path: root/contrib/libs/curl/lib/parsedate.c

/*************************************************************************** 
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 *  Project                     ___| | | |  _ \| | 
 *                             / __| | | | |_) | | 
 *                            | (__| |_| |  _ <| |___ 
 *                             \___|\___/|_| \_\_____| 
 * 
 * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
 * 
 * This software is licensed as described in the file COPYING, which 
 * you should have received as part of this distribution. The terms 
 * are also available at https://curl.se/docs/copyright.html.
 * 
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 
 * copies of the Software, and permit persons to whom the Software is 
 * furnished to do so, under the terms of the COPYING file. 
 * 
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 
 * KIND, either express or implied. 
 * 
 ***************************************************************************/ 
/* 
  A brief summary of the date string formats this parser groks: 
 
  RFC 2616 3.3.1 
 
  Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 822, updated by RFC 1123 
  Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036 
  Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format 
 
  we support dates without week day name: 
 
  06 Nov 1994 08:49:37 GMT 
  06-Nov-94 08:49:37 GMT 
  Nov  6 08:49:37 1994 
 
  without the time zone: 
 
  06 Nov 1994 08:49:37 
  06-Nov-94 08:49:37 
 
  weird order: 
 
  1994 Nov 6 08:49:37  (GNU date fails) 
  GMT 08:49:37 06-Nov-94 Sunday 
  94 6 Nov 08:49:37    (GNU date fails) 
 
  time left out: 
 
  1994 Nov 6 
  06-Nov-94 
  Sun Nov 6 94 
 
  unusual separators: 
 
  1994.Nov.6 
  Sun/Nov/6/94/GMT 
 
  commonly used time zone names: 
 
  Sun, 06 Nov 1994 08:49:37 CET 
  06 Nov 1994 08:49:37 EST 
 
  time zones specified using RFC822 style: 
 
  Sun, 12 Sep 2004 15:05:58 -0700 
  Sat, 11 Sep 2004 21:32:11 +0200 
 
  compact numerical date strings: 
 
  20040912 15:05:58 -0700 
  20040911 +0200 
 
*/ 
 
#include "curl_setup.h" 
 
#include <limits.h> 
 
#include <curl/curl.h> 
#include "strcase.h"
#include "warnless.h" 
#include "parsedate.h" 
 
/* 
 * parsedate() 
 * 
 * Returns: 
 * 
 * PARSEDATE_OK     - a fine conversion 
 * PARSEDATE_FAIL   - failed to convert 
 * PARSEDATE_LATER  - time overflow at the far end of time_t 
 * PARSEDATE_SOONER - time underflow at the low end of time_t 
 */ 
 
static int parsedate(const char *date, time_t *output); 
 
#define PARSEDATE_OK     0 
#define PARSEDATE_FAIL   -1 
#define PARSEDATE_LATER  1 
#define PARSEDATE_SOONER 2 
 
#if !defined(CURL_DISABLE_PARSEDATE) || !defined(CURL_DISABLE_FTP) || \
  !defined(CURL_DISABLE_FILE)
/* These names are also used by FTP and FILE code */
const char * const Curl_wkday[] =
{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
const char * const Curl_month[]=
{ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
#endif

#ifndef CURL_DISABLE_PARSEDATE
static const char * const weekday[] =
{ "Monday", "Tuesday", "Wednesday", "Thursday",
  "Friday", "Saturday", "Sunday" };

struct tzinfo {
  char name[5];
  int offset; /* +/- in minutes */
};

