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 "zbxmedia.h"

​

#include "zbxstr.h"

#include "log.h"

#include "zbxcomms.h"

#include "base64.h"

#include "zbxalgo.h"

​

/* number of characters per line when wrapping Base64 data in Email */

#define ZBX_EMAIL_B64_MAXLINE           76

​

/* number of characters per "encoded-word" in RFC-2047 message header */

#define ZBX_EMAIL_B64_MAXWORD_RFC2047       75

​

/* multiple 'encoded-word's should be separated by <CR><LF><SPACE> */

#define ZBX_EMAIL_ENCODED_WORD_SEPARATOR    "\r\n "

​

/* separator for multipart mixed messages */

#define ZBX_MULTIPART_MIXED_BOUNDARY    "MULTIPART-MIXED-BOUNDARY"

​

#define OK_250  "250"

​

extern char *CONFIG_SSL_CA_LOCATION;

​

/* SMTP security options */

#define SMTP_SECURITY_NONE  0

#define SMTP_SECURITY_STARTTLS  1

#define SMTP_SECURITY_SSL   2

​

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

 *                                                                            *

 * Purpose: Encode a string into a base64 string as required by rfc2047.      *

 *          Used for encoding e-mail headers.                                 *

 *                                                                            *

 * Parameters: src      - [IN] a null-terminated UTF-8 string to encode       *

 *             p_base64 - [OUT] a pointer to the encoded string               *

 *                                                                            *

 * Comments: Based on the patch submitted by                                  *

 *           Jairo Eduardo Lopez Fuentes Nacarino                             *

 *                                                                            *

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

static void str_base64_encode_rfc2047(const char *src, char **p_base64)

{

    const char  *p0;            /* pointer in src to start encoding from */

    const char  *p1;            /* pointer in src: 1st byte of UTF-8 character */

    size_t      c_len;          /* length of UTF-8 character sequence */

    size_t      p_base64_alloc;     /* allocated memory size for subject */

    size_t      p_base64_offset = 0;    /* offset for writing into subject */

​

    assert(src);

    assert(NULL == *p_base64);      /* do not accept already allocated memory */

​

    p_base64_alloc = ZBX_EMAIL_B64_MAXWORD_RFC2047 + sizeof(ZBX_EMAIL_ENCODED_WORD_SEPARATOR);

    *p_base64 = (char *)zbx_malloc(NULL, p_base64_alloc);

    **p_base64 = '\0';

​

    for (p0 = src; '\0' != *p0; p0 = p1)

    {

        /* Max length of line is 76 characters (without line separator). */

        /* Max length of "encoded-word" is 75 characters (without word separator). */

        /* 3 characters are taken by word separator "<CR><LF><Space>" which also includes the line separator. */

        /* 12 characters are taken by header "=?UTF-8?B?" and trailer "?=". */

        /* So, one "encoded-word" can hold up to 63 characters of Base64-encoded string. */

        /* Encoding 45 bytes produces a 61 byte long Base64-encoded string which meets the limit. */

        /* Encoding 46 bytes produces a 65 byte long Base64-encoded string which exceeds the limit. */

        for (p1 = p0; '\0' != *p1; p1 += c_len)

        {

            /* an invalid UTF-8 character or length of a string more than 45 bytes */

            if (0 == (c_len = zbx_utf8_char_len(p1)) || 45 < p1 - p0 + c_len)

                break;

        }

​