libewf_string.c

sleuthit-2.09 一个磁盘的工具集

/*
 * libewf character type string functions
 *
 * 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 <errno.h>

#include <libewf/libewf_definitions.h>

#include "libewf_common.h"
#include "libewf_notify.h"
#include "libewf_string.h"

#include "ewf_char.h"

/* Duplicates a string
 * Returns the pointer to the duplicate string, or NULL on error
 */
LIBEWF_CHAR *libewf_string_duplicate( LIBEWF_CHAR *string, size_t size )
{
	LIBEWF_CHAR *duplicate = NULL;

	if( string == NULL )
	{
		return( NULL );
	}
	if( size == 0 )
	{
		return( NULL );
	}
	if( size > (size_t) SSIZE_MAX )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_duplicate: invalid size value exceeds maximum.\n" );

		return( NULL );
	}
	/* Add an additional character for the end of string
	 */
	size += 1;

	duplicate = (LIBEWF_CHAR *) libewf_common_alloc( LIBEWF_CHAR_SIZE * size );

	if( duplicate == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_duplicate: unable to create duplicate string.\n" );

		return( NULL );
	}
	if( libewf_string_copy( duplicate, string, size ) == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_duplicate: unable to set duplicate string.\n" );

		libewf_common_free( duplicate );

		return( NULL );
	}
	duplicate[ size - 1 ] = (LIBEWF_CHAR) '\0';

	return( duplicate );
}

#ifdef HAVE_WIDE_CHARACTER_TYPE

#ifdef HAVE_WCSTOL
#define libewf_string_to_signed_long( string, end_of_string, base )	(int64_t) wcstol( string, end_of_string, base )
#endif

#else

#ifdef HAVE_STRTOL
#define libewf_string_to_signed_long( string, end_of_string, base )	(int64_t) strtol( string, end_of_string, base )
#elif defined(HAVE_ATOL)
#define libewf_string_to_signed_long( string, end_of_string, base )	(int64_t) atol( string )
#endif

#endif

/* Returns the value represented by a string, returns 0 and sets errno on error
 */
int64_t libewf_string_to_int64( const LIBEWF_CHAR *string, size_t size )
{
	LIBEWF_CHAR *end_of_string = NULL;
	int64_t value              = 0;

	if( string == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_to_int64: invalid string.\n" );

		errno = EINVAL;

		return( 0 );
	}
	if( size == 0 )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_to_int64: string is emtpy.\n" );

		errno = EINVAL;

		return( 0 );
	}
	if( size > (size_t) SSIZE_MAX )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_to_int64: invalid size value exceeds maximum.\n" );

		errno = EINVAL;

		return( 0 );
	}
	end_of_string = (LIBEWF_CHAR *) &string[ size - 1 ];

#if defined( libewf_string_to_signed_long )
	value = libewf_string_to_signed_long( string, &end_of_string, 0 );
#else
#error Missing equivalent of strtol
#endif

	if( value == (int64_t) LONG_MAX )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_to_int64: unable to convert string.\n" );

		return( 0 );
	}
	return( value );
}


#ifdef HAVE_WIDE_CHARACTER_TYPE

#ifdef HAVE_WCSTOUL
#define libewf_string_to_unsigned_long( string, end_of_string, base )	(uint64_t) wcstoul( string, end_of_string, base )
#endif

#else

#ifdef HAVE_STRTOUL
#define libewf_string_to_unsigned_long( string, end_of_string, base )	(uint64_t) strtoul( string, end_of_string, base )
#elif defined(HAVE_ATOL)
#define libewf_string_to_unsigned_long( string, end_of_string, base )	(uint64_t) atol( string )
#endif

#endif

/* Returns the value represented by a string, returns 0 and sets errno on error
 */
uint64_t libewf_string_to_uint64( const LIBEWF_CHAR *string, size_t size )
{
	LIBEWF_CHAR *end_of_string = NULL;
	uint64_t value             = 0;

	if( string == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_to_uint64: invalid string.\n" );

		errno = EINVAL;

		return( 0 );
	}
	if( size == 0 )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_to_uint64: string is emtpy.\n" );

		errno = EINVAL;

		return( 0 );
	}
	if( size > (size_t) SSIZE_MAX )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_to_uint64: invalid size value exceeds maximum.\n" );

		errno = EINVAL;

		return( 0 );
	}
	end_of_string = (LIBEWF_CHAR *) &string[ size - 1 ];

#if defined( libewf_string_to_unsigned_long )
	value = libewf_string_to_unsigned_long( string, &end_of_string, 0 );
#else
#error Missing equivalent of strtoul
#endif

	if( value == (uint64_t) LONG_MAX )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_to_uint64: unable to convert string.\n" );

		return( 0 );
	}
	return( value );
}

/* Split a string into elements using a delimiter character
 * Returns a pointer to the new instance, NULL on error
 */
LIBEWF_CHAR **libewf_string_split( LIBEWF_CHAR *string, size_t size, LIBEWF_CHAR delimiter, uint32_t *amount )
{
	LIBEWF_CHAR **lines     = NULL;
	LIBEWF_CHAR *line_start = NULL;
	LIBEWF_CHAR *line_end   = NULL;
	LIBEWF_CHAR *string_end = NULL;
	size_t size_string      = 0;
	size_t line_size        = 0;
	uint32_t iterator       = 0;

