/* * libewf file reading * * Copyright (c) 2006-2007, Joachim Metz <forensics@hoffmannbv.nl>, * 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_endian.h"#include "libewf_notify.h"#include "libewf_file.h"#include "libewf_read.h"#include "libewf_section.h"#include "libewf_segment_table.h"#include "ewf_crc.h"#include "ewf_file_header.h"/* Builds the index (section list and offset table) from the input files * Returns 1 if successful, or -1 on error */int8_t libewf_read_build_index( LIBEWF_INTERNAL_HANDLE *internal_handle ){	EWF_SECTION *last_section = NULL;	uint16_t segment_number   = 0;	if( internal_handle == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_read_build_index: invalid handle.\n" );		return( -1 );	}	if( internal_handle->index_build != 0 )	{		LIBEWF_WARNING_PRINT( "libewf_read_build_index: index has already been build.\n" );		return( -1 );	}	if( libewf_internal_handle_read_initialize( internal_handle ) != 1 )	{		LIBEWF_WARNING_PRINT( "libewf_read_build_index: unable to initialize read values in handle.\n" );		return( -1 );	}	for( segment_number = 1; segment_number < internal_handle->segment_table->amount; segment_number++ )	{		if( last_section != NULL )		{			libewf_common_free( last_section );		}		LIBEWF_VERBOSE_PRINT( "libewf_read_build_index: building index for segment number: %" PRIu32 ".\n", segment_number );		last_section = libewf_read_sections_from_segment( internal_handle, segment_number );	}	/* Check to see if the done section has been found	 */	if( last_section == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_read_build_index: invalid last section.\n" );		return( -1 );	}	else if( ewf_section_is_type_done( last_section ) == 0 )	{		LIBEWF_WARNING_PRINT( "libewf_read_build_index: unable to find the last segment file (done section).\n" );		libewf_common_free( last_section );		return( -1 );	}	libewf_common_free( last_section );	/* Determine the EWF file format	 */	if( libewf_internal_handle_determine_format( internal_handle ) != 1 )	{		LIBEWF_WARNING_PRINT( "libewf_read_build_index: unable to determine file format.\n" );	}	LIBEWF_VERBOSE_PRINT( "libewf_read_build_index: index successful build.\n" );	/* Calculate the media size	 */	internal_handle->media->media_size = (uint64_t) internal_handle->media->amount_of_sectors * (uint64_t) internal_handle->media->bytes_per_sector;	/* Flag that the index was build	 */	internal_handle->index_build = 1;	return( 1 );}/* Reads and processes sections of a segment file * Returns the last section read, or NULL on error */EWF_SECTION *libewf_read_sections_from_segment( LIBEWF_INTERNAL_HANDLE *internal_handle, uint16_t segment_number ){	EWF_SECTION *section = NULL;	int file_descriptor  = 0;	/* The first offset is directly after the file header (13 byte)	 */	off_t previous_offset = (off_t) EWF_FILE_HEADER_SIZE;	if( internal_handle == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_sections_read_segment: invalid handle.\n" );		return( NULL );	}	if( libewf_segment_table_values_is_set( internal_handle->segment_table, segment_number ) == 0 )	{		LIBEWF_WARNING_PRINT( "libewf_sections_read_segment: missing a segment file for segment %" PRIu32 ".\n", segment_number );		return( NULL );	}	file_descriptor = libewf_segment_table_get_file_descriptor( internal_handle->segment_table, segment_number );	if( file_descriptor <= -1 )	{		LIBEWF_WARNING_PRINT( "libewf_sections_read_segment: invalid file descriptor.\n" );		return( NULL );	}	do	{		if( section != NULL )		{			libewf_common_free( section );		}		section = libewf_section_read( internal_handle, file_descriptor, internal_handle->segment_table->section_list[ segment_number ], segment_number, &previous_offset );		if( section == NULL )		{			LIBEWF_WARNING_PRINT( "libewf_sections_read_segment: unable to read section.\n" );			return( NULL );		}		/* The done and next sections point back at themselves		 */		if( ( ewf_section_is_type_next( section ) == 1 ) || ( ewf_section_is_type_done( section ) == 1 ) )		{			break;		}	}	while( section != NULL );	return( section );}/* Reads a certain chunk of data from the segment file(s) * Will read until the requested size is filled or the entire chunk is read * This function swaps byte pairs if specified * Returns the amount of bytes read, 0 if no bytes can be read, or -1 on error */ssize_t libewf_read_chunk( LIBEWF_INTERNAL_HANDLE *internal_handle, uint32_t chunk, uint32_t chunk_offset, void *buffer, size_t size ){	EWF_CHUNK *chunk_data       = NULL;	EWF_CHUNK *chunk_read       = NULL;	EWF_CRC calculated_crc      = 0;	EWF_CRC stored_crc          = 0;#if defined( HAVE_WIDE_CHARACTER_TYPE ) && defined( HAVE_WIDE_CHARACTER_SUPPORT_FUNCTIONS )	wchar_t *filename           = NULL;#else	char *filename              = NULL;#endif	ssize_t chunk_read_count    = 0;	ssize_t crc_read_count      = 0;	size_t chunk_data_size      = 0;	size_t bytes_available      = 0;	size_t md5_hash_size        = 0;	uint16_t segment_number     = 0;	int8_t chunk_cache_used     = 0;	int8_t result               = 0;	uint8_t percentage          = 0;	int file_descriptor         = 0;	if( internal_handle == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_read_chunk: invalid handle.