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Date:: Sun Mar 20 15:44:37 2022 UTC
Message:: Fix osmtpd_mheader_skip_hyphenatedword: Don't return a NULL-pointer if content is valid
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1 /*
2  * Copyright (c) 2020 Martijn van Duren <martijn@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <ctype.h>
18 #include <errno.h>
19 #include <stddef.h>
20 #include <string.h>
21 #include <strings.h>
22 
23 #include "mheader.h"
24 
25 #include <stdio.h>
26 
27 char *
28 osmtpd_mheader_skip_sp(char *ptr, int optional)
29 {
30 	if (ptr[0] == 0x20)
31 		return ptr + 1;
32 	return optional ? ptr : NULL;
33 }
34 
35 char *
36 osmtpd_mheader_skip_htab(char *ptr, int optional)
37 {
38 	if (ptr[0] == 0x9)
39 		return ptr + 1;
40 	return optional ? ptr : NULL;
41 }
42 
43 char *
44 osmtpd_mheader_skip_char(char *ptr, int optional)
45 {
46 	if (ptr[0] >= 0x01 && ptr[0] <= 0x7f)
47 		return ptr + 1;
48 	return optional ? ptr : NULL;
49 }
50 
51 char *
52 osmtpd_mheader_skip_ctl(char *ptr, int optional)
53 {
54 	if ((ptr[0] >= 0x00 && ptr[0] <= 0x1f) || ptr[0] == 0x7f)
55 		return ptr + 1;
56 	return optional ? ptr : NULL;
57 }
58 
59 char *
60 osmtpd_mheader_skip_wsp(char *ptr, int optional)
61 {
62 	char *start = ptr;
63 
64 	if ((ptr = osmtpd_mheader_skip_sp(start, 0)) != NULL ||
65 	    (ptr = osmtpd_mheader_skip_htab(start, 0)) != NULL)
66 		return ptr;
67 	return optional ? start : NULL;
68 }
69 
70 char *
71 osmtpd_mheader_skip_crlf(char *ptr, int optional)
72 {
73 	if (ptr[0] == 13 && ptr[1] == 10)
74 		return ptr + 2;
75 	return optional ? ptr : NULL;
76 }
77 
78 char *
79 osmtpd_mheader_skip_vchar(char *ptr, int optional)
80 {
81 	if (ptr[0] >= 0x21 && ptr[0] <= 0x7e)
82 		return ptr + 1;
83 	return optional ? ptr : NULL;
84 }
85 
86 char *
87 osmtpd_mheader_skip_lf(char *ptr, int optional)
88 {
89 	if (ptr[0] == 0xa)
90 		return ptr + 1;
91 	return optional ? ptr : NULL;
92 }
93 
94 char *
95 osmtpd_mheader_skip_cr(char *ptr, int optional)
96 {
97 	if (ptr[0] == 0xd)
98 		return ptr + 1;
99 	return optional ? ptr : NULL;
100 }
101 
102 char *
103 osmtpd_mheader_skip_alpha(char *ptr, int optional)
104 {
105 	if ((ptr[0] >= 0x41 && ptr[0] <= 0x5a) ||
106 	    (ptr[0] >= 0x61 && ptr[0] <= 0x7a))
107 		return ptr + 1;
108 	return optional ? ptr : NULL;
109 }
110 
111 char *
112 osmtpd_mheader_skip_digit(char *ptr, int optional)
113 {
114 	if (ptr[0] >= 0x30 && ptr[0] <= 0x39)
115 		return ptr + 1;
116 	return optional ? ptr : NULL;
117 }
118 
119 char *
120 osmtpd_mheader_skip_letdig(char *ptr, int optional)
121 {
122 	char *start = ptr;
123 
124 	if ((ptr = osmtpd_mheader_skip_alpha(start, 0)) == NULL &&
125 	    (ptr = osmtpd_mheader_skip_digit(start, 0)) == NULL)
126 		return optional ? start : NULL;
127 	return ptr;
128 }
129 
130 char *
131 osmtpd_mheader_skip_ldhstring(char *ptr, int optional)
132 {
133 	char *start = ptr, *prev;
134 	int letdig = 0;
135 
136 	while (1) {
137 		prev = ptr;
138 		if ((ptr = osmtpd_mheader_skip_alpha(prev, 0)) != NULL ||
139 		    (ptr = osmtpd_mheader_skip_digit(prev, 0)) != NULL) {
140 			letdig = 1;
141 			continue;
142 		}
143 		if (prev[0] == '-') {
144 			letdig = 0;
145 			ptr = prev + 1;
146 			continue;
147 		}
148 		ptr = prev;
149 		break;
150 	}
151 	if (letdig)
152 		return ptr;
153 	if (ptr == start)
154 		return optional ? start : NULL;
155 	return ptr;
156 }
157 
158 char *
159 osmtpd_mheader_skip_dquote(char *ptr, int optional)
160 {
161 	if (ptr[0] == 0x22)
162 		return ptr + 1;
163 	return optional ? ptr : NULL;
164 }
165 
166 char *
167 osmtpd_mheader_skip_hexoctet(char *ptr, int optional)
168 {
169 	char *start = ptr;
170 
171 	if (ptr[0] != '=')
172 		return optional ? ptr : NULL;
173 	ptr++;
174 	if (ptr[0] == 'A' || ptr[0] == 'B' || ptr[0] == 'C' || ptr[0] == 'D' ||
175 	    ptr[0] == 'E' || ptr[0] == 'F')
176 		ptr++;
177 	else if ((ptr = osmtpd_mheader_skip_digit(ptr, 0)) == NULL)
178 		return optional ? start : NULL;
179 	if (ptr[0] == 'A' || ptr[0] == 'B' || ptr[0] == 'C' || ptr[0] == 'D' ||
180 	    ptr[0] == 'E' || ptr[0] == 'F')
181 		ptr++;
182 	else if ((ptr = osmtpd_mheader_skip_digit(ptr, 0)) == NULL)
183 		return optional ? start : NULL;
184 	return ptr;
185 }
186 
187 char *
188 osmtpd_mheader_skip_obs_fws(char *ptr, int optional)
189 {
190 	char *start = ptr, *prev;
191 
192 	if ((ptr = osmtpd_mheader_skip_wsp(ptr, 0)) == NULL)
193 		return optional ? start : NULL;
194 	prev = ptr;
195 	while ((ptr = osmtpd_mheader_skip_wsp(ptr, 0)) != NULL)
196 		prev = ptr;
197 
198 	ptr = prev;
199 	while (1) {
200 		if ((ptr = osmtpd_mheader_skip_crlf(ptr, 0)) == NULL)
201 			return prev;
202 		if ((ptr = osmtpd_mheader_skip_wsp(ptr, 0)) == NULL)
203 			return prev;
204 		prev = ptr;
205 		while ((ptr = osmtpd_mheader_skip_wsp(ptr, 0)) != NULL)
206 			prev = ptr;
207 		ptr = prev;
208 	}
209 }
210 
211 char *
212 osmtpd_mheader_skip_fws(char *ptr, int optional)
213 {
214 	char *start = ptr, *prev = ptr;
215 
216 	while ((ptr = osmtpd_mheader_skip_wsp(ptr, 0)) != NULL)
217 		prev = ptr;
