xref: /freebsd/lib/libiconv_modules/UTF7/citrus_utf7.c (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
1 /* $FreeBSD$ */
2 /*	$NetBSD: citrus_utf7.c,v 1.5 2006/08/23 12:57:24 tnozaki Exp $	*/
3 
4 /*-
5  * SPDX-License-Identifier: BSD-2-Clause
6  *
7  * Copyright (c)2004, 2005 Citrus Project,
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  */
32 
33 #include <sys/cdefs.h>
34 
35 #include <assert.h>
36 #include <errno.h>
37 #include <limits.h>
38 #include <stdio.h>
39 #include <stdint.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <wchar.h>
43 
44 #include "citrus_namespace.h"
45 #include "citrus_types.h"
46 #include "citrus_module.h"
47 #include "citrus_stdenc.h"
48 #include "citrus_utf7.h"
49 
50 /* ----------------------------------------------------------------------
51  * private stuffs used by templates
52  */
53 
54 #define EI_MASK		UINT16_C(0xff)
55 #define EI_DIRECT	UINT16_C(0x100)
56 #define EI_OPTION	UINT16_C(0x200)
57 #define EI_SPACE	UINT16_C(0x400)
58 
59 typedef struct {
60 	uint16_t	 cell[0x80];
61 } _UTF7EncodingInfo;
62 
63 typedef struct {
64 	unsigned int
65 		mode: 1,	/* whether base64 mode */
66 		bits: 4,	/* need to hold 0 - 15 */
67 		cache: 22;	/* 22 = BASE64_BIT + UTF16_BIT */
68 	int chlen;
69 	char ch[4]; /* BASE64_IN, 3 * 6 = 18, most closed to UTF16_BIT */
70 } _UTF7State;
71 
72 #define	_CEI_TO_EI(_cei_)		(&(_cei_)->ei)
73 #define	_CEI_TO_STATE(_cei_, _func_)	(_cei_)->states.s_##_func_
74 
75 #define	_FUNCNAME(m)			_citrus_UTF7_##m
76 #define	_ENCODING_INFO			_UTF7EncodingInfo
77 #define	_ENCODING_STATE			_UTF7State
78 #define	_ENCODING_MB_CUR_MAX(_ei_)		4
79 #define	_ENCODING_IS_STATE_DEPENDENT		1
80 #define	_STATE_NEEDS_EXPLICIT_INIT(_ps_)	0
81 
82 static __inline void
83 /*ARGSUSED*/
84 _citrus_UTF7_init_state(_UTF7EncodingInfo * __restrict ei __unused,
85     _UTF7State * __restrict s)
86 {
87 
88 	memset((void *)s, 0, sizeof(*s));
89 }
90 
91 #if 0
92 static __inline void
93 /*ARGSUSED*/
94 _citrus_UTF7_pack_state(_UTF7EncodingInfo * __restrict ei __unused,
95     void *__restrict pspriv, const _UTF7State * __restrict s)
96 {
97 
98 	memcpy(pspriv, (const void *)s, sizeof(*s));
99 }
100 
101 static __inline void
102 /*ARGSUSED*/
103 _citrus_UTF7_unpack_state(_UTF7EncodingInfo * __restrict ei __unused,
104     _UTF7State * __restrict s, const void * __restrict pspriv)
105 {
106 
107 	memcpy((void *)s, pspriv, sizeof(*s));
108 }
109 #endif
110 
111 static const char base64[] =
112 	"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
113 	"abcdefghijklmnopqrstuvwxyz"
114 	"0123456789+/";
115 
116 static const char direct[] =
117 	"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
118 	"abcdefghijklmnopqrstuvwxyz"
119 	"0123456789'(),-./:?";
120 
121 static const char option[] = "!\"#$%&*;<=>@[]^_`{|}";
122 static const char spaces[] = " \t\r\n";
123 
124 #define	BASE64_BIT	6
125 #define	UTF16_BIT	16
126 
127 #define	BASE64_MAX	0x3f
128 #define	UTF16_MAX	UINT16_C(0xffff)
129 #define	UTF32_MAX	UINT32_C(0x10ffff)
130 
131 #define	BASE64_IN	'+'
132 #define	BASE64_OUT	'-'
133 
134 #define	SHIFT7BIT(c)	((c) >> 7)
135 #define	ISSPECIAL(c)	((c) == '\0' || (c) == BASE64_IN)
136 
