libewf_file.c

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/*
 * libewf file handling
 *
 * 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"

#if HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <errno.h>

#include <libewf/libewf_definitions.h>

#include "libewf_common.h"
#include "libewf_endian.h"
#include "libewf_notify.h"
#include "libewf_file.h"
#include "libewf_offset_table.h"
#include "libewf_read.h"
#include "libewf_section_list.h"
#include "libewf_segment_table.h"
#include "libewf_string.h"
#include "libewf_write.h"

#include "ewf_compress.h"
#include "ewf_crc.h"
#include "ewf_digest_hash.h"
#include "ewf_file_header.h"
#include "ewf_header.h"
#include "ewf_section.h"
#include "ewf_volume.h"
#include "ewf_table.h"

/* Return the library version
 */
const LIBEWF_CHAR *libewf_get_version( void )
{
	return( (const LIBEWF_CHAR *) LIBEWF_VERSION );
}

#if defined( HAVE_WIDE_CHARACTER_TYPE ) && defined( HAVE_WIDE_CHARACTER_SUPPORT_FUNCTIONS )

/* Detects if a file is an EWF file (check for the EWF file signature)
 * Returns 1 if true, 0 if not, or -1 on error
 */
int8_t libewf_check_file_signature( const wchar_t *filename )
{
	uint8_t signature[ 8 ];

	wchar_t *error_string = NULL;
	ssize_t count         = 0;
	int file_descriptor   = 0;

	if( filename == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_check_file_signature: invalid filename.\n" );

		return( -1 );
	}
	file_descriptor = libewf_common_wide_open( filename, LIBEWF_OPEN_READ );

	if( file_descriptor < 0 )
	{
		error_string = libewf_common_wide_strerror( errno );

		if( error_string == NULL )
		{
			LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to open file: %ls.\n", filename );
		}
		else
		{
			LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to open file: %ls with error: %ls.\n", filename, error_string );

			libewf_common_free( error_string );
		}
		return( -1 );
	}
	count = libewf_common_read( file_descriptor, signature, 8 );

	if( libewf_common_close( file_descriptor ) != 0 )
	{
		error_string = libewf_common_strerror( errno );

		if( error_string == NULL )
		{
			LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to close file: %ls.\n", filename );
		}
		else
		{
			LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to close file: %ls with error: %ls.\n", filename, error_string );

			libewf_common_free( error_string );
		}
		return( -1 );
	}
	if( count <= -1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_check_file_signature: error reading signature from file: %ls.\n", filename );

		return( -1 );
	}
	else if( count != 8 )
	{
		LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to read signature from file: %ls.\n", filename );

		return( -1 );
	}
	return( ewf_file_header_check_signature( signature ) );
}
#else

/* Detects if a file is an EWF file (check for the EWF file signature)
 * Returns 1 if true, 0 if not, or -1 on error
 */
int8_t libewf_check_file_signature( const char *filename )
{
	uint8_t signature[ 8 ];

	char *error_string  = NULL;
	ssize_t count       = 0;
	int file_descriptor = 0;

	if( filename == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_check_file_signature: invalid filename.\n" );

		return( -1 );
	}
	file_descriptor = libewf_common_open( filename, LIBEWF_OPEN_READ );

	if( file_descriptor < 0 )
	{
		error_string = libewf_common_strerror( errno );

		if( error_string == NULL )
		{
			LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to open file: %s.\n", filename );
		}
		else
		{
			LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to open file: %s with error: %s.\n", filename, error_string );

			libewf_common_free( error_string );
		}
		return( -1 );
	}
	count = libewf_common_read( file_descriptor, signature, 8 );

	if( libewf_common_close( file_descriptor ) != 0 )
	{
		error_string = libewf_common_strerror( errno );

		if( error_string == NULL )
		{
			LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to close file: %s.\n", filename );
		}
		else
		{
			LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to close file: %s with error: %s.\n", filename, error_string );

			libewf_common_free( error_string );
		}
		return( -1 );
	}
	if( count <= -1 )
	{
		LIBEWF_WARNING_PRINT( "libewf_check_file_signature: error reading signature from file: %s.\n", filename );

		return( -1 );
	}
	else if( count != 8 )
	{
		LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to read signature from file: %s.\n", filename );

		return( -1 );
	}
	return( ewf_file_header_check_signature( signature ) );
}
#endif

#if defined( HAVE_WIDE_CHARACTER_TYPE ) && defined( HAVE_WIDE_CHARACTER_SUPPORT_FUNCTIONS )

/* Opens EWF file(s)
 * For reading files should contain all filenames that make up an EWF image
 * For writing files should contain the base of the filename, extentions like .e01 will be automatically added
 * Returns a pointer to the new instance of handle, NULL on error
 */
LIBEWF_HANDLE *libewf_open( wchar_t * const filenames[], uint16_t file_amount, uint8_t flags )
{
	EWF_FILE_HEADER file_header;

	LIBEWF_INTERNAL_HANDLE *internal_handle = NULL;
	wchar_t *error_string                   = NULL;
	uint32_t iterator                       = 0;
	uint16_t fields_segment                 = 0;
	int file_descriptor                     = 0;

	if( ( flags == LIBEWF_OPEN_READ ) || ( flags == LIBEWF_OPEN_READ_WRITE ) )
	{
		/* 1 additional entry required because
		 * entry [ 0 ] is not used for reading
		 */
		handle = libewf_internal_handle_alloc( ( file_amount + 1 ), flags );

