1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2019, 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.haxx.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 ***************************************************************************/
22/*
23 A brief summary of the date string formats this parser groks:
24
25 RFC 2616 3.3.1
26
27 Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123
28 Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
29 Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format
30
31 we support dates without week day name:
32
33 06 Nov 1994 08:49:37 GMT
34 06-Nov-94 08:49:37 GMT
35 Nov 6 08:49:37 1994
36
37 without the time zone:
38
39 06 Nov 1994 08:49:37
40 06-Nov-94 08:49:37
41
42 weird order:
43
44 1994 Nov 6 08:49:37 (GNU date fails)
45 GMT 08:49:37 06-Nov-94 Sunday
46 94 6 Nov 08:49:37 (GNU date fails)
47
48 time left out:
49
50 1994 Nov 6
51 06-Nov-94
52 Sun Nov 6 94
53
54 unusual separators:
55
56 1994.Nov.6
57 Sun/Nov/6/94/GMT
58
59 commonly used time zone names:
60
61 Sun, 06 Nov 1994 08:49:37 CET
62 06 Nov 1994 08:49:37 EST
63
64 time zones specified using RFC822 style:
65
66 Sun, 12 Sep 2004 15:05:58 -0700
67 Sat, 11 Sep 2004 21:32:11 +0200
68
69 compact numerical date strings:
70
71 20040912 15:05:58 -0700
72 20040911 +0200
73
74*/
75
76#include "curl_setup.h"
77
78#include <limits.h>
79
80#include <curl/curl.h>
81#include "strcase.h"
82#include "warnless.h"
83#include "parsedate.h"
84
85/*
86 * parsedate()
87 *
88 * Returns:
89 *
90 * PARSEDATE_OK - a fine conversion
91 * PARSEDATE_FAIL - failed to convert
92 * PARSEDATE_LATER - time overflow at the far end of time_t
93 * PARSEDATE_SOONER - time underflow at the low end of time_t
94 */
95
96static int parsedate(const char *date, time_t *output);
97
98#define PARSEDATE_OK 0
99#define PARSEDATE_FAIL -1
100#define PARSEDATE_LATER 1
101#define PARSEDATE_SOONER 2
102
103#if !defined(CURL_DISABLE_PARSEDATE) || !defined(CURL_DISABLE_FTP) || \
104 !defined(CURL_DISABLE_FILE)
105/* These names are also used by FTP and FILE code */
106const char * const Curl_wkday[] =
107{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
108const char * const Curl_month[]=
109{ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
110 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
111#endif
112
113#ifndef CURL_DISABLE_PARSEDATE
114static const char * const weekday[] =
115{ "Monday", "Tuesday", "Wednesday", "Thursday",
116 "Friday", "Saturday", "Sunday" };
117
118struct tzinfo {
119 char name[5];
120 int offset; /* +/- in minutes */
121};
122
123/* Here's a bunch of frequently used time zone names. These were supported
124 by the old getdate parser. */
125#define tDAYZONE -60 /* offset for daylight savings time */
126static const struct tzinfo tz[]= {
127 {"GMT", 0}, /* Greenwich Mean */
128 {"UT", 0}, /* Universal Time */
129 {"UTC", 0}, /* Universal (Coordinated) */
130 {"WET", 0}, /* Western European */
131 {"BST", 0 tDAYZONE}, /* British Summer */
132 {"WAT", 60}, /* West Africa */
133 {"AST", 240}, /* Atlantic Standard */
134 {"ADT", 240 tDAYZONE}, /* Atlantic Daylight */
135 {"EST", 300}, /* Eastern Standard */
