MDL-49032 lib/bennu: use HTAB only when folding lines
[moodle.git] / lib / bennu / iCalendar_rfc2445.php
CommitLineData
32e11709 1<?php
f3b6ac15 2
3/**
4 * BENNU - PHP iCalendar library
5 * (c) 2005-2006 Ioannis Papaioannou (pj@moodle.org). All rights reserved.
6 *
7 * Released under the LGPL.
8 *
9 * See http://bennu.sourceforge.net/ for more information and downloads.
10 *
11 * @author Ioannis Papaioannou
f3b6ac15 12 * @license http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
13 */
14
15/*
16
17 All names of properties, property parameters, enumerated property
18 values and property parameter values are case-insensitive. However,
19 all other property values are case-sensitive, unless otherwise
20 stated.
21
22*/
23
24define('RFC2445_CRLF', "\r\n");
25define('RFC2445_WSP', "\t ");
26define('RFC2445_WEEKDAYS', 'MO,TU,WE,TH,FR,SA,SU');
27define('RFC2445_FOLDED_LINE_LENGTH', 75);
28
6e9ce8e7
JH
29define('RFC2445_PARAMETER_SEPARATOR', ';');
30define('RFC2445_VALUE_SEPARATOR', ':');
31
f3b6ac15 32define('RFC2445_REQUIRED', 0x01);
33define('RFC2445_OPTIONAL', 0x02);
34define('RFC2445_ONCE', 0x04);
35
36define('RFC2445_PROP_FLAGS', 0);
37define('RFC2445_PROP_TYPE', 1);
38define('RFC2445_PROP_DEFAULT', 2);
39
40define('RFC2445_XNAME', 'X-');
41
42define('RFC2445_TYPE_BINARY', 0);
43define('RFC2445_TYPE_BOOLEAN', 1);
44define('RFC2445_TYPE_CAL_ADDRESS', 2);
45define('RFC2445_TYPE_DATE', 3);
46define('RFC2445_TYPE_DATE_TIME', 4);
47define('RFC2445_TYPE_DURATION', 5);
48define('RFC2445_TYPE_FLOAT', 6);
49define('RFC2445_TYPE_INTEGER', 7);
50define('RFC2445_TYPE_PERIOD', 8);
51define('RFC2445_TYPE_RECUR', 9);
52define('RFC2445_TYPE_TEXT', 10);
53define('RFC2445_TYPE_TIME', 11);
54define('RFC2445_TYPE_URI', 12); // CAL_ADDRESS === URI
55define('RFC2445_TYPE_UTC_OFFSET', 13);
56
57
58function rfc2445_fold($string) {
2f1e464a 59 if(core_text::strlen($string, 'utf-8') <= RFC2445_FOLDED_LINE_LENGTH) {
f3b6ac15 60 return $string;
61 }
62
63 $retval = '';
fa8431d7 64
65 $i=0;
66 $len_count=0;
67
68 //multi-byte string, get the correct length
2f1e464a 69 $section_len = core_text::strlen($string, 'utf-8');
fa8431d7 70
71 while($len_count<$section_len) {
72
73 //get the current portion of the line
2f1e464a 74 $section = core_text::substr($string, ($i * RFC2445_FOLDED_LINE_LENGTH), (RFC2445_FOLDED_LINE_LENGTH), 'utf-8');
fa8431d7 75
76 //increment the length we've processed by the length of the new portion
2f1e464a 77 $len_count += core_text::strlen($section, 'utf-8');
fa8431d7 78
79 /* Add the portion to the return value, terminating with CRLF.HTAB
80 As per RFC 2445, CRLF.HTAB will be replaced by the processor of the
81 data */
f66cc723 82 $retval .= $section . RFC2445_CRLF . substr(RFC2445_WSP, 0, 1);
fa8431d7 83
84 $i++;
f3b6ac15 85 }
86
f3b6ac15 87 return $retval;
88
89}
90
91function rfc2445_unfold($string) {
92 for($i = 0; $i < strlen(RFC2445_WSP); ++$i) {
93 $string = str_replace(RFC2445_CRLF.substr(RFC2445_WSP, $i, 1), '', $string);
94 }
95
96 return $string;
97}
98
99function rfc2445_is_xname($name) {
100
101 // If it's less than 3 chars, it cannot be legal
102 if(strlen($name) < 3) {
103 return false;
