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author | arpi <arpi@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2002-08-16 22:35:45 +0000 |
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committer | arpi <arpi@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2002-08-16 22:35:45 +0000 |
commit | 211d6637bc15556bc2efa1d82cfe178c563ac2af (patch) | |
tree | 75b251c0d52b4011567b973a50dd6a27ab3a1eab /libmpdvdkit2/libdvdcss.c | |
parent | 131935f8ad6cd277153915c11fffcc7729cbac0b (diff) | |
download | mpv-211d6637bc15556bc2efa1d82cfe178c563ac2af.tar.bz2 mpv-211d6637bc15556bc2efa1d82cfe178c563ac2af.tar.xz |
importing libdvdcss 1.2.2 files
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@7028 b3059339-0415-0410-9bf9-f77b7e298cf2
Diffstat (limited to 'libmpdvdkit2/libdvdcss.c')
-rw-r--r-- | libmpdvdkit2/libdvdcss.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/libmpdvdkit2/libdvdcss.c b/libmpdvdkit2/libdvdcss.c new file mode 100644 index 0000000000..946d916530 --- /dev/null +++ b/libmpdvdkit2/libdvdcss.c @@ -0,0 +1,513 @@ +/* libdvdcss.c: DVD reading library. + * + * Authors: Stéphane Borel <stef@via.ecp.fr> + * Samuel Hocevar <sam@zoy.org> + * Håkan Hjort <d95hjort@dtek.chalmers.se> + * + * Copyright (C) 1998-2002 VideoLAN + * $Id$ + * + * 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. + */ + +/** + * \mainpage libdvdcss developer documentation + * + * \section intro Introduction + * + * \e libdvdcss is a simple library designed for accessing DVDs like a block + * device without having to bother about the decryption. The important features + * are: + * \li portability: currently supported platforms are GNU/Linux, FreeBSD, + * NetBSD, OpenBSD, BSD/OS, BeOS, Windows 95/98, Windows NT/2000, MacOS X, + * Solaris, HP-UX and OS/2. + * \li adaptability: unlike most similar projects, libdvdcss doesn't require + * the region of your drive to be set and will try its best to read from + * the disc even in the case of a region mismatch. + * \li simplicity: a DVD player can be built around the \e libdvdcss API using + * no more than 4 or 5 library calls. + * + * \e libdvdcss is free software, released under the General Public License. + * This ensures that \e libdvdcss remains free and used only with free + * software. + * + * \section api The libdvdcss API + * + * The complete \e libdvdcss programming interface is documented in the + * dvdcss.h file. + * + * \section env Environment variables + * + * Some environment variables can be used to change the behaviour of + * \e libdvdcss without having to modify the program which uses it. These + * variables are: + * + * \li \b DVDCSS_VERBOSE: sets the verbosity level. + * - \c 0 outputs no messages at all. + * - \c 1 outputs error messages to stderr. + * - \c 2 outputs error messages and debug messages to stderr. + * + * \li \b DVDCSS_METHOD: sets the authentication and decryption method + * that \e libdvdcss will use to read scrambled discs. Can be one + * of \c title, \c key or \c disc. + * - \c key is the default method. \e libdvdcss will use a set of + * calculated player keys to try and get the disc key. This can fail + * if the drive does not recognize any of the player keys. + * - \c disc is a fallback method when \c key has failed. Instead of + * using player keys, \e libdvdcss will crack the disc key using + * a brute force algorithm. This process is CPU intensive and requires + * 64 MB of memory to store temporary data. + * - \c title is the fallback when all other methods have failed. It does + * not rely on a key exchange with the DVD drive, but rather uses a + * crypto attack to guess the title key. On rare cases this may fail + * because there is not enough encrypted data on the disc to perform + * a statistical attack, but in the other hand it is the only way to + * decrypt a DVD stored on a hard disc, or a DVD with the wrong region + * on an RPC2 drive. + * + * \li \b DVDCSS_RAW_DEVICE: specify the raw device to use. + * + */ + +/* + * 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" + +/** + * \brief Symbol for version checks. + * + * The name of this symbol contains the library major number, which makes it + * easy to check which \e libdvdcss development headers are installed on the + * system with tools such as autoconf. + * + * The variable itself contains the exact version number of the library, + * which can be useful for specific feature needs. + */ +char * dvdcss_interface_2 = VERSION; + +/** + * \brief Open a DVD device or directory and return a dvdcss instance. + * + * \param psz_target a string containing the target name, for instance + * "/dev/hdc" or "E:". + * \return a handle to a dvdcss instance or NULL on error. + * + * Initialize the \e libdvdcss library and open the requested DVD device or + * directory. \e libdvdcss checks whether ioctls can be performed on the disc, + * and when possible, the disc key is retrieved. + * + * dvdcss_open() returns a handle to be used for all