136 {"EDT", 300 tDAYZONE}, /* Eastern Daylight */
137 {"CST", 360}, /* Central Standard */
138 {"CDT", 360 tDAYZONE}, /* Central Daylight */
139 {"MST", 420}, /* Mountain Standard */
140 {"MDT", 420 tDAYZONE}, /* Mountain Daylight */
141 {"PST", 480}, /* Pacific Standard */
142 {"PDT", 480 tDAYZONE}, /* Pacific Daylight */
143 {"YST", 540}, /* Yukon Standard */
144 {"YDT", 540 tDAYZONE}, /* Yukon Daylight */
145 {"HST", 600}, /* Hawaii Standard */
146 {"HDT", 600 tDAYZONE}, /* Hawaii Daylight */
147 {"CAT", 600}, /* Central Alaska */
148 {"AHST", 600}, /* Alaska-Hawaii Standard */
149 {"NT", 660}, /* Nome */
150 {"IDLW", 720}, /* International Date Line West */
151 {"CET", -60}, /* Central European */
152 {"MET", -60}, /* Middle European */
153 {"MEWT", -60}, /* Middle European Winter */
154 {"MEST", -60 tDAYZONE}, /* Middle European Summer */
155 {"CEST", -60 tDAYZONE}, /* Central European Summer */
156 {"MESZ", -60 tDAYZONE}, /* Middle European Summer */
157 {"FWT", -60}, /* French Winter */
158 {"FST", -60 tDAYZONE}, /* French Summer */
159 {"EET", -120}, /* Eastern Europe, USSR Zone 1 */
160 {"WAST", -420}, /* West Australian Standard */
161 {"WADT", -420 tDAYZONE}, /* West Australian Daylight */
162 {"CCT", -480}, /* China Coast, USSR Zone 7 */
163 {"JST", -540}, /* Japan Standard, USSR Zone 8 */
164 {"EAST", -600}, /* Eastern Australian Standard */
165 {"EADT", -600 tDAYZONE}, /* Eastern Australian Daylight */
166 {"GST", -600}, /* Guam Standard, USSR Zone 9 */
167 {"NZT", -720}, /* New Zealand */
168 {"NZST", -720}, /* New Zealand Standard */
169 {"NZDT", -720 tDAYZONE}, /* New Zealand Daylight */
170 {"IDLE", -720}, /* International Date Line East */
171 /* Next up: Military timezone names. RFC822 allowed these, but (as noted in
172 RFC 1123) had their signs wrong. Here we use the correct signs to match
173 actual military usage.
174 */
175 {"A", 1 * 60}, /* Alpha */
176 {"B", 2 * 60}, /* Bravo */
177 {"C", 3 * 60}, /* Charlie */
178 {"D", 4 * 60}, /* Delta */
179 {"E", 5 * 60}, /* Echo */
180 {"F", 6 * 60}, /* Foxtrot */
181 {"G", 7 * 60}, /* Golf */
182 {"H", 8 * 60}, /* Hotel */
183 {"I", 9 * 60}, /* India */
184 /* "J", Juliet is not used as a timezone, to indicate the observer's local
185 time */
186 {"K", 10 * 60}, /* Kilo */
187 {"L", 11 * 60}, /* Lima */
188 {"M", 12 * 60}, /* Mike */
189 {"N", -1 * 60}, /* November */
190 {"O", -2 * 60}, /* Oscar */
191 {"P", -3 * 60}, /* Papa */
192 {"Q", -4 * 60}, /* Quebec */
193 {"R", -5 * 60}, /* Romeo */
194 {"S", -6 * 60}, /* Sierra */
195 {"T", -7 * 60}, /* Tango */
196 {"U", -8 * 60}, /* Uniform */
197 {"V", -9 * 60}, /* Victor */
198 {"W", -10 * 60}, /* Whiskey */
199 {"X", -11 * 60}, /* X-ray */
200 {"Y", -12 * 60}, /* Yankee */
201 {"Z", 0}, /* Zulu, zero meridian, a.k.a. UTC */
202};
203
204/* returns:
205 -1 no day
206 0 monday - 6 sunday
207*/
208
209static int checkday(const char *check, size_t len)
210{
211 int i;
212 const char * const *what;
213 bool found = FALSE;
214 if(len > 3)
215 what = &weekday[0];
216 else
217 what = &Curl_wkday[0];
218 for(i = 0; i<7; i++) {
219 if(strcasecompare(check, what[0])) {
220 found = TRUE;
221 break;
222 }
223 what++;
