1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24/*
25 A brief summary of the date string formats this parser groks:
26
27 RFC 2616 3.3.1
28
29 Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123
30 Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
31 Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format
32
33 we support dates without week day name:
34
35 06 Nov 1994 08:49:37 GMT
36 06-Nov-94 08:49:37 GMT
37 Nov 6 08:49:37 1994
38
39 without the time zone:
40
41 06 Nov 1994 08:49:37
42 06-Nov-94 08:49:37
43
44 weird order:
45
46 1994 Nov 6 08:49:37 (GNU date fails)
47 GMT 08:49:37 06-Nov-94 Sunday
48 94 6 Nov 08:49:37 (GNU date fails)
49
50 time left out:
51
52 1994 Nov 6
53 06-Nov-94
54 Sun Nov 6 94
55
56 unusual separators:
57
58 1994.Nov.6
59 Sun/Nov/6/94/GMT
60
61 commonly used time zone names:
62
63 Sun, 06 Nov 1994 08:49:37 CET
64 06 Nov 1994 08:49:37 EST
65
66 time zones specified using RFC822 style:
67
68 Sun, 12 Sep 2004 15:05:58 -0700
69 Sat, 11 Sep 2004 21:32:11 +0200
70
71 compact numerical date strings:
72
73 20040912 15:05:58 -0700
74 20040911 +0200
75
76*/
77
78#include "curl_setup.h"
79
80#include <limits.h>
81
82#include <curl/curl.h>
83#include "strcase.h"
84#include "warnless.h"
85#include "parsedate.h"
86
87/*
88 * parsedate()
89 *
90 * Returns:
91 *
92 * PARSEDATE_OK - a fine conversion
93 * PARSEDATE_FAIL - failed to convert
94 * PARSEDATE_LATER - time overflow at the far end of time_t
95 * PARSEDATE_SOONER - time underflow at the low end of time_t
96 */
97
98static int parsedate(const char *date, time_t *output);
99
100#define PARSEDATE_OK 0
101#define PARSEDATE_FAIL -1
102#define PARSEDATE_LATER 1
103#define PARSEDATE_SOONER 2
104
105#if !defined(CURL_DISABLE_PARSEDATE) || !defined(CURL_DISABLE_FTP) || \
106 !defined(CURL_DISABLE_FILE)
107/* These names are also used by FTP and FILE code */
108const char * const Curl_wkday[] =
109{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
110const char * const Curl_month[]=
111{ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
112 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
113#endif
114
115#ifndef CURL_DISABLE_PARSEDATE
116static const char * const weekday[] =
117{ "Monday", "Tuesday", "Wednesday", "Thursday",
118 "Friday", "Saturday", "Sunday" };
119
120struct tzinfo {
121 char name[5];
122 int offset; /* +/- in minutes */
123};
124
125/* Here's a bunch of frequently used time zone names. These were supported
126 by the old getdate parser. */
127#define tDAYZONE -60 /* offset for daylight savings time */
128static const struct tzinfo tz[]= {
129 {"GMT", 0}, /* Greenwich Mean */
130 {"UT", 0}, /* Universal Time */
131 {"UTC", 0}, /* Universal (Coordinated) */
132 {"WET", 0}, /* Western European */
133 {"BST", 0 tDAYZONE}, /* British Summer */
134 {.name: "WAT", .offset: 60}, /* West Africa */
135 {"AST", 240}, /* Atlantic Standard */
136 {"ADT", 240 tDAYZONE}, /* Atlantic Daylight */
137 {.name: "EST", .offset: 300}, /* Eastern Standard */
138 {"EDT", 300 tDAYZONE}, /* Eastern Daylight */
139 {.name: "CST", .offset: 360}, /* Central Standard */
140 {"CDT", 360 tDAYZONE}, /* Central Daylight */
141 {.name: "MST", .offset: 420}, /* Mountain Standard */
142 {"MDT", 420 tDAYZONE}, /* Mountain Daylight */
143 {.name: "PST", .offset: 480}, /* Pacific Standard */
144 {"PDT", 480 tDAYZONE}, /* Pacific Daylight */
145 {.name: "YST", .offset: 540}, /* Yukon Standard */
146 {"YDT", 540 tDAYZONE}, /* Yukon Daylight */
147 {.name: "HST", .offset: 600}, /* Hawaii Standard */