104 }
105
106 // If it contains an illegal char anywhere, reject it
107 if(strspn($name, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-') != strlen($name)) {
108 return false;
109 }
110
111 // To be legal, it must still start with "X-"
112 return substr($name, 0, 2) === 'X-';
113}
114
115function rfc2445_is_valid_value($value, $type) {
116
117 // This branch should only be taken with xname values
118 if($type === NULL) {
119 return true;
120 }
121
122 switch($type) {
123 case RFC2445_TYPE_CAL_ADDRESS:
124 case RFC2445_TYPE_URI:
125 if(!is_string($value)) {
126 return false;
127 }
128
129 $valid_schemes = array('ftp', 'http', 'ldap', 'gopher', 'mailto', 'news', 'nntp', 'telnet', 'wais', 'file', 'prospero');
130
131 $pos = strpos($value, ':');
132 if(!$pos) {
133 return false;
134 }
135
136 $scheme = strtolower(substr($value, 0, $pos));
137 $remain = substr($value, $pos + 1);
138
139 if(!in_array($scheme, $valid_schemes)) {
140 return false;
141 }
142
143 if($scheme === 'mailto') {
69593309 144 $regexp = '#^[a-zA-Z0-9]+[_a-zA-Z0-9\-]*(\.[_a-z0-9\-]+)*@(([0-9a-zA-Z\-]+\.)+[a-zA-Z][0-9a-zA-Z\-]+|([0-9]{1,3}\.){3}[0-9]{1,3})$#';
f3b6ac15 145 }
146 else {
69593309 147 $regexp = '#^//(.+(:.*)?@)?(([0-9a-zA-Z\-]+\.)+[a-zA-Z][0-9a-zA-Z\-]+|([0-9]{1,3}\.){3}[0-9]{1,3})(:[0-9]{1,5})?(/.*)?$#';
f3b6ac15 148 }
149
69593309 150 return preg_match($regexp, $remain);
f3b6ac15 151 break;
152
153 case RFC2445_TYPE_BINARY:
154 if(!is_string($value)) {
155 return false;
156 }
157
158 $len = strlen($value);
159
160 if($len % 4 != 0) {
161 return false;
162 }
163
164 for($i = 0; $i < $len; ++$i) {
165 $ch = $value{$i};
166 if(!($ch >= 'a' && $ch <= 'z' || $ch >= 'A' && $ch <= 'Z' || $ch >= '0' && $ch <= '9' || $ch == '-' || $ch == '+')) {
167 if($ch == '=' && $len - $i <= 2) {
168 continue;
169 }
170 return false;
171 }
172 }
173 return true;
174 break;
175
176 case RFC2445_TYPE_BOOLEAN:
177 if(is_bool($value)) {
178 return true;
179 }
180 if(is_string($value)) {
181 $value = strtoupper($value);
182 return ($value == 'TRUE' || $value == 'FALSE');
183 }
184 return false;
185 break;
186
187 case RFC2445_TYPE_DATE:
188 if(is_int($value)) {
189 if($value < 0) {
190 return false;
191 }
192 $value = "$value";
193 }
194 else if(!is_string($value)) {
195 return false;
196 }
197
198 if(strlen($value) != 8) {
199 return false;
200 }
201
202 $y = intval(substr($value, 0, 4));
203 $m = intval(substr($value, 4, 2));
204 $d = intval(substr($value, 6, 2));
205
206 return checkdate($m, $d, $y);
207 break;
208
209 case RFC2445_TYPE_DATE_TIME:
210 if(!is_string($value) || strlen($value) < 15) {
211 return false;
212 }
213
214 return($value{8} == 'T' &&
215 rfc2445_is_valid_value(substr($value, 0, 8), RFC2445_TYPE_DATE) &&
216 rfc2445_is_valid_value(substr($value, 9), RFC2445_TYPE_TIME));
217 break;
218
219 case RFC2445_TYPE_DURATION:
220 if(!is_string($value)) {
221 return false;
222 }
223
224 $len = strlen($value);
225
226 if($len < 3) {
227 // Minimum conformant length: "P1W"
228 return false;
229 }
230
231 if($value{0} == '+' || $value{0} == '-') {
232 $value = substr($value, 1);
233 --$len; // Don't forget to update this!
