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1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2016, 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 #ifdef HAVE_LIMITS_H
79 #include <limits.h>
80 #endif
81 
82 #include <curl/curl.h>
83 #include "strcase.h"
84 #include "warnless.h"
85 #include "parsedate.h"
86 
87 const char * const Curl_wkday[] =
88 {"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
89 static const char * const weekday[] =
90 { "Monday", "Tuesday", "Wednesday", "Thursday",
91   "Friday", "Saturday", "Sunday" };
92 const char * const Curl_month[]=
93 { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
94   "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
95 
96 struct tzinfo {
97   char name[5];
98   int offset; /* +/- in minutes */
99 };
100 
101 /*
102  * parsedate()
103  *
104  * Returns:
105  *
106  * PARSEDATE_OK     - a fine conversion
107  * PARSEDATE_FAIL   - failed to convert
108  * PARSEDATE_LATER  - time overflow at the far end of time_t
109  * PARSEDATE_SOONER - time underflow at the low end of time_t
110  */
111 
112 static int parsedate(const char *date, time_t *output);
113 
114 #define PARSEDATE_OK     0
115 #define PARSEDATE_FAIL   -1
116 #define PARSEDATE_LATER  1
117 #define PARSEDATE_SOONER 2
118 
119 /* Here's a bunch of frequently used time zone names. These were supported
120    by the old getdate parser. */
121 #define tDAYZONE -60       /* offset for daylight savings time */
122 static const struct tzinfo tz[]= {
123   {"GMT", 0},              /* Greenwich Mean */
124   {"UTC", 0},              /* Universal (Coordinated) */
125   {"WET", 0},              /* Western European */
126   {"BST", 0 tDAYZONE},     /* British Summer */
127   {"WAT", 60},             /* West Africa */
128   {"AST", 240},            /* Atlantic Standard */
129   {"ADT", 240 tDAYZONE},   /* Atlantic Daylight */
130   {"EST", 300},            /* Eastern Standard */
131   {"EDT", 300 tDAYZONE},   /* Eastern Daylight */
132   {"CST", 360},            /* Central Standard */
133   {"CDT", 360 tDAYZONE},   /* Central Daylight */
134   {"MST", 420},            /* Mountain Standard */
135   {"MDT", 420 tDAYZONE},   /* Mountain Daylight */
136   {"PST", 480},            /* Pacific Standard */
137   {"PDT", 480 tDAYZONE},   /* Pacific Daylight */
138   {"YST", 540},            /* Yukon Standard */
139   {"YDT", 540 tDAYZONE},   /* Yukon Daylight */
140   {"HST", 600},            /* Hawaii Standard */
141   {"HDT", 600 tDAYZONE},   /* Hawaii Daylight */
142   {"CAT", 600},            /* Central Alaska */
143   {"AHST", 600},           /* Alaska-Hawaii Standard */
144   {"NT",  660},            /* Nome */
145   {"IDLW", 720},           /* International Date Line West */
146   {"CET", -60},            /* Central European */
147   {"MET", -60},            /* Middle European */
148   {"MEWT", -60},           /* Middle European Winter */
149   {"MEST", -60 tDAYZONE},  /* Middle European Summer */
150   {"CEST", -60 tDAYZONE},  /* Central European Summer */
151   {"MESZ", -60 tDAYZONE},  /* Middle European Summer */
152   {"FWT", -60},            /* French Winter */
153   {"FST", -60 tDAYZONE},   /* French Summer */
154   {"EET", -120},           /* Eastern Europe, USSR Zone 1 */
155   {"WAST", -420},          /* West Australian Standard */
156   {"WADT", -420 tDAYZONE}, /* West Australian Daylight */
157   {"CCT", -480},           /* China Coast, USSR Zone 7 */
158   {"JST", -540},           /* Japan Standard, USSR Zone 8 */
159   {"EAST", -600},          /* Eastern Australian Standard */
160   {"EADT", -600 tDAYZONE}, /* Eastern Australian Daylight */
161   {"GST", -600},           /* Guam Standard, USSR Zone 9 */
162   {"NZT", -720},           /* New Zealand */
163   {"NZST", -720},          /* New Zealand Standard */
164   {"NZDT", -720 tDAYZONE}, /* New Zealand Daylight */
165   {"IDLE", -720},          /* International Date Line East */
166   /* Next up: Military timezone names. RFC822 allowed these, but (as noted in
167      RFC 1123) had their signs wrong. Here we use the correct signs to match
168      actual military usage.
