Files
ustreamer/src/http/base64.c
Devaev Maxim fcdb8f5d42 headers sanity
2019-09-17 19:45:56 +03:00

72 lines
3.1 KiB
C

/*****************************************************************************
# #
# uStreamer - Lightweight and fast MJPG-HTTP streamer. #
# #
# Copyright (C) 2018 Maxim Devaev <mdevaev@gmail.com> #
# #
# 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 3 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, see <https://www.gnu.org/licenses/>. #
# #
*****************************************************************************/
#include "base64.h"
#include <stdlib.h>
#include <string.h>
#include "../tools.h"
static const char _ENCODING_TABLE[] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '+', '/',
};
static const unsigned _MOD_TABLE[] = {0, 2, 1};
char *base64_encode(const unsigned char *str) {
size_t str_len = strlen((const char *)str);
size_t encoded_size = 4 * ((str_len + 2) / 3) + 1; // +1 for '\0'
char *encoded;
A_CALLOC(encoded, encoded_size);
for (unsigned str_index = 0, encoded_index = 0; str_index < str_len;) {
unsigned octet_a = (str_index < str_len ? (unsigned char)str[str_index++] : 0);
unsigned octet_b = (str_index < str_len ? (unsigned char)str[str_index++] : 0);
unsigned octet_c = (str_index < str_len ? (unsigned char)str[str_index++] : 0);
unsigned triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;
encoded[encoded_index++] = _ENCODING_TABLE[(triple >> 3 * 6) & 0x3F];
encoded[encoded_index++] = _ENCODING_TABLE[(triple >> 2 * 6) & 0x3F];
encoded[encoded_index++] = _ENCODING_TABLE[(triple >> 1 * 6) & 0x3F];
encoded[encoded_index++] = _ENCODING_TABLE[(triple >> 0 * 6) & 0x3F];
}
for (unsigned index = 0; index < _MOD_TABLE[str_len % 3]; index++) {
encoded[encoded_size - 2 - index] = '=';
}
encoded[encoded_size - 1] = '\0';
return encoded;
}