234 }
235
236 if($value{0} != 'P') {
237 return false;
238 }
239
240 // OK, now break it up
241 $num = '';
242 $allowed = 'WDT';
243
244 for($i = 1; $i < $len; ++$i) {
245 $ch = $value{$i};
246 if($ch >= '0' && $ch <= '9') {
247 $num .= $ch;
248 continue;
249 }
250 if(strpos($allowed, $ch) === false) {
251 // Non-numeric character which shouldn't be here
252 return false;
253 }
254 if($num === '' && $ch != 'T') {
255 // Allowed non-numeric character, but no digits came before it
256 return false;
257 }
258
259 // OK, $ch now holds a character which tells us what $num is
260 switch($ch) {
261 case 'W':
262 // If duration in weeks is specified, this must end the string
263 return ($i == $len - 1);
264 break;
265
266 case 'D':
267 // Days specified, now if anything comes after it must be a 'T'
268 $allowed = 'T';
269 break;
270
271 case 'T':
272 // Starting to specify time, H M S are now valid delimiters
273 $allowed = 'HMS';
274 break;
275
276 case 'H':
277 $allowed = 'M';
278 break;
279
280 case 'M':
281 $allowed = 'S';
282 break;
283
284 case 'S':
285 return ($i == $len - 1);
286 break;
287 }
288
289 // If we 're going to continue, reset $num
290 $num = '';
291
292 }
293
294 // $num is kept for this reason: if we 're here, we ran out of chars
295 // therefore $num must be empty for the period to be legal
296 return ($num === '' && $ch != 'T');
297
298 break;
299
300 case RFC2445_TYPE_FLOAT:
301 if(is_float($value)) {
302 return true;
303 }
304 if(!is_string($value) || $value === '') {
305 return false;
306 }
307
308 $dot = false;
309 $int = false;
310 $len = strlen($value);
311 for($i = 0; $i < $len; ++$i) {
312 switch($value{$i}) {
313 case '-': case '+':
314 // A sign can only be seen at position 0 and cannot be the only char
315 if($i != 0 || $len == 1) {
316 return false;
317 }
318 break;
319 case '.':
320 // A second dot is an error
321 // Make sure we had at least one int before the dot
322 if($dot || !$int) {
323 return false;
324 }
325 $dot = true;
326 // Make also sure that the float doesn't end with a dot
327 if($i == $len - 1) {
328 return false;
329 }
330 break;
331 case '0': case '1': case '2': case '3': case '4':
332 case '5': case '6': case '7': case '8': case '9':
333 $int = true;
334 break;
335 default:
336 // Any other char is a no-no
337 return false;
338 break;
339 }
340 }
341 return true;
342 break;
343
344 case RFC2445_TYPE_INTEGER:
345 if(is_int($value)) {
346 return true;
347 }
348 if(!is_string($value) || $value === '') {
349 return false;
350 }
351
352 if($value{0} == '+' || $value{0} == '-') {
353 if(strlen($value) == 1) {
354 return false;
355 }
356 $value = substr($value, 1);
357 }
358
359 if(strspn($value, '0123456789') != strlen($value)) {
360 return false;
361 }
362
363 return ($value >= -2147483648 && $value <= 2147483647);
364 break;
365
366 case RFC2445_TYPE_PERIOD:
367 if(!is_string($value) || empty($value)) {
368 return false;
369 }
370
371 $parts = explode('/', $value);
372 if(count($parts) != 2) {
373 return false;
374 }
375
376 if(!rfc2445_is_valid_value($parts[0], RFC2445_TYPE_DATE_TIME)) {
377 return false;
378 }
379
380 // Two legal cases for the second part:
381 if(rfc2445_is_valid_value($parts[1], RFC2445_TYPE_DATE_TIME)) {
382 // It has to be after the start time, so
383 return ($parts[1] > $parts[0]);
384 }
385 else if(rfc2445_is_valid_value($parts[1], RFC2445_TYPE_DURATION)) {
386 // The period MUST NOT be negative
387 return ($parts[1]{0} != '-');
388 }
389
390 // It seems to be illegal
391 return false;
392 break;
393
394 case RFC2445_TYPE_RECUR:
395 if(!is_string($value)) {
396 return false;
397 }
398
399 $parts = explode(';', strtoupper($value));
400
29a05a56
AA
401 // We need at least one part for a valid rule, for example: "FREQ=DAILY".
