/*====================================================================*
*
* size_t hexencode (void * memory, size_t extent, char const * string);
*
* memory.h
*
* encode a hexadecimal string into a fixed length memory region;
* return the number of bytes encoded or 0 on error; an error will
* occur of the entire region cannot be encoded or the entire
* string cannot be converted due to illegal or excessive digits;
*
* permit an optional HEX_EXTENDER character between successive
* octets; constant character HEX_EXTENDER is defined in number.h;
*
* Motley Tools by Charles Maier <cmaier@cmassoc.net>;
* Copyright (c) 2001-2006 by Charles Maier Associates;
* Licensed under the Internet Software Consortium License;
*
*--------------------------------------------------------------------*/
#ifndef HEXENCODE_SOURCE
#define HEXENCODE_SOURCE
#include <errno.h>
#include <ctype.h>
#include "../tools/memory.h"
#include "../tools/number.h"
size_t hexencode (void * memory, register size_t extent, register char const * string)
{
register byte * origin = (byte *)(memory);
register byte * offset = (byte *)(memory);
unsigned radix = RADIX_HEX;
unsigned digit = 0;
while ((extent) && (*string))
{
unsigned field = HEX_DIGITS;
unsigned value = 0;
if ((offset > origin) && (*string == HEX_EXTENDER))
{
string++;
}
while (field--)
{
if ((digit = todigit (*string)) < radix)
{
value *= radix;
value += digit;
string++;
continue;
}
errno = EINVAL;
return (0);
}
*offset = value;
offset++;
extent--;
}
#if defined (WIN32)
while (isspace (*string))
{
string++;
}
#endif
if ((extent) || (*string))
{
errno = EINVAL;
return (0);
}
return (offset - origin);
}
#endif