2023-11-14 01:00:23 +01:00

71 lines
2.8 KiB
C++

#pragma once
/**
* The MIT License (MIT)
* Copyright (c) 2016 tomykaira
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <string>
namespace macaron {
class Base64 {
public:
static std::string Encode(const char* data, size_t length) {
static constexpr char sEncodingTable[] = {
'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', '+', '/'
};
size_t out_len = 4 * ((length + 2) / 3);
std::string ret(out_len, '\0');
size_t i;
char* p = const_cast<char*>(ret.c_str());
for (i = 0; i < length - 2; i += 3) {
*p++ = sEncodingTable[(data[i] >> 2) & 0x3F];
*p++ = sEncodingTable[((data[i] & 0x3) << 4) | ((int)(data[i + 1] & 0xF0) >> 4)];
*p++ = sEncodingTable[((data[i + 1] & 0xF) << 2) | ((int)(data[i + 2] & 0xC0) >> 6)];
*p++ = sEncodingTable[data[i + 2] & 0x3F];
}
if (i < length) {
*p++ = sEncodingTable[(data[i] >> 2) & 0x3F];
if (i == (length - 1)) {
*p++ = sEncodingTable[((data[i] & 0x3) << 4)];
*p++ = '=';
}
else {
*p++ = sEncodingTable[((data[i] & 0x3) << 4) | ((int)(data[i + 1] & 0xF0) >> 4)];
*p++ = sEncodingTable[((data[i + 1] & 0xF) << 2)];
}
*p++ = '=';
}
return ret;
}
};
}