218 	if ((ptr = osmtpd_mheader_skip_crlf(prev, 1)) == prev)
219 		ptr = start;
220 	if ((ptr = osmtpd_mheader_skip_wsp(ptr, 0)) == NULL)
221 		return osmtpd_mheader_skip_obs_fws(start, optional);
222 	prev = ptr;
223 	while ((ptr = osmtpd_mheader_skip_wsp(ptr, 0)) != NULL)
224 		prev = ptr;
225 	return prev;
226 }
227 
228 char *
229 osmtpd_mheader_skip_obs_no_ws_ctl(char *ptr, int optional)
230 {
231 	if ((ptr[0] >= 1 && ptr[0] <= 8) || ptr[0] == 11 || ptr[0] == 12 ||
232 	    (ptr[0] >= 14 && ptr[0] <= 31) || ptr[0] == 127)
233 		return ptr + 1;
234 	return optional ? ptr : NULL;
235 }
236 
237 char *
238 osmtpd_mheader_skip_obs_ctext(char *ptr, int optional)
239 {
240 	return osmtpd_mheader_skip_obs_no_ws_ctl(ptr, optional);
241 }
242 
243 char *
244 osmtpd_mheader_skip_ctext(char *ptr, int optional)
245 {
246 	char *start = ptr;
247 
248 	if ((ptr[0] >= 33 && ptr[0] <= 39) || (ptr[0] >= 42 && ptr[0] <= 91) ||
249 	    (ptr[0] >= 93 && ptr[0] <= 126))
250 		return ptr + 1;
251 	if ((ptr = osmtpd_mheader_skip_obs_ctext(ptr, 0)) != NULL)
252 		return ptr;
253 	return optional ? start : NULL;
254 }
255 
256 char *
257 osmtpd_mheader_skip_obs_qp(char *ptr, int optional)
258 {
259 	char *start = ptr;
260 
261 	if (ptr[0] == '\\' && (
262 	    (ptr = osmtpd_mheader_skip_obs_no_ws_ctl(start + 1, 0)) != NULL ||
263 	    (ptr = osmtpd_mheader_skip_lf(start + 1, 0)) != NULL ||
264 	    (ptr = osmtpd_mheader_skip_cr(start + 1, 0)) != NULL))
265 		return ptr;
266 	return optional ? start : NULL;
267 }
268 
269 char *
270 osmtpd_mheader_skip_quoted_pair(char *ptr, int optional)
271 {
272 	char *start = ptr;
273 
274 	if (ptr[0] == '\\' && (
275 	    (ptr = osmtpd_mheader_skip_vchar(start + 1, 0)) != NULL ||
276 	    (ptr = osmtpd_mheader_skip_wsp(start + 1, 0)) != NULL))
277 		return ptr;
278 	return osmtpd_mheader_skip_obs_qp(start, optional);
279 }
280 
281 char *
282 osmtpd_mheader_skip_ccontent(char *ptr, int optional)
283 {
284 	char *start = ptr;
285 
286 	if ((ptr = osmtpd_mheader_skip_ctext(ptr, 0)) != NULL)
287 		return ptr;
288 	if ((ptr = osmtpd_mheader_skip_quoted_pair(start, 0)) != NULL)
289 		return ptr;
290 	if ((ptr = osmtpd_mheader_skip_comment(start, 0)) != NULL)
291 		return ptr;
292 	return optional ? start : NULL;
293 }
294 
295 char *
296 osmtpd_mheader_skip_comment(char *ptr, int optional)
297 {
298 	char *start = ptr;
299 
300 	if (ptr++[0] != '(')
301 		return optional ? start : NULL;
302 	while (1) {
303 		ptr = osmtpd_mheader_skip_fws(ptr, 1);
304 		if (ptr[0] == ')')
305 			return ptr + 1;
306 		if ((ptr = osmtpd_mheader_skip_ccontent(ptr, 0)) == NULL)
307 			return optional ? start : NULL;
308 	}
309 }
310 
311 char *
312 osmtpd_mheader_skip_cfws(char *ptr, int optional)
313 {
314 	char *start = ptr, *prev;
315 
316 	while (1) {
317 		ptr = osmtpd_mheader_skip_fws(ptr, 1);
318 		prev = ptr;
319 		if ((ptr = osmtpd_mheader_skip_comment(ptr, 0)) == NULL) {
320 			ptr = prev;
321 			break;
322 		}
323 	}
324 	return ptr == start && !optional ? NULL : ptr;
325 }
326 
327 char *
328 osmtpd_mheader_skip_atext(char *ptr, int optional)
329 {
330 	char *start = ptr;
331 
332 	if ((ptr = osmtpd_mheader_skip_alpha(start, 0)) != NULL ||
333 	    (ptr = osmtpd_mheader_skip_digit(start, 0)) != NULL)
334 		return ptr;
335 	ptr = start;
336 	if (ptr[0] == '!' || ptr[0] == '#' || ptr[0] == '$' || ptr[0] == '%' ||
337 	    ptr[0] == '&' || ptr[0] == '\'' || ptr[0] == '*' || ptr[0] == '+' ||
338 	    ptr[0] == '-' || ptr[0] == '/' || ptr[0] == '=' || ptr[0] == '?' ||
339 	    ptr[0] == '^' || ptr[0] == '_' || ptr[0] == '`' || ptr[0] == '{' ||
340 	    ptr[0] == '|' || ptr[0] == '}' || ptr[0] == '~')
341 		return ptr + 1;
342 	return optional ? start : NULL;
343 }
344 
345 char *
346 osmtpd_mheader_skip_atom(char *ptr, int optional)
347 {
348 	char *start = ptr, *prev;
349 
350 	ptr = osmtpd_mheader_skip_cfws(ptr, 1);
351 	if ((ptr = osmtpd_mheader_skip_atext(ptr, 0)) == NULL)
352 		return optional ? start : NULL;
353 	do {
354 		prev = ptr;
355 		ptr = osmtpd_mheader_skip_atext(ptr, 1);
356 	} while (prev != ptr);
357 	return osmtpd_mheader_skip_cfws(ptr, 1);
358 }
359 
360 char *
361 osmtpd_mheader_skip_dot_atom_text(char *ptr, int optional)
362 {
363 	char *start = ptr, *prev;
364 
365 	if ((ptr = osmtpd_mheader_skip_atext(ptr, 0)) == NULL)
366 		return optional ? start : NULL;
367 	do {
368 		prev = ptr;
369 		ptr = osmtpd_mheader_skip_atext(ptr, 1);
370 	} while (ptr != prev);
371 
372 	while (ptr[0] == '.') {
373 		ptr++;
374 		if ((ptr = osmtpd_mheader_skip_atext(ptr, 0)) == NULL)
375 			return prev;
376 		do {
377 			prev = ptr;
378 			ptr = osmtpd_mheader_skip_atext(ptr, 1);
379 		} while (ptr != prev);
380 	}
381 	return ptr;
382 }
383 
384 char *
385 osmtpd_mheader_skip_dot_atom(char *ptr, int optional)
386 {
387 	char *start = ptr;
388 
389 	ptr = osmtpd_mheader_skip_cfws(ptr, 1);
390 	if ((ptr = osmtpd_mheader_skip_dot_atom_text(ptr, 0)) == NULL)
391 		return optional ? start : NULL;
392 	return osmtpd_mheader_skip_cfws(ptr, 1);
393 }
394 
395 char *