402 if(empty($parts)) {
f3b6ac15 403 return false;
404 }
405
406 // Let's get that into a more easily comprehensible format
407 $vars = array();
408 foreach($parts as $part) {
409
410 $pieces = explode('=', $part);
411 // There must be exactly 2 pieces, e.g. FREQ=WEEKLY
412 if(count($pieces) != 2) {
413 return false;
414 }
415
416 // It's illegal for a variable to appear twice
417 if(isset($vars[$pieces[0]])) {
418 return false;
419 }
420
421 // Sounds good
422 $vars[$pieces[0]] = $pieces[1];
423 }
424
425 // OK... now to test everything else
426
427 // FREQ must be the first thing appearing
428 reset($vars);
429 if(key($vars) != 'FREQ') {
430 return false;
431 }
432
433 // It's illegal to have both UNTIL and COUNT appear
434 if(isset($vars['UNTIL']) && isset($vars['COUNT'])) {
435 return false;
436 }
437
438 // Special case: BYWEEKNO is only valid for FREQ=YEARLY
439 if(isset($vars['BYWEEKNO']) && $vars['FREQ'] != 'YEARLY') {
440 return false;
441 }
442
443 // Special case: BYSETPOS is only valid if another BY option is specified
444 if(isset($vars['BYSETPOS'])) {
445 $options = array('BYSECOND', 'BYMINUTE', 'BYHOUR', 'BYDAY', 'BYMONTHDAY', 'BYYEARDAY', 'BYWEEKNO', 'BYMONTH');
446 $defined = array_keys($vars);
447 $common = array_intersect($options, $defined);
448 if(empty($common)) {
449 return false;
450 }
451 }
452
453 // OK, now simply check if each element has a valid value,
454 // unsetting them on the way. If at the end the array still
455 // has some elements, they are illegal.
456
457 if($vars['FREQ'] != 'SECONDLY' && $vars['FREQ'] != 'MINUTELY' && $vars['FREQ'] != 'HOURLY' &&
458 $vars['FREQ'] != 'DAILY' && $vars['FREQ'] != 'WEEKLY' &&
459 $vars['FREQ'] != 'MONTHLY' && $vars['FREQ'] != 'YEARLY') {
460 return false;
461 }
462 unset($vars['FREQ']);
463
464 // Set this, we may need it later
465 $weekdays = explode(',', RFC2445_WEEKDAYS);
466
467 if(isset($vars['UNTIL'])) {
468 if(rfc2445_is_valid_value($vars['UNTIL'], RFC2445_TYPE_DATE_TIME)) {
469 // The time MUST be in UTC format
470 if(!(substr($vars['UNTIL'], -1) == 'Z')) {
471 return false;
472 }
473 }
474 else if(!rfc2445_is_valid_value($vars['UNTIL'], RFC2445_TYPE_DATE_TIME)) {
475 return false;
476 }
477 }
478 unset($vars['UNTIL']);
479
480
481 if(isset($vars['COUNT'])) {
482 if(empty($vars['COUNT'])) {
483 // This also catches the string '0', which makes no sense
484 return false;
485 }
486 if(strspn($vars['COUNT'], '0123456789') != strlen($vars['COUNT'])) {
487 return false;
488 }
489 }
490 unset($vars['COUNT']);
491
492
493 if(isset($vars['INTERVAL'])) {
494 if(empty($vars['INTERVAL'])) {
495 // This also catches the string '0', which makes no sense
496 return false;
497 }
498 if(strspn($vars['INTERVAL'], '0123456789') != strlen($vars['INTERVAL'])) {
499 return false;
500 }
501 }
502 unset($vars['INTERVAL']);
503
504
505 if(isset($vars['BYSECOND'])) {
506 if($vars['BYSECOND'] == '') {
507 return false;
508 }
509 // Comma also allowed
510 if(strspn($vars['BYSECOND'], '0123456789,') != strlen($vars['BYSECOND'])) {
511 return false;
512 }
513 $secs = explode(',', $vars['BYSECOND']);
514 foreach($secs as $sec) {
515 if($sec == '' || $sec < 0 || $sec > 59) {
516 return false;
517 }
518 }
519 }
520 unset($vars['BYSECOND']);
521
522
523 if(isset($vars['BYMINUTE'])) {
524 if($vars['BYMINUTE'] == '') {
525 return false;
526 }
527 // Comma also allowed
528 if(strspn($vars['BYMINUTE'], '0123456789,') != strlen($vars['BYMINUTE'])) {
529 return false;
530 }
531 $mins = explode(',', $vars['BYMINUTE']);
532 foreach($mins as $min) {
