xref: /netbsd-src/external/mpl/bind/dist/lib/isc/include/isc/base32.h (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
1 /*	$NetBSD: base32.h,v 1.6 2022/09/23 12:15:33 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 #ifndef ISC_BASE32_H
17 #define ISC_BASE32_H 1
18 
19 /*! \file */
20 
21 /*
22  * Routines for manipulating base 32 and base 32 hex encoded data.
23  * Based on RFC 4648.
24  *
25  * Base 32 hex preserves the sort order of data when it is encoded /
26  * decoded.
27  *
28  * Base 32 hex "np" is base 32 hex but no padding is produced or accepted.
29  */
30 
31 #include <isc/lang.h>
32 #include <isc/types.h>
33 
34 ISC_LANG_BEGINDECLS
35 
36 /***
37  *** Functions
38  ***/
39 
40 isc_result_t
41 isc_base32_totext(isc_region_t *source, int wordlength, const char *wordbreak,
42 		  isc_buffer_t *target);
43 isc_result_t
44 isc_base32hex_totext(isc_region_t *source, int wordlength,
45 		     const char *wordbreak, isc_buffer_t *target);
46 isc_result_t
47 isc_base32hexnp_totext(isc_region_t *source, int wordlength,
48 		       const char *wordbreak, isc_buffer_t *target);
49 /*!<
50  * \brief Convert data into base32 encoded text.
51  *
52  * Notes:
53  *\li	The base32 encoded text in 'target' will be divided into
54  *	words of at most 'wordlength' characters, separated by
55  * 	the 'wordbreak' string.  No parentheses will surround
56  *	the text.
57  *
58  * Requires:
59  *\li	'source' is a region containing binary data
60  *\li	'target' is a text buffer containing available space
61  *\li	'wordbreak' points to a null-terminated string of
62  *		zero or more whitespace characters
63  *
64  * Ensures:
65  *\li	target will contain the base32 encoded version of the data
66  *	in source.  The 'used' pointer in target will be advanced as
67  *	necessary.
68  */
69 
70 isc_result_t
71 isc_base32_decodestring(const char *cstr, isc_buffer_t *target);
72 isc_result_t
73 isc_base32hex_decodestring(const char *cstr, isc_buffer_t *target);
74 isc_result_t
75 isc_base32hexnp_decodestring(const char *cstr, isc_buffer_t *target);
76 /*!<
77  * \brief Decode a null-terminated string in base32, base32hex, or
78  * base32hex non-padded.
79  *
80  * Requires:
81  *\li	'cstr' is non-null.
82  *\li	'target' is a valid buffer.
83  *
84  * Returns:
85  *\li	#ISC_R_SUCCESS	-- the entire decoded representation of 'cstring'
86  *			   fit in 'target'.
87  *\li	#ISC_R_BADBASE32 -- 'cstr' is not a valid base32 encoding.
88  *
89  * 	Other error returns are any possible error code from:
90  *\li		isc_lex_create(),
91  *\li		isc_lex_openbuffer(),
92  *\li		isc_base32_tobuffer().
93  */
94 
95 isc_result_t
96 isc_base32_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length);
97 isc_result_t
98 isc_base32hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length);
99 isc_result_t
100 isc_base32hexnp_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length);
101 /*!<
102  * \brief Convert text encoded in base32, base32hex, or base32hex
103  * non-padded from a lexer context into `target`. If 'length' is
104  * non-negative, it is the expected number of encoded octets to convert.
105  *
106  * If 'length' is -1 then 0 or more encoded octets are expected.
107  * If 'length' is -2 then 1 or more encoded octets are expected.
108  *
109  * Returns:
110  *\li	#ISC_R_BADBASE32 -- invalid base32 encoding.
111  *\li	#ISC_R_UNEXPECTEDEND: the text does not contain the expected
112  *			      number of encoded octets.
113  *
114  * Requires:
115  *\li	'lexer' is a valid lexer context
116  *\li	'target' is a buffer containing binary data
117  *\li	'length' is -2, -1, or non-negative
118  *
119  * Ensures:
120  *\li	target will contain the data represented by the base32 encoded
121  *	string parsed by the lexer.  No more than `length` octets will
122  *	be read, if `length` is non-negative.  The 'used' pointer in
123  *	'target' will be advanced as necessary.
124  */
125 
126 isc_result_t
127 isc_base32_decoderegion(isc_region_t *source, isc_buffer_t *target);
128 isc_result_t
129 isc_base32hex_decoderegion(isc_region_t *source, isc_buffer_t *target);
130 isc_result_t
131 isc_base32hexnp_decoderegion(isc_region_t *source, isc_buffer_t *target);
132 /*!<
133  * \brief Decode a packed (no white space permitted) region in
134  * base32, base32hex or base32hex non-padded.
135  *
136  * Requires:
137  *\li   'source' is a valid region.
138  *\li   'target' is a valid buffer.
139  *
140  * Returns:
141  *\li   #ISC_R_SUCCESS  -- the entire decoded representation of 'cstring'
142  *                         fit in 'target'.
143  *\li   #ISC_R_BADBASE32 -- 'source' is not a valid base32 encoding.
144  */
145 
146 ISC_LANG_ENDDECLS
147 
148 #endif /* ISC_BASE32_H */
149