nyorain
7 years ago
parent
42547cafb6
commit
c0f2acce4e
@ -0,0 +1,221 @@
|
||||
/*
|
||||
* Adapted from https://github.com/littlstar/b64.c
|
||||
* License under the MIT License:
|
||||
* Copyright (c) 2014 Little Star Media, Inc.
|
||||
*
|
||||
* 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 <ctype.h>
|
||||
#include <stdlib.h>
|
||||
#include "util.h"
|
||||
|
||||
static const char b64_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', '+', '/'
|
||||
};
|
||||
|
||||
char *b64_encode(const char *src, size_t len, size_t *flen) {
|
||||
int i = 0;
|
||||
int j = 0;
|
||||
char *enc = NULL;
|
||||
size_t size = len * 4 / 3;
|
||||
size_t idx = 0;
|
||||
unsigned char buf[4];
|
||||
char tmp[3];
|
||||
|
||||
// alloc
|
||||
enc = (char *) malloc(size + 1);
|
||||
if (NULL == enc) { return NULL; }
|
||||
|
||||
// parse until end of source
|
||||
while (len--) {
|
||||
// read up to 3 bytes at a time into `tmp'
|
||||
tmp[i++] = *(src++);
|
||||
|
||||
// if 3 bytes read then encode into `buf'
|
||||
if (3 == i) {
|
||||
buf[0] = (tmp[0] & 0xfc) >> 2;
|
||||
buf[1] = ((tmp[0] & 0x03) << 4) + ((tmp[1] & 0xf0) >> 4);
|
||||
buf[2] = ((tmp[1] & 0x0f) << 2) + ((tmp[2] & 0xc0) >> 6);
|
||||
buf[3] = tmp[2] & 0x3f;
|
||||
|
||||
// shouldn't really happen
|
||||
if (idx + 4 > size) {
|
||||
size += 16;
|
||||
enc = (char *) realloc(enc, size + 1);
|
||||
}
|
||||
for (i = 0; i < 4; ++i) {
|
||||
enc[idx++] = b64_table[buf[i]];
|
||||
}
|
||||
|
||||
// reset index
|
||||
i = 0;
|
||||
}
|
||||
}
|
||||
|
||||
// remainder
|
||||
if (i > 0) {
|
||||
// fill `tmp' with `\0' at most 3 times
|
||||
for (j = i; j < 3; ++j) {
|
||||
tmp[j] = '\0';
|
||||
}
|
||||
|
||||
// perform same codec as above
|
||||
buf[0] = (tmp[0] & 0xfc) >> 2;
|
||||
buf[1] = ((tmp[0] & 0x03) << 4) + ((tmp[1] & 0xf0) >> 4);
|
||||
buf[2] = ((tmp[1] & 0x0f) << 2) + ((tmp[2] & 0xc0) >> 6);
|
||||
buf[3] = tmp[2] & 0x3f;
|
||||
|
||||
// perform same write to `enc` with new allocation
|
||||
size_t delta = (i > 3 ? 0 : 3 - i) + (j > i + 1 ? 0 : i + 1 - j);
|
||||
if (idx + delta > size) {
|
||||
size += delta;
|
||||
enc = (char *) realloc(enc, size + 1);
|
||||
}
|
||||
for (j = 0; (j < i + 1); ++j) {
|
||||
enc[idx++] = b64_table[buf[j]];
|
||||
}
|
||||
|
||||
// while there is still a remainder
|
||||
// append `=' to `enc'
|
||||
while ((i++ < 3)) {
|
||||
enc[idx++] = '=';
|
||||
}
|
||||
}
|
||||
|
||||
enc[idx] = '\0';
|
||||
|
||||
if (flen)
|
||||
*flen = size;
|
||||
return enc;
|
||||
}
|
||||
|
||||
unsigned char *b64_decode(const char *src, size_t len, size_t *decsize) {
|
||||
int i = 0;
|
||||
int j = 0;
|
||||
int l = 0;
|
||||