148 {"HDT", 600 tDAYZONE}, /* Hawaii Daylight */
149 {.name: "CAT", .offset: 600}, /* Central Alaska */
150 {"AHST", 600}, /* Alaska-Hawaii Standard */
151 {"NT", 660}, /* Nome */
152 {"IDLW", 720}, /* International Date Line West */
153 {"CET", -60}, /* Central European */
154 {.name: "MET", .offset: -60}, /* Middle European */
155 {.name: "MEWT", .offset: -60}, /* Middle European Winter */
156 {.name: "MEST", .offset: -60 tDAYZONE}, /* Middle European Summer */
157 {.name: "CEST", .offset: -60 tDAYZONE}, /* Central European Summer */
158 {.name: "MESZ", .offset: -60 tDAYZONE}, /* Middle European Summer */
159 {.name: "FWT", .offset: -60}, /* French Winter */
160 {.name: "FST", .offset: -60 tDAYZONE}, /* French Summer */
161 {.name: "EET", .offset: -120}, /* Eastern Europe, USSR Zone 1 */
162 {.name: "WAST", .offset: -420}, /* West Australian Standard */
163 {.name: "WADT", .offset: -420 tDAYZONE}, /* West Australian Daylight */
164 {.name: "CCT", .offset: -480}, /* China Coast, USSR Zone 7 */
165 {.name: "JST", .offset: -540}, /* Japan Standard, USSR Zone 8 */
166 {.name: "EAST", .offset: -600}, /* Eastern Australian Standard */
167 {.name: "EADT", .offset: -600 tDAYZONE}, /* Eastern Australian Daylight */
168 {.name: "GST", .offset: -600}, /* Guam Standard, USSR Zone 9 */
169 {.name: "NZT", .offset: -720}, /* New Zealand */
170 {.name: "NZST", .offset: -720}, /* New Zealand Standard */
171 {.name: "NZDT", .offset: -720 tDAYZONE}, /* New Zealand Daylight */
172 {.name: "IDLE", .offset: -720}, /* International Date Line East */
173 /* Next up: Military timezone names. RFC822 allowed these, but (as noted in
174 RFC 1123) had their signs wrong. Here we use the correct signs to match
175 actual military usage.
176 */
177 {.name: "A", .offset: 1 * 60}, /* Alpha */
178 {.name: "B", .offset: 2 * 60}, /* Bravo */
179 {.name: "C", .offset: 3 * 60}, /* Charlie */
180 {.name: "D", .offset: 4 * 60}, /* Delta */
181 {.name: "E", .offset: 5 * 60}, /* Echo */
182 {.name: "F", .offset: 6 * 60}, /* Foxtrot */
183 {.name: "G", .offset: 7 * 60}, /* Golf */
184 {.name: "H", .offset: 8 * 60}, /* Hotel */
185 {.name: "I", .offset: 9 * 60}, /* India */
186 /* "J", Juliet is not used as a timezone, to indicate the observer's local
187 time */
188 {.name: "K", .offset: 10 * 60}, /* Kilo */
189 {.name: "L", .offset: 11 * 60}, /* Lima */
190 {.name: "M", .offset: 12 * 60}, /* Mike */
191 {.name: "N", .offset: -1 * 60}, /* November */
192 {.name: "O", .offset: -2 * 60}, /* Oscar */
193 {.name: "P", .offset: -3 * 60}, /* Papa */
194 {.name: "Q", .offset: -4 * 60}, /* Quebec */
195 {.name: "R", .offset: -5 * 60}, /* Romeo */
196 {.name: "S", .offset: -6 * 60}, /* Sierra */
197 {.name: "T", .offset: -7 * 60}, /* Tango */
198 {.name: "U", .offset: -8 * 60}, /* Uniform */
199 {.name: "V", .offset: -9 * 60}, /* Victor */
200 {.name: "W", .offset: -10 * 60}, /* Whiskey */
201 {.name: "X", .offset: -11 * 60}, /* X-ray */
202 {.name: "Y", .offset: -12 * 60}, /* Yankee */
203 {.name: "Z", .offset: 0}, /* Zulu, zero meridian, a.k.a. UTC */
204};
205
206/* returns:
207 -1 no day
208 0 monday - 6 sunday
209*/
210
211static int checkday(const char *check, size_t len)
212{
213 int i;
214 const char * const *what;
215 if(len > 3)
216 what = &weekday[0];
217 else if(len == 3)
218 what = &Curl_wkday[0];
219 else
220 return -1; /* too short */
221 for(i = 0; i<7; i++) {
222 size_t ilen = strlen(s: what[0]);
223 if((ilen == len) &&
224 strncasecompare(check, what[0], len))
225 return i;
226 what++;