224 }
225 return found?i:-1;
226}
227
228static int checkmonth(const char *check)
229{
230 int i;
231 const char * const *what;
232 bool found = FALSE;
233
234 what = &Curl_month[0];
235 for(i = 0; i<12; i++) {
236 if(strcasecompare(check, what[0])) {
237 found = TRUE;
238 break;
239 }
240 what++;
241 }
242 return found?i:-1; /* return the offset or -1, no real offset is -1 */
243}
244
245/* return the time zone offset between GMT and the input one, in number
246 of seconds or -1 if the timezone wasn't found/legal */
247
248static int checktz(const char *check)
249{
250 unsigned int i;
251 const struct tzinfo *what;
252 bool found = FALSE;
253
254 what = tz;
255 for(i = 0; i< sizeof(tz)/sizeof(tz[0]); i++) {
256 if(strcasecompare(check, what->name)) {
257 found = TRUE;
258 break;
259 }
260 what++;
261 }
262 return found?what->offset*60:-1;
263}
264
265static void skip(const char **date)
266{
267 /* skip everything that aren't letters or digits */
268 while(**date && !ISALNUM(**date))
269 (*date)++;
270}
271
272enum assume {
273 DATE_MDAY,
274 DATE_YEAR,
275 DATE_TIME
276};
277
278/* this is a clone of 'struct tm' but with all fields we don't need or use
279 cut out */
280struct my_tm {
281 int tm_sec;
282 int tm_min;
283 int tm_hour;
284 int tm_mday;
285 int tm_mon;
286 int tm_year; /* full year */
287};
288
289/* struct tm to time since epoch in GMT time zone.
290 * This is similar to the standard mktime function but for GMT only, and
291 * doesn't suffer from the various bugs and portability problems that
292 * some systems' implementations have.
293 *
294 * Returns 0 on success, otherwise non-zero.
295 */
296static void my_timegm(struct my_tm *tm, time_t *t)
297{
298 static const int month_days_cumulative [12] =
299 { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
300 int month, year, leap_days;
301
302 year = tm->tm_year;
303 month = tm->tm_mon;
304 if(month < 0) {
305 year += (11 - month) / 12;
306 month = 11 - (11 - month) % 12;
307 }
308 else if(month >= 12) {
309 year -= month / 12;
310 month = month % 12;
311 }
312
313 leap_days = year - (tm->tm_mon <= 1);
314 leap_days = ((leap_days / 4) - (leap_days / 100) + (leap_days / 400)
315 - (1969 / 4) + (1969 / 100) - (1969 / 400));
316
317 *t = ((((time_t) (year - 1970) * 365
318 + leap_days + month_days_cumulative[month] + tm->tm_mday - 1) * 24
319 + tm->tm_hour) * 60 + tm->tm_min) * 60 + tm->tm_sec;
320}
321
322/*
323 * parsedate()
324 *
325 * Returns:
326 *
327 * PARSEDATE_OK - a fine conversion
328 * PARSEDATE_FAIL - failed to convert
329 * PARSEDATE_LATER - time overflow at the far end of time_t
330 * PARSEDATE_SOONER - time underflow at the low end of time_t
331 */
332
333static int parsedate(const char *date, time_t *output)
334{
335 time_t t = 0;
336 int wdaynum = -1; /* day of the week number, 0-6 (mon-sun) */
337 int monnum = -1; /* month of the year number, 0-11 */
338 int mdaynum = -1; /* day of month, 1 - 31 */
339 int hournum = -1;
340 int minnum = -1;
341 int secnum = -1;
342 int yearnum = -1;
343 int tzoff = -1;
344 struct my_tm tm;
345 enum assume dignext = DATE_MDAY;
346 const char *indate = date; /* save the original pointer */