// max size estimate
|
||||
size_t size = len * 3 / 4;
|
||||
size_t idx = 0;
|
||||
unsigned char *dec = NULL;
|
||||
unsigned char buf[3];
|
||||
unsigned char tmp[4];
|
||||
|
||||
// alloc
|
||||
dec = (unsigned char *) malloc(size + 1);
|
||||
if (NULL == dec) { return NULL; }
|
||||
|
||||
// parse until end of source
|
||||
while (len--) {
|
||||
if (isspace(src[j])) { j++; continue; }
|
||||
// break if char is `=' or not base64 char
|
||||
if ('=' == src[j]) { break; }
|
||||
if (!(isalnum(src[j]) || '+' == src[j] || '/' == src[j])) { break; }
|
||||
|
||||
// read up to 4 bytes at a time into `tmp'
|
||||
tmp[i++] = src[j++];
|
||||
|
||||
// if 4 bytes read then decode into `buf'
|
||||
if (4 == i) {
|
||||
// translate values in `tmp' from table
|
||||
for (i = 0; i < 4; ++i) {
|
||||
// find translation char in `b64_table'
|
||||
for (l = 0; l < 64; ++l) {
|
||||
if (tmp[i] == b64_table[l]) {
|
||||
tmp[i] = l;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// decode
|
||||
buf[0] = (tmp[0] << 2) + ((tmp[1] & 0x30) >> 4);
|
||||
buf[1] = ((tmp[1] & 0xf) << 4) + ((tmp[2] & 0x3c) >> 2);
|
||||
buf[2] = ((tmp[2] & 0x3) << 6) + tmp[3];
|
||||
|
||||
// unlikely
|
||||
if (idx + 3 > size) {
|
||||
size += 16;
|
||||
dec = (unsigned char *) realloc(dec, size + 1);
|
||||
}
|
||||
if (dec != NULL){
|
||||
for (i = 0; i < 3; ++i) {
|
||||
dec[idx++] = buf[i];
|
||||
}
|
||||
} else {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
// reset
|
||||
i = 0;
|
||||
}
|
||||
}
|
||||
|
||||
// remainder
|
||||
if (i > 0) {
|
||||
// fill `tmp' with `\0' at most 4 times
|
||||
for (j = i; j < 4; ++j) {
|
||||
tmp[j] = '\0';
|
||||
}
|
||||
|
||||
// translate remainder
|
||||
for (j = 0; j < 4; ++j) {
|
||||
// find translation char in `b64_table'
|
||||
for (l = 0; l < 64; ++l) {
|
||||
if (tmp[j] == b64_table[l]) {
|
||||
tmp[j] = l;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// decode remainder
|
||||
buf[0] = (tmp[0] << 2) + ((tmp[1] & 0x30) >> 4);
|
||||
buf[1] = ((tmp[1] & 0xf) << 4) + ((tmp[2] & 0x3c) >> 2);
|
||||
buf[2] = ((tmp[2] & 0x3) << 6) + tmp[3];
|
||||
|
||||
// write remainer decoded buffer to `dec'
|
||||
if (idx + (i - 1) > size) {
|
||||
size += 16;
|
||||
dec = (unsigned char *) realloc(dec, size + 1);
|
||||
}
|
||||
if (dec != NULL){
|
||||
for (j = 0; (j < i - 1); ++j) {
|
||||
dec[idx++] = buf[j];
|
||||
}
|
||||
} else {
|
||||
return NULL;
|
||||
}
|
||||
}
|
||||
|
||||
dec[idx] = '\0';
|
||||
// Return back the size of decoded string if demanded.
|
||||
if (decsize != NULL) {
|
||||
*decsize = size;
|
||||
}
|
||||
|
||||
return dec;
|
||||
}
|
||||
Loading…
Reference in new issue