambled
|| !(i_flags & DVDCSS_READ_DECRYPT) )
{
return i_ret;
}
/* Initialize loop for decryption */
iov_base = p_iovec->iov_base;
iov_len = p_iovec->iov_len;
/* Decrypt the blocks we managed to read */
for( i_index = i_ret; i_index; i_index-- )
{
/* Check that iov_len is a multiple of 2048 */
if( iov_len & 0x7ff )
{
return -1;
}
while( iov_len == 0 )
{
p_iovec++;
iov_base = p_iovec->iov_base;
iov_len = p_iovec->iov_len;
}
_dvdcss_unscramble( dvdcss->css.p_title_key, iov_base );
((u8*)iov_base)[0x14] &= 0x8f;
iov_base = (void *) ((u8*)iov_base + DVDCSS_BLOCK_SIZE);
iov_len -= DVDCSS_BLOCK_SIZE;
}
return i_ret;
}
/*****************************************************************************
* dvdcss_close: close the DVD device and clean up the library
*****************************************************************************/
extern int dvdcss_close ( dvdcss_handle dvdcss )
{
dvd_title_t *p_title;
int i_ret;
/* Free our list of keys */
p_title = dvdcss->p_titles;
while( p_title )
{
dvd_title_t *p_tmptitle = p_title->p_next;
free( p_title );
p_title = p_tmptitle;
}
i_ret = _dvdcss_close( dvdcss );
if( i_ret < 0 )
{
return i_ret;
}
free( dvdcss->psz_device );
free( dvdcss );
return 0;
}