347 int part = 0; /* max 6 parts */
348
349 while(*date && (part < 6)) {
350 bool found = FALSE;
351
352 skip(&date);
353
354 if(ISALPHA(*date)) {
355 /* a name coming up */
356 char buf[32]="";
357 size_t len;
358 if(sscanf(date, "%31[ABCDEFGHIJKLMNOPQRSTUVWXYZ"
359 "abcdefghijklmnopqrstuvwxyz]", buf))
360 len = strlen(buf);
361 else
362 len = 0;
363
364 if(wdaynum == -1) {
365 wdaynum = checkday(buf, len);
366 if(wdaynum != -1)
367 found = TRUE;
368 }
369 if(!found && (monnum == -1)) {
370 monnum = checkmonth(buf);
371 if(monnum != -1)
372 found = TRUE;
373 }
374
375 if(!found && (tzoff == -1)) {
376 /* this just must be a time zone string */
377 tzoff = checktz(buf);
378 if(tzoff != -1)
379 found = TRUE;
380 }
381
382 if(!found)
383 return PARSEDATE_FAIL; /* bad string */
384
385 date += len;
386 }
387 else if(ISDIGIT(*date)) {
388 /* a digit */
389 int val;
390 char *end;
391 int len = 0;
392 if((secnum == -1) &&
393 (3 == sscanf(date, "%02d:%02d:%02d%n",
394 &hournum, &minnum, &secnum, &len))) {
395 /* time stamp! */
396 date += len;
397 }
398 else if((secnum == -1) &&
399 (2 == sscanf(date, "%02d:%02d%n", &hournum, &minnum, &len))) {
400 /* time stamp without seconds */
401 date += len;
402 secnum = 0;
403 }
404 else {
405 long lval;
406 int error;
407 int old_errno;
408
409 old_errno = errno;
410 errno = 0;
411 lval = strtol(date, &end, 10);
412 error = errno;
413 if(errno != old_errno)
414 errno = old_errno;
415
416 if(error)
417 return PARSEDATE_FAIL;
418
419#if LONG_MAX != INT_MAX
420 if((lval > (long)INT_MAX) || (lval < (long)INT_MIN))
421 return PARSEDATE_FAIL;
422#endif
423
424 val = curlx_sltosi(lval);
425
426 if((tzoff == -1) &&
427 ((end - date) == 4) &&
428 (val <= 1400) &&
429 (indate< date) &&
430 ((date[-1] == '+' || date[-1] == '-'))) {
431 /* four digits and a value less than or equal to 1400 (to take into
432 account all sorts of funny time zone diffs) and it is preceded
433 with a plus or minus. This is a time zone indication. 1400 is
434 picked since +1300 is frequently used and +1400 is mentioned as
435 an edge number in the document "ISO C 200X Proposal: Timezone
436 Functions" at http://david.tribble.com/text/c0xtimezone.html If
437 anyone has a more authoritative source for the exact maximum time
438 zone offsets, please speak up! */
439 found = TRUE;
440 tzoff = (val/100 * 60 + val%100)*60;
441
442 /* the + and - prefix indicates the local time compared to GMT,
443 this we need their reversed math to get what we want */
444 tzoff = date[-1]=='+'?-tzoff:tzoff;
445 }
446
447 if(((end - date) == 8) &&
448 (yearnum == -1) &&
449 (monnum == -1) &&
450 (mdaynum == -1)) {
451 /* 8 digits, no year, month or day yet. This is YYYYMMDD */
452 found = TRUE;
453 yearnum = val/10000;
454 monnum = (val%10000)/100-1; /* month is 0 - 11 */
455 mdaynum = val%100;
456 }
457
458 if(!found && (dignext == DATE_MDAY) && (mdaynum == -1)) {
459 if((val > 0) && (val<32)) {
460 mdaynum = val;
461 found = TRUE;
462 }
463 dignext = DATE_YEAR;
464 }
465
466 if(!found && (dignext == DATE_YEAR) && (yearnum == -1)) {
467 yearnum = val;
468 found = TRUE;
469 if(yearnum < 100) {
470 if(yearnum > 70)
471 yearnum += 1900;
472 else