396 osmtpd_mheader_skip_obs_qtext(char *ptr, int optional)
397 {
398 	return osmtpd_mheader_skip_obs_no_ws_ctl(ptr, optional);
399 }
400 
401 char *
402 osmtpd_mheader_skip_qtext(char *ptr, int optional)
403 {
404 	char *start = ptr;
405 
406 	if (ptr[0] == 33 || (ptr[0] >= 35 && ptr[0] <= 91) ||
407 	    (ptr[0] >= 93 && ptr[0] <= 126))
408 		return ptr + 1;
409 	if ((ptr = osmtpd_mheader_skip_obs_qtext(ptr, 0)) != NULL)
410 		return ptr;
411 	return optional ? start : NULL;
412 }
413 
414 char *
415 osmtpd_mheader_skip_qcontent(char *ptr, int optional)
416 {
417 	char *start = ptr;
418 
419 	if ((ptr = osmtpd_mheader_skip_qtext(ptr, 0)) != NULL)
420 		return ptr;
421 	return osmtpd_mheader_skip_quoted_pair(start, optional);
422 }
423 
424 char *
425 osmtpd_mheader_skip_quoted_string(char *ptr, int optional)
426 {
427 	char *start = ptr, *prev;
428 
429 	ptr = osmtpd_mheader_skip_cfws(ptr, 1);
430 	if ((ptr = osmtpd_mheader_skip_dquote(ptr, 0)) == NULL)
431 		return optional ? start : NULL;
432 	prev = ptr;
433 	while (1) {
434 		ptr = osmtpd_mheader_skip_fws(ptr, 1);
435 		if ((ptr = osmtpd_mheader_skip_qcontent(ptr, 0)) == NULL)
436 			break;
437 		prev = ptr;
438 	}
439 	if ((ptr = osmtpd_mheader_skip_dquote(prev, 0)) == NULL)
440 		return optional ? start : NULL;
441 	return osmtpd_mheader_skip_cfws(ptr, 1);
442 }
443 
444 char *
445 osmtpd_mheader_skip_keyword(char *ptr, int optional)
446 {
447 	return osmtpd_mheader_skip_ldhstring(ptr, optional);
448 }
449 
450 char *
451 osmtpd_mheader_skip_word(char *ptr, int optional)
452 {
453 	char *start = ptr;
454 
455 	if ((ptr = osmtpd_mheader_skip_atom(ptr, 0)) != NULL)
456 		return ptr;
457 	return osmtpd_mheader_skip_quoted_string(start, optional);
458 }
459 
460 char *
461 osmtpd_mheader_skip_obs_phrase(char *ptr, int optional)
462 {
463 	char *start = ptr, *prev;
464 
465 	if ((ptr = osmtpd_mheader_skip_word(ptr, 0)) == NULL)
466 		return optional ? start : NULL;
467 	while (1) {
468 		prev = ptr;
469 		if ((ptr = osmtpd_mheader_skip_word(ptr, 0)) != NULL)
470 			continue;
471 		ptr = prev;
472 		if (ptr[0] == '.') {
473 			ptr++;
474 			continue;
475 		}
476 		if ((ptr = osmtpd_mheader_skip_cfws(ptr, 0)) != NULL)
477 			continue;
478 		return prev;
479 	}
480 }
481 
482 char *
483 osmtpd_mheader_skip_phrase(char *ptr, int optional)
484 {
485 	/* obs-phrase is a superset of phrae */
486 	return osmtpd_mheader_skip_obs_phrase(ptr, optional);
487 #if 0
488 	char *start = ptr, *prev;
489 
490 	if ((ptr = osmtpd_mheader_skip_word(ptr, 0)) == NULL)
491 		return optional ? start : NULL;
492 	while (1) {
493 		prev = ptr;
494 		if ((ptr = osmtpd_mheader_skip_word(ptr, 0)) == NULL)
495 			return prev;
496 	}
497 #endif
498 }
499 
500 char *
501 osmtpd_mheader_skip_obs_local_part(char *ptr, int optional)
502 {
503 	char *start = ptr, *prev;
504 
505 	if ((ptr = osmtpd_mheader_skip_word(ptr, 0)) == NULL)
506 		return optional ? start : NULL;
507 	prev = ptr;
508 	while (ptr[0] == '.') {
509 		ptr++;
510 		if ((ptr = osmtpd_mheader_skip_word(ptr, 0)) == NULL)
511 			return prev;
512 		prev = ptr;
513 	}
514 	return ptr;
515 }
516 
517 char *
518 osmtpd_mheader_skip_local_part(char *ptr, int optional)
519 {
520 	char *start = ptr;
521 
522 	if ((ptr = osmtpd_mheader_skip_dot_atom(ptr, 0)) != NULL)
523 		return ptr;
524 	ptr = start;
525 	if ((ptr = osmtpd_mheader_skip_quoted_string(ptr, 0)) != NULL)
526 		return ptr;
527 	return osmtpd_mheader_skip_obs_local_part(start, optional);
528 }
529 
530 char *
531 osmtpd_mheader_skip_subdomain(char *ptr, int optional)
532 {
533 	char *start = ptr;
534 
535 	if ((ptr = osmtpd_mheader_skip_letdig(ptr, 0)) == NULL)
536 		return optional ? start : NULL;
537 	return osmtpd_mheader_skip_ldhstring(ptr, 1);
538 }
539 
540 char *
541 osmtpd_mheader_skip_obs_dtext(char *ptr, int optional)
542 {
543 	char *start = ptr;
544 
545 	if ((ptr = osmtpd_mheader_skip_obs_no_ws_ctl(ptr, 0)) != NULL)
546 		return ptr;
547 	return osmtpd_mheader_skip_quoted_pair(start, optional);
548 }
549 
550 char *
551 osmtpd_mheader_skip_dtext(char *ptr, int optional)
552 {
553 	if ((ptr[0] >= 33 && ptr[0] <= 90) || (ptr[0] >= 94 && ptr[0] <= 126))
554 		return ptr + 1;
555 	return osmtpd_mheader_skip_obs_dtext(ptr, optional);
556 
557 }
558 
559 char *
560 osmtpd_mheader_skip_domain_literal(char *ptr, int optional)
561 {
562 	char *start = ptr, *prev;
563 
564 	ptr = osmtpd_mheader_skip_cfws(ptr, 1);
565 	if (ptr++[0] != '[')
566 		return optional ? start : NULL;
567 	while (1) {
568 		ptr = osmtpd_mheader_skip_fws(ptr, 1);
569 		prev = ptr;
570 		if ((ptr = osmtpd_mheader_skip_dtext(ptr, 0)) == NULL) {
571 			ptr = prev;
572 			break;
573 		}
574 	}
575 	if (ptr[0] != ']')
576 		return optional ? start : NULL;
577 	ptr++;
578 	return osmtpd_mheader_skip_cfws(ptr, 1);
579 }
580 
581 char *
582 osmtpd_mheader_skip_obs_domain(char *ptr, int optional)
583 {
584 	char *start = ptr, *prev;
585 
586 	if ((ptr = osmtpd_mheader_skip_atom(ptr, 0)) == NULL)
587 		return optional ? start : NULL;
588 	prev = ptr;
589 	while (1) {
590 		if (ptr++[0] != '.')
