mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-28 22:18:29 +00:00
dcbd2b8668
Lua Server Pages may now call the EncodeBase64() and DecodeBase64() functions should they wish to do things like emit embeded data URIs See #97
85 lines
4.2 KiB
C
85 lines
4.2 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2021 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/mem/mem.h"
|
|
#include "libc/str/str.h"
|
|
#include "net/http/base64.h"
|
|
|
|
static const signed char kBase64[256] = {
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x00
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x10
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, // 0x20
|
|
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1, // 0x30
|
|
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 0x40
|
|
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, // 0x50
|
|
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, // 0x60
|
|
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, // 0x70
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x80
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x90
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0xa0
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0xb0
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0xc0
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0xd0
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0xe0
|
|
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0xf0
|
|
};
|
|
|
|
/**
|
|
* Decodes base64 ascii representation to binary.
|
|
*/
|
|
void *DecodeBase64(const char *data, size_t size, size_t *out_size) {
|
|
unsigned w;
|
|
char *r, *q;
|
|
int a, b, c, d;
|
|
const char *p, *pe;
|
|
if (size == -1) size = strlen(data);
|
|
if ((r = malloc(size / 4 * 3 + 1))) {
|
|
q = r;
|
|
p = data;
|
|
pe = p + size;
|
|
for (;;) {
|
|
do {
|
|
if (p == pe) goto Done;
|
|
a = kBase64[*p++ & 0xff];
|
|
} while (a == -1);
|
|
if (a == -2) continue;
|
|
do {
|
|
if (p == pe) goto Done;
|
|
b = kBase64[*p++ & 0xff];
|
|
} while (b == -1);
|
|
if (b == -2) continue;
|
|
do {
|
|
c = p < pe ? kBase64[*p++ & 0xff] : -2;
|
|
} while (c == -1);
|
|
do {
|
|
d = p < pe ? kBase64[*p++ & 0xff] : -2;
|
|
} while (d == -1);
|
|
w = a << 18 | b << 12;
|
|
if (c != -2) w |= c << 6;
|
|
if (d != -2) w |= d;
|
|
*q++ = (w & 0xFF0000) >> 020;
|
|
if (c != -2) *q++ = (w & 0x00FF00) >> 010;
|
|
if (d != -2) *q++ = (w & 0x0000FF) >> 000;
|
|
}
|
|
Done:
|
|
if (out_size) *out_size = q - r;
|
|
*q++ = '\0';
|
|
if ((q = realloc(r, q - r))) r = q;
|
|
}
|
|
return r;
|
|
}
|