\n" );		return( -1 );	}	if( internal_handle->media == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_read_chunk: invalid handle - missing subhandle media.\n" );		return( -1 );	}	if( internal_handle->read == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_read_chunk: invalid handle - missing subhandle read.\n" );		return( -1 );	}	if( internal_handle->offset_table == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_read_chunk: invalid handle - missing offset table.\n" );		return( -1 );	}	if( internal_handle->segment_table == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_read_chunk: invalid handle - missing segment table.\n" );		return( -1 );	}	if( internal_handle->chunk_cache == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_read_chunk: invalid chunk cache.\n" );		return( -1 );	}	if( internal_handle->index_build == 0 )	{		LIBEWF_WARNING_PRINT( "libewf_read_chunk: index was not build.\n" );		return( -1 );	}	if( buffer == NULL )	{		LIBEWF_WARNING_PRINT( "libewf_read_chunk: invalid buffer.\n" );		return( -1 );	}	if( buffer == internal_handle->chunk_cache->compressed )	{		LIBEWF_WARNING_PRINT( "libewf_read_chunk: invalid buffer - same as chunk cache compressed.\n" );		return( -1 );	}	/* Check if the chunk is available	 */	if( chunk >= internal_handle->offset_table->amount )	{		return( 0 );	}	/* Check if the chunk is cached	 */	if( ( internal_handle->chunk_cache->chunk != chunk ) || ( internal_handle->chunk_cache->cached == 0 ) )	{		file_descriptor = internal_handle->offset_table->file_descriptor[ chunk ];		segment_number  = internal_handle->offset_table->segment_number[ chunk ];		/* Check if chunk cache passthrough is used		 * if the chunk cache is used as the chunk data buffer		 */		chunk_cache_used = (int8_t) ( buffer == internal_handle->chunk_cache->data );		/* Determine the size of the chunk including the CRC		 */		chunk_data_size = internal_handle->offset_table->size[ chunk ];		/* Make sure the chunk cache is large enough		 */		if( chunk_data_size > internal_handle->chunk_cache->allocated_size )		{			LIBEWF_VERBOSE_PRINT( "libewf_read_chunk: reallocating chunk data size: %zu.\n", chunk_data_size );			if( libewf_internal_handle_chunk_cache_realloc( internal_handle, chunk_data_size ) == NULL )			{				LIBEWF_WARNING_PRINT( "libewf_read_chunk: unable to reallocate chunk cache.\n");				return( -1 );			}			/* Adjust chunk data buffer if necessary			 */			if( ( chunk_cache_used == 1 ) && ( buffer != internal_handle->chunk_cache->data ) )			{				buffer = internal_handle->chunk_cache->data;			}		}		chunk_data = internal_handle->chunk_cache->data;#ifdef HAVE_BUFFER_PASSTHROUGH		/* Determine if the chunk data should be put directly in the buffer		 */		if( ( buffer != internal_handle->chunk_cache->data ) && ( chunk_offset == 0 ) && ( size >= (uint64_t) internal_handle->media->chunk_size ) )		{			chunk_data = (EWF_CHUNK *) buffer;		}#endif		/* Determine if the chunk data should be directly read into chunk data buffer		 * or to use the intermediate storage for a compressed chunk		 */		if( internal_handle->offset_table->compressed[ chunk ] == 1 )		{			chunk_read = internal_handle->chunk_cache->compressed;		}		else		{			chunk_read = chunk_data;		}		/* If buffer passthrough is used the CRC is read seperately		 */		if( ( chunk_read != internal_handle->chunk_cache->compressed ) && ( chunk_read != internal_handle->chunk_cache->data ) )		{			chunk_data_size -= EWF_CRC_SIZE;		}		/* Make sure the file offset is in the right place		 */		if( libewf_seek_chunk( internal_handle, chunk ) <= -1 )		{			LIBEWF_WARNING_PRINT( "libewf_read_chunk: unable to seek chunk.\n");			return( -1 );		}		/* Read the chunk data		 */		chunk_read_count = ewf_chunk_read( chunk_read, file_descriptor, chunk_data_size );		if( chunk_read_count <= -1 )		{			LIBEWF_WARNING_PRINT( "libewf_read_chunk: unable to read chunk.\n");			return( -1 );		}		internal_handle->segment_table->file_offset[ segment_number ] += (off_t) chunk_read_count;		if( ( internal_handle->offset_table->last > 0 ) && ( chunk > 0 ) )		{			percentage = (uint8_t) ( (uint32_t) ( chunk * 100 ) / internal_handle->offset_table->last );		}		/* Determine if the chunk is not compressed		 */		if( internal_handle->offset_table->compressed[ chunk ] == 0 )		{			LIBEWF_VERBOSE_PRINT( "libewf_read_chunk: chunk %" PRIu32 " of %" PRIu32 " (%" PRIu8 "%%) is UNCOMPRESSED.\n", ( chunk + 1 ), internal_handle->offset_table->amount, percentage );			/* If buffer passthrough is used the CRC needs to be read seperately			 */			if( ( chunk_read != internal_handle->chunk_cache->compressed ) && ( chunk_read != internal_handle->chunk_cache->data ) )			{				crc_read_count = ewf_crc_read( &stored_crc, file_descriptor );