xref: /netbsd-src/external/mpl/bind/dist/lib/isc/include/isc/base32.h (revision bcda20f65a8566e103791ec395f7f499ef322704)
1 /*	$NetBSD: base32.h,v 1.8 2025/01/26 16:25:40 christos Exp $	*/
2 
3 /*
4  * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5  *
6  * SPDX-License-Identifier: MPL-2.0
7  *
8  * This Source Code Form is subject to the terms of the Mozilla Public
9  * License, v. 2.0. If a copy of the MPL was not distributed with this
10  * file, you can obtain one at https://mozilla.org/MPL/2.0/.
11  *
12  * See the COPYRIGHT file distributed with this work for additional
13  * information regarding copyright ownership.
14  */
15 
16 #pragma once
17 
18 /*! \file */
19 
20 /*
21  * Routines for manipulating base 32 and base 32 hex encoded data.
22  * Based on RFC 4648.
23  *
24  * Base 32 hex preserves the sort order of data when it is encoded /
25  * decoded.
26  *
27  * Base 32 hex "np" is base 32 hex but no padding is produced or accepted.
28  */
29 
30 #include <isc/lang.h>
31 #include <isc/types.h>
32 
33 ISC_LANG_BEGINDECLS
34 
35 /***
36  *** Functions
37  ***/
38 
39 isc_result_t
40 isc_base32_totext(isc_region_t *source, int wordlength, const char *wordbreak,
41 		  isc_buffer_t *target);
42 isc_result_t
43 isc_base32hex_totext(isc_region_t *source, int wordlength,
44 		     const char *wordbreak, isc_buffer_t *target);
45 isc_result_t
46 isc_base32hexnp_totext(isc_region_t *source, int wordlength,
47 		       const char *wordbreak, isc_buffer_t *target);
48 /*!<
49  * \brief Convert data into base32 encoded text.
50  *
51  * Notes:
52  *\li	The base32 encoded text in 'target' will be divided into
53  *	words of at most 'wordlength' characters, separated by
54  * 	the 'wordbreak' string.  No parentheses will surround
55  *	the text.
56  *
57  * Requires:
58  *\li	'source' is a region containing binary data
59  *\li	'target' is a text buffer containing available space
60  *\li	'wordbreak' points to a null-terminated string of
61  *		zero or more whitespace characters
62  *
63  * Ensures:
64  *\li	target will contain the base32 encoded version of the data
65  *	in source.  The 'used' pointer in target will be advanced as
66  *	necessary.
67  */
68 
69 isc_result_t
70 isc_base32_decodestring(const char *cstr, isc_buffer_t *target);
71 isc_result_t
72 isc_base32hex_decodestring(const char *cstr, isc_buffer_t *target);
73 isc_result_t
74 isc_base32hexnp_decodestring(const char *cstr, isc_buffer_t *target);
75 /*!<
76  * \brief Decode a null-terminated string in base32, base32hex, or
77  * base32hex non-padded.
78  *
79  * Requires:
80  *\li	'cstr' is non-null.
81  *\li	'target' is a valid buffer.
82  *
83  * Returns:
84  *\li	#ISC_R_SUCCESS	-- the entire decoded representation of 'cstring'
85  *			   fit in 'target'.
86  *\li	#ISC_R_BADBASE32 -- 'cstr' is not a valid base32 encoding.
87  *
88  * 	Other error returns are any possible error code from:
89  *\li		isc_lex_create(),
90  *\li		isc_lex_openbuffer(),
91  *\li		isc_base32_tobuffer().
92  */
93 
94 isc_result_t
95 isc_base32_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length);
96 isc_result_t
97 isc_base32hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length);
98 isc_result_t
99 isc_base32hexnp_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length);
100 /*!<
101  * \brief Convert text encoded in base32, base32hex, or base32hex
102  * non-padded from a lexer context into `target`. If 'length' is
103  * non-negative, it is the expected number of encoded octets to convert.
104  *
105  * If 'length' is -1 then 0 or more encoded octets are expected.
106  * If 'length' is -2 then 1 or more encoded octets are expected.
107  *
108  * Returns:
109  *\li	#ISC_R_BADBASE32 -- invalid base32 encoding.
110  *\li	#ISC_R_UNEXPECTEDEND: the text does not contain the expected
111  *			      number of encoded octets.
112  *
113  * Requires:
114  *\li	'lexer' is a valid lexer context
115  *\li	'target' is a buffer containing binary data
116  *\li	'length' is -2, -1, or non-negative
117  *
118  * Ensures:
119  *\li	target will contain the data represented by the base32 encoded
120  *	string parsed by the lexer.  No more than `length` octets will
121  *	be read, if `length` is non-negative.  The 'used' pointer in
122  *	'target' will be advanced as necessary.
123  */
124 
125 isc_result_t
126 isc_base32_decoderegion(isc_region_t *source, isc_buffer_t *target);
127 isc_result_t
128 isc_base32hex_decoderegion(isc_region_t *source, isc_buffer_t *target);
129 isc_result_t
130 isc_base32hexnp_decoderegion(isc_region_t *source, isc_buffer_t *target);
131 /*!<
132  * \brief Decode a packed (no white space permitted) region in
133  * base32, base32hex or base32hex non-padded.
134  *
135  * Requires:
136  *\li   'source' is a valid region.
137  *\li   'target' is a valid buffer.
138  *
139  * Returns:
140  *\li   #ISC_R_SUCCESS  -- the entire decoded representation of 'cstring'
141  *                         fit in 'target'.
142  *\li   #ISC_R_BADBASE32 -- 'source' is not a valid base32 encoding.
143  */
144 
145 ISC_LANG_ENDDECLS
146