227 }
228 return -1;
229}
230
231static int checkmonth(const char *check, size_t len)
232{
233 int i;
234 const char * const *what = &Curl_month[0];
235 if(len != 3)
236 return -1; /* not a month */
237
238 for(i = 0; i<12; i++) {
239 if(strncasecompare(check, what[0], 3))
240 return i;
241 what++;
242 }
243 return -1; /* return the offset or -1, no real offset is -1 */
244}
245
246/* return the time zone offset between GMT and the input one, in number
247 of seconds or -1 if the timezone wasn't found/legal */
248
249static int checktz(const char *check, size_t len)
250{
251 unsigned int i;
252 const struct tzinfo *what = tz;
253 if(len > 4) /* longer than any valid timezone */
254 return -1;
255
256 for(i = 0; i< sizeof(tz)/sizeof(tz[0]); i++) {
257 size_t ilen = strlen(s: what->name);
258 if((ilen == len) &&
259 strncasecompare(check, what->name, len))
260 return what->offset*60;
261 what++;
262 }
263 return -1;
264}
265
266static void skip(const char **date)
267{
268 /* skip everything that aren't letters or digits */
269 while(**date && !ISALNUM(**date))
270 (*date)++;
271}
272
273enum assume {
274 DATE_MDAY,
275 DATE_YEAR,
276 DATE_TIME
277};
278
279/*
280 * time2epoch: time stamp to seconds since epoch in GMT time zone. Similar to
281 * mktime but for GMT only.
282 */
283static time_t time2epoch(int sec, int min, int hour,
284 int mday, int mon, int year)
285{
286 static const int month_days_cumulative [12] =
287 { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
288 int leap_days = year - (mon <= 1);
289 leap_days = ((leap_days / 4) - (leap_days / 100) + (leap_days / 400)
290 - (1969 / 4) + (1969 / 100) - (1969 / 400));
291 return ((((time_t) (year - 1970) * 365
292 + leap_days + month_days_cumulative[mon] + mday - 1) * 24
293 + hour) * 60 + min) * 60 + sec;
294}
295
296/* Returns the value of a single-digit or two-digit decimal number, return
297 then pointer to after the number. The 'date' pointer is known to point to a
298 digit. */
299static int oneortwodigit(const char *date, const char **endp)
300{
301 int num = date[0] - '0';
302 if(ISDIGIT(date[1])) {
303 *endp = &date[2];
304 return num*10 + (date[1] - '0');
305 }
306 *endp = &date[1];
307 return num;
308}
309
310
311/* HH:MM:SS or HH:MM and accept single-digits too */
312static bool match_time(const char *date,
313 int *h, int *m, int *s, char **endp)
314{
315 const char *p;
316 int hh, mm, ss = 0;
317 hh = oneortwodigit(date, endp: &p);
318 if((hh < 24) && (*p == ':') && ISDIGIT(p[1])) {
319 mm = oneortwodigit(date: &p[1], endp: &p);
320 if(mm < 60) {
321 if((*p == ':') && ISDIGIT(p[1])) {
322 ss = oneortwodigit(date: &p[1], endp: &p);
323 if(ss <= 60) {
324 /* valid HH:MM:SS */
325 goto match;
326 }
327 }
328 else {
329 /* valid HH:MM */
330 goto match;
331 }
332 }
333 }
334 return FALSE; /* not a time string */
335match:
336 *h = hh;
337 *m = mm;
338 *s = ss;
339 *endp = (char *)p;
340 return TRUE;
341}
342
343/*
344 * parsedate()
345 *
346 * Returns:
347 *
348 * PARSEDATE_OK - a fine conversion
349 * PARSEDATE_FAIL - failed to convert
350 * PARSEDATE_LATER - time overflow at the far end of time_t
351 * PARSEDATE_SOONER - time underflow at the low end of time_t
352 */
353
354/* Wednesday is the longest name this parser knows about */
355#define NAME_LEN 12
356
357static int parsedate(const char *date, time_t *output)
358{
359 time_t t = 0;
360 int wdaynum = -1; /* day of the week number, 0-6 (mon-sun) */
361 int monnum = -1; /* month of the year number, 0-11 */
