xref: /freebsd/lib/libiconv_modules/UTF7/citrus_utf7.c (revision 6574b8ed19b093f0af09501d2c9676c28993cb97)
1 /* $FreeBSD$ */
2 /*	$NetBSD: citrus_utf7.c,v 1.5 2006/08/23 12:57:24 tnozaki Exp $	*/
3 
4 /*-
5  * Copyright (c)2004, 2005 Citrus Project,
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 
31 #include <sys/cdefs.h>
32 
33 #include <assert.h>
34 #include <errno.h>
35 #include <limits.h>
36 #include <stdio.h>
37 #include <stdint.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <wchar.h>
41 
42 #include "citrus_namespace.h"
43 #include "citrus_types.h"
44 #include "citrus_module.h"
45 #include "citrus_stdenc.h"
46 #include "citrus_utf7.h"
47 
48 /* ----------------------------------------------------------------------
49  * private stuffs used by templates
50  */
51 
52 #define EI_MASK		UINT16_C(0xff)
53 #define EI_DIRECT	UINT16_C(0x100)
54 #define EI_OPTION	UINT16_C(0x200)
55 #define EI_SPACE	UINT16_C(0x400)
56 
57 typedef struct {
58 	uint16_t	 cell[0x80];
59 } _UTF7EncodingInfo;
60 
61 typedef struct {
62 	unsigned int
63 		mode: 1,	/* whether base64 mode */
64 		bits: 4,	/* need to hold 0 - 15 */
65 		cache: 22,	/* 22 = BASE64_BIT + UTF16_BIT */
66 		surrogate: 1;	/* whether surrogate pair or not */
67 	int chlen;
68 	char ch[4]; /* BASE64_IN, 3 * 6 = 18, most closed to UTF16_BIT */
69 } _UTF7State;
70 
71 #define	_CEI_TO_EI(_cei_)		(&(_cei_)->ei)
72 #define	_CEI_TO_STATE(_cei_, _func_)	(_cei_)->states.s_##_func_
73 
74 #define	_FUNCNAME(m)			_citrus_UTF7_##m
75 #define	_ENCODING_INFO			_UTF7EncodingInfo
76 #define	_ENCODING_STATE			_UTF7State
77 #define	_ENCODING_MB_CUR_MAX(_ei_)		4
78 #define	_ENCODING_IS_STATE_DEPENDENT		1
79 #define	_STATE_NEEDS_EXPLICIT_INIT(_ps_)	0
80 
81 static __inline void
82 /*ARGSUSED*/
83 _citrus_UTF7_init_state(_UTF7EncodingInfo * __restrict ei __unused,
84     _UTF7State * __restrict s)
85 {
86 
87 	memset((void *)s, 0, sizeof(*s));
88 }
89 
90 #if 0
91 static __inline void
92 /*ARGSUSED*/
93 _citrus_UTF7_pack_state(_UTF7EncodingInfo * __restrict ei __unused,
94     void *__restrict pspriv, const _UTF7State * __restrict s)
95 {
96 
97 	memcpy(pspriv, (const void *)s, sizeof(*s));
98 }
99 
100 static __inline void
101 /*ARGSUSED*/
102 _citrus_UTF7_unpack_state(_UTF7EncodingInfo * __restrict ei __unused,
103     _UTF7State * __restrict s, const void * __restrict pspriv)
104 {
105 
106 	memcpy((void *)s, pspriv, sizeof(*s));
107 }
108 #endif
109 
110 static const char base64[] =
111 	"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
112 	"abcdefghijklmnopqrstuvwxyz"
113 	"0123456789+/";
114 
115 static const char direct[] =
116 	"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
117 	"abcdefghijklmnopqrstuvwxyz"
118 	"0123456789'(),-./:?";
119 
120 static const char option[] = "!\"#$%&*;<=>@[]^_`{|}";
121 static const char spaces[] = " \t\r\n";
122 
123 #define	BASE64_BIT	6
124 #define	UTF16_BIT	16
125 
126 #define	BASE64_MAX	0x3f
127 #define	UTF16_MAX	UINT16_C(0xffff)
128 #define	UTF32_MAX	UINT32_C(0x10ffff)
129 
130 #define	BASE64_IN	'+'
131 #define	BASE64_OUT	'-'
132 
133 #define	SHIFT7BIT(c)	((c) >> 7)
134 #define	ISSPECIAL(c)	((c) == '\0' || (c) == BASE64_IN)
135 
136 #define	FINDLEN(ei, c) \
