1 /* base64.h -- Encode binary data using printable characters.
2    Copyright (C) 2004-2006, 2009-2018 Free Software Foundation, Inc.
3    Written by Simon Josefsson.
4 
5    This program is free software; you can redistribute it and/or modify
6    it under the terms of the GNU General Public License as published by
7    the Free Software Foundation; either version 3, or (at your option)
8    any later version.
9 
10    This program is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13    GNU General Public License for more details.
14 
15    You should have received a copy of the GNU General Public License
16    along with this program; if not, see <https://www.gnu.org/licenses/>.  */
17 
18 #ifndef BASE64_H
19 # define BASE64_H
20 
21 /* Get size_t. */
22 # include <stddef.h>
23 
24 /* Get bool. */
25 # include <stdbool.h>
26 
27 # ifdef __cplusplus
28 extern "C" {
29 # endif
30 
31 /* This uses that the expression (n+(k-1))/k means the smallest
32    integer >= n/k, i.e., the ceiling of n/k.  */
33 # define BASE64_LENGTH(inlen) ((((inlen) + 2) / 3) * 4)
34 
35 struct base64_decode_context
36 {
37   unsigned int i;
38   char buf[4];
39 };
40 
41 extern bool isbase64 (char ch) _GL_ATTRIBUTE_CONST;
42 
43 extern void base64_encode (const char *restrict in, size_t inlen,
44                            char *restrict out, size_t outlen);
45 
46 extern size_t base64_encode_alloc (const char *in, size_t inlen, char **out);
47 
48 extern void base64_decode_ctx_init (struct base64_decode_context *ctx);
49 
50 extern bool base64_decode_ctx (struct base64_decode_context *ctx,
51                                const char *restrict in, size_t inlen,
52                                char *restrict out, size_t *outlen);
53 
54 extern bool base64_decode_alloc_ctx (struct base64_decode_context *ctx,
55                                      const char *in, size_t inlen,
56                                      char **out, size_t *outlen);
57 
58 #define base64_decode(in, inlen, out, outlen) \
59         base64_decode_ctx (NULL, in, inlen, out, outlen)
60 
61 #define base64_decode_alloc(in, inlen, out, outlen) \
62         base64_decode_alloc_ctx (NULL, in, inlen, out, outlen)
63 
64 # ifdef __cplusplus
65 }
66 # endif
67 
68 #endif /* BASE64_H */
69