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

			return( NULL );
		}
		if( internal_handle->segment_table == NULL )
		{
			LIBEWF_WARNING_PRINT( "libewf_open: invalid handle - missing segment table.\n" );

			libewf_internal_handle_free( handle );

			return( NULL );
		}
		for( iterator = 0; iterator < file_amount; iterator++ )
		{
			file_descriptor = libewf_common_wide_open( filenames[ iterator ], flags );

			if( file_descriptor == -1 )
			{
				error_string = libewf_common_wide_strerror( errno );

				if( error_string == NULL )
				{
					LIBEWF_WARNING_PRINT( "libewf_open: unable to open file: %s.\n", filenames[ iterator ] );
				}
				else
				{
					LIBEWF_WARNING_PRINT( "libewf_open: unable to open file: %s with error: %s.\n", filenames[ iterator ], error_string );

					libewf_common_free( error_string );
				}
				libewf_internal_handle_free( handle );

				return( NULL );
			}
			if( ewf_file_header_read( &file_header, file_descriptor ) <= -1 )
			{
				LIBEWF_WARNING_PRINT( "libewf_open: invalid file header in: %s.\n", filenames[ iterator ] );

				libewf_internal_handle_free( handle );

				return( NULL );
			}
			if( ewf_file_header_check_signature( file_header.signature ) == 0 )
			{
				LIBEWF_WARNING_PRINT( "libewf_open: file signature does not match.\n" );

				libewf_internal_handle_free( handle );

				return( NULL );
			}
			if( libewf_endian_convert_16bit( &fields_segment, file_header.fields_segment ) != 1 )
			{
				LIBEWF_WARNING_PRINT( "libewf_open: unable to convert fields segment value.\n" );

				libewf_internal_handle_free( handle );

				return( NULL );
			}
			LIBEWF_VERBOSE_PRINT( "libewf_open: added segment file: %s with file descriptor: %d with segment number: %" PRIu16 ".\n",
				filenames[ iterator ], file_descriptor, fields_segment );

			if( libewf_segment_table_set_wide_filename( internal_handle->segment_table, fields_segment, filenames[ iterator ], libewf_common_string_length( filenames[ iterator ] ) ) != 1 )
			{
				LIBEWF_WARNING_PRINT( "libewf_open: unable to set filename in segment table.\n" );

				libewf_internal_handle_free( handle );

				return( NULL );
			}
			if( libewf_segment_table_set_file_descriptor( internal_handle->segment_table, fields_segment, file_descriptor ) != 1 )
			{
				LIBEWF_WARNING_PRINT( "libewf_open: unable to set file descriptor in segment table.\n" );

				libewf_internal_handle_free( handle );

				return( NULL );
			}
		}
		if( libewf_read_build_index( handle ) != 1 )
		{
			LIBEWF_WARNING_PRINT( "libewf_open: unable to create index.\n" );

			libewf_internal_handle_free( handle );

			return( NULL );
		}
	}
	else if( flags == LIBEWF_OPEN_WRITE )
	{
		/* Allocate 2 entries
		 * entry [ 0 ] is used for the base filename
		 */
		handle = libewf_internal_handle_alloc( 1, flags );

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

			return( NULL );
		}
		if( internal_handle->segment_table == NULL )
		{
			LIBEWF_WARNING_PRINT( "libewf_open: invalid handle - missing segment table.\n" );

			libewf_internal_handle_free( handle );

			return( NULL );
		}
		if( libewf_segment_table_set_wide_filename( internal_handle->segment_table, 0, filenames[ iterator ], libewf_common_wide_string_length( filenames[ iterator ] ) ) != 1 )
		{
			LIBEWF_WARNING_PRINT( "libewf_open: unable to set filename in segment table.\n" );

			libewf_internal_handle_free( handle );

			return( NULL );
		}
		if( libewf_segment_table_set_file_descriptor( internal_handle->segment_table, 0, -1 ) != 1 )
		{
			LIBEWF_WARNING_PRINT( "libewf_open: unable to set file descriptor in segment table.\n" );

			libewf_internal_handle_free( handle );

			return( NULL );
		}
	}
	else
	{
		LIBEWF_WARNING_PRINT( "libewf_open: unsupported flags.\n" );

		return( NULL );
	}
	LIBEWF_VERBOSE_PRINT( "libewf_open: open successful.\n" );

	return( (LIBEWF_HANDLE *) handle );
}
#else
/* Opens EWF file(s)
 * For reading files should contain all filenames that make up an EWF image
 * For writing files should contain the base of the filename, extentions like .e01 will be automatically added
 * Returns a pointer to the new instance of handle, NULL on error
 */
LIBEWF_HANDLE *libewf_open( char * const filenames[], uint16_t file_amount, uint8_t flags )
{
	EWF_FILE_HEADER file_header;

	LIBEWF_INTERNAL_HANDLE *internal_handle = NULL;
	char *error_string                      = NULL;
	uint32_t iterator                       = 0;
	uint16_t fields_segment                 = 0;
	int file_descriptor                     = 0;

	if( ( flags == LIBEWF_OPEN_READ ) || ( flags == LIBEWF_OPEN_READ_WRITE ) )
	{
		/* 1 additional entry required because
		 * entry [ 0 ] is not used for reading
		 */
		internal_handle = libewf_internal_handle_alloc( ( file_amount + 1 ), flags );