169    */
170   {"A",  +1 * 60},         /* Alpha */
171   {"B",  +2 * 60},         /* Bravo */
172   {"C",  +3 * 60},         /* Charlie */
173   {"D",  +4 * 60},         /* Delta */
174   {"E",  +5 * 60},         /* Echo */
175   {"F",  +6 * 60},         /* Foxtrot */
176   {"G",  +7 * 60},         /* Golf */
177   {"H",  +8 * 60},         /* Hotel */
178   {"I",  +9 * 60},         /* India */
179   /* "J", Juliet is not used as a timezone, to indicate the observer's local
180      time */
181   {"K", +10 * 60},         /* Kilo */
182   {"L", +11 * 60},         /* Lima */
183   {"M", +12 * 60},         /* Mike */
184   {"N",  -1 * 60},         /* November */
185   {"O",  -2 * 60},         /* Oscar */
186   {"P",  -3 * 60},         /* Papa */
187   {"Q",  -4 * 60},         /* Quebec */
188   {"R",  -5 * 60},         /* Romeo */
189   {"S",  -6 * 60},         /* Sierra */
190   {"T",  -7 * 60},         /* Tango */
191   {"U",  -8 * 60},         /* Uniform */
192   {"V",  -9 * 60},         /* Victor */
193   {"W", -10 * 60},         /* Whiskey */
194   {"X", -11 * 60},         /* X-ray */
195   {"Y", -12 * 60},         /* Yankee */
196   {"Z", 0},                /* Zulu, zero meridian, a.k.a. UTC */
197 };
198 
199 /* returns:
200    -1 no day
201    0 monday - 6 sunday
202 */
203 
checkday(const char * check,size_t len)204 static int checkday(const char *check, size_t len)
205 {
206   int i;
207   const char * const *what;
208   bool found= FALSE;
209   if(len > 3)
210     what = &weekday[0];
211   else
212     what = &Curl_wkday[0];
213   for(i=0; i<7; i++) {
214     if(strcasecompare(check, what[0])) {
215       found=TRUE;
216       break;
217     }
218     what++;
219   }
220   return found?i:-1;
221 }
222 
checkmonth(const char * check)223 static int checkmonth(const char *check)
224 {
225   int i;
226   const char * const *what;
227   bool found= FALSE;
228 
229   what = &Curl_month[0];
230   for(i=0; i<12; i++) {
231     if(strcasecompare(check, what[0])) {
232       found=TRUE;
233       break;
234     }
235     what++;
236   }
237   return found?i:-1; /* return the offset or -1, no real offset is -1 */
238 }
239 
240 /* return the time zone offset between GMT and the input one, in number
241    of seconds or -1 if the timezone wasn't found/legal */
242 
checktz(const char * check)243 static int checktz(const char *check)
244 {
245   unsigned int i;
246   const struct tzinfo *what;
247   bool found= FALSE;
248 
249   what = tz;
250   for(i=0; i< sizeof(tz)/sizeof(tz[0]); i++) {
251     if(strcasecompare(check, what->name)) {
252       found=TRUE;
253       break;
254     }
255     what++;
256   }
257   return found?what->offset*60:-1;
258 }
259 
skip(const char ** date)260 static void skip(const char **date)
261 {
262   /* skip everything that aren't letters or digits */
263   while(**date && !ISALNUM(**date))
264     (*date)++;
265 }
266 
267 enum assume {
268   DATE_MDAY,
269   DATE_YEAR,
270   DATE_TIME
271 };
272 
273 /* this is a clone of 'struct tm' but with all fields we don't need or use
274    cut out */
275 struct my_tm {
276   int tm_sec;
277   int tm_min;
278   int tm_hour;
279   int tm_mday;
280   int tm_mon;
281   int tm_year;
282 };
283 
284 /* struct tm to time since epoch in GMT time zone.
285  * This is similar to the standard mktime function but for GMT only, and
286  * doesn't suffer from the various bugs and portability problems that
287  * some systems' implementations have.