137 #define	FINDLEN(ei, c) \
138 	(SHIFT7BIT((c)) ? -1 : (((ei)->cell[(c)] & EI_MASK) - 1))
139 
140 #define	ISDIRECT(ei, c)	(!SHIFT7BIT((c)) && (ISSPECIAL((c)) || \
141 	ei->cell[(c)] & (EI_DIRECT | EI_OPTION | EI_SPACE)))
142 
143 #define	ISSAFE(ei, c)	(!SHIFT7BIT((c)) && (ISSPECIAL((c)) || \
144 	(c < 0x80 && ei->cell[(c)] & (EI_DIRECT | EI_SPACE))))
145 
146 /* surrogate pair */
147 #define	SRG_BASE	UINT32_C(0x10000)
148 #define	HISRG_MIN	UINT16_C(0xd800)
149 #define	HISRG_MAX	UINT16_C(0xdbff)
150 #define	LOSRG_MIN	UINT16_C(0xdc00)
151 #define	LOSRG_MAX	UINT16_C(0xdfff)
152 
153 static int
154 _citrus_UTF7_mbtoutf16(_UTF7EncodingInfo * __restrict ei,
155     uint16_t * __restrict u16, char ** __restrict s, size_t n,
156     _UTF7State * __restrict psenc, size_t * __restrict nresult)
157 {
158 	char *s0;
159 	int done, i, len;
160 
161 	*nresult = 0;
162 	s0 = *s;
163 
164 	for (i = 0, done = 0; done == 0; i++) {
165 		if (i == psenc->chlen) {
166 			if (n-- < 1) {
167 				*nresult = (size_t)-2;
168 				*s = s0;
169 				return (0);
170 			}
171 			psenc->ch[psenc->chlen++] = *s0++;
172 		}
173 		if (SHIFT7BIT((int)psenc->ch[i]))
174 			goto ilseq;
175 		if (!psenc->mode) {
176 			if (psenc->bits > 0 || psenc->cache > 0)
177 				return (EINVAL);
178 			if (psenc->ch[i] == BASE64_IN)
179 				psenc->mode = 1;
180 			else {
181 				if (!ISDIRECT(ei, (int)psenc->ch[i]))
182 					goto ilseq;
183 				*u16 = (uint16_t)psenc->ch[i];
184 				done = 1;
185 				continue;
186 			}
187 		} else {
188 			if (psenc->ch[i] == BASE64_OUT && psenc->cache == 0) {
189 				psenc->mode = 0;
190 				*u16 = (uint16_t)BASE64_IN;
191 				done = 1;
192 				continue;
193 			}
194 			len = FINDLEN(ei, (int)psenc->ch[i]);
195 			if (len < 0) {
196 				if (psenc->bits >= BASE64_BIT)
197 					return (EINVAL);
198 				psenc->mode = 0;
199 				psenc->bits = psenc->cache = 0;
200 				if (psenc->ch[i] != BASE64_OUT) {
201 					if (!ISDIRECT(ei, (int)psenc->ch[i]))
202 						goto ilseq;
203 					*u16 = (uint16_t)psenc->ch[i];
204 					done = 1;
205 				} else {
206 					psenc->chlen--;
207 					i--;
208 				}
209 			} else {
210 				psenc->cache =
211 				    (psenc->cache << BASE64_BIT) | len;
212 				switch (psenc->bits) {
213 				case 0: case 2: case 4: case 6: case 8:
214 					psenc->bits += BASE64_BIT;
215 					break;
216 				case 10: case 12: case 14:
217 					psenc->bits -= (UTF16_BIT - BASE64_BIT);
218 					*u16 = (psenc->cache >> psenc->bits) &
219 					    UTF16_MAX;
220 					done = 1;
221 					break;
222 				default:
223 					return (EINVAL);
224 				}
225 			}
226 		}
227 	}
228 
229 	if (psenc->chlen > i)
230 		return (EINVAL);
231 	psenc->chlen = 0;
232 	*nresult = (size_t)((*u16 == 0) ? 0 : s0 - *s);
233 	*s = s0;
234 
235 	return (0);
236 
237 ilseq:
238 	*nresult = (size_t)-1;
239 	return (EILSEQ);
240 }
241 
242 static int
243 _citrus_UTF7_mbrtowc_priv(_UTF7EncodingInfo * __restrict ei,
244     wchar_t * __restrict pwc, char ** __restrict s, size_t n,
245     _UTF7State * __restrict psenc, size_t * __restrict nresult)
246 {
247 	uint32_t u32;
248 	uint16_t hi, lo;
249 	size_t nr, siz;
250 	int err;
251 
252 	if (*s == NULL) {