/* Here's a bunch of frequently used time zone names. These were supported 
   by the old getdate parser. */ 
#define tDAYZONE -60       /* offset for daylight savings time */ 
static const struct tzinfo tz[]= { 
  {"GMT", 0},              /* Greenwich Mean */ 
  {"UT",  0},              /* Universal Time */
  {"UTC", 0},              /* Universal (Coordinated) */ 
  {"WET", 0},              /* Western European */ 
  {"BST", 0 tDAYZONE},     /* British Summer */ 
  {"WAT", 60},             /* West Africa */ 
  {"AST", 240},            /* Atlantic Standard */ 
  {"ADT", 240 tDAYZONE},   /* Atlantic Daylight */ 
  {"EST", 300},            /* Eastern Standard */ 
  {"EDT", 300 tDAYZONE},   /* Eastern Daylight */ 
  {"CST", 360},            /* Central Standard */ 
  {"CDT", 360 tDAYZONE},   /* Central Daylight */ 
  {"MST", 420},            /* Mountain Standard */ 
  {"MDT", 420 tDAYZONE},   /* Mountain Daylight */ 
  {"PST", 480},            /* Pacific Standard */ 
  {"PDT", 480 tDAYZONE},   /* Pacific Daylight */ 
  {"YST", 540},            /* Yukon Standard */ 
  {"YDT", 540 tDAYZONE},   /* Yukon Daylight */ 
  {"HST", 600},            /* Hawaii Standard */ 
  {"HDT", 600 tDAYZONE},   /* Hawaii Daylight */ 
  {"CAT", 600},            /* Central Alaska */ 
  {"AHST", 600},           /* Alaska-Hawaii Standard */ 
  {"NT",  660},            /* Nome */ 
  {"IDLW", 720},           /* International Date Line West */ 
  {"CET", -60},            /* Central European */ 
  {"MET", -60},            /* Middle European */ 
  {"MEWT", -60},           /* Middle European Winter */ 
  {"MEST", -60 tDAYZONE},  /* Middle European Summer */ 
  {"CEST", -60 tDAYZONE},  /* Central European Summer */ 
  {"MESZ", -60 tDAYZONE},  /* Middle European Summer */ 
  {"FWT", -60},            /* French Winter */ 
  {"FST", -60 tDAYZONE},   /* French Summer */ 
  {"EET", -120},           /* Eastern Europe, USSR Zone 1 */ 
  {"WAST", -420},          /* West Australian Standard */ 
  {"WADT", -420 tDAYZONE}, /* West Australian Daylight */ 
  {"CCT", -480},           /* China Coast, USSR Zone 7 */ 
  {"JST", -540},           /* Japan Standard, USSR Zone 8 */ 
  {"EAST", -600},          /* Eastern Australian Standard */ 
  {"EADT", -600 tDAYZONE}, /* Eastern Australian Daylight */ 
  {"GST", -600},           /* Guam Standard, USSR Zone 9 */ 
  {"NZT", -720},           /* New Zealand */ 
  {"NZST", -720},          /* New Zealand Standard */ 
  {"NZDT", -720 tDAYZONE}, /* New Zealand Daylight */ 
  {"IDLE", -720},          /* International Date Line East */ 
  /* Next up: Military timezone names. RFC822 allowed these, but (as noted in 
     RFC 1123) had their signs wrong. Here we use the correct signs to match 
     actual military usage. 
   */ 
  {"A",  1 * 60},         /* Alpha */
  {"B",  2 * 60},         /* Bravo */
  {"C",  3 * 60},         /* Charlie */
  {"D",  4 * 60},         /* Delta */
  {"E",  5 * 60},         /* Echo */
  {"F",  6 * 60},         /* Foxtrot */
  {"G",  7 * 60},         /* Golf */
  {"H",  8 * 60},         /* Hotel */
  {"I",  9 * 60},         /* India */
  /* "J", Juliet is not used as a timezone, to indicate the observer's local 
     time */ 
  {"K", 10 * 60},         /* Kilo */
  {"L", 11 * 60},         /* Lima */
  {"M", 12 * 60},         /* Mike */
  {"N",  -1 * 60},         /* November */ 
  {"O",  -2 * 60},         /* Oscar */ 
  {"P",  -3 * 60},         /* Papa */ 
  {"Q",  -4 * 60},         /* Quebec */ 
  {"R",  -5 * 60},         /* Romeo */ 
  {"S",  -6 * 60},         /* Sierra */ 
  {"T",  -7 * 60},         /* Tango */ 
  {"U",  -8 * 60},         /* Uniform */ 
  {"V",  -9 * 60},         /* Victor */ 
  {"W", -10 * 60},         /* Whiskey */ 
  {"X", -11 * 60},         /* X-ray */ 
  {"Y", -12 * 60},         /* Yankee */ 
  {"Z", 0},                /* Zulu, zero meridian, a.k.a. UTC */ 
}; 
 
