/*
* Copyright (c) 2008-2023 Jonathan Schleifer <js@nil.im>
*
* All rights reserved.
*
* This file is part of ObjFW. It may be distributed under the terms of the
* Q Public License 1.0, which can be found in the file LICENSE.QPL included in
* the packaging of this file.
*
* Alternatively, it may be distributed under the terms of the GNU General
* Public License, either version 2 or 3, which can be found in the file
* LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
* file.
*/
#include "config.h"
#import "OFBase64.h"
#import "OFString.h"
#import "OFData.h"
static const unsigned char encodeTable[64] = {
'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 signed char decodeTable[128] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54,
55, 56, 57, 58, 59, 60, 61, -1, -1, -1, 0, -1, -1, -1, 0, 1, 2,
3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30,
31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
48, 49, 50, 51, -1, -1, -1, -1, -1
};
OFString *
OFBase64Encode(const void *data, size_t length)
{
OFMutableString *ret = [OFMutableString string];
uint8_t *buffer = (uint8_t *)data;
size_t i;
uint8_t rest;
char tb[4];
uint32_t sb;
rest = length % 3;
for (i = 0; i < length - rest; i += 3) {
sb = (buffer[i] << 16) | (buffer[i + 1] << 8) | buffer[i + 2];
tb[0] = encodeTable[(sb & 0xFC0000) >> 18];
tb[1] = encodeTable[(sb & 0x03F000) >> 12];
tb[2] = encodeTable[(sb & 0x000FC0) >> 6];
tb[3] = encodeTable[sb & 0x00003F];
[ret appendCString: tb
encoding: OFStringEncodingASCII
length: 4];
}
switch (rest) {
case 1:
tb[0] = encodeTable[buffer[i] >> 2];
tb[1] = encodeTable[(buffer[i] & 3) << 4];
tb[2] = tb[3] = '=';
[ret appendCString: tb
encoding: OFStringEncodingASCII
length: 4];
break;
case 2:
sb = (buffer[i] << 16) | (buffer[i + 1] << 8);
tb[0] = encodeTable[(sb & 0xFC0000) >> 18];
tb[1] = encodeTable[(sb & 0x03F000) >> 12];
tb[2] = encodeTable[(sb & 0x000FC0) >> 6];
tb[3] = '=';
[ret appendCString: tb
encoding: OFStringEncodingASCII
length: 4];
break;
}
[ret makeImmutable];
return ret;
}
bool
OFBase64Decode(OFMutableData *data, const char *string, size_t length)
{
const uint8_t *buffer = (const uint8_t *)string;
size_t i;
if ((length & 3) != 0)
return false;
if (data.itemSize != 1)
return false;
for (i = 0; i < length; i += 4) {
uint32_t sb = 0;
uint8_t count = 3;
char db[3];
int8_t tmp;
if (buffer[i] > 0x7F || buffer[i + 1] > 0x7F ||
buffer[i + 2] > 0x7F || buffer[i + 3] > 0x7F)
return false;
if (buffer[i] == '=' || buffer[i + 1] == '=' ||
(buffer[i + 2] == '=' && buffer[i + 3] != '='))
return false;
if (buffer[i + 2] == '=')
count--;
if (buffer[i + 3] == '=')
count--;
if ((tmp = decodeTable[buffer[i]]) == -1)
return false;
sb |= tmp << 18;
if ((tmp = decodeTable[buffer[i + 1]]) == -1)
return false;
sb |= tmp << 12;
if ((tmp = decodeTable[buffer[i + 2]]) == -1)
return false;
sb |= tmp << 6;
if ((tmp = decodeTable[buffer[i + 3]]) == -1)
return false;
sb |= tmp;
db[0] = (sb & 0xFF0000) >> 16;
db[1] = (sb & 0x00FF00) >> 8;
db[2] = sb & 0x0000FF;
[data addItems: db count: count];
}
return true;
}