362 int mdaynum = -1; /* day of month, 1 - 31 */
363 int hournum = -1;
364 int minnum = -1;
365 int secnum = -1;
366 int yearnum = -1;
367 int tzoff = -1;
368 enum assume dignext = DATE_MDAY;
369 const char *indate = date; /* save the original pointer */
370 int part = 0; /* max 6 parts */
371
372 while(*date && (part < 6)) {
373 bool found = FALSE;
374
375 skip(date: &date);
376
377 if(ISALPHA(*date)) {
378 /* a name coming up */
379 size_t len = 0;
380 const char *p = date;
381 while(ISALPHA(*p) && (len < NAME_LEN)) {
382 p++;
383 len++;
384 }
385
386 if(len != NAME_LEN) {
387 if(wdaynum == -1) {
388 wdaynum = checkday(check: date, len);
389 if(wdaynum != -1)
390 found = TRUE;
391 }
392 if(!found && (monnum == -1)) {
393 monnum = checkmonth(check: date, len);
394 if(monnum != -1)
395 found = TRUE;
396 }
397
398 if(!found && (tzoff == -1)) {
399 /* this just must be a time zone string */
400 tzoff = checktz(check: date, len);
401 if(tzoff != -1)
402 found = TRUE;
403 }
404 }
405 if(!found)
406 return PARSEDATE_FAIL; /* bad string */
407
408 date += len;
409 }
410 else if(ISDIGIT(*date)) {
411 /* a digit */
412 int val;
413 char *end;
414 if((secnum == -1) &&
415 match_time(date, h: &hournum, m: &minnum, s: &secnum, endp: &end)) {
416 /* time stamp */
417 date = end;
418 }
419 else {
420 long lval;
421 int error;
422 int old_errno;
423
424 old_errno = errno;
425 errno = 0;
426 lval = strtol(nptr: date, endptr: &end, base: 10);
427 error = errno;
428 if(errno != old_errno)
429 errno = old_errno;
430
431 if(error)
432 return PARSEDATE_FAIL;
433
434#if LONG_MAX != INT_MAX
435 if((lval > (long)INT_MAX) || (lval < (long)INT_MIN))
436 return PARSEDATE_FAIL;
437#endif
438
439 val = curlx_sltosi(slnum: lval);
440
441 if((tzoff == -1) &&
442 ((end - date) == 4) &&
443 (val <= 1400) &&
444 (indate< date) &&
445 ((date[-1] == '+' || date[-1] == '-'))) {
446 /* four digits and a value less than or equal to 1400 (to take into
447 account all sorts of funny time zone diffs) and it is preceded
448 with a plus or minus. This is a time zone indication. 1400 is
449 picked since +1300 is frequently used and +1400 is mentioned as
450 an edge number in the document "ISO C 200X Proposal: Timezone
451 Functions" at http://david.tribble.com/text/c0xtimezone.html If
452 anyone has a more authoritative source for the exact maximum time
453 zone offsets, please speak up! */
454 found = TRUE;
455 tzoff = (val/100 * 60 + val%100)*60;
456
457 /* the + and - prefix indicates the local time compared to GMT,
458 this we need their reversed math to get what we want */
459 tzoff = date[-1]=='+'?-tzoff:tzoff;
460 }
461
462 if(((end - date) == 8) &&
463 (yearnum == -1) &&
464 (monnum == -1) &&
465 (mdaynum == -1)) {
466 /* 8 digits, no year, month or day yet. This is YYYYMMDD */
467 found = TRUE;
468 yearnum = val/10000;
469 monnum = (val%10000)/100-1; /* month is 0 - 11 */
470 mdaynum = val%100;
471 }
472
473 if(!found && (dignext == DATE_MDAY) && (mdaynum == -1)) {
474 if((val > 0) && (val<32)) {
475 mdaynum = val;
476 found = TRUE;
477 }
478 dignext = DATE_YEAR;
479 }
480
481 if(!found && (dignext == DATE_YEAR) && (yearnum == -1)) {
482 yearnum = val;
483 found = TRUE;
484 if(yearnum < 100) {
485 if(yearnum > 70)
486 yearnum += 1900;
487 else
488 yearnum += 2000;
489 }
490 if(mdaynum == -1)
491 dignext = DATE_MDAY;
492 }
493
494 if(!found)
495 return PARSEDATE_FAIL;
496
497 date = end;
498 }
499 }
500
501 part++;
502 }
503
504 if(-1 == secnum)
505 secnum = minnum = hournum = 0; /* no time, make it zero */
506