/* returns: 
   -1 no day 
   0 monday - 6 sunday 
*/ 
 
static int checkday(const char *check, size_t len) 
{ 
  int i; 
  const char * const *what; 
  bool found = FALSE;
  if(len > 3) 
    what = &weekday[0]; 
  else 
    what = &Curl_wkday[0]; 
  for(i = 0; i<7; i++) {
    if(strcasecompare(check, what[0])) {
      found = TRUE;
      break; 
    } 
    what++; 
  } 
  return found?i:-1; 
} 
 
static int checkmonth(const char *check) 
{ 
  int i; 
  const char * const *what; 
  bool found = FALSE;
 
  what = &Curl_month[0]; 
  for(i = 0; i<12; i++) {
    if(strcasecompare(check, what[0])) {
      found = TRUE;
      break; 
    } 
    what++; 
  } 
  return found?i:-1; /* return the offset or -1, no real offset is -1 */ 
} 
 
/* return the time zone offset between GMT and the input one, in number 
   of seconds or -1 if the timezone wasn't found/legal */ 
 
static int checktz(const char *check) 
{ 
  unsigned int i; 
  const struct tzinfo *what; 
  bool found = FALSE;
 
  what = tz; 
  for(i = 0; i< sizeof(tz)/sizeof(tz[0]); i++) {
    if(strcasecompare(check, what->name)) {
      found = TRUE;
      break; 
    } 
    what++; 
  } 
  return found?what->offset*60:-1; 
} 
 
static void skip(const char **date) 
{ 
  /* skip everything that aren't letters or digits */ 
  while(**date && !ISALNUM(**date)) 
    (*date)++; 
} 
 
enum assume { 
  DATE_MDAY, 
  DATE_YEAR, 
  DATE_TIME 
}; 
 
/*
 * time2epoch: time stamp to seconds since epoch in GMT time zone.  Similar to
 * mktime but for GMT only.
 */ 
static time_t time2epoch(int sec, int min, int hour,
                         int mday, int mon, int year)
{ 
  static const int month_days_cumulative [12] = 
    { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; 
  int leap_days = year - (mon <= 1);
  leap_days = ((leap_days / 4) - (leap_days / 100) + (leap_days / 400) 
               - (1969 / 4) + (1969 / 100) - (1969 / 400)); 
  return ((((time_t) (year - 1970) * 365
            + leap_days + month_days_cumulative[mon] + mday - 1) * 24
           + hour) * 60 + min) * 60 + sec;
} 
 
/* 
 * parsedate() 
 * 
 * Returns: 
 * 
 * PARSEDATE_OK     - a fine conversion 
 * PARSEDATE_FAIL   - failed to convert 
 * PARSEDATE_LATER  - time overflow at the far end of time_t 
 * PARSEDATE_SOONER - time underflow at the low end of time_t 
 */ 
 
static int parsedate(const char *date, time_t *output) 
{ 
  time_t t = 0; 
  int wdaynum = -1;  /* day of the week number, 0-6 (mon-sun) */
  int monnum = -1;   /* month of the year number, 0-11 */
  int mdaynum = -1; /* day of month, 1 - 31 */
  int hournum = -1;
  int minnum = -1;
  int secnum = -1;
  int yearnum = -1;
  int tzoff = -1;
  enum assume dignext = DATE_MDAY; 
  const char *indate = date; /* save the original pointer */ 
  int part = 0; /* max 6 parts */ 
 
  while(*date && (part < 6)) { 
    bool found = FALSE;
 
    skip(&date); 
 
    if(ISALPHA(*date)) { 
      /* a name coming up */ 
      char buf[32]=""; 
      size_t len; 
      if(sscanf(date, "%31[ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                          "abcdefghijklmnopqrstuvwxyz]", buf))
        len = strlen(buf);
      else
        len = 0;
 
