• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2017, 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 const char * const Curl_wkday[] =
86 {"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
87 static const char * const weekday[] =
88 { "Monday", "Tuesday", "Wednesday", "Thursday",
89   "Friday", "Saturday", "Sunday" };
90 const char * const Curl_month[]=
91 { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
92   "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
93 
94 struct tzinfo {
95   char name[5];
96   int offset; /* +/- in minutes */
97 };
98 
99 /*
100  * parsedate()
101  *
102  * Returns:
103  *
104  * PARSEDATE_OK     - a fine conversion
105  * PARSEDATE_FAIL   - failed to convert
106  * PARSEDATE_LATER  - time overflow at the far end of time_t
107  * PARSEDATE_SOONER - time underflow at the low end of time_t
108  */
109 
110 static int parsedate(const char *date, time_t *output);
111 
112 #define PARSEDATE_OK     0
113 #define PARSEDATE_FAIL   -1
114 #define PARSEDATE_LATER  1
115 #define PARSEDATE_SOONER 2
116 
117 /* Here's a bunch of frequently used time zone names. These were supported
118    by the old getdate parser. */
119 #define tDAYZONE -60       /* offset for daylight savings time */
120 static const struct tzinfo tz[]= {
121   {"GMT", 0},              /* Greenwich Mean */
122   {"UTC", 0},              /* Universal (Coordinated) */
123   {"WET", 0},              /* Western European */
124   {"BST", 0 tDAYZONE},     /* British Summer */
125   {"WAT", 60},             /* West Africa */
126   {"AST", 240},            /* Atlantic Standard */
127   {"ADT", 240 tDAYZONE},   /* Atlantic Daylight */
128   {"EST", 300},            /* Eastern Standard */
129   {"EDT", 300 tDAYZONE},   /* Eastern Daylight */
130   {"CST", 360},            /* Central Standard */
131   {"CDT", 360 tDAYZONE},   /* Central Daylight */
132   {"MST", 420},            /* Mountain Standard */
133   {"MDT", 420 tDAYZONE},   /* Mountain Daylight */
134   {"PST", 480},            /* Pacific Standard */
135   {"PDT", 480 tDAYZONE},   /* Pacific Daylight */
136   {"YST", 540},            /* Yukon Standard */
137   {"YDT", 540 tDAYZONE},   /* Yukon Daylight */
138   {"HST", 600},            /* Hawaii Standard */
139   {"HDT", 600 tDAYZONE},   /* Hawaii Daylight */
140   {"CAT", 600},            /* Central Alaska */
141   {"AHST", 600},           /* Alaska-Hawaii Standard */
142   {"NT",  660},            /* Nome */
143   {"IDLW", 720},           /* International Date Line West */
144   {"CET", -60},            /* Central European */
145   {"MET", -60},            /* Middle European */
146   {"MEWT", -60},           /* Middle European Winter */
147   {"MEST", -60 tDAYZONE},  /* Middle European Summer */
148   {"CEST", -60 tDAYZONE},  /* Central European Summer */
149   {"MESZ", -60 tDAYZONE},  /* Middle European Summer */
150   {"FWT", -60},            /* French Winter */
151   {"FST", -60 tDAYZONE},   /* French Summer */
152   {"EET", -120},           /* Eastern Europe, USSR Zone 1 */
153   {"WAST", -420},          /* West Australian Standard */
154   {"WADT", -420 tDAYZONE}, /* West Australian Daylight */
155   {"CCT", -480},           /* China Coast, USSR Zone 7 */
156   {"JST", -540},           /* Japan Standard, USSR Zone 8 */
157   {"EAST", -600},          /* Eastern Australian Standard */
158   {"EADT", -600 tDAYZONE}, /* Eastern Australian Daylight */
159   {"GST", -600},           /* Guam Standard, USSR Zone 9 */
160   {"NZT", -720},           /* New Zealand */
161   {"NZST", -720},          /* New Zealand Standard */
162   {"NZDT", -720 tDAYZONE}, /* New Zealand Daylight */
163   {"IDLE", -720},          /* International Date Line East */
164   /* Next up: Military timezone names. RFC822 allowed these, but (as noted in
165      RFC 1123) had their signs wrong. Here we use the correct signs to match
166      actual military usage.
