Zabbix
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for (pc = p_str, pc_r = *p_b64str; 0 != full_block_num; pc += c_per_block, pc_r += b_per_block, full_block_num--)/*** 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.**//********************************************************************** * Purpose: Check if supplied character is a valid base64 character. * * Not a complete check, since it ignores equal sign '=' * * as it depends on the context where this is placed. * * Corresponds to the [A-Za-z0-9+\\/] block validation from * * zbx_base64_validate() function below. * **********************************************************************/static int is_valid_base64_char(const char c){ if (('A' <= c && 'Z' >= c) || ('a' <= c && 'z' >= c) || ('/' <= c && '9' >= c) || '+' == c) { return SUCCEED; } return FAIL;}/************************************************************************************************* * * * Purpose: Checks if the string is a valid Base64 encoded string. * * Check is based on RFC 4648, based on the following regexp: * * "^(?:[A-Za-z0-9+\\/]{4})*(?:[A-Za-z0-9+\\/]{2}==|[A-Za-z0-9+\\/]{3}=|[A-Za-z0-9+\\/]{4})$" * * * * Note, that pcre regexp matching cannot be used, because it would exceed max * * stack frame limit when recursively checking long strings, * * (check compute_recursion_limit() for more details). * * * * Parameters: p_str - [IN] string to validate * * * * Return value: SUCCEED - string is a valid Base64 encoded string * * FAIL - otherwise * * * *************************************************************************************************/int zbx_base64_validate(const char *p_str){ size_t i; /* consider empty strings - valid Base64 encodings */ if ('\0' == p_str[0]) return SUCCEED; for (i = 1; '\0' != p_str[i] || (0 == i % 4); i++) { if (0 != i % 4) continue; /* validate first/repeated block: (?:[A-Za-z0-9+\\/]{4}) */ if (SUCCEED == is_valid_base64_char(p_str[i - 4]) && SUCCEED == is_valid_base64_char(p_str[i - 3]) && SUCCEED == is_valid_base64_char(p_str[i - 2]) && SUCCEED == is_valid_base64_char(p_str[i - 1])) { if ('\0' == p_str[i]) return SUCCEED; else continue; } /* validate second/final block: (?:[A-Za-z0-9+\\/]{2}==|[A-Za-z0-9+\\/]{3}=|[A-Za-z0-9+\\/]{4}) */ else if ('\0' == p_str[i]) { if (SUCCEED == is_valid_base64_char(p_str[i - 4]) && SUCCEED == is_valid_base64_char(p_str[i - 3]) && '=' == p_str[i - 2] && '=' == p_str[i - 1]) {