137 	(SHIFT7BIT((c)) ? -1 : (((ei)->cell[(c)] & EI_MASK) - 1))
138 
139 #define	ISDIRECT(ei, c)	(!SHIFT7BIT((c)) && (ISSPECIAL((c)) || \
140 	ei->cell[(c)] & (EI_DIRECT | EI_OPTION | EI_SPACE)))
141 
142 #define	ISSAFE(ei, c)	(!SHIFT7BIT((c)) && (ISSPECIAL((c)) || \
143 	(c < 0x80 && ei->cell[(c)] & (EI_DIRECT | EI_SPACE))))
144 
145 /* surrogate pair */
146 #define	SRG_BASE	UINT32_C(0x10000)
147 #define	HISRG_MIN	UINT16_C(0xd800)
148 #define	HISRG_MAX	UINT16_C(0xdbff)
149 #define	LOSRG_MIN	UINT16_C(0xdc00)
150 #define	LOSRG_MAX	UINT16_C(0xdfff)
151 
152 static int
153 _citrus_UTF7_mbtoutf16(_UTF7EncodingInfo * __restrict ei,
154     uint16_t * __restrict u16, const char ** __restrict s, size_t n,
155     _UTF7State * __restrict psenc, size_t * __restrict nresult)
156 {
157 	_UTF7State sv;
158 	const char *s0;
159 	int done, i, len;
160 
161 	s0 = *s;
162 	sv = *psenc;
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 				sv.chlen = psenc->chlen;
170 				memcpy(sv.ch, psenc->ch, sizeof(sv.ch));
171 				*psenc = sv;
172 				return (0);
173 			}
174 			psenc->ch[psenc->chlen++] = *s0++;
175 		}
176 		if (SHIFT7BIT((int)psenc->ch[i]))
177 			goto ilseq;
178 		if (!psenc->mode) {
179 			if (psenc->bits > 0 || psenc->cache > 0)
180 				return (EINVAL);
181 			if (psenc->ch[i] == BASE64_IN)
182 				psenc->mode = 1;
183 			else {
184 				if (!ISDIRECT(ei, (int)psenc->ch[i]))
185 					goto ilseq;
186 				*u16 = (uint16_t)psenc->ch[i];
187 				done = 1;
188 				continue;
189 			}
190 		} else {
191 			if (psenc->ch[i] == BASE64_OUT && psenc->cache == 0) {
192 				psenc->mode = 0;
193 				*u16 = (uint16_t)BASE64_IN;
194 				done = 1;
195 				continue;
196 			}
197 			len = FINDLEN(ei, (int)psenc->ch[i]);
198 			if (len < 0) {
199 				if (psenc->bits >= BASE64_BIT)
200 					return (EINVAL);
201 				psenc->mode = 0;
202 				psenc->bits = psenc->cache = 0;
203 				if (psenc->ch[i] != BASE64_OUT) {
204 					if (!ISDIRECT(ei, (int)psenc->ch[i]))
205 						goto ilseq;
206 					*u16 = (uint16_t)psenc->ch[i];
207 					done = 1;
208 				} else {
209 					psenc->chlen--;
210 					i--;
211 				}
212 			} else {
213 				psenc->cache =
214 				    (psenc->cache << BASE64_BIT) | len;
215 				switch (psenc->bits) {
216 				case 0: case 2: case 4: case 6: case 8:
217 					psenc->bits += BASE64_BIT;
218 					break;
219 				case 10: case 12: case 14:
220 					psenc->bits -= (UTF16_BIT - BASE64_BIT);
221 					*u16 = (psenc->cache >> psenc->bits) &
222 					    UTF16_MAX;
223 					done = 1;
224 					break;
225 				default:
226 					return (EINVAL);
227 				}
228 			}
229 		}
230 	}
231 
232 	if (psenc->chlen > i)
233 		return (EINVAL);
234 	psenc->chlen = 0;
235 	*nresult = (size_t)((*u16 == 0) ? 0 : s0 - *s);
236 	*s = s0;
237 
238 	return (0);
239 
240 ilseq:
241 	*nresult = (size_t)-1;
242 	return (EILSEQ);
243 }
244 
245 static int
246 _citrus_UTF7_mbrtowc_priv(_UTF7EncodingInfo * __restrict ei,
247     wchar_t * __restrict pwc, const char ** __restrict s, size_t n,
248     _UTF7State * __restrict psenc, size_t * __restrict nresult)
249 {
250 	uint32_t u32;
251 	uint16_t hi, lo;
252 	size_t nr, siz;
253 	int err;
254 
255 	if (*s == NULL) {
256 		_citrus_UTF7_init_state(ei, psenc);