288  */
my_timegm(struct my_tm * tm)289 static time_t my_timegm(struct my_tm *tm)
290 {
291   static const int month_days_cumulative [12] =
292     { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
293   int month, year, leap_days;
294 
295   if(tm->tm_year < 70)
296     /* we don't support years before 1970 as they will cause this function
297        to return a negative value */
298     return -1;
299 
300   year = tm->tm_year + 1900;
301   month = tm->tm_mon;
302   if(month < 0) {
303     year += (11 - month) / 12;
304     month = 11 - (11 - month) % 12;
305   }
306   else if(month >= 12) {
307     year -= month / 12;
308     month = month % 12;
309   }
310 
311   leap_days = year - (tm->tm_mon <= 1);
312   leap_days = ((leap_days / 4) - (leap_days / 100) + (leap_days / 400)
313                - (1969 / 4) + (1969 / 100) - (1969 / 400));
314 
315   return ((((time_t) (year - 1970) * 365
316             + leap_days + month_days_cumulative [month] + tm->tm_mday - 1) * 24
317            + tm->tm_hour) * 60 + tm->tm_min) * 60 + tm->tm_sec;
318 }
319 
320 /*
321  * parsedate()
322  *
323  * Returns:
324  *
325  * PARSEDATE_OK     - a fine conversion
326  * PARSEDATE_FAIL   - failed to convert
327  * PARSEDATE_LATER  - time overflow at the far end of time_t
328  * PARSEDATE_SOONER - time underflow at the low end of time_t
329  */
330 
parsedate(const char * date,time_t * output)331 static int parsedate(const char *date, time_t *output)
332 {
333   time_t t = 0;
334   int wdaynum=-1;  /* day of the week number, 0-6 (mon-sun) */
335   int monnum=-1;   /* month of the year number, 0-11 */
336   int mdaynum=-1; /* day of month, 1 - 31 */
337   int hournum=-1;
338   int minnum=-1;
339   int secnum=-1;
340   int yearnum=-1;
341   int tzoff=-1;
342   struct my_tm tm;
343   enum assume dignext = DATE_MDAY;
344   const char *indate = date; /* save the original pointer */
345   int part = 0; /* max 6 parts */
346 
347   while(*date && (part < 6)) {
348     bool found=FALSE;
349 
350     skip(&date);
351 
352     if(ISALPHA(*date)) {
353       /* a name coming up */
354       char buf[32]="";
355       size_t len;
356       if(sscanf(date, "%31[ABCDEFGHIJKLMNOPQRSTUVWXYZ"
357                           "abcdefghijklmnopqrstuvwxyz]", buf))
358         len = strlen(buf);
359       else
360         len = 0;
361 
362       if(wdaynum == -1) {
363         wdaynum = checkday(buf, len);
364         if(wdaynum != -1)
365           found = TRUE;
366       }
367       if(!found && (monnum == -1)) {
368         monnum = checkmonth(buf);
369         if(monnum != -1)
370           found = TRUE;
371       }
372 
373       if(!found && (tzoff == -1)) {
374         /* this just must be a time zone string */
375         tzoff = checktz(buf);
376         if(tzoff != -1)
377           found = TRUE;
378       }
379 
380       if(!found)
381         return PARSEDATE_FAIL; /* bad string */
382 
383       date += len;
384     }
385     else if(ISDIGIT(*date)) {
386       /* a digit */
387       int val;
388       char *end;
389       int len=0;
390       if((secnum == -1) &&
391          (3 == sscanf(date, "%02d:%02d:%02d%n",
392                       &hournum, &minnum, &secnum, &len))) {
393         /* time stamp! */
394         date += len;
395       }
396       else if((secnum == -1) &&
397               (2 == sscanf(date, "%02d:%02d%n", &hournum, &minnum, &len))) {
398         /* time stamp without seconds */
399         date += len;
400         secnum = 0;
401       }
402       else {
403         long lval;
404         int error;
405         int old_errno;
406 
407         old_errno = ERRNO;
408         SET_ERRNO(0);
409         lval = strtol(date, &end, 10);
410         error = ERRNO;
411         if(error != old_errno)
412           SET_ERRNO(old_errno);
413 
414         if(error)
415           return PARSEDATE_FAIL;
416 
417 #if LONG_MAX != INT_MAX
418         if((lval > (long)INT_MAX) || (lval < (long)INT_MIN))
419           return PARSEDATE_FAIL;
420 #endif
421 
422         val = curlx_sltosi(lval);
423 
424         if((tzoff == -1) &&
425            ((end - date) == 4) &&
426            (val <= 1400) &&
427            (indate< date) &&
428            ((date[-1] == '+' || date[-1] == '-'))) {
429           /* four digits and a value less than or equal to 1400 (to take into
430              account all sorts of funny time zone diffs) and it is preceded
431              with a plus or minus. This is a time zone indication.  1400 is
432              picked since +1300 is frequently used and +1400 is mentioned as