591 			return prev;
592 		if ((ptr = osmtpd_mheader_skip_atom(ptr, 0)) == NULL)
593 			return prev;
594 		prev = ptr;
595 	}
596 }
597 
598 char *
599 osmtpd_mheader_skip_domain(char *ptr, int optional)
600 {
601 	char *start = ptr;
602 
603 	if ((ptr = osmtpd_mheader_skip_dot_atom(start, 0)) != NULL)
604 		return ptr;
605 	if ((ptr = osmtpd_mheader_skip_domain_literal(start, 0)) != NULL)
606 		return ptr;
607 	return osmtpd_mheader_skip_obs_domain(start, optional);
608 }
609 
610 char *
611 osmtpd_mheader_skip_display_name(char *ptr, int optional)
612 {
613 	return osmtpd_mheader_skip_phrase(ptr, optional);
614 }
615 
616 char *
617 osmtpd_mheader_skip_obs_domain_list(char *ptr, int optional)
618 {
619 	char *start = ptr, *prev = ptr;
620 
621 	while (1) {
622 		if (ptr[0] == ',') {
623 			ptr++;
624 			prev = ptr;
625 			continue;
626 		} else if ((ptr = osmtpd_mheader_skip_cfws(ptr, 0)) != NULL) {
627 			prev = ptr;
628 			continue;
629 		}
630 		break;
631 	}
632 	ptr = prev;
633 
634 	if (ptr++[0] != '@')
635 		return optional ? start : NULL;
636 	if ((ptr = osmtpd_mheader_skip_domain(ptr, 0)) == NULL)
637 		return optional ? start : NULL;
638 	while (1) {
639 		if (ptr[0] != ',')
640 			break;
641 		ptr++;
642 		ptr = osmtpd_mheader_skip_cfws(ptr, 1);
643 		if (ptr[0] != '@')
644 			continue;
645 		prev = ptr;
646 		if ((ptr = osmtpd_mheader_skip_domain(ptr + 1, 0)) == NULL) {
647 			ptr = prev;
648 			break;
649 		}
650 	}
651 	return ptr;
652 }
653 
654 char *
655 osmtpd_mheader_skip_obs_route(char *ptr, int optional)
656 {
657 	char *start = ptr;
658 
659 	if ((ptr = osmtpd_mheader_skip_obs_domain_list(ptr, 0)) == NULL)
660 		return optional ? start : NULL;
661 	if (ptr++[0] != ':')
662 		return optional ? start : NULL;
663 	return ptr;
664 }
665 
666 char *
667 osmtpd_mheader_skip_addr_spec(char *ptr, int optional)
668 {
669 	char *start = ptr;
670 
671 	if ((ptr = osmtpd_mheader_skip_local_part(ptr, 0)) == NULL)
672 		return optional ? start : NULL;
673 	if (ptr++[0] != '@')
674 		return optional ? start : NULL;
675 	if ((ptr = osmtpd_mheader_skip_domain(ptr, 0)) == NULL)
676 		return optional ? start : NULL;
677 	return ptr;
678 }
679 
680 char *
681 osmtpd_mheader_skip_obs_angle_addr(char *ptr, int optional)
682 {
683 	char *start = ptr;
684 
685 	ptr = osmtpd_mheader_skip_cfws(ptr, 1);
686 	if (ptr++[0] != '<')
687 		return optional ? start : NULL;
688 	if ((ptr = osmtpd_mheader_skip_obs_route(ptr, 0)) == NULL)
689 		return optional ? start : NULL;
690 	if ((ptr = osmtpd_mheader_skip_addr_spec(ptr, 0)) == NULL)
691 		return optional ? start : NULL;
692 	if (ptr++[0] != '>')
693 		return optional ? start : NULL;
694 	return osmtpd_mheader_skip_cfws(ptr, 1);
695 }
696 
697 char *
698 osmtpd_mheader_skip_angle_addr(char *ptr, int optional)
699 {
700 	char *start = ptr;
701 
702 	ptr = osmtpd_mheader_skip_cfws(ptr, 1);
703 	if (ptr++[0] != '<')
704 		return osmtpd_mheader_skip_obs_angle_addr(start, optional);
705 	if ((ptr = osmtpd_mheader_skip_addr_spec(ptr, 0)) == NULL)
706 		return osmtpd_mheader_skip_obs_angle_addr(start, optional);
707 	if (ptr++[0] != '>')
708 		return osmtpd_mheader_skip_obs_angle_addr(start, optional);
709 	return osmtpd_mheader_skip_cfws(ptr, 1);
710 }
711 
712 char *
713 osmtpd_mheader_skip_name_addr(char *ptr, int optional)
714 {
715 	char *start = ptr;
716 
717 	ptr = osmtpd_mheader_skip_display_name(ptr, 1);
718 	if ((ptr = osmtpd_mheader_skip_angle_addr(ptr, 0)) == NULL)
719 		return optional ? start : NULL;
720 	return ptr;
721 }
722 
723 char *
724 osmtpd_mheader_skip_alphadigitps(char *ptr, int optional)
725 {
726 	char *end;
727 
728 	if ((end = osmtpd_mheader_skip_alpha(ptr, 0)) == NULL &&
729 	    (end = osmtpd_mheader_skip_digit(ptr, 0)) == NULL &&
730 	    ptr[0] != '+' && ptr[0] != '/')
731 		return optional ? ptr : NULL;
732 	return end == NULL ? ptr + 1 : end;
733 }
734 
735 char *
736 osmtpd_mheader_skip_base64string(char *ptr, int optional)
737 {
738 	char *start = ptr;
739 
740 	if ((ptr = osmtpd_mheader_skip_alphadigitps(ptr, 0)) == NULL)
741 		return optional ? start : NULL;
742 	while (1) {
743 		start = ptr;
744 		ptr = osmtpd_mheader_skip_fws(ptr, 1);
745 		if ((ptr = osmtpd_mheader_skip_alphadigitps(ptr, 0)) == NULL)
746 			break;
747 	}
748 	ptr = start;
749 	ptr = osmtpd_mheader_skip_fws(ptr, 1);
750 	if (ptr[0] == '=') {
751 		ptr++;
752 		start = ptr;
753 		ptr = osmtpd_mheader_skip_fws(ptr, 1);
754 		if (ptr[0] == '=')
755 			ptr++;
756 		else
757 			ptr = start;
758 	} else