533 if($min == '' || $min < 0 || $min > 59) {
534 return false;
535 }
536 }
537 }
538 unset($vars['BYMINUTE']);
539
540
541 if(isset($vars['BYHOUR'])) {
542 if($vars['BYHOUR'] == '') {
543 return false;
544 }
545 // Comma also allowed
546 if(strspn($vars['BYHOUR'], '0123456789,') != strlen($vars['BYHOUR'])) {
547 return false;
548 }
549 $hours = explode(',', $vars['BYHOUR']);
550 foreach($hours as $hour) {
551 if($hour == '' || $hour < 0 || $hour > 23) {
552 return false;
553 }
554 }
555 }
556 unset($vars['BYHOUR']);
557
558
559 if(isset($vars['BYDAY'])) {
560 if(empty($vars['BYDAY'])) {
561 return false;
562 }
563
564 // First off, split up all values we may have
565 $days = explode(',', $vars['BYDAY']);
566
567 foreach($days as $day) {
568 $daypart = substr($day, -2);
569 if(!in_array($daypart, $weekdays)) {
570 return false;
571 }
572
573 if(strlen($day) > 2) {
574 $intpart = substr($day, 0, strlen($day) - 2);
575 if(!rfc2445_is_valid_value($intpart, RFC2445_TYPE_INTEGER)) {
576 return false;
577 }
578 if(intval($intpart) == 0) {
579 return false;
580 }
581 }
582 }
583 }
584 unset($vars['BYDAY']);
585
586
587 if(isset($vars['BYMONTHDAY'])) {
588 if(empty($vars['BYMONTHDAY'])) {
589 return false;
590 }
591 $mdays = explode(',', $vars['BYMONTHDAY']);
592 foreach($mdays as $mday) {
593 if(!rfc2445_is_valid_value($mday, RFC2445_TYPE_INTEGER)) {
594 return false;
595 }
596 $mday = abs(intval($mday));
597 if($mday == 0 || $mday > 31) {
598 return false;
599 }
600 }
601 }
602 unset($vars['BYMONTHDAY']);
603
604
605 if(isset($vars['BYYEARDAY'])) {
606 if(empty($vars['BYYEARDAY'])) {
607 return false;
608 }
609 $ydays = explode(',', $vars['BYYEARDAY']);
610 foreach($ydays as $yday) {
611 if(!rfc2445_is_valid_value($yday, RFC2445_TYPE_INTEGER)) {
612 return false;
613 }
614 $yday = abs(intval($yday));
615 if($yday == 0 || $yday > 366) {
616 return false;
617 }
618 }
619 }
620 unset($vars['BYYEARDAY']);
621
622
623 if(isset($vars['BYWEEKNO'])) {
624 if(empty($vars['BYWEEKNO'])) {
625 return false;
626 }
627 $weeknos = explode(',', $vars['BYWEEKNO']);
628 foreach($weeknos as $weekno) {
629 if(!rfc2445_is_valid_value($weekno, RFC2445_TYPE_INTEGER)) {
630 return false;
631 }
632 $weekno = abs(intval($weekno));
633 if($weekno == 0 || $weekno > 53) {
634 return false;
635 }
636 }
637 }
638 unset($vars['BYWEEKNO']);
639
640
641 if(isset($vars['BYMONTH'])) {
642 if(empty($vars['BYMONTH'])) {
643 return false;
644 }
645 // Comma also allowed
646 if(strspn($vars['BYMONTH'], '0123456789,') != strlen($vars['BYMONTH'])) {
647 return false;
648 }
649 $months = explode(',', $vars['BYMONTH']);
650 foreach($months as $month) {
651 if($month == '' || $month < 1 || $month > 12) {
652 return false;
653 }
654 }
655 }
656 unset($vars['BYMONTH']);
657
658
659 if(isset($vars['BYSETPOS'])) {
660 if(empty($vars['BYSETPOS'])) {
661 return false;
662 }
663 $sets = explode(',', $vars['BYSETPOS']);
664 foreach($sets as $set) {
665 if(!rfc2445_is_valid_value($set, RFC2445_TYPE_INTEGER)) {
666 return false;
667 }
668 $set = abs(intval($set));
669 if($set == 0 || $set > 366) {
670 return false;
671 }
672 }
673 }
674 unset($vars['BYSETPOS']);
675
676
677 if(isset($vars['WKST'])) {
678 if(!in_array($vars['WKST'], $weekdays)) {
679 return false;
680 }
681 }
682 unset($vars['WKST']);
683
684
685 // Any remaining vars must be x-names
686 if(empty($vars)) {
687 return true;
688 }
689
690 foreach($vars as $name => $var) {
691 if(!rfc2445_is_xname($name)) {
692 return false;
693 }
694 }
695
696 // At last, all is OK!
