libewf_section.c

sleuthit-2.09 一个磁盘的工具集

/*
 * libewf file reading
 *
 * Copyright (c) 2006-2007, Joachim Metz <[e-mail]>,
 * Hoffmann Investigations. All rights reserved.
 *
 * Refer to AUTHORS for acknowledgements.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * - Neither the name of the creator, related organisations, nor the names of
 *   its contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 * - All advertising materials mentioning features or use of this software
 *   must acknowledge the contribution by people stated in the acknowledgements.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER, COMPANY AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "libewf_includes.h"

#include <libewf/libewf_definitions.h>

#include "libewf_common.h"
#include "libewf_debug.h"
#include "libewf_endian.h"
#include "libewf_header_values.h"
#include "libewf_notify.h"
#include "libewf_segment_table.h"

#include "ewf_chunk.h"
#include "ewf_compress.h"
#include "ewf_crc.h"
#include "ewf_data.h"
#include "ewf_definitions.h"
#include "ewf_error2.h"
#include "ewf_file_header.h"
#include "ewf_hash.h"
#include "ewf_header.h"
#include "ewf_header2.h"
#include "ewf_ltree.h"
#include "ewf_section.h"
#include "ewf_volume.h"
#include "ewf_volume_smart.h"
#include "ewf_table.h"

/* Reads and processes a section start
 * Returns the section start, or NULL on error
 */
EWF_SECTION *libewf_section_start_read( LIBEWF_INTERNAL_HANDLE *internal_handle, int file_descriptor )
{
	EWF_SECTION *section   = NULL;
	EWF_CRC calculated_crc = 0;
	EWF_CRC stored_crc     = 0;

	if( internal_handle == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_read: invalid handle.\n" );

		return( NULL );
	}
	section = (EWF_SECTION *) libewf_common_alloc( EWF_SECTION_SIZE );

	if( section == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_read: unable to allocate section start.\n" );

		return( NULL );
	}
	if( ewf_section_read( section, file_descriptor ) <= -1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_read: unable to read section start.\n" );

		libewf_common_free( section );

		return( NULL );
	}
	LIBEWF_VERBOSE_EXEC( libewf_debug_section_fprint( stderr, section ); );

#ifdef HAVE_DEBUG_OUTPUT
	LIBEWF_VERBOSE_EXEC( libewf_dump_data( section->padding, 40 ); );
#endif

	if( ewf_crc_calculate( &calculated_crc, (uint8_t *) section, ( EWF_SECTION_SIZE - EWF_CRC_SIZE ), 1 ) != 1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_read: unable to calculate CRC.\n" );

		libewf_common_free( section );

		return( NULL );
	}
	if( libewf_endian_convert_32bit( &stored_crc, section->crc ) != 1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_read: unable to convert stored CRC value.\n" );

		libewf_common_free( section );

		return( NULL );
	}
	if( stored_crc != calculated_crc )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_read: CRC does not match (in file: %" PRIu32 ", calculated: %" PRIu32 ").\n", stored_crc, calculated_crc );

		if( internal_handle->error_tollerance < LIBEWF_ERROR_TOLLERANCE_COMPENSATE )
		{
			libewf_common_free( section );

			return( NULL );
		}
	}
	return( section );
}

/* Write a section start to file
 * Returns the amount of bytes written, or -1 on error
 */
ssize_t libewf_section_start_write( LIBEWF_INTERNAL_HANDLE *internal_handle, int file_descriptor, EWF_CHAR *section_type, size_t section_data_size, off_t start_offset )
{
	EWF_SECTION *section     = NULL;
	ssize_t write_count      = 0;
	size_t section_type_size = 0;
	uint64_t section_size    = 0;
	uint64_t section_offset  = 0;

	if( internal_handle == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_write: invalid handle.\n" );

		return( -1 );
	}
	section_type_size = ewf_string_length( section_type );

	if( section_type_size == 0 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_write: section type is empty.\n" );

