1 /* base64.h -- Encode binary data using printable characters.
2 Copyright (C) 2004-2006, 2009-2021 Free Software Foundation, Inc.
3 Written by Simon Josefsson.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file 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 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser 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 idx_t. */
22 # include <idx.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 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, idx_t inlen,
44 char *restrict out, idx_t outlen);
45
46 extern idx_t base64_encode_alloc (const char *in, idx_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, idx_t inlen,
52 char *restrict out, idx_t *outlen);
53
54 extern bool base64_decode_alloc_ctx (struct base64_decode_context *ctx,
55 const char *in, idx_t inlen,
56 char **out, idx_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 */