759 		ptr = start;
760 	return ptr;
761 }
762 
763 char *
764 osmtpd_mheader_skip_hyphenatedword(char *ptr, int optional)
765 {
766 	char *start = ptr, *end, *hyphen;
767 
768 	if ((ptr = osmtpd_mheader_skip_alpha(ptr, 0)) == NULL)
769 		return optional ? start : NULL;
770 
771 	end = ptr;
772 	while (1) {
773 		if (ptr[0] == '-') {
774 			hyphen = hyphen == NULL ? ptr - 1 : hyphen;
775 			ptr++;
776 			continue;
777 		}
778 		start = ptr;
779 		if ((ptr = osmtpd_mheader_skip_alpha(start, 0)) == NULL &&
780 		    (ptr = osmtpd_mheader_skip_digit(start, 0)) == NULL)
781 			break;
782 		hyphen = NULL;
783 		end = ptr;
784 		
785 	}
786 	return hyphen == NULL ? end : hyphen;
787 }
788 
789 char *
790 osmtpd_mheader_skip_ftext(char *ptr, int optional)
791 {
792 	if ((ptr[0] >= 33 && ptr[0] <= 57) ||
793 	    (ptr[0] >= 59 && ptr[0] <= 126))
794 		return ptr + 1;
795 	return optional ? ptr : NULL;
796 }
797 
798 char *
799 osmtpd_mheader_skip_fieldname(char *ptr, int optional)
800 {
801 	char *start = ptr;
802 
803 	if ((ptr = osmtpd_mheader_skip_ftext(ptr, 0)) == NULL)
804 		return optional ? start : NULL;
805 	while (1) {
806 		start = ptr;
807 		if ((ptr = osmtpd_mheader_skip_ftext(ptr, 0)) == NULL)
808 			return start;
809 	}
810 }
811 
812 char *
813 osmtpd_mheader_skip_hdrname(char *ptr, int optional)
814 {
815 	return osmtpd_mheader_skip_fieldname(ptr, optional);
816 }
817 
818 char *
819 osmtpd_mheader_skip_tspecials(char *ptr, int optional)
820 {
821 	if (ptr[0] == '(' || ptr[0] == ')' || ptr[0] == '<' || ptr[0] == '>' ||
822 	    ptr[0] == '@' || ptr[0] == ',' || ptr[0] == ';' || ptr[0] == ':' ||
823 	    ptr[0] == '\\' || ptr[0] == '"' || ptr[0] == '/' || ptr[0] == '[' ||
824 	    ptr[0] == ']' || ptr[0] == '?' || ptr[0] == '=')
825 		return ptr + 1;
826 	return optional ? ptr : NULL;
827 }
828 
829 char *
830 osmtpd_mheader_skip_token(char *ptr, int optional)
831 {
832 	char *start;
833 	int first = 1;
834 
835 	while (1) {
836 		start = ptr;
837 		if ((ptr = osmtpd_mheader_skip_char(start, 0)) != NULL &&
838 		    osmtpd_mheader_skip_sp(start, 0) == NULL &&
839 		    osmtpd_mheader_skip_ctl(start, 0) == NULL &&
840 		    osmtpd_mheader_skip_tspecials(start, 0) == NULL) {
841 			first = 0;
842 			continue;
843 		}
844 		return optional || !first ? start : NULL;
845 	}
846 }
847 
848 char *
849 osmtpd_mheader_skip_value(char *ptr, int optional)
850 {
851 	char *start = ptr;
852 
853 	if ((ptr = osmtpd_mheader_skip_token(start, 0)) != NULL)
854 		return ptr;
855 	if ((ptr = osmtpd_mheader_skip_quoted_string(start, 0)) != NULL)
856 		return ptr;
857 	return optional ? start : NULL;
858 }
859 
860 char *
861 osmtpd_mheader_skip_dkim_safe_char(char *ptr, int optional)
862 {
863 	if ((ptr[0] >= 0x21 && ptr[0] <= 0x3a) || ptr[0] == 0x3c ||
864 	    (ptr[0] >= 0x3e && ptr[0] <= 0x7e))
865 		return ptr + 1;
866 	return optional ? ptr : NULL;
867 }
868 
869 char *
870 osmtpd_mheader_skip_dkim_quoted_printable(char *ptr, int optional)
871 {
872 	char *start;
873 
874 	while (1) {
875 		start = ptr;
876 		if ((ptr = osmtpd_mheader_skip_fws(start, 0)) != NULL)
877 			continue;
878 		if ((ptr = osmtpd_mheader_skip_hexoctet(start, 0)) != NULL)
879 			continue;
880 		ptr = osmtpd_mheader_skip_dkim_safe_char(start, 0);
881 		if (ptr == NULL)
882 			break;
883 	}
884 	return start;
885 }
886 
887 char *
888 osmtpd_mheader_skip_dkim_qp_hdr_value(char *ptr, int optional)
889 {
890 	return osmtpd_mheader_skip_dkim_quoted_printable(ptr, optional);
891 }
892 
893 char *
894 osmtpd_mheader_skip_dkimsig_alnumpunc(char *ptr, int optional)
895 {
896 	char *start = ptr;
897 
898 	if ((ptr = osmtpd_mheader_skip_alpha(start, 0)) != NULL)
899 		return ptr;
900 	if ((ptr = osmtpd_mheader_skip_digit(start, 0)) != NULL)
901 		return ptr;
902 	if (start[0] == '_')
903 		return start + 1;
904 	return optional ? start : NULL;
905 }
906 
907 char *
908 osmtpd_mheader_skip_dkimsig_valchar(char *ptr, int optional)
909 {
910 	if ((ptr[0] >= 0x21 && ptr[0] <= 0x3A) ||
911 	    (ptr[0] >= 0x3C && ptr[0] <= 0x7E))
912 		return ptr + 1;
913 	return optional ? ptr : NULL;
914 }
915 
916 char *
917 osmtpd_mheader_skip_dkimsig_tval(char *ptr, int optional)
918 {
919 	char *start = ptr, *prev;
920 
921 	if ((ptr = osmtpd_mheader_skip_dkimsig_valchar(ptr, 0)) == NULL)
922 		return optional ? start : NULL;
923 	prev = ptr;
924 	while ((ptr = osmtpd_mheader_skip_dkimsig_valchar(ptr, 0)) != NULL)
925 		prev = ptr;
926 	return prev;
927 }
928 
929 char *
930 osmtpd_mheader_skip_dkimsig_tagvalue(char *ptr, int optional)