473 yearnum += 2000;
474 }
475 if(mdaynum == -1)
476 dignext = DATE_MDAY;
477 }
478
479 if(!found)
480 return PARSEDATE_FAIL;
481
482 date = end;
483 }
484 }
485
486 part++;
487 }
488
489 if(-1 == secnum)
490 secnum = minnum = hournum = 0; /* no time, make it zero */
491
492 if((-1 == mdaynum) ||
493 (-1 == monnum) ||
494 (-1 == yearnum))
495 /* lacks vital info, fail */
496 return PARSEDATE_FAIL;
497
498#ifdef HAVE_TIME_T_UNSIGNED
499 if(yearnum < 1970) {
500 /* only positive numbers cannot return earlier */
501 *output = TIME_T_MIN;
502 return PARSEDATE_SOONER;
503 }
504#endif
505
506#if (SIZEOF_TIME_T < 5)
507
508#ifdef HAVE_TIME_T_UNSIGNED
509 /* an unsigned 32 bit time_t can only hold dates to 2106 */
510 if(yearnum > 2105) {
511 *output = TIME_T_MAX;
512 return PARSEDATE_LATER;
513 }
514#else
515 /* a signed 32 bit time_t can only hold dates to the beginning of 2038 */
516 if(yearnum > 2037) {
517 *output = TIME_T_MAX;
518 return PARSEDATE_LATER;
519 }
520 if(yearnum < 1903) {
521 *output = TIME_T_MIN;
522 return PARSEDATE_SOONER;
523 }
524#endif
525
526#else
527 /* The Gregorian calendar was introduced 1582 */
528 if(yearnum < 1583)
529 return PARSEDATE_FAIL;
530#endif
531
532 if((mdaynum > 31) || (monnum > 11) ||
533 (hournum > 23) || (minnum > 59) || (secnum > 60))
534 return PARSEDATE_FAIL; /* clearly an illegal date */
535
536 tm.tm_sec = secnum;
537 tm.tm_min = minnum;
538 tm.tm_hour = hournum;
539 tm.tm_mday = mdaynum;
540 tm.tm_mon = monnum;
541 tm.tm_year = yearnum;
542
543 /* my_timegm() returns a time_t. time_t is often 32 bits, sometimes even on
544 architectures that feature 64 bit 'long' but ultimately time_t is the
545 correct data type to use.
546 */
547 my_timegm(&tm, &t);
548
549 /* Add the time zone diff between local time zone and GMT. */
550 if(tzoff == -1)
551 tzoff = 0;
552
553 if((tzoff > 0) && (t > TIME_T_MAX - tzoff)) {
554 *output = TIME_T_MAX;
555 return PARSEDATE_LATER; /* time_t overflow */
556 }
557
558 t += tzoff;
559
560 *output = t;
561
562 return PARSEDATE_OK;
563}
564#else
565/* disabled */
566static int parsedate(const char *date, time_t *output)
567{
568 (void)date;
569 *output = 0;
570 return PARSEDATE_OK; /* a lie */
571}
572#endif
573
574time_t curl_getdate(const char *p, const time_t *now)
575{
576 time_t parsed = -1;
577 int rc = parsedate(p, &parsed);
578 (void)now; /* legacy argument from the past that we ignore */
579
580 if(rc == PARSEDATE_OK) {
581 if(parsed == -1)
582 /* avoid returning -1 for a working scenario */
583 parsed++;
584 return parsed;
585 }
586 /* everything else is fail */
587 return -1;
588}
589
590/*
591 * Curl_gmtime() is a gmtime() replacement for portability. Do not use the
592 * gmtime_r() or gmtime() functions anywhere else but here.
593 *
594 */
595
596CURLcode Curl_gmtime(time_t intime, struct tm *store)
597{
598 const struct tm *tm;
599#ifdef HAVE_GMTIME_R
600 /* thread-safe version */
601 tm = (struct tm *)gmtime_r(&intime, store);
602#else
603 tm = gmtime(&intime);
604 if(tm)
605 *store = *tm; /* copy the pointed struct to the local copy */
606#endif
607
608 if(!tm)
609 return CURLE_BAD_FUNCTION_ARGUMENT;
610 return CURLE_OK;
611}
612