167    */
168   {"A",  1 * 60},         /* Alpha */
169   {"B",  2 * 60},         /* Bravo */
170   {"C",  3 * 60},         /* Charlie */
171   {"D",  4 * 60},         /* Delta */
172   {"E",  5 * 60},         /* Echo */
173   {"F",  6 * 60},         /* Foxtrot */
174   {"G",  7 * 60},         /* Golf */
175   {"H",  8 * 60},         /* Hotel */
176   {"I",  9 * 60},         /* India */
177   /* "J", Juliet is not used as a timezone, to indicate the observer's local
178      time */
179   {"K", 10 * 60},         /* Kilo */
180   {"L", 11 * 60},         /* Lima */
181   {"M", 12 * 60},         /* Mike */
182   {"N",  -1 * 60},         /* November */
183   {"O",  -2 * 60},         /* Oscar */
184   {"P",  -3 * 60},         /* Papa */
185   {"Q",  -4 * 60},         /* Quebec */
186   {"R",  -5 * 60},         /* Romeo */
187   {"S",  -6 * 60},         /* Sierra */
188   {"T",  -7 * 60},         /* Tango */
189   {"U",  -8 * 60},         /* Uniform */
190   {"V",  -9 * 60},         /* Victor */
191   {"W", -10 * 60},         /* Whiskey */
192   {"X", -11 * 60},         /* X-ray */
193   {"Y", -12 * 60},         /* Yankee */
194   {"Z", 0},                /* Zulu, zero meridian, a.k.a. UTC */
195 };
196 
197 /* returns:
198    -1 no day
199    0 monday - 6 sunday
200 */
201 
checkday(const char * check,size_t len)202 static int checkday(const char *check, size_t len)
203 {
204   int i;
205   const char * const *what;
206   bool found = FALSE;
207   if(len > 3)
208     what = &weekday[0];
209   else
210     what = &Curl_wkday[0];
211   for(i = 0; i<7; i++) {
212     if(strcasecompare(check, what[0])) {
213       found = TRUE;
214       break;
215     }
216     what++;
217   }
218   return found?i:-1;
219 }
220 
checkmonth(const char * check)221 static int checkmonth(const char *check)
222 {
223   int i;
224   const char * const *what;
225   bool found = FALSE;
226 
227   what = &Curl_month[0];
228   for(i = 0; i<12; i++) {
229     if(strcasecompare(check, what[0])) {
230       found = TRUE;
231       break;
232     }
233     what++;
234   }
235   return found?i:-1; /* return the offset or -1, no real offset is -1 */
236 }
237 
238 /* return the time zone offset between GMT and the input one, in number
239    of seconds or -1 if the timezone wasn't found/legal */
240 
checktz(const char * check)241 static int checktz(const char *check)
242 {
243   unsigned int i;
244   const struct tzinfo *what;
245   bool found = FALSE;
246 
247   what = tz;
248   for(i = 0; i< sizeof(tz)/sizeof(tz[0]); i++) {
249     if(strcasecompare(check, what->name)) {
250       found = TRUE;
251       break;
252     }
253     what++;
254   }
255   return found?what->offset*60:-1;
256 }
257 
skip(const char ** date)258 static void skip(const char **date)
259 {
260   /* skip everything that aren't letters or digits */
261   while(**date && !ISALNUM(**date))
262     (*date)++;
263 }
264 
265 enum assume {
266   DATE_MDAY,
267   DATE_YEAR,
268   DATE_TIME
269 };
270 
271 /* this is a clone of 'struct tm' but with all fields we don't need or use
272    cut out */
273 struct my_tm {
274   int tm_sec;
275   int tm_min;
276   int tm_hour;
277   int tm_mday;
278   int tm_mon;
279   int tm_year;
280 };
281 
282 /* struct tm to time since epoch in GMT time zone.
283  * This is similar to the standard mktime function but for GMT only, and
284  * doesn't suffer from the various bugs and portability problems that
285  * some systems' implementations have.
286  */
my_timegm(struct my_tm * tm)287 static time_t my_timegm(struct my_tm *tm)
288 {
289   static const int month_days_cumulative [12] =
290     { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
291   int month, year, leap_days;
292 
293   if(tm->tm_year < 70)
294     /* we don't support years before 1970 as they will cause this function
295        to return a negative value */
296     return -1;
297 
298   year = tm->tm_year + 1900;
299   month = tm->tm_mon;
300   if(month < 0) {
301     year += (11 - month) / 12;
302     month = 11 - (11 - month) % 12;
303   }
304   else if(month >= 12) {
305     year -= month / 12;
306     month = month % 12;
307   }
308 
309   leap_days = year - (tm->tm_mon <= 1);
310   leap_days = ((leap_days / 4) - (leap_days / 100) + (leap_days / 400)
311                - (1969 / 4) + (1969 / 100) - (1969 / 400));
312 
313   return ((((time_t) (year - 1970) * 365
314             + leap_days + month_days_cumulative [month] + tm->tm_mday - 1) * 24
315            + tm->tm_hour) * 60 + tm->tm_min) * 60 + tm->tm_sec;
316 }
317 
318 /*
319  * parsedate()
320  *
321  * Returns:
322  *
323  * PARSEDATE_OK     - a fine conversion
324  * PARSEDATE_FAIL   - failed to convert
325  * PARSEDATE_LATER  - time overflow at the far end of time_t
326  * PARSEDATE_SOONER - time underflow at the low end of time_t
327  */
328 
parsedate(const char * date,time_t * output)329 static int parsedate(const char *date, time_t *output)
330 {
331   time_t t = 0;
332   int wdaynum = -1;  /* day of the week number, 0-6 (mon-sun) */
333   int monnum = -1;   /* month of the year number, 0-11 */
334   int mdaynum = -1; /* day of month, 1 - 31 */
335   int hournum = -1;