      if(wdaynum == -1) { 
        wdaynum = checkday(buf, len); 
        if(wdaynum != -1) 
          found = TRUE; 
      } 
      if(!found && (monnum == -1)) { 
        monnum = checkmonth(buf); 
        if(monnum != -1) 
          found = TRUE; 
      } 
 
      if(!found && (tzoff == -1)) { 
        /* this just must be a time zone string */ 
        tzoff = checktz(buf); 
        if(tzoff != -1) 
          found = TRUE; 
      } 
 
      if(!found) 
        return PARSEDATE_FAIL; /* bad string */ 
 
      date += len; 
    } 
    else if(ISDIGIT(*date)) { 
      /* a digit */ 
      int val; 
      char *end; 
      int len = 0;
      if((secnum == -1) && 
         (3 == sscanf(date, "%02d:%02d:%02d%n",
                      &hournum, &minnum, &secnum, &len))) {
        /* time stamp! */ 
        date += len;
      } 
      else if((secnum == -1) && 
              (2 == sscanf(date, "%02d:%02d%n", &hournum, &minnum, &len))) {
        /* time stamp without seconds */ 
        date += len;
        secnum = 0; 
      } 
      else { 
        long lval; 
        int error; 
        int old_errno; 
 
        old_errno = errno;
        errno = 0;
        lval = strtol(date, &end, 10); 
        error = errno;
        if(errno != old_errno)
          errno = old_errno;
 
        if(error) 
          return PARSEDATE_FAIL; 
 
#if LONG_MAX != INT_MAX
        if((lval > (long)INT_MAX) || (lval < (long)INT_MIN)) 
          return PARSEDATE_FAIL; 
#endif
 
        val = curlx_sltosi(lval); 
 
        if((tzoff == -1) && 
           ((end - date) == 4) && 
           (val <= 1400) && 
           (indate< date) && 
           ((date[-1] == '+' || date[-1] == '-'))) { 
          /* four digits and a value less than or equal to 1400 (to take into 
             account all sorts of funny time zone diffs) and it is preceded 
             with a plus or minus. This is a time zone indication.  1400 is 
             picked since +1300 is frequently used and +1400 is mentioned as 
             an edge number in the document "ISO C 200X Proposal: Timezone 
             Functions" at http://david.tribble.com/text/c0xtimezone.html If 
             anyone has a more authoritative source for the exact maximum time 
             zone offsets, please speak up! */ 
          found = TRUE; 
          tzoff = (val/100 * 60 + val%100)*60; 
 
          /* the + and - prefix indicates the local time compared to GMT, 
             this we need their reversed math to get what we want */
          tzoff = date[-1]=='+'?-tzoff:tzoff; 
        } 
 
        if(((end - date) == 8) && 
           (yearnum == -1) && 
           (monnum == -1) && 
           (mdaynum == -1)) { 
          /* 8 digits, no year, month or day yet. This is YYYYMMDD */ 
          found = TRUE; 
          yearnum = val/10000; 
          monnum = (val%10000)/100-1; /* month is 0 - 11 */ 
          mdaynum = val%100; 
        } 
 
        if(!found && (dignext == DATE_MDAY) && (mdaynum == -1)) { 
          if((val > 0) && (val<32)) { 
            mdaynum = val; 
            found = TRUE; 
          } 
          dignext = DATE_YEAR; 
        } 
 
        if(!found && (dignext == DATE_YEAR) && (yearnum == -1)) { 
          yearnum = val; 
          found = TRUE; 
          if(yearnum < 100) {
            if(yearnum > 70) 
              yearnum += 1900; 
            else 
              yearnum += 2000; 
          } 
          if(mdaynum == -1) 
            dignext = DATE_MDAY; 
        } 
 
        if(!found) 
          return PARSEDATE_FAIL; 
 
        date = end; 
      } 
    } 
 
    part++; 
  } 
 
  if(-1 == secnum) 
    secnum = minnum = hournum = 0; /* no time, make it zero */ 
 
  if((-1 == mdaynum) || 
     (-1 == monnum) || 
     (-1 == yearnum)) 
    /* lacks vital info, fail */ 
    return PARSEDATE_FAIL; 
 
