base16.h 3.13 KB
Newer Older
Niels Möller's avatar
Niels Möller committed
1
2
3
4
5
6
7
8
/* base16.h
 *
 * Hex encoding and decoding, following spki conventions (i.e.
 * allowing whitespace between digits).
 */

/* nettle, low-level cryptographics library
 *
Niels Möller's avatar
Niels Möller committed
9
 * Copyright (C) 2002 Niels Möller
Niels Möller's avatar
Niels Möller committed
10
11
12
13
14
15
16
17
18
19
20
21
22
 *  
 * The nettle library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 * 
 * The nettle library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
23
24
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02111-1301, USA.
Niels Möller's avatar
Niels Möller committed
25
26
27
28
29
 */
 
#ifndef NETTLE_BASE16_H_INCLUDED
#define NETTLE_BASE16_H_INCLUDED

30
#include "nettle-types.h"
Niels Möller's avatar
Niels Möller committed
31

Niels Möller's avatar
Niels Möller committed
32
33
34
35
#ifdef __cplusplus
extern "C" {
#endif

36
37
38
39
40
41
42
/* Name mangling */
#define base16_encode_single nettle_base16_encode_single
#define base16_encode_update nettle_base16_encode_update
#define base16_decode_init nettle_base16_decode_init
#define base16_decode_single nettle_base16_decode_single
#define base16_decode_update nettle_base16_decode_update
#define base16_decode_final nettle_base16_decode_final
Niels Möller's avatar
Niels Möller committed
43
44
45
46
47
48
49
50
51
52
53
54
55
56

/* Base16 encoding */

/* Maximum length of output for base16_encode_update. */
#define BASE16_ENCODE_LENGTH(length) ((length) * 2)

/* Encodes a single byte. Always stores two digits in dst[0] and dst[1]. */
void
base16_encode_single(uint8_t *dst,
		     uint8_t src);

/* Always stores BASE16_ENCODE_LENGTH(length) digits in dst. */
void
base16_encode_update(uint8_t *dst,
57
		     size_t length,
Niels Möller's avatar
Niels Möller committed
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
		     const uint8_t *src);


/* Base16 decoding */

/* Maximum length of output for base16_decode_update. */
/* We have at most 4 buffered bits, and a total of (length + 1) * 4 bits. */
#define BASE16_DECODE_LENGTH(length) (((length) + 1) / 2)

struct base16_decode_ctx
{
  unsigned word;   /* Leftover bits */
  unsigned bits;   /* Number buffered bits */
};

void
base16_decode_init(struct base16_decode_ctx *ctx);

/* Decodes a single byte. Returns amount of output (0 or 1), or -1 on
 * errors. */
int
base16_decode_single(struct base16_decode_ctx *ctx,
		     uint8_t *dst,
		     uint8_t src);

/* Returns 1 on success, 0 on error. DST should point to an area of
 * size at least BASE16_DECODE_LENGTH(length), and for sanity
 * checking, *DST_LENGTH should be initialized to the size of that
 * area before the call. *DST_LENGTH is updated to the amount of
 * decoded output. */

Niels Möller's avatar
Niels Möller committed
89
90
/* Currently results in an assertion failure if *DST_LENGTH is
 * too small. FIXME: Return some error instead? */
Niels Möller's avatar
Niels Möller committed
91
92
int
base16_decode_update(struct base16_decode_ctx *ctx,
93
		     size_t *dst_length,
Niels Möller's avatar
Niels Möller committed
94
		     uint8_t *dst,
95
		     size_t src_length,
Niels Möller's avatar
Niels Möller committed
96
97
98
99
100
101
		     const uint8_t *src);

/* Returns 1 on success. */
int
base16_decode_final(struct base16_decode_ctx *ctx);

Niels Möller's avatar
Niels Möller committed
102
103
104
105
#ifdef __cplusplus
}
#endif

Niels Möller's avatar
Niels Möller committed
106
#endif /* NETTLE_BASE16_H_INCLUDED */