Files
create/src/Base/Base64.cpp
2023-10-10 10:19:43 -05:00

163 lines
5.8 KiB
C++

/*
base64.cpp and base64.h
Copyright (C) 2004-2008 René Nyffenegger
This source code is provided 'as-is', without any express or implied
warranty. In no event will the author be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this source code must not be misrepresented; you must not
claim that you wrote the original source code. If you use this source code
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original source code.
3. This notice may not be removed or altered from any source distribution.
René Nyffenegger rene.nyffenegger@adp-gmbh.ch
Copyright (C) 2019 Zheng Lei (realthunder.dev@gmail.com)
* Added support of in-line transformation using boost iostream for memory
efficiency
*/
#include "PreCompiled.h"
#ifndef _PreComp_
#include <iostream>
#include <string>
#endif
#include "Base64.h"
static const std::string base64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
const signed char* Base::base64_decode_table()
{
static const signed char _table[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -2, -1, -2, -1, -1, // 0-15
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 16-31
-2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, // 32-47
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1, // 48-63
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 64-79
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, // 80-95
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, // 96-111
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, // 112-127
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 128-143
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 144-159
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 160-175
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 176-191
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 192-207
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 208-223
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 224-239
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 // 240-255
};
return _table;
}
std::size_t Base::base64_encode(char* out, void const* in, std::size_t in_len)
{
char* ret = out;
unsigned char const* bytes_to_encode = reinterpret_cast<unsigned char const*>(in);
int i = 0;
int j = 0;
unsigned char char_array_3[3];
unsigned char char_array_4[4];
while (in_len--) {
char_array_3[i++] = *(bytes_to_encode++);
if (i == 3) {
char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;
for (i = 0; (i < 4); i++) {
*ret++ = base64_chars[char_array_4[i]];
}
i = 0;
}
}
if (i) {
for (j = i; j < 3; j++) {
char_array_3[j] = '\0';
}
char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;
for (j = 0; (j < i + 1); j++) {
*ret++ = base64_chars[char_array_4[j]];
}
while ((i++ < 3)) {
*ret++ = '=';
}
}
return ret - out;
}
std::pair<std::size_t, std::size_t>
Base::base64_decode(void* _out, char const* in, std::size_t in_len)
{
unsigned char* out = reinterpret_cast<unsigned char*>(_out);
unsigned char* ret = out;
char const* input = in;
int i = 0;
int j = 0;
unsigned char char_array_4[4], char_array_3[3];
static const signed char* table = base64_decode_table();
while (in_len-- && *in != '=') {
const signed char v = table[(int)(*in++)];
if (v < 0) {
break;
}
char_array_4[i++] = (unsigned char)v;
if (i == 4) {
char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
for (i = 0; (i < 3); i++) {
*ret++ = char_array_3[i];
}
i = 0;
}
}
if (i) {
for (j = i; j < 4; j++) {
char_array_4[j] = 0;
}
char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
for (j = 0; (j < i - 1); j++) {
*ret++ = char_array_3[j];
}
}
return std::make_pair((std::size_t)(ret - out), (std::size_t)(in - input));
}