257 		*nresult = (size_t)_ENCODING_IS_STATE_DEPENDENT;
258 		return (0);
259 	}
260 	if (psenc->surrogate) {
261 		hi = (psenc->cache >> psenc->bits) & UTF16_MAX;
262 		if (hi < HISRG_MIN || hi > HISRG_MAX)
263 			return (EINVAL);
264 		siz = 0;
265 	} else {
266 		err = _citrus_UTF7_mbtoutf16(ei, &hi, s, n, psenc, &nr);
267 		if (nr == (size_t)-1 || nr == (size_t)-2) {
268 			*nresult = nr;
269 			return (err);
270 		}
271 		if (err != 0)
272 			return (err);
273 		n -= nr;
274 		siz = nr;
275 		if (hi < HISRG_MIN || hi > HISRG_MAX) {
276 			u32 = (uint32_t)hi;
277 			goto done;
278 		}
279 		psenc->surrogate = 1;
280 	}
281 	err = _citrus_UTF7_mbtoutf16(ei, &lo, s, n, psenc, &nr);
282 	if (nr == (size_t)-1 || nr == (size_t)-2) {
283 		*nresult = nr;
284 		return (err);
285 	}
286 	if (err != 0)
287 		return (err);
288 	hi -= HISRG_MIN;
289 	lo -= LOSRG_MIN;
290 	u32 = (hi << 10 | lo) + SRG_BASE;
291 	siz += nr;
292 done:
293 	if (pwc != NULL)
294 		*pwc = (wchar_t)u32;
295 	if (u32 == (uint32_t)0) {
296 		*nresult = (size_t)0;
297 		_citrus_UTF7_init_state(ei, psenc);
298 	} else {
299 		*nresult = siz;
300 		psenc->surrogate = 0;
301 	}
302 	return (err);
303 }
304 
305 static int
306 _citrus_UTF7_utf16tomb(_UTF7EncodingInfo * __restrict ei,
307     char * __restrict s, size_t n __unused, uint16_t u16,
308     _UTF7State * __restrict psenc, size_t * __restrict nresult)
309 {
310 	int bits, i;
311 
312 	if (psenc->chlen != 0 || psenc->bits > BASE64_BIT)
313 		return (EINVAL);
314 
315 	if (ISSAFE(ei, u16)) {
316 		if (psenc->mode) {
317 			if (psenc->bits > 0) {
318 				bits = BASE64_BIT - psenc->bits;
319 				i = (psenc->cache << bits) & BASE64_MAX;
320 				psenc->ch[psenc->chlen++] = base64[i];
321 				psenc->bits = psenc->cache = 0;
322 			}
323 			if (u16 == BASE64_OUT || FINDLEN(ei, u16) >= 0)
324 				psenc->ch[psenc->chlen++] = BASE64_OUT;
325 			psenc->mode = 0;
326 		}
327 		if (psenc->bits != 0)
328 			return (EINVAL);
329 		psenc->ch[psenc->chlen++] = (char)u16;
330 		if (u16 == BASE64_IN)
331 			psenc->ch[psenc->chlen++] = BASE64_OUT;
332 	} else {
333 		if (!psenc->mode) {
334 			if (psenc->bits > 0)
335 				return (EINVAL);
336 			psenc->ch[psenc->chlen++] = BASE64_IN;
337 			psenc->mode = 1;
338 		}
339 		psenc->cache = (psenc->cache << UTF16_BIT) | u16;
340 		bits = UTF16_BIT + psenc->bits;
341 		psenc->bits = bits % BASE64_BIT;
342 		while ((bits -= BASE64_BIT) >= 0) {
343 			i = (psenc->cache >> bits) & BASE64_MAX;
344 			psenc->ch[psenc->chlen++] = base64[i];
345 		}
346 	}
347 	memcpy(s, psenc->ch, psenc->chlen);
348 	*nresult = psenc->chlen;
349 	psenc->chlen = 0;
350 
351 	return (0);
352 }
353 
354 static int
355 _citrus_UTF7_wcrtomb_priv(_UTF7EncodingInfo * __restrict ei,
356     char * __restrict s, size_t n, wchar_t wchar,
357     _UTF7State * __restrict psenc, size_t * __restrict nresult)
358 {
359 	uint32_t u32;
360 	uint16_t u16[2];
361 	int err, i, len;
362 	size_t nr, siz;
363 
364 	u32 = (uint32_t)wchar;
365 	if (u32 <= UTF16_MAX) {
366 		u16[0] = (uint16_t)u32;
367 		len = 1;
368 	} else if (u32 <= UTF32_MAX) {
369 		u32 -= SRG_BASE;
370 		u16[0] = (u32 >> 10) + HISRG_MIN;
371 		u16[1] = ((uint16_t)(u32 & UINT32_C(0x3ff))) + LOSRG_MIN;