		return( -1 );
	}
	if( section_type_size >= 16 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_write: section type is too long.\n" );

		return( -1 );
	}
	section = (EWF_SECTION *) libewf_common_alloc( EWF_SECTION_SIZE );

	if( section == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_write: unable to create section.\n" );

		return( -1 );
	}
	if( libewf_common_memset( section, 0, EWF_SECTION_SIZE ) == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_write: unable to clear section.\n" );

		libewf_common_free( section );

		return( -1 );
	}
	/* Add one character for the end of string
	 */
	if( ewf_string_copy( section->type, section_type, ( section_type_size + 1 ) ) == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_write: unable to set section type.\n" );

		libewf_common_free( section );

		return( -1 );
	}
	section_size   = EWF_SECTION_SIZE + section_data_size;
	section_offset = start_offset + section_size;

	if( libewf_endian_revert_64bit( section_size, section->size ) != 1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_write: unable to revert size value.\n" );

		libewf_common_free( section );

		return( -1 );
	}
	if( libewf_endian_revert_64bit( section_offset, section->next ) != 1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_write: unable to revert next offset value.\n" );

		libewf_common_free( section );

		return( -1 );
	}
	write_count = ewf_section_write( section, file_descriptor );

	libewf_common_free( section );

	if( write_count == -1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_start_write: unable to write section to file.\n" );

		return( -1 );
	}
	return( write_count );
}

/* Write a compressed string section to file
 * Returns the amount of bytes written, or -1 on error
 */
ssize_t libewf_section_compressed_string_write( LIBEWF_INTERNAL_HANDLE *internal_handle, int file_descriptor, off_t start_offset, EWF_CHAR *section_type, EWF_CHAR *uncompressed_string, size_t size, int8_t compression_level )
{
	EWF_CHAR *compressed_string = NULL;
	ssize_t section_write_count = 0;
	ssize_t string_write_count  = 0;

	if( internal_handle == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_compressed_string_write: invalid handle.\n" );

		return( -1 );
	}
	if( section_type == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_compressed_string_write: invalid section type.\n" );

		return( -1 );
	}
	if( uncompressed_string == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_compressed_string_write: invalid uncompressed string.\n" );

		return( -1 );
	}
	LIBEWF_VERBOSE_PRINT( "libewf_section_compressed_string_write: String:\n" );
	LIBEWF_VERBOSE_EXEC( libewf_debug_header_fprint( stderr, uncompressed_string, size ); );

	compressed_string = ewf_string_compress( uncompressed_string, &size, compression_level );

	if( compressed_string == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_compressed_string_write: unable to compress string.\n" );

		return( -1 );
	}
	section_write_count = libewf_section_start_write( internal_handle, file_descriptor, section_type, size, start_offset );

	if( section_write_count == -1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_compressed_string_write: unable to write section to file.\n" );

		libewf_common_free( compressed_string );

		return( -1 );
	}
	string_write_count = ewf_string_write_from_buffer( compressed_string, file_descriptor, size );

	libewf_common_free( compressed_string );

	if( string_write_count == -1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_compressed_string_write: unable to write string to file.\n" );

		return( -1 );
	}
	return( section_write_count + string_write_count );
}

/* Reads a header section
 * Returns the amount of bytes read, or -1 on error
 */
ssize_t libewf_section_header_read( LIBEWF_INTERNAL_HANDLE *internal_handle, int file_descriptor, size_t size )
{
	EWF_HEADER *header = NULL;
	ssize_t read_count = (ssize_t) size;

	if( internal_handle == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_header_read: invalid handle.\n" );

		return( -1 );
	}
	header = ewf_header_read( file_descriptor, &size );

	if( header == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_header_read: unable to read header.\n" );

		return( -1 );
	}
	LIBEWF_VERBOSE_PRINT( "libewf_section_header_read: Header:\n" );
	LIBEWF_VERBOSE_EXEC( libewf_debug_header_fprint( stderr, header, size ); );