931 {
932 	char *start = ptr, *prev;
933 
934 	if ((ptr = osmtpd_mheader_skip_dkimsig_tval(ptr, 0)) == NULL)
935 		return start;
936 
937 	while (1) {
938 		start = ptr;
939 		/* FWS contains WSP */
940 		if ((ptr = osmtpd_mheader_skip_fws(ptr, 0)) == NULL)
941 			return start;
942 		prev = ptr;
943 		while ((ptr = osmtpd_mheader_skip_fws(ptr, 0)) != NULL)
944 			prev = ptr;
945 		ptr = prev;
946 		if ((ptr = osmtpd_mheader_skip_dkimsig_tval(ptr, 0)) == NULL)
947 			return start;
948 	}
949 }
950 
951 char *
952 osmtpd_mheader_skip_dkimsig_tagname(char *ptr, int optional)
953 {
954 	char *start = ptr, *prev;
955 
956 	if ((ptr = osmtpd_mheader_skip_alpha(ptr, 0)) == NULL)
957 		return optional ? start : NULL;
958 	prev = ptr;
959 	while ((ptr = osmtpd_mheader_skip_dkimsig_alnumpunc(ptr, 0)) != NULL)
960 		prev = ptr;
961 	return prev;
962 }
963 
964 char *
965 osmtpd_mheader_skip_dkimsig_tagspec(char *ptr, int optional)
966 {
967 	char *start = ptr;
968 
969 	ptr = osmtpd_mheader_skip_fws(ptr, 1);
970 	if ((ptr = osmtpd_mheader_skip_dkimsig_tagname(ptr, 0)) == NULL)
971 		return optional ? start : NULL;
972 	ptr = osmtpd_mheader_skip_fws(ptr, 1);
973 	if (ptr[0] != '=')
974 		return optional ? start : NULL;
975 	ptr++;
976 	ptr = osmtpd_mheader_skip_fws(ptr, 1);
977 	if ((ptr = osmtpd_mheader_skip_dkimsig_tagvalue(ptr, 0)) == NULL)
978 		return optional ? start : NULL;
979 	return osmtpd_mheader_skip_fws(ptr, 1);
980 }
981 
982 char *
983 osmtpd_mheader_skip_dkimsig_taglist(char *ptr, int optional)
984 {
985 	char *start = ptr;
986 
987 	if ((ptr = osmtpd_mheader_skip_dkimsig_tagspec(ptr, 0)) == NULL)
988 		return optional ? start : NULL;
989 	while (1) {
990 		/* Starting or trailing ';' */
991 		if (ptr[0] != ';')
992 			return ptr;
993 		ptr++;
994 		start = ptr;
995 		if ((ptr = osmtpd_mheader_skip_dkimsig_tagspec(ptr, 0)) == NULL)
996 			return start;
997 	}
998 }
999 
1000 char *
1001 osmtpd_mheader_skip_dkimsig_xsigatagh(char *ptr, int optional)
1002 {
1003 	char *start = ptr, *prev, *end;
1004 
1005 	if ((ptr = osmtpd_mheader_skip_alpha(ptr, 0)) == NULL)
1006 		return optional ? start : NULL;
1007 	prev = ptr;
1008 	while ((end = osmtpd_mheader_skip_alpha(ptr, 0)) != NULL ||
1009 	    (end = osmtpd_mheader_skip_digit(ptr, 0)) != NULL) {
1010 		ptr = end;
1011 		prev = end;
1012 	}
1013 	return prev;
1014 }
1015 
1016 char *
1017 osmtpd_mheader_skip_dkimsig_xsigatagk(char *ptr, int optional)
1018 {
1019 	char *start = ptr, *prev, *end;
1020 
1021 	if ((ptr = osmtpd_mheader_skip_alpha(ptr, 0)) == NULL)
1022 		return optional ? start : NULL;
1023 	prev = ptr;
1024 	while ((end = osmtpd_mheader_skip_alpha(ptr, 0)) != NULL ||
1025 	    (end = osmtpd_mheader_skip_digit(ptr, 0)) != NULL) {
1026 		ptr = end;
1027 		prev = end;
1028 	}
1029 	return prev;
1030 }
1031 
1032 char *
1033 osmtpd_mheader_skip_dkimsig_sigatagh(char *ptr, int optional)
1034 {
1035 	/* rsa / ed25519 covered by x-sig-a-tag-h */
1036 	return osmtpd_mheader_skip_dkimsig_xsigatagh(ptr, optional);
1037 }
1038 
1039 char *
1040 osmtpd_mheader_skip_dkimsig_sigatagk(char *ptr, int optional)
1041 {
1042 	/* sha1 / sha256 covered by x-sig-a-tag-k */
1043 	return osmtpd_mheader_skip_dkimsig_xsigatagk(ptr, optional);
1044 }
1045 
1046 char *
1047 osmtpd_mheader_skip_dkimsig_sigatagalg(char *ptr, int optional)
1048 {
1049 	char *start = ptr;
1050 
1051 	if ((ptr = osmtpd_mheader_skip_dkimsig_sigatagk(ptr, 0)) == NULL)
1052 		return optional ? start : NULL;
1053 	if (ptr[0] != '-')
1054 		return optional ? start : NULL;
1055 	ptr++;
1056 	if ((ptr = osmtpd_mheader_skip_dkimsig_sigatagh(ptr, 0)) == NULL)
1057 		return optional ? start : NULL;
1058 	return ptr;
1059 }
1060 
1061 char *
1062 osmtpd_mheader_skip_dkimsig_xsigctagalg(char *ptr, int optional)
1063 {
1064 	return osmtpd_mheader_skip_hyphenatedword(ptr, optional);
1065 }
1066 
1067 char *
1068 osmtpd_mheader_skip_dkimsig_sigctagalg(char *ptr, int optional)
1069 {
1070 	/* simple / relaxed covered by x-sig-c-tag-alga */
1071 	return osmtpd_mheader_skip_dkimsig_xsigctagalg(ptr, optional);
1072 }
1073 
1074 char *
1075 osmtpd_mheader_skip_dkimsig_xkeyhtagalg(char *ptr, int optional)
1076 {
1077 	return osmtpd_mheader_skip_hyphenatedword(ptr, optional);
1078 }
1079 
1080 char *
1081 osmtpd_mheader_skip_dkimsig_keyhtagalg(char *ptr, int optional)
1082 {
1083 	/* sha1 / sha256 covered by x-key-h-tag-alg */
1084 	return osmtpd_mheader_skip_dkimsig_xkeyhtagalg(ptr, optional);
1085 }
1086 
1087 char *