253 		_citrus_UTF7_init_state(ei, psenc);
254 		*nresult = (size_t)_ENCODING_IS_STATE_DEPENDENT;
255 		return (0);
256 	}
257 	err = _citrus_UTF7_mbtoutf16(ei, &hi, s, n, psenc, &nr);
258 	if (nr == (size_t)-1 || nr == (size_t)-2) {
259 		*nresult = nr;
260 		return (err);
261 	}
262 	if (err != 0)
263 		return (err);
264 	n -= nr;
265 	siz = nr;
266 	if (hi < HISRG_MIN || hi > HISRG_MAX) {
267 		u32 = (uint32_t)hi;
268 		goto done;
269 	}
270 	err = _citrus_UTF7_mbtoutf16(ei, &lo, s, n, psenc, &nr);
271 	if (nr == (size_t)-1 || nr == (size_t)-2) {
272 		psenc->chlen = 1; /* make get_state_desc return incomplete */
273 		*nresult = nr;
274 		return (err);
275 	}
276 	if (err != 0)
277 		return (err);
278 	if (lo < LOSRG_MIN || lo > LOSRG_MAX) {
279 		*nresult = (size_t)-1;
280 		return (EILSEQ);
281 	}
282 	hi -= HISRG_MIN;
283 	lo -= LOSRG_MIN;
284 	u32 = (hi << 10 | lo) + SRG_BASE;
285 	siz += nr;
286 done:
287 	if (pwc != NULL)
288 		*pwc = (wchar_t)u32;
289 	if (u32 == (uint32_t)0) {
290 		*nresult = (size_t)0;
291 		_citrus_UTF7_init_state(ei, psenc);
292 	} else {
293 		*nresult = siz;
294 	}
295 	return (err);
296 }
297 
298 static int
299 _citrus_UTF7_utf16tomb(_UTF7EncodingInfo * __restrict ei,
300     char * __restrict s, size_t n __unused, uint16_t u16,
301     _UTF7State * __restrict psenc, size_t * __restrict nresult)
302 {
303 	int bits, i;
304 
305 	if (psenc->chlen != 0 || psenc->bits > BASE64_BIT)
306 		return (EINVAL);
307 
308 	if (ISSAFE(ei, u16)) {
309 		if (psenc->mode) {
310 			if (psenc->bits > 0) {
311 				bits = BASE64_BIT - psenc->bits;
312 				i = (psenc->cache << bits) & BASE64_MAX;
313 				psenc->ch[psenc->chlen++] = base64[i];
314 				psenc->bits = psenc->cache = 0;
315 			}
316 			if (u16 == BASE64_OUT || FINDLEN(ei, u16) >= 0)
317 				psenc->ch[psenc->chlen++] = BASE64_OUT;
318 			psenc->mode = 0;
319 		}
320 		if (psenc->bits != 0)
321 			return (EINVAL);
322 		psenc->ch[psenc->chlen++] = (char)u16;
323 		if (u16 == BASE64_IN)
324 			psenc->ch[psenc->chlen++] = BASE64_OUT;
325 	} else {
326 		if (!psenc->mode) {
327 			if (psenc->bits > 0)
328 				return (EINVAL);
329 			psenc->ch[psenc->chlen++] = BASE64_IN;
330 			psenc->mode = 1;
331 		}
332 		psenc->cache = (psenc->cache << UTF16_BIT) | u16;
333 		bits = UTF16_BIT + psenc->bits;
334 		psenc->bits = bits % BASE64_BIT;
335 		while ((bits -= BASE64_BIT) >= 0) {
336 			i = (psenc->cache >> bits) & BASE64_MAX;
337 			psenc->ch[psenc->chlen++] = base64[i];
338 		}
339 	}
340 	memcpy(s, psenc->ch, psenc->chlen);
341 	*nresult = psenc->chlen;
342 	psenc->chlen = 0;
343 
344 	return (0);
345 }
346 
347 static int
348 _citrus_UTF7_wcrtomb_priv(_UTF7EncodingInfo * __restrict ei,
349     char * __restrict s, size_t n, wchar_t wchar,
350     _UTF7State * __restrict psenc, size_t * __restrict nresult)
351 {
352 	uint32_t u32;
353 	uint16_t u16[2];
354 	int err, i, len;
355 	size_t nr, siz;
356 
357 	u32 = (uint32_t)wchar;
358 	if (u32 <= UTF16_MAX) {
359 		u16[0] = (uint16_t)u32;
360 		len = 1;
361 	} else if (u32 <= UTF32_MAX) {
362 		u32 -= SRG_BASE;
363 		u16[0] = (u32 >> 10) + HISRG_MIN;
364 		u16[1] = ((uint16_t)(u32 & UINT32_C(0x3ff))) + LOSRG_MIN;
365 		len = 2;