433              an edge number in the document "ISO C 200X Proposal: Timezone
434              Functions" at http://david.tribble.com/text/c0xtimezone.html If
435              anyone has a more authoritative source for the exact maximum time
436              zone offsets, please speak up! */
437           found = TRUE;
438           tzoff = (val/100 * 60 + val%100)*60;
439 
440           /* the + and - prefix indicates the local time compared to GMT,
441              this we need ther reversed math to get what we want */
442           tzoff = date[-1]=='+'?-tzoff:tzoff;
443         }
444 
445         if(((end - date) == 8) &&
446            (yearnum == -1) &&
447            (monnum == -1) &&
448            (mdaynum == -1)) {
449           /* 8 digits, no year, month or day yet. This is YYYYMMDD */
450           found = TRUE;
451           yearnum = val/10000;
452           monnum = (val%10000)/100-1; /* month is 0 - 11 */
453           mdaynum = val%100;
454         }
455 
456         if(!found && (dignext == DATE_MDAY) && (mdaynum == -1)) {
457           if((val > 0) && (val<32)) {
458             mdaynum = val;
459             found = TRUE;
460           }
461           dignext = DATE_YEAR;
462         }
463 
464         if(!found && (dignext == DATE_YEAR) && (yearnum == -1)) {
465           yearnum = val;
466           found = TRUE;
467           if(yearnum < 1900) {
468             if(yearnum > 70)
469               yearnum += 1900;
470             else
471               yearnum += 2000;
472           }
473           if(mdaynum == -1)
474             dignext = DATE_MDAY;
475         }
476 
477         if(!found)
478           return PARSEDATE_FAIL;
479 
480         date = end;
481       }
482     }
483 
484     part++;
485   }
486 
487   if(-1 == secnum)
488     secnum = minnum = hournum = 0; /* no time, make it zero */
489 
490   if((-1 == mdaynum) ||
491      (-1 == monnum) ||
492      (-1 == yearnum))
493     /* lacks vital info, fail */
494     return PARSEDATE_FAIL;
495 
496   /* 32 bit time_t can only hold dates to the beginning of 2038 */
497   if(sizeof(time_t) < 5 && yearnum > 2037) {
498     *output = 0x7fffffff;
499     return PARSEDATE_LATER;
500   }
501 
502   if(yearnum < 1970) {
503     *output = 0;
504     return PARSEDATE_SOONER;
505   }
506 
507   if((mdaynum > 31) || (monnum > 11) ||
508      (hournum > 23) || (minnum > 59) || (secnum > 60))
509     return PARSEDATE_FAIL; /* clearly an illegal date */
510 
511   tm.tm_sec = secnum;
512   tm.tm_min = minnum;
513   tm.tm_hour = hournum;
514   tm.tm_mday = mdaynum;
515   tm.tm_mon = monnum;
516   tm.tm_year = yearnum - 1900;
517 
518   /* my_timegm() returns a time_t. time_t is often 32 bits, even on many
519      architectures that feature 64 bit 'long'.
520 
521      Some systems have 64 bit time_t and deal with years beyond 2038. However,
522      even on some of the systems with 64 bit time_t mktime() returns -1 for
523      dates beyond 03:14:07 UTC, January 19, 2038. (Such as AIX 5100-06)
524   */
525   t = my_timegm(&tm);
526 
527   /* time zone adjust (cast t to int to compare to negative one) */
528   if(-1 != (int)t) {
529 
530     /* Add the time zone diff between local time zone and GMT. */
531     long delta = (long)(tzoff!=-1?tzoff:0);
532 
533     if((delta>0) && (t > LONG_MAX - delta)) {
534       *output = 0x7fffffff;
535       return PARSEDATE_LATER; /* time_t overflow */
536     }
537 
538     t += delta;
539   }
540 
541   *output = t;
542 
543   return PARSEDATE_OK;
544 }
545 
curl_getdate(const char * p,const time_t * now)546 time_t curl_getdate(const char *p, const time_t *now)
547 {
548   time_t parsed = -1;
549   int rc = parsedate(p, &parsed);
550   (void)now; /* legacy argument from the past that we ignore */
551 
552   switch(rc) {
553   case PARSEDATE_OK:
554   case PARSEDATE_LATER:
555   case PARSEDATE_SOONER:
556     return parsed;
557   }
558   /* everything else is fail */
559   return -1;
560 }
561 
562 /*
563  * Curl_gmtime() is a gmtime() replacement for portability. Do not use the
564  * gmtime_r() or gmtime() functions anywhere else but here.
565  *
566  */
567 
Curl_gmtime(time_t intime,struct tm * store)568 CURLcode Curl_gmtime(time_t intime, struct tm *store)
569 {
570   const struct tm *tm;
571 #ifdef HAVE_GMTIME_R
572   /* thread-safe version */
573   tm = (struct tm *)gmtime_r(&intime, store);
574 #else
575   tm = gmtime(&intime);
576   if(tm)
577     *store = *tm; /* copy the pointed struct to the local copy */
578 #endif
579 
580   if(!tm)
581     return CURLE_BAD_FUNCTION_ARGUMENT;
582   return CURLE_OK;
583 }
584