372 		len = 2;
373 	} else {
374 		*nresult = (size_t)-1;
375 		return (EILSEQ);
376 	}
377 	siz = 0;
378 	for (i = 0; i < len; ++i) {
379 		err = _citrus_UTF7_utf16tomb(ei, s, n, u16[i], psenc, &nr);
380 		if (err != 0)
381 			return (err); /* XXX: state has been modified */
382 		s += nr;
383 		n -= nr;
384 		siz += nr;
385 	}
386 	*nresult = siz;
387 
388 	return (0);
389 }
390 
391 static int
392 /* ARGSUSED */
393 _citrus_UTF7_put_state_reset(_UTF7EncodingInfo * __restrict ei __unused,
394     char * __restrict s, size_t n, _UTF7State * __restrict psenc,
395     size_t * __restrict nresult)
396 {
397 	int bits, pos;
398 
399 	if (psenc->chlen != 0 || psenc->bits > BASE64_BIT || psenc->surrogate)
400 		return (EINVAL);
401 
402 	if (psenc->mode) {
403 		if (psenc->bits > 0) {
404 			if (n-- < 1)
405 				return (E2BIG);
406 			bits = BASE64_BIT - psenc->bits;
407 			pos = (psenc->cache << bits) & BASE64_MAX;
408 			psenc->ch[psenc->chlen++] = base64[pos];
409 			psenc->ch[psenc->chlen++] = BASE64_OUT;
410 			psenc->bits = psenc->cache = 0;
411 		}
412 		psenc->mode = 0;
413 	}
414 	if (psenc->bits != 0)
415 		return (EINVAL);
416 	if (n-- < 1)
417 		return (E2BIG);
418 
419 	*nresult = (size_t)psenc->chlen;
420 	if (psenc->chlen > 0) {
421 		memcpy(s, psenc->ch, psenc->chlen);
422 		psenc->chlen = 0;
423 	}
424 
425 	return (0);
426 }
427 
428 static __inline int
429 /*ARGSUSED*/
430 _citrus_UTF7_stdenc_wctocs(_UTF7EncodingInfo * __restrict ei __unused,
431     _csid_t * __restrict csid, _index_t * __restrict idx, wchar_t wc)
432 {
433 
434 	*csid = 0;
435 	*idx = (_index_t)wc;
436 
437 	return (0);
438 }
439 
440 static __inline int
441 /*ARGSUSED*/
442 _citrus_UTF7_stdenc_cstowc(_UTF7EncodingInfo * __restrict ei __unused,
443     wchar_t * __restrict wc, _csid_t csid, _index_t idx)
444 {
445 
446 	if (csid != 0)
447 		return (EILSEQ);
448 	*wc = (wchar_t)idx;
449 
450 	return (0);
451 }
452 
453 static __inline int
454 /*ARGSUSED*/
455 _citrus_UTF7_stdenc_get_state_desc_generic(_UTF7EncodingInfo * __restrict ei __unused,
456     _UTF7State * __restrict psenc, int * __restrict rstate)
457 {
458 
459 	*rstate = (psenc->chlen == 0) ? _STDENC_SDGEN_INITIAL :
460 	    _STDENC_SDGEN_INCOMPLETE_CHAR;
461 	return (0);
462 }
463 
464 static void
465 /*ARGSUSED*/
466 _citrus_UTF7_encoding_module_uninit(_UTF7EncodingInfo *ei __unused)
467 {
468 
469 	/* ei seems to be unused */
470 }
471 
472 static int
473 /*ARGSUSED*/
474 _citrus_UTF7_encoding_module_init(_UTF7EncodingInfo * __restrict ei,
475     const void * __restrict var __unused, size_t lenvar __unused)
476 {
477 	const char *s;
478 
479 	memset(ei, 0, sizeof(*ei));
480 
481 #define FILL(str, flag)				\
482 do {						\
483 	for (s = str; *s != '\0'; s++)		\
484 		ei->cell[*s & 0x7f] |= flag;	\
485 } while (/*CONSTCOND*/0)
486 
487 	FILL(base64, (s - base64) + 1);
488 	FILL(direct, EI_DIRECT);
489 	FILL(option, EI_OPTION);
490 	FILL(spaces, EI_SPACE);
491 
492 	return (0);
493 }
494 
495 /* ----------------------------------------------------------------------
496  * public interface for stdenc
497  */
498 
499 _CITRUS_STDENC_DECLS(UTF7);
500 _CITRUS_STDENC_DEF_OPS(UTF7);
501 
502 #include "citrus_stdenc_template.h"
503