697 return true;
698
699 break;
700
701 case RFC2445_TYPE_TEXT:
702 return true;
703 break;
704
705 case RFC2445_TYPE_TIME:
706 if(is_int($value)) {
707 if($value < 0) {
708 return false;
709 }
710 $value = "$value";
711 }
712 else if(!is_string($value)) {
713 return false;
714 }
715
716 if(strlen($value) == 7) {
717 if(strtoupper(substr($value, -1)) != 'Z') {
718 return false;
719 }
720 $value = substr($value, 0, 6);
721 }
722 if(strlen($value) != 6) {
723 return false;
724 }
725
726 $h = intval(substr($value, 0, 2));
727 $m = intval(substr($value, 2, 2));
728 $s = intval(substr($value, 4, 2));
729
730 return ($h <= 23 && $m <= 59 && $s <= 60);
731 break;
732
733 case RFC2445_TYPE_UTC_OFFSET:
734 if(is_int($value)) {
735 if($value >= 0) {
736 $value = "+$value";
737 }
738 else {
739 $value = "$value";
740 }
741 }
742 else if(!is_string($value)) {
743 return false;
744 }
745
6e9ce8e7 746 $s = 0;
f3b6ac15 747 if(strlen($value) == 7) {
748 $s = intval(substr($value, 5, 2));
749 $value = substr($value, 0, 5);
750 }
751 if(strlen($value) != 5 || $value == "-0000") {
752 return false;
753 }
754
755 if($value{0} != '+' && $value{0} != '-') {
756 return false;
757 }
758
759 $h = intval(substr($value, 1, 2));
760 $m = intval(substr($value, 3, 2));
761
762 return ($h <= 23 && $m <= 59 && $s <= 59);
763 break;
764 }
765
766 // TODO: remove this assertion
767 trigger_error('bad code path', E_USER_WARNING);
768 var_dump($type);
769 return false;
770}
771
772function rfc2445_do_value_formatting($value, $type) {
773 // Note: this does not only do formatting; it also does conversion to string!
774 switch($type) {
775 case RFC2445_TYPE_CAL_ADDRESS:
776 case RFC2445_TYPE_URI:
777 // Enclose in double quotes
778 $value = '"'.$value.'"';
779 break;
780 case RFC2445_TYPE_TEXT:
781 // Escape entities
f3b205b8 782 $value = strtr($value, array("\r\n" => '\\n', "\n" => '\\n', '\\' => '\\\\', ',' => '\\,', ';' => '\\;'));
f3b6ac15 783 break;
784 }
785 return $value;
786}
787
788function rfc2445_undo_value_formatting($value, $type) {
789 switch($type) {
790 case RFC2445_TYPE_CAL_ADDRESS:
791 case RFC2445_TYPE_URI:
792 // Trim beginning and end double quote
793 $value = substr($value, 1, strlen($value) - 2);
794 break;
795 case RFC2445_TYPE_TEXT:
796 // Unescape entities
797 $value = strtr($value, array('\\n' => "\n", '\\N' => "\n", '\\\\' => '\\', '\\,' => ',', '\\;' => ';'));
798 break;
799 }
800 return $value;
801}