	if( string == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_split: invalid string.\n" );

		return( NULL );
	}
	if( amount == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_split: invalid amount.\n" );

		return( NULL );
	}
	if( size == 0 )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_split: string is empty.\n" );

		return( NULL );
	}
	if( size > (size_t) SSIZE_MAX )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_split: invalid size value exceeds maximum.\n" );

		return( NULL );
	}
	size_string = size;
	line_start  = string;
	line_end    = string;
	string_end  = &string[ size ];

	do
	{
		line_end = (LIBEWF_CHAR *) libewf_string_search( line_start, delimiter, size_string );

		iterator++;

		if( line_end == NULL )
		{
			break;
		}
		/* Include delimiter character
		 */
		size_string -= (size_t) ( line_end - line_start ) + 1;

		if( line_end == line_start )
		{
			line_start += 1;
		}
		else if( line_end != string )
		{
			line_start = line_end + 1;
		}
	}
	while( line_end != NULL );

	*amount = iterator;
	lines   = (LIBEWF_CHAR **) libewf_common_alloc_cleared( ( sizeof( LIBEWF_CHAR * ) * *amount ), 0 );

	if( lines == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_split: unable to allocate dynamic array lines.\n" );

		return( NULL );
	}
	size_string = size;
	line_start  = string;
	line_end    = string;

	for( iterator = 0; iterator < *amount; iterator++ )
	{
		if( line_end != string )
		{
			line_start = line_end + 1;
		}
		line_end = (LIBEWF_CHAR *) libewf_string_search( line_start, delimiter, size_string );

		/* Check for last value
		 */
		if( line_end == NULL )
		{
			line_size = (size_t) ( string_end - line_start );
		}
		else
		{
			line_size = (size_t) ( line_end - line_start );
		}
		/* Add 1 additional byte required for the end of string character
		 */
		line_size += 1;

		lines[ iterator ] = (LIBEWF_CHAR *) libewf_common_alloc( LIBEWF_CHAR_SIZE * line_size );

		if( lines[ iterator ] == NULL )
		{
			LIBEWF_WARNING_PRINT( "libewf_string_split: unable to allocate line string.\n" );

			libewf_string_split_values_free( lines, ( iterator - 1 ) );

			return( NULL );
		}
		if( libewf_string_copy( lines[ iterator ], line_start, line_size ) == NULL )
		{
			LIBEWF_WARNING_PRINT( "libewf_string_split: unable to set dynamic array lines.\n" );

			libewf_string_split_values_free( lines, iterator );

			return( NULL );
		}
		lines[ iterator ][ line_size - 1 ] = (LIBEWF_CHAR) '\0';

		/* Include delimiter character
		 */
		size_string -= (size_t) ( line_end - line_start ) + 1;

		/* Correct if first value is empty
		 */
		if( line_end == string )
		{
			line_start += 1;
		}
	}
	return( lines );
}

/* Clears a split values array
 */
void libewf_string_split_values_free( LIBEWF_CHAR **split_values, uint32_t amount )
{
	uint32_t iterator = 0;

	if( split_values == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_split_values_free: invalid split values array.\n" );

		return;
	}
	for( iterator = 0; iterator < amount; iterator++ )
	{
		if( split_values[ iterator ] == NULL )
		{
			LIBEWF_WARNING_PRINT( "libewf_string_split_values_free: empty value.\n" );
		}
		else
		{
			libewf_common_free( split_values[ iterator ] );
		}
	}
	libewf_common_free( split_values );
}

/* Copies a multi byte UTF16 string to a single byte ASCII string
 * Returns 1 if successful, on -1 on error
 */
int8_t libewf_string_copy_utf16_to_ascii( LIBEWF_CHAR *utf16_string, size_t size_utf16, LIBEWF_CHAR* ascii_string, size_t size_ascii )
{
	size_t utf16_iterator = 2;
	size_t ascii_iterator = 0;
	uint8_t byte_order    = 0;

	if( utf16_string == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_copy_utf16_to_ascii: invalid UTF16 string.\n" );

		return( -1 );
	}
	if( ascii_string == NULL )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_copy_utf16_to_ascii: invalid ASCII string.\n" );

		return( -1 );
	}
	if( ( size_utf16 > (size_t) SSIZE_MAX ) || ( size_ascii > (size_t) SSIZE_MAX ) )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_copy_utf16_to_ascii: invalid size value exceeds maximum.\n" );

		return( -1 );
	}
	/* The UTF16 string contains twice as much bytes needed for the ASCII string
	 * with two additional bytes representing byte order
	 */
	if( size_ascii < ( ( size_utf16 - 2 ) / 2 ) )
	{
		LIBEWF_WARNING_PRINT( "libewf_string_copy_utf16_to_ascii: ASCII string too small.\n" );

		return( -1 );
	}
	/* Check if UTF16 string is in big or little endian
	 */
	if( ( (uint8_t) utf16_string[ 0 ] == 0xff ) && ( (uint8_t) utf16_string[ 1 ] == 0xfe ) )
	{
		byte_order = LIBEWF_STRING_LITTLE_ENDIAN;
	}
	else if( ( (uint8_t) utf16_string[ 0 ] == 0xfe ) && ( (uint8_t) utf16_string[ 1 ] == 0xff ) )
	{
		byte_order = LIBEWF_STRING_BIG_ENDIAN;
	}