1088 osmtpd_mheader_skip_dkimsig_keyhtagvalue(char *ptr, int optional)
1089 {
1090 	char *start = ptr;
1091 
1092 	if ((ptr = osmtpd_mheader_skip_dkimsig_keyhtagalg(ptr, 0)) == NULL)
1093 		return optional ? start : NULL;
1094 	while (1) {
1095 		start = ptr;
1096 		ptr = osmtpd_mheader_skip_fws(ptr, 1);
1097 		if (ptr[0] != ':')
1098 			return start;
1099 		ptr = osmtpd_mheader_skip_fws(ptr + 1, 1);
1100 		ptr = osmtpd_mheader_skip_dkimsig_keyhtagalg(ptr, 0);
1101 		if (ptr == NULL)
1102 			return start;
1103 	}
1104 }
1105 
1106 char *
1107 osmtpd_mheader_skip_dkimsig_xsigqtagargs(char *ptr, int optional)
1108 {
1109 	return osmtpd_mheader_skip_dkim_qp_hdr_value(ptr, optional);
1110 }
1111 
1112 char *
1113 osmtpd_mheader_skip_dkimsig_xsigqtagtype(char *ptr, int optional)
1114 {
1115 	return osmtpd_mheader_skip_hyphenatedword(ptr, optional);
1116 }
1117 
1118 char *
1119 osmtpd_mheader_skip_dkimsig_sigqtagmethod(char *ptr, int optional)
1120 {
1121 	char *start = ptr;
1122 
1123 	/* dns/txt covered by x-sig-q-tag-type ["/" x-sig-q-tag-args] */
1124 	if ((ptr = osmtpd_mheader_skip_dkimsig_xsigqtagtype(ptr, 0)) == NULL)
1125 		return optional ? start : NULL;
1126 	start = ptr;
1127 	if (ptr[0] != '/')
1128 		return ptr;
1129 	if ((ptr = osmtpd_mheader_skip_dkimsig_xsigqtagargs(ptr, 0)) == NULL)
1130 		return start;
1131 	return ptr;
1132 }
1133 
1134 char *
1135 osmtpd_mheader_skip_dkimsig_sigztagcopy(char *ptr, int optional)
1136 {
1137 	char *start = ptr;
1138 
1139 	if ((ptr = osmtpd_mheader_skip_hdrname(ptr, 0)) == NULL)
1140 		return optional ? start : NULL;
1141 	ptr = osmtpd_mheader_skip_fws(ptr, 1);
1142 	if (ptr[0] != ':')
1143 		return optional ? start : NULL;
1144 	if ((ptr = osmtpd_mheader_skip_dkim_qp_hdr_value(ptr, 0)) == NULL)
1145 		return optional ? start : NULL;
1146 	return ptr;
1147 }
1148 
1149 char *
1150 osmtpd_mheader_skip_dkimsig_sigztagvalue(char *ptr, int optional)
1151 {
1152 	char *start = ptr;
1153 
1154 	if ((ptr = osmtpd_mheader_skip_dkimsig_sigztagcopy(ptr, 0)) == NULL)
1155 		return optional ? start : NULL;
1156 	while (1) {
1157 		start = ptr;
1158 		if (ptr[0] != '|')
1159 			return start;
1160 		osmtpd_mheader_skip_fws(ptr + 1, 1);
1161 		ptr = osmtpd_mheader_skip_dkimsig_sigztagcopy(ptr, 0);
1162 		if (ptr == NULL)
1163 			return start;
1164 	}
1165 }
1166 
1167 char *
1168 osmtpd_mheader_skip_dkimsig_xkeystagtype(char *ptr, int optional)
1169 {
1170 	return osmtpd_mheader_skip_hyphenatedword(ptr, optional);
1171 }
1172 
1173 char *
1174 osmtpd_mheader_skip_dkimsig_keystagtype(char *ptr, int optional)
1175 {
1176 	if (ptr[0] == '*')
1177 		return ptr + 1;
1178 	/* email covered by x-key-s-tag-type */
1179 	return osmtpd_mheader_skip_dkimsig_xkeystagtype(ptr, optional);
1180 }
1181 
1182 char *
1183 osmtpd_mheader_skip_dkimsig_keystagvalue(char *ptr, int optional)
1184 {
1185 	char *start = ptr;
1186 
1187 	if ((ptr = osmtpd_mheader_skip_dkimsig_keystagtype(ptr, 0)) == NULL)
1188 		return optional ? start : NULL;
1189 	while (1) {
1190 		start = ptr;
1191 		ptr = osmtpd_mheader_skip_fws(ptr, 1);
1192 		if (ptr[0] != ':')
1193 			return start;
1194 		ptr = osmtpd_mheader_skip_fws(ptr + 1, 1);
1195 		ptr = osmtpd_mheader_skip_dkimsig_keystagtype(ptr, 0);
1196 		if (ptr == NULL)
1197 			return start;
1198 	}
1199 	
1200 }
1201 
1202 char *
1203 osmtpd_mheader_skip_dkimsig_xkeyttagflag(char *ptr, int optional)
1204 {
1205 	return osmtpd_mheader_skip_hyphenatedword(ptr, optional);
1206 }
1207 
1208 char *
1209 osmtpd_mheader_skip_dkimsig_keyttagflag(char *ptr, int optional)
1210 {
1211 	/* y / s covered by x-key-t-tag-flag */
1212 	return osmtpd_mheader_skip_dkimsig_xkeyttagflag(ptr, optional);
1213 }
1214 
1215 char *
1216 osmtpd_mheader_skip_dkimsig_keyttagvalue(char *ptr, int optional)
1217 {
1218 	char *start = ptr;
1219 
1220 	if ((ptr = osmtpd_mheader_skip_dkimsig_keyttagflag(ptr, 0)) == NULL)
1221 		return optional ? start : NULL;
1222 	while (1) {
1223 		start = ptr;
1224 		ptr = osmtpd_mheader_skip_fws(ptr, 1);
1225 		if (ptr[0] != ':')
1226 			return start;
1227 		ptr = osmtpd_mheader_skip_fws(ptr + 1, 1);
1228 		ptr = osmtpd_mheader_skip_dkimsig_keyttagflag(ptr, 0);
1229 		if (ptr == NULL)
1230 			return start;
1231 	}
1232 }
1233 
1234 char *
1235 osmtpd_mheader_skip_dkimsig_selector(char *ptr, int optional)
1236 {
1237 	char *start = ptr;
1238 
1239 	if ((ptr = osmtpd_mheader_skip_subdomain(ptr, 0)) == NULL)
1240 		return optional ? start : NULL;
1241 	while (1) {
1242 		start = ptr;
1243 		if (ptr[0] != '.')