507 if((-1 == mdaynum) ||
508 (-1 == monnum) ||
509 (-1 == yearnum))
510 /* lacks vital info, fail */
511 return PARSEDATE_FAIL;
512
513#ifdef HAVE_TIME_T_UNSIGNED
514 if(yearnum < 1970) {
515 /* only positive numbers cannot return earlier */
516 *output = TIME_T_MIN;
517 return PARSEDATE_SOONER;
518 }
519#endif
520
521#if (SIZEOF_TIME_T < 5)
522
523#ifdef HAVE_TIME_T_UNSIGNED
524 /* an unsigned 32 bit time_t can only hold dates to 2106 */
525 if(yearnum > 2105) {
526 *output = TIME_T_MAX;
527 return PARSEDATE_LATER;
528 }
529#else
530 /* a signed 32 bit time_t can only hold dates to the beginning of 2038 */
531 if(yearnum > 2037) {
532 *output = TIME_T_MAX;
533 return PARSEDATE_LATER;
534 }
535 if(yearnum < 1903) {
536 *output = TIME_T_MIN;
537 return PARSEDATE_SOONER;
538 }
539#endif
540
541#else
542 /* The Gregorian calendar was introduced 1582 */
543 if(yearnum < 1583)
544 return PARSEDATE_FAIL;
545#endif
546
547 if((mdaynum > 31) || (monnum > 11) ||
548 (hournum > 23) || (minnum > 59) || (secnum > 60))
549 return PARSEDATE_FAIL; /* clearly an illegal date */
550
551 /* time2epoch() returns a time_t. time_t is often 32 bits, sometimes even on
552 architectures that feature 64 bit 'long' but ultimately time_t is the
553 correct data type to use.
554 */
555 t = time2epoch(sec: secnum, min: minnum, hour: hournum, mday: mdaynum, mon: monnum, year: yearnum);
556
557 /* Add the time zone diff between local time zone and GMT. */
558 if(tzoff == -1)
559 tzoff = 0;
560
561 if((tzoff > 0) && (t > TIME_T_MAX - tzoff)) {
562 *output = TIME_T_MAX;
563 return PARSEDATE_LATER; /* time_t overflow */
564 }
565
566 t += tzoff;
567
568 *output = t;
569
570 return PARSEDATE_OK;
571}
572#else
573/* disabled */
574static int parsedate(const char *date, time_t *output)
575{
576 (void)date;
577 *output = 0;
578 return PARSEDATE_OK; /* a lie */
579}
580#endif
581
582time_t curl_getdate(const char *p, const time_t *now)
583{
584 time_t parsed = -1;
585 int rc = parsedate(date: p, output: &parsed);
586 (void)now; /* legacy argument from the past that we ignore */
587
588 if(rc == PARSEDATE_OK) {
589 if(parsed == -1)
590 /* avoid returning -1 for a working scenario */
591 parsed++;
592 return parsed;
593 }
594 /* everything else is fail */
595 return -1;
596}
597
598/* Curl_getdate_capped() differs from curl_getdate() in that this will return
599 TIME_T_MAX in case the parsed time value was too big, instead of an
600 error. */
601
602time_t Curl_getdate_capped(const char *p)
603{
604 time_t parsed = -1;
605 int rc = parsedate(date: p, output: &parsed);
606
607 switch(rc) {
608 case PARSEDATE_OK:
609 if(parsed == -1)
610 /* avoid returning -1 for a working scenario */
611 parsed++;
612 return parsed;
613 case PARSEDATE_LATER:
614 /* this returns the maximum time value */
615 return parsed;
616 default:
617 return -1; /* everything else is fail */
618 }
619 /* UNREACHABLE */
620}
621
622/*
623 * Curl_gmtime() is a gmtime() replacement for portability. Do not use the
624 * gmtime_r() or gmtime() functions anywhere else but here.
625 *
626 */
627
628CURLcode Curl_gmtime(time_t intime, struct tm *store)
629{
630 const struct tm *tm;
631#ifdef HAVE_GMTIME_R
632 /* thread-safe version */
633 tm = (struct tm *)gmtime_r(timer: &intime, tp: store);
634#else
635 /* !checksrc! disable BANNEDFUNC 1 */
636 tm = gmtime(&intime);
637 if(tm)
638 *store = *tm; /* copy the pointed struct to the local copy */
639#endif
640
641 if(!tm)
642 return CURLE_BAD_FUNCTION_ARGUMENT;
643 return CURLE_OK;
644}
645