336   int minnum = -1;
337   int secnum = -1;
338   int yearnum = -1;
339   int tzoff = -1;
340   struct my_tm tm;
341   enum assume dignext = DATE_MDAY;
342   const char *indate = date; /* save the original pointer */
343   int part = 0; /* max 6 parts */
344 
345   while(*date && (part < 6)) {
346     bool found = FALSE;
347 
348     skip(&date);
349 
350     if(ISALPHA(*date)) {
351       /* a name coming up */
352       char buf[32]="";
353       size_t len;
354       if(sscanf(date, "%31[ABCDEFGHIJKLMNOPQRSTUVWXYZ"
355                           "abcdefghijklmnopqrstuvwxyz]", buf))
356         len = strlen(buf);
357       else
358         len = 0;
359 
360       if(wdaynum == -1) {
361         wdaynum = checkday(buf, len);
362         if(wdaynum != -1)
363           found = TRUE;
364       }
365       if(!found && (monnum == -1)) {
366         monnum = checkmonth(buf);
367         if(monnum != -1)
368           found = TRUE;
369       }
370 
371       if(!found && (tzoff == -1)) {
372         /* this just must be a time zone string */
373         tzoff = checktz(buf);
374         if(tzoff != -1)
375           found = TRUE;
376       }
377 
378       if(!found)
379         return PARSEDATE_FAIL; /* bad string */
380 
381       date += len;
382     }
383     else if(ISDIGIT(*date)) {
384       /* a digit */
385       int val;
386       char *end;
387       int len = 0;
388       if((secnum == -1) &&
389          (3 == sscanf(date, "%02d:%02d:%02d%n",
390                       &hournum, &minnum, &secnum, &len))) {
391         /* time stamp! */
392         date += len;
393       }
394       else if((secnum == -1) &&
395               (2 == sscanf(date, "%02d:%02d%n", &hournum, &minnum, &len))) {
396         /* time stamp without seconds */
397         date += len;
398         secnum = 0;
399       }
400       else {
401         long lval;
402         int error;
403         int old_errno;
404 
405         old_errno = errno;
406         errno = 0;
407         lval = strtol(date, &end, 10);
408         error = errno;
409         if(errno != old_errno)
410           errno = old_errno;
411 
412         if(error)
413           return PARSEDATE_FAIL;
414 
415 #if LONG_MAX != INT_MAX
416         if((lval > (long)INT_MAX) || (lval < (long)INT_MIN))
417           return PARSEDATE_FAIL;
418 #endif
419 
420         val = curlx_sltosi(lval);
421 
422         if((tzoff == -1) &&
423            ((end - date) == 4) &&
424            (val <= 1400) &&
425            (indate< date) &&
426            ((date[-1] == '+' || date[-1] == '-'))) {
427           /* four digits and a value less than or equal to 1400 (to take into
428              account all sorts of funny time zone diffs) and it is preceded
429              with a plus or minus. This is a time zone indication.  1400 is
430              picked since +1300 is frequently used and +1400 is mentioned as
431              an edge number in the document "ISO C 200X Proposal: Timezone
432              Functions" at http://david.tribble.com/text/c0xtimezone.html If
433              anyone has a more authoritative source for the exact maximum time
434              zone offsets, please speak up! */
435           found = TRUE;
436           tzoff = (val/100 * 60 + val%100)*60;
437 
438           /* the + and - prefix indicates the local time compared to GMT,
439              this we need ther reversed math to get what we want */
440           tzoff = date[-1]=='+'?-tzoff:tzoff;
441         }
442 
443         if(((end - date) == 8) &&
444            (yearnum == -1) &&
445            (monnum == -1) &&
446            (mdaynum == -1)) {
447           /* 8 digits, no year, month or day yet. This is YYYYMMDD */
448           found = TRUE;
449           yearnum = val/10000;
450           monnum = (val%10000)/100-1; /* month is 0 - 11 */
451           mdaynum = val%100;
452         }
453 
454         if(!found && (dignext == DATE_MDAY) && (mdaynum == -1)) {
455           if((val > 0) && (val<32)) {
456             mdaynum = val;
457             found = TRUE;
458           }
459           dignext = DATE_YEAR;
460         }
461 
462         if(!found && (dignext == DATE_YEAR) && (yearnum == -1)) {
463           yearnum = val;
464           found = TRUE;
465           if(yearnum < 1900) {
466             if(yearnum > 70)
467               yearnum += 1900;
468             else
469               yearnum += 2000;
470           }
471           if(mdaynum == -1)
472             dignext = DATE_MDAY;
473         }
474 
475         if(!found)
476           return PARSEDATE_FAIL;
477 
478         date = end;
479       }
480     }
481 
482     part++;
483   }
484 
485   if(-1 == secnum)
486     secnum = minnum = hournum = 0; /* no time, make it zero */
487 
488   if((-1 == mdaynum) ||
489      (-1 == monnum) ||
490      (-1 == yearnum))
491     /* lacks vital info, fail */
492     return PARSEDATE_FAIL;
493 
494 #if SIZEOF_TIME_T < 5
495   /* 32 bit time_t can only hold dates to the beginning of 2038 */
496   if(yearnum > 2037) {
497     *output = 0x7fffffff;
498     return PARSEDATE_LATER;
499   }
500 #endif
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