1/* punycode.h Declarations for punycode functions.
2 * Copyright (C) 2002, 2003 Simon Josefsson
3 *
4 * This file is part of GNU Libidn.
5 *
6 * GNU Libidn is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * GNU Libidn is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with GNU Libidn; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20/*
21 * This file is derived from RFC 3492bis written by Adam M. Costello.
22 *
23 * Disclaimer and license: Regarding this entire document or any
24 * portion of it (including the pseudocode and C code), the author
25 * makes no guarantees and is not responsible for any damage resulting
26 * from its use. The author grants irrevocable permission to anyone
27 * to use, modify, and distribute it in any way that does not diminish
28 * the rights of anyone else to use, modify, and distribute it,
29 * provided that redistributed derivative works do not contain
30 * misleading author or version information. Derivative works need
31 * not be licensed under similar terms.
32 *
33 * Copyright (C) The Internet Society (2003). All Rights Reserved.
34 *
35 * This document and translations of it may be copied and furnished to
36 * others, and derivative works that comment on or otherwise explain it
37 * or assist in its implementation may be prepared, copied, published
38 * and distributed, in whole or in part, without restriction of any
39 * kind, provided that the above copyright notice and this paragraph are
40 * included on all such copies and derivative works. However, this
41 * document itself may not be modified in any way, such as by removing
42 * the copyright notice or references to the Internet Society or other
43 * Internet organizations, except as needed for the purpose of
44 * developing Internet standards in which case the procedures for
45 * copyrights defined in the Internet Standards process must be
46 * followed, or as required to translate it into languages other than
47 * English.
48 *
49 * The limited permissions granted above are perpetual and will not be
50 * revoked by the Internet Society or its successors or assigns.
51 *
52 * This document and the information contained herein is provided on an
53 * "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
54 * TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
55 * BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
56 * HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
57 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
58 */
59
60#ifndef _PUNYCODE_H
61#define _PUNYCODE_H
62
63#ifdef __cplusplus
64extern "C"
65{
66#endif
67
68#include <stddef.h> /* size_t */
69#include <stdint.h> /* uint32_t */
70
71 enum punycode_status
72 {
73 punycode_success = 0,
74 punycode_bad_input = 1, /* Input is invalid. */
75 punycode_big_output = 2, /* Output would exceed the space provided. */
76 punycode_overflow = 3 /* Wider integers needed to process input. */
77 };
78
79 typedef enum
80 {
81 PUNYCODE_SUCCESS = punycode_success,
82 PUNYCODE_BAD_INPUT = punycode_bad_input,
83 PUNYCODE_BIG_OUTPUT = punycode_big_output,
84 PUNYCODE_OVERFLOW = punycode_overflow
85 } Punycode_status;
86
87/* punycode_uint needs to be unsigned and needs to be */
88/* at least 26 bits wide. */
89
90 typedef uint32_t punycode_uint;
91
92 extern int punycode_encode (size_t input_length,
93 const punycode_uint input[],
94 const unsigned char case_flags[],
95 size_t * output_length, char output[]);
96
97/*
98 punycode_encode() converts a sequence of code points (presumed to be
99 Unicode code points) to Punycode.
100
101 Input arguments (to be supplied by the caller):
102
103 input_length
104 The number of code points in the input array and the number
105 of flags in the case_flags array.
106
107 input
108 An array of code points. They are presumed to be Unicode
109 code points, but that is not strictly REQUIRED. The
110 array contains code points, not code units. UTF-16 uses
111 code units D800 through DFFF to refer to code points
112 10000..10FFFF. The code points D800..DFFF do not occur in
113 any valid Unicode string. The code points that can occur in
114 Unicode strings (0..D7FF and E000..10FFFF) are also called
115 Unicode scalar values.
116
117 case_flags
118 A null pointer or an array of boolean values parallel to
119 the input array. Nonzero (true, flagged) suggests that the
120 corresponding Unicode character be forced to uppercase after
121 being decoded (if possible), and zero (false, unflagged)
122 suggests that it be forced to lowercase (if possible).
123 ASCII code points (0..7F) are encoded literally, except that
124 ASCII letters are forced to uppercase or lowercase according
125 to the corresponding case flags. If case_flags is a null
126 pointer then ASCII letters are left as they are, and other
127 code points are treated as unflagged.
128
129 Output arguments (to be filled in by the function):
130
131 output
132 An array of ASCII code points. It is *not* null-terminated;
133 it will contain zeros if and only if the input contains
134 zeros. (Of course the caller can leave room for a
135 terminator and add one if needed.)
136
137 Input/output arguments (to be supplied by the caller and overwritten
138 by the function):
139
140 output_length
141 The caller passes in the maximum number of ASCII code points
142 that it can receive. On successful return it will contain
143 the number of ASCII code points actually output.
144
145 Return value:
146
147 Can be any of the punycode_status values defined above except
148 punycode_bad_input. If not punycode_success, then output_size
149 and output might contain garbage.
150*/
151
152 extern int punycode_decode (size_t input_length,
153 const char input[],
154 size_t * output_length,
155 punycode_uint output[],
156 unsigned char case_flags[]);
157
158/*
159 punycode_decode() converts Punycode to a sequence of code points
160 (presumed to be Unicode code points).
161
162 Input arguments (to be supplied by the caller):
163
164 input_length
165 The number of ASCII code points in the input array.
166
167 input
168 An array of ASCII code points (0..7F).
169
170 Output arguments (to be filled in by the function):
171
172 output
173 An array of code points like the input argument of
174 punycode_encode() (see above).
175
176 case_flags
177 A null pointer (if the flags are not needed by the caller)
178 or an array of boolean values parallel to the output array.
179 Nonzero (true, flagged) suggests that the corresponding
180 Unicode character be forced to uppercase by the caller (if
181 possible), and zero (false, unflagged) suggests that it
182 be forced to lowercase (if possible). ASCII code points
183 (0..7F) are output already in the proper case, but their
184 flags will be set appropriately so that applying the flags
185 would be harmless.
186
187 Input/output arguments (to be supplied by the caller and overwritten
188 by the function):
189
190 output_length
191 The caller passes in the maximum number of code points
192 that it can receive into the output array (which is also
193 the maximum number of flags that it can receive into the
194 case_flags array, if case_flags is not a null pointer). On
195 successful return it will contain the number of code points
196 actually output (which is also the number of flags actually
197 output, if case_flags is not a null pointer). The decoder
198 will never need to output more code points than the number
199 of ASCII code points in the input, because of the way the
200 encoding is defined. The number of code points output
201 cannot exceed the maximum possible value of a punycode_uint,
202 even if the supplied output_length is greater than that.
203
204 Return value:
205
206 Can be any of the punycode_status values defined above. If not
207 punycode_success, then output_length, output, and case_flags
208 might contain garbage.
209*/
210
211#ifdef __cplusplus
212}
213#endif
214#endif /* _PUNYCODE_H */
215