1 /* $Id: base64.c,v 1.9 2017/01/24 13:32:55 jsing Exp $ */
2 /*
3 * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <netinet/in.h>
19 #include <resolv.h>
20
21 #include <stdlib.h>
22
23 #include "extern.h"
24
25 /*
26 * Compute the maximum buffer required for a base64 encoded string of
27 * length "len".
28 */
29 size_t
base64len(size_t len)30 base64len(size_t len)
31 {
32
33 return (len + 2) / 3 * 4 + 1;
34 }
35
36 /*
37 * Pass a stream of bytes to be base64 encoded, then converted into
38 * base64url format.
39 * Returns NULL on allocation failure (not logged).
40 */
41 char *
base64buf_url(const char * data,size_t len)42 base64buf_url(const char *data, size_t len)
43 {
44 size_t i, sz;
45 char *buf;
46
47 sz = base64len(len);
48 if ((buf = malloc(sz)) == NULL)
49 return NULL;
50
51 b64_ntop(data, len, buf, sz);
52
53 for (i = 0; i < sz; i++)
54 switch (buf[i]) {
55 case '+':
56 buf[i] = '-';
57 break;
58 case '/':
59 buf[i] = '_';
60 break;
61 case '=':
62 buf[i] = '\0';
63 break;
64 }
65
66 return buf;
67 }
68