366 	} else {
367 		*nresult = (size_t)-1;
368 		return (EILSEQ);
369 	}
370 	siz = 0;
371 	for (i = 0; i < len; ++i) {
372 		err = _citrus_UTF7_utf16tomb(ei, s, n, u16[i], psenc, &nr);
373 		if (err != 0)
374 			return (err); /* XXX: state has been modified */
375 		s += nr;
376 		n -= nr;
377 		siz += nr;
378 	}
379 	*nresult = siz;
380 
381 	return (0);
382 }
383 
384 static int
385 /* ARGSUSED */
386 _citrus_UTF7_put_state_reset(_UTF7EncodingInfo * __restrict ei __unused,
387     char * __restrict s, size_t n, _UTF7State * __restrict psenc,
388     size_t * __restrict nresult)
389 {
390 	int bits, pos;
391 
392 	if (psenc->chlen != 0 || psenc->bits > BASE64_BIT)
393 		return (EINVAL);
394 
395 	if (psenc->mode) {
396 		if (psenc->bits > 0) {
397 			if (n-- < 1)
398 				return (E2BIG);
399 			bits = BASE64_BIT - psenc->bits;
400 			pos = (psenc->cache << bits) & BASE64_MAX;
401 			psenc->ch[psenc->chlen++] = base64[pos];
402 			psenc->ch[psenc->chlen++] = BASE64_OUT;
403 			psenc->bits = psenc->cache = 0;
404 		}
405 		psenc->mode = 0;
406 	}
407 	if (psenc->bits != 0)
408 		return (EINVAL);
409 	if (n-- < 1)
410 		return (E2BIG);
411 
412 	*nresult = (size_t)psenc->chlen;
413 	if (psenc->chlen > 0) {
414 		memcpy(s, psenc->ch, psenc->chlen);
415 		psenc->chlen = 0;
416 	}
417 
418 	return (0);
419 }
420 
421 static __inline int
422 /*ARGSUSED*/
423 _citrus_UTF7_stdenc_wctocs(_UTF7EncodingInfo * __restrict ei __unused,
424     _csid_t * __restrict csid, _index_t * __restrict idx, wchar_t wc)
425 {
426 
427 	*csid = 0;
428 	*idx = (_index_t)wc;
429 
430 	return (0);
431 }
432 
433 static __inline int
434 /*ARGSUSED*/
435 _citrus_UTF7_stdenc_cstowc(_UTF7EncodingInfo * __restrict ei __unused,
436     wchar_t * __restrict wc, _csid_t csid, _index_t idx)
437 {
438 
439 	if (csid != 0)
440 		return (EILSEQ);
441 	*wc = (wchar_t)idx;
442 
443 	return (0);
444 }
445 
446 static __inline int
447 /*ARGSUSED*/
448 _citrus_UTF7_stdenc_get_state_desc_generic(_UTF7EncodingInfo * __restrict ei __unused,
449     _UTF7State * __restrict psenc, int * __restrict rstate)
450 {
451 
452 	*rstate = (psenc->chlen == 0) ? _STDENC_SDGEN_INITIAL :
453 	    _STDENC_SDGEN_INCOMPLETE_CHAR;
454 	return (0);
455 }
456 
457 static void
458 /*ARGSUSED*/
459 _citrus_UTF7_encoding_module_uninit(_UTF7EncodingInfo *ei __unused)
460 {
461 
462 	/* ei seems to be unused */
463 }
464 
465 static int
466 /*ARGSUSED*/
467 _citrus_UTF7_encoding_module_init(_UTF7EncodingInfo * __restrict ei,
468     const void * __restrict var __unused, size_t lenvar __unused)
469 {
470 	const char *s;
471 
472 	memset(ei, 0, sizeof(*ei));
473 
474 #define FILL(str, flag)				\
475 do {						\
476 	for (s = str; *s != '\0'; s++)		\
477 		ei->cell[*s & 0x7f] |= flag;	\
478 } while (/*CONSTCOND*/0)
479 
480 	FILL(base64, (s - base64) + 1);
481 	FILL(direct, EI_DIRECT);
482 	FILL(option, EI_OPTION);
483 	FILL(spaces, EI_SPACE);
484 
485 	return (0);
486 }
487 
488 /* ----------------------------------------------------------------------
489  * public interface for stdenc
490  */
491 
492 _CITRUS_STDENC_DECLS(UTF7);
493 _CITRUS_STDENC_DEF_OPS(UTF7);
494 
495 #include "citrus_stdenc_template.h"
496