subsequent \e libdvdcss + * calls. If an error occured, NULL is returned. + */ +extern dvdcss_t 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_t 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; +} + +/** + * \brief Return a string containing the latest error that occured in the + * given \e libdvdcss instance. + * + * \param dvdcss a \e libdvdcss instance. + * \return a null-terminated string containing the latest error message. + * + * This function returns a constant string containing the latest error that + * occured in \e libdvdcss. It can be used to format error messages at your + * convenience in your application. + */ +extern char * dvdcss_error ( dvdcss_t dvdcss ) +{ + return dvdcss->psz_error; +} + +/** + * \brief Seek in the disc and change the current key if requested. + * + * \param dvdcss a \e libdvdcss instance. + * \param i_blocks an absolute block offset to seek to. + * \param i_flags #DVDCSS_NOFLAGS, optionally ored with one of #DVDCSS_SEEK_KEY + * or #DVDCSS_SEEK_MPEG. + * \return the new position in blocks, or a negative value in case an error + * happened. + * + * This function seeks to the requested position, in logical blocks. + * + * You typically set \p i_flags to #DVDCSS_NOFLAGS when seeking in a .IFO. + * + * If #DVDCSS_SEEK_MPEG is specified in \p i_flags and if \e libdvdcss finds it + * reasonable to do so (ie, if the dvdcss method is not "title"), the current + * title key will be checked and a new one will be calculated if necessary. + * This flag is typically used when reading data from a VOB. + * + * If #DVDCSS_SEEK_KEY is specified, the title key will be always checked, + * even with the "title" method. This is equivalent to using the now + * deprecated dvdcss_title() call. This flag is typically used when seeking + * in a new title. + */ +extern int dvdcss_seek ( dvdcss_t 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 ); +} + +/** + * \brief Read from the disc and decrypt data if requested. + * + * \param dvdcss a \e libdvdcss instance. + * \param p_buffer a buffer that will contain the data read from the disc. + * \param i_blocks the amount of blocks to read. + * \param i_flags #DVDCSS_NOFLAGS, optionally ored with #DVDCSS_READ_DECRYPT. + * \return the amount of blocks read, or a negative value in case an + * error happened. + * + * This function reads \p i_blocks logical blocks from the DVD. + * + * You typically set \p i_flags to #DVDCSS_NOFLAGS when reading data from a + * .IFO file on the DVD. + * + * If #DVDCSS_READ_DECRYPT is specified in \p i_flags, dvdcss_read() will + * automatically decrypt scrambled sectors. This flag is typically used when + * reading data from a .VOB file on the DVD. It has no effect on unscrambled + * discs or unscrambled sectors, and can be safely used on those. + * + * \warning dvdcss_read() expects to be able to write \p i_blocks * + * #DVDCSS_BLOCK_SIZE bytes in \p p_buffer. + */ +extern int dvdcss_read ( dvdcss_t 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; +} + +/** + * \brief Read from the disc into multiple buffers and decrypt data if + * requested. + * + * \param dvdcss a \e libdvdcss instance. + * \param p_iovec a pointer to an array of iovec structures that will contain + * the data read from the disc. + * \param i_blocks the amount of blocks to read. + * \param i_flags #DVDCSS_NOFLAGS, optionally ored with #DVDCSS_READ_DECRYPT. + * \return the amount of blocks read, or a negative value in case an + * error happened. + * + * This function reads \p i_blocks logical blocks from the DVD and writes them + * to an array of iovec structures. + * + * You typically set \p i_flags to #DVDCSS_NOFLAGS when reading data from a + * .IFO file on the DVD. + * + * If #DVDCSS_READ_DECRYPT is specified in \p i_flags, dvdcss_readv() will + * automatically decrypt scrambled sectors. This flag is typically used when + * reading data from a .VOB file on the DVD. It has no effect on unscrambled + * discs or unscrambled sectors, and can be safely used on those. + * + * \warning dvdcss_readv() expects to be able to write \p i_blocks * + * #DVDCSS_BLOCK_SIZE bytes in the buffers pointed by \p p_iovec. + * Moreover, all iov_len members of the iovec structures should be + * multiples of #DVDCSS_BLOCK_SIZE. + */ +extern int dvdcss_readv ( dvdcss_t 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; +} + +/** + * \brief Close the DVD and clean up the library. + * + * \param dvdcss a \e libdvdcss instance. + * \return zero in case of success, a negative value otherwise. + * + * This function closes the DVD device and frees all the memory allocated + * by \e libdvdcss. On return, the #dvdcss_t is invalidated and may not be + * used again. + */ +extern int dvdcss_close ( dvdcss_t 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; +} + +/* + * Deprecated. See dvdcss_seek(). + */ +#undef dvdcss_title +extern int dvdcss_title ( dvdcss_t dvdcss, int i_block ) +{ + return _dvdcss_title( dvdcss, i_block ); +} + |