1244 			return start;
1245 		ptr++;
1246 		if ((ptr = osmtpd_mheader_skip_subdomain(ptr, 0)) == NULL)
1247 			return start;
1248 	}
1249 }
1250 
1251 char *
1252 osmtpd_mheader_skip_ar_pvalue(char *ptr, int optional)
1253 {
1254 	char *start = ptr, *tmp;
1255 
1256 	ptr = osmtpd_mheader_skip_cfws(ptr, 1);
1257 	if ((tmp = osmtpd_mheader_skip_value(ptr, 0)) != NULL)
1258 		return tmp;
1259 	ptr = osmtpd_mheader_skip_local_part(ptr, 1);
1260 	if (ptr[0] == '@')
1261 		ptr++;
1262 	if ((ptr = osmtpd_mheader_skip_domain(ptr, 0)) == NULL)
1263 		return optional ? start : NULL;
1264 	return ptr;
1265 }
1266 
1267 char *
1268 osmtpd_mheader_domain_uncomment(char *ptr)
1269 {
1270 	char *domain0, *domain, *tmp, *end;
1271 
1272 	if (osmtpd_mheader_skip_dot_atom(ptr, 0) != NULL) {
1273 		ptr = osmtpd_mheader_skip_cfws(ptr, 1);
1274 		return strndup(ptr,
1275 		    osmtpd_mheader_skip_dot_atom_text(ptr, 0) - ptr);
1276 	}
1277 	if ((tmp = osmtpd_mheader_skip_domain_literal(ptr, 0)) != NULL) {
1278 		ptr = osmtpd_mheader_skip_cfws(ptr, 1) + 1;
1279 		domain0 = domain = strndup(ptr, (size_t)(tmp - ptr));
1280 		if (domain0 == NULL)
1281 			return NULL;
1282 		end = domain0 + (tmp - ptr) + 1;
1283 		domain++;
1284 		while (1) {
1285 			tmp = osmtpd_mheader_skip_fws(domain, 1);
1286 			if (tmp != domain) {
1287 				memmove(domain, tmp, end - tmp);
1288 				end -= (tmp - domain);
1289 			}
1290 			tmp = osmtpd_mheader_skip_dtext(domain, 0);
1291 			if (tmp == NULL)
1292 				break;
1293 			domain = tmp;
1294 		}
1295 		/* domain[0] ==  ']' */
1296 		domain[0] = '\0';
1297 		return domain0;
1298 	}
1299 	return strndup(ptr, osmtpd_mheader_skip_obs_domain(ptr, 1) - ptr);
1300 }
1301 
1302 /* Return the domain component of the first mailbox */
1303 char *
1304 osmtpd_mheader_from_domain(char *ptr)
1305 {
1306 	char *tmp;
1307 
1308 	/* from */
1309 	if (strncasecmp(ptr, "from:", 5) == 0) {
1310 		ptr += 5;
1311 	/* obs-from */
1312 	} else if (strncasecmp(ptr, "from", 4) == 0) {
1313 		ptr += 4;
1314 		do {
1315 			tmp = ptr;
1316 		} while ((ptr = osmtpd_mheader_skip_wsp(ptr, 0)) != NULL);
1317 		ptr = tmp;
1318 		if (ptr++[0] != ':')
1319 			return NULL;
1320 	} else {
1321 		errno = EINVAL;
1322 		return NULL;
1323 	}
1324 
1325 	/* Both from and obs-from use Mailbox-list CRLF */
1326 	/* obs-mbox-list has just a prefix compared to mailbox-list */
1327 	while (1) {
1328 		tmp = ptr;
1329 		ptr = osmtpd_mheader_skip_cfws(ptr, 1);
1330 		if (ptr++[0] != ',') {
1331 			ptr = tmp;
1332 			break;
1333 		}
1334 	}
1335 	/* We're only interested in the first mailbox */
1336 	if (osmtpd_mheader_skip_name_addr(ptr, 0) != NULL) {
1337 		ptr = osmtpd_mheader_skip_display_name(ptr, 1);
1338 		ptr = osmtpd_mheader_skip_cfws(ptr, 1);
1339 		/* < */
1340 		ptr++;
1341 		/* addr-spec */
1342 		ptr = osmtpd_mheader_skip_local_part(ptr, 0);
1343 		/* @ */
1344 		ptr++;
1345 		return osmtpd_mheader_domain_uncomment(ptr);
1346 	}
1347 	if (osmtpd_mheader_skip_addr_spec(ptr, 0) != NULL) {
1348 		ptr = osmtpd_mheader_skip_local_part(ptr, 0);
1349 		/* @ */
1350 		ptr++;
1351 		return osmtpd_mheader_domain_uncomment(ptr);
1352 	}
1353 	errno = EINVAL;
1354 	return NULL;
1355 }
1356 
1357 char *
1358 osmtpd_mheader_quoted_string_normalize(char *ptr)
1359 {
1360 	char *end;
1361 	size_t d = 0, s;
1362 
1363 	end = osmtpd_mheader_skip_cfws(ptr, 1);
1364 	s = end - ptr;
1365 	if (osmtpd_mheader_skip_dquote(end, 0) == NULL)
1366 		return NULL;
1367 	ptr[d++] = ptr[s++];
1368 	while (ptr[s] != '\0') {
1369 		if (osmtpd_mheader_skip_quoted_pair(ptr + s, 0) != NULL) {
1370 			end = osmtpd_mheader_skip_qtext(ptr + s + 1, 0);
1371 			if (end != NULL)
1372 				s++;
1373 			else
1374 				ptr[d++] = ptr[s++];
1375 			ptr[d++] = ptr[s++];
1376 			continue;
1377 		} else if (osmtpd_mheader_skip_qtext(ptr + s, 0) != NULL) {
1378 			ptr[d++] = ptr[s++];
1379 		} else if ((end = osmtpd_mheader_skip_fws(
1380 		    ptr + s, 0)) != NULL) {
1381 			ptr[d++] = ' ';
1382 			s = end - ptr;
1383 		} else
1384 			return NULL;
1385 	}
1386 	if (osmtpd_mheader_skip_dquote(end, 0) == NULL)
1387 		return NULL;
1388 	ptr[d++] = ptr[s++];
1389 	end = osmtpd_mheader_skip_cfws(ptr + s, 1);
1390 	if (end[0] != '\0')
1391 		return NULL;
1392 	ptr[d] = '\0';
1393 	return ptr;
1394 }