Zabbix

/*

** Zabbix

** Copyright (C) 2001-2023 Zabbix SIA

**

** This program is free software; you can redistribute it and/or modify

** it under the terms of the GNU General Public License as published by

** the Free Software Foundation; either version 2 of the License, or

** (at your option) any later version.

**

** This program is distributed in the hope that it will be useful,

** but WITHOUT ANY WARRANTY; without even the implied warranty of

** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

** GNU General Public License for more details.

**

** You should have received a copy of the GNU General Public License

** along with this program; if not, write to the Free Software

** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

**/

​

#include "zbxcrypto.h"

​

#include "zbxtime.h"

​

/******************************************************************************

 *                                                                            *

 * Purpose:                                                                   *

 *     convert ASCII hex digit string to a binary representation (byte        *

 *     string)                                                                *

 *                                                                            *

 * Parameters:                                                                *

 *     p_hex   - [IN] null-terminated input string                            *

 *     buf     - [OUT] output buffer                                          *

 *     buf_len - [IN] output buffer size                                      *

 *                                                                            *

 * Return value:                                                              *

 *     Number of bytes written into 'buf' on successful conversion.           *

 *     -1 - an error occurred.                                                *

 *                                                                            *

 * Comments:                                                                  *

 *     In case of error incomplete useless data may be written into 'buf'.    *

 *                                                                            *

 ******************************************************************************/

int zbx_hex2bin(const unsigned char *p_hex, unsigned char *buf, int buf_len)

{

    unsigned char   *q = buf;

    int     len = 0;

​

    while ('\0' != *p_hex)

    {

        if (0 != isxdigit(*p_hex) && 0 != isxdigit(*(p_hex + 1)) && buf_len > len)

        {

            unsigned char   hi = *p_hex & 0x0f;

            unsigned char   lo;

​

            if ('9' < *p_hex++)

                hi = (unsigned char)(hi + 9u);

​

            lo = *p_hex & 0x0f;

​

            if ('9' < *p_hex++)

                lo = (unsigned char)(lo + 9u);

​

            *q++ = (unsigned char)(hi << 4 | lo);