#ifdef HAVE_TIME_T_UNSIGNED
  if(yearnum < 1970) {
    /* only positive numbers cannot return earlier */
    *output = TIME_T_MIN;
    return PARSEDATE_SOONER;
  }
#endif

#if (SIZEOF_TIME_T < 5)

#ifdef HAVE_TIME_T_UNSIGNED
  /* an unsigned 32 bit time_t can only hold dates to 2106 */
  if(yearnum > 2105) {
    *output = TIME_T_MAX;
    return PARSEDATE_LATER;
  }
#else
  /* a signed 32 bit time_t can only hold dates to the beginning of 2038 */
  if(yearnum > 2037) { 
    *output = TIME_T_MAX;
    return PARSEDATE_LATER; 
  } 
  if(yearnum < 1903) {
    *output = TIME_T_MIN;
    return PARSEDATE_SOONER; 
  } 
#endif
 
#else
  /* The Gregorian calendar was introduced 1582 */
  if(yearnum < 1583)
    return PARSEDATE_FAIL;
#endif

  if((mdaynum > 31) || (monnum > 11) || 
     (hournum > 23) || (minnum > 59) || (secnum > 60)) 
    return PARSEDATE_FAIL; /* clearly an illegal date */ 
 
  /* time2epoch() returns a time_t. time_t is often 32 bits, sometimes even on
     architectures that feature 64 bit 'long' but ultimately time_t is the
     correct data type to use.
  */ 
  t = time2epoch(secnum, minnum, hournum, mdaynum, monnum, yearnum);
 
  /* Add the time zone diff between local time zone and GMT. */
  if(tzoff == -1)
    tzoff = 0;
 
  if((tzoff > 0) && (t > TIME_T_MAX - tzoff)) {
    *output = TIME_T_MAX;
    return PARSEDATE_LATER; /* time_t overflow */
  }
 
  t += tzoff;
 
  *output = t; 
 
  return PARSEDATE_OK; 
} 
#else
/* disabled */
static int parsedate(const char *date, time_t *output)
{
  (void)date;
  *output = 0;
  return PARSEDATE_OK; /* a lie */
}
#endif
 
time_t curl_getdate(const char *p, const time_t *now) 
{ 
  time_t parsed = -1;
  int rc = parsedate(p, &parsed); 
  (void)now; /* legacy argument from the past that we ignore */ 
 
  if(rc == PARSEDATE_OK) {
    if(parsed == -1)
      /* avoid returning -1 for a working scenario */
      parsed++;
    return parsed; 
  } 
  /* everything else is fail */ 
  return -1; 
} 
 
/* Curl_getdate_capped() differs from curl_getdate() in that this will return
   TIME_T_MAX in case the parsed time value was too big, instead of an
   error. */

time_t Curl_getdate_capped(const char *p)
{
  time_t parsed = -1;
  int rc = parsedate(p, &parsed);

  switch(rc) {
  case PARSEDATE_OK:
    if(parsed == -1)
      /* avoid returning -1 for a working scenario */
      parsed++;
    return parsed;
  case PARSEDATE_LATER:
    /* this returns the maximum time value */
    return parsed;
  default:
    return -1; /* everything else is fail */
  }
  /* UNREACHABLE */
}

/* 
 * Curl_gmtime() is a gmtime() replacement for portability. Do not use the 
 * gmtime_r() or gmtime() functions anywhere else but here. 
 * 
 */ 
 
CURLcode Curl_gmtime(time_t intime, struct tm *store) 
{ 
  const struct tm *tm; 
#ifdef HAVE_GMTIME_R 
  /* thread-safe version */ 
  tm = (struct tm *)gmtime_r(&intime, store); 
#else 
  /* !checksrc! disable BANNEDFUNC 1 */
  tm = gmtime(&intime); 
  if(tm) 
    *store = *tm; /* copy the pointed struct to the local copy */ 
#endif 
 
  if(!tm) 
    return CURLE_BAD_FUNCTION_ARGUMENT; 
  return CURLE_OK; 
}