	if( libewf_internal_handle_is_set_header( internal_handle ) == 0 )
	{
		if( libewf_internal_handle_set_header( internal_handle, header, size ) != 1 )
		{
			LIBEWF_WARNING_PRINT( "libewf_section_header_read: unable to set header in handle.\n" );

			libewf_common_free( header );

			if( internal_handle->error_tollerance < LIBEWF_ERROR_TOLLERANCE_COMPENSATE )
			{
				return( -1 );
			}
		}
	}
	else
	{
		libewf_common_free( header );
	}
	internal_handle->amount_of_header_sections++;

	return( read_count );
}

/* Write a header section to file
 * Returns the amount of bytes written, or -1 on error
 */
ssize_t libewf_section_header_write( LIBEWF_INTERNAL_HANDLE *internal_handle, int file_descriptor, off_t start_offset, EWF_HEADER *header, size_t size, int8_t compression_level )
{
	ssize_t section_write_count = 0;

	section_write_count = libewf_section_compressed_string_write( internal_handle, file_descriptor, start_offset, (EWF_CHAR *) "header", header, size, compression_level );

	if( section_write_count != -1 )
	{
		internal_handle->amount_of_header_sections++;
	}
	return( section_write_count );
}

/* Reads a header2 section
 * Returns the amount of bytes read, or -1 on error
 */
ssize_t libewf_section_header2_read( LIBEWF_INTERNAL_HANDLE *internal_handle, int file_descriptor, size_t size )
{
	EWF_HEADER *header2 = NULL;
	ssize_t read_count  = (ssize_t) size;

	if( internal_handle == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_header2_read: invalid handle.\n" );

		return( -1 );
	}
	header2 = ewf_header2_read( file_descriptor, &size );

	if( header2 == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_header2_read: unable to read header2.\n" );

		return( -1 );
	}
	LIBEWF_VERBOSE_PRINT( "libewf_section_header2_read: Header2:\n" );
	LIBEWF_VERBOSE_EXEC( libewf_debug_header2_fprint( stderr, header2, size ); );

	if( libewf_internal_handle_is_set_header2( internal_handle ) == 0 )
	{
		if( libewf_internal_handle_set_header2( internal_handle, header2, size ) != 1 )
		{
			LIBEWF_WARNING_PRINT( "libewf_section_header2_read: unable to set header2 in handle.\n" );

			libewf_common_free( header2 );

			if( internal_handle->error_tollerance < LIBEWF_ERROR_TOLLERANCE_COMPENSATE )
			{
				return( -1 );
			}
		}
	}
	else
	{
		libewf_common_free( header2 );
	}
	internal_handle->amount_of_header_sections++;

	return( read_count );
}

/* Write a header2 section to file
 * Returns the amount of bytes written, or -1 on error
 */
ssize_t libewf_section_header2_write( LIBEWF_INTERNAL_HANDLE *internal_handle, int file_descriptor, off_t start_offset, EWF_HEADER2 *header2, size_t size, int8_t compression_level )
{
	ssize_t section_write_count = 0;

	section_write_count = libewf_section_compressed_string_write( internal_handle, file_descriptor, start_offset, (EWF_CHAR *) "header2", header2, size, compression_level );

	if( section_write_count != -1 )
	{
		internal_handle->amount_of_header_sections++;
	}
	return( section_write_count );
}

/* Reads an EWF-S01 (SMART) volume section
 * Returns the amount of bytes read, or -1 on error
 */
ssize_t libewf_section_volume_s01_read( LIBEWF_INTERNAL_HANDLE *internal_handle, int file_descriptor, size_t size )
{
	EWF_VOLUME_SMART *volume_smart = NULL;
	EWF_CRC calculated_crc         = 0;
	EWF_CRC stored_crc             = 0;
	int32_t bytes_per_chunk        = 0;

	if( internal_handle == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_section_volume_s01_read: invalid handle.\n" );

		return( -1 );