/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) Daniel Stenberg, , 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. * * SPDX-License-Identifier: curl * ***************************************************************************/ #include "curl_setup.h" #include "parsedate.h" #include "curlx/strparse.h" /* 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 */ #if !defined(CURL_DISABLE_PARSEDATE) || !defined(CURL_DISABLE_FTP) || \ !defined(CURL_DISABLE_FILE) || defined(USE_GNUTLS) /* 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 #define PARSEDATE_OK 0 #define PARSEDATE_FAIL (-1) #ifndef CURL_DISABLE_PARSEDATE #define PARSEDATE_LATER 1 #if defined(HAVE_TIME_T_UNSIGNED) || (SIZEOF_TIME_T < 5) #define PARSEDATE_SOONER 2 #endif 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 */ /* spellchecker:disable-line */ { "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 }, /* spellchecker:disable-line */ /* 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; if(len > 3) what = &weekday[0]; else if(len == 3) what = &Curl_wkday[0]; else return -1; /* too short */ for(i = 0; i < 7; i++) { size_t ilen = strlen(what[0]); if((ilen == len) && curl_strnequal(check, what[0], len)) return i; what++; } return -1; } static int checkmonth(const char *check, size_t len) { int i; const char * const *what = &Curl_month[0]; if(len != 3) return -1; /* not a month */ for(i = 0; i < 12; i++) { if(curl_strnequal(check, what[0], 3)) return i; what++; } return -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 was not found/legal */ static int checktz(const char *check, size_t len) { unsigned int i; const struct tzinfo *what = tz; if(len > 4) /* longer than any valid timezone */ return -1; for(i = 0; i < CURL_ARRAYSIZE(tz); i++) { size_t ilen = strlen(what->name); if((ilen == len) && curl_strnequal(check, what->name, len)) return what->offset * 60; what++; } return -1; } static void skip(const char **date) { /* skip everything that are not 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; } /* Returns the value of a single-digit or two-digit decimal number, return then pointer to after the number. The 'date' pointer is known to point to a digit. */ static int oneortwodigit(const char *date, const char **endp) { int num = date[0] - '0'; if(ISDIGIT(date[1])) { *endp = &date[2]; return (num * 10) + (date[1] - '0'); } *endp = &date[1]; return num; } /* HH:MM:SS or HH:MM and accept single-digits too */ static bool match_time(const char *date, int *h, int *m, int *s, char **endp) { const char *p; int hh, mm, ss = 0; hh = oneortwodigit(date, &p); if((hh < 24) && (*p == ':') && ISDIGIT(p[1])) { mm = oneortwodigit(&p[1], &p); if(mm < 60) { if((*p == ':') && ISDIGIT(p[1])) { ss = oneortwodigit(&p[1], &p); if(ss <= 60) { /* valid HH:MM:SS */ goto match; } } else { /* valid HH:MM */ goto match; } } } return FALSE; /* not a time string */ match: *h = hh; *m = mm; *s = ss; *endp = (char *)CURL_UNCONST(p); return TRUE; } /* * 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 */ /* Wednesday is the longest name this parser knows about */ #define NAME_LEN 12 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 */ size_t len = 0; const char *p = date; while(ISALPHA(*p) && (len < NAME_LEN)) { p++; len++; } if(len != NAME_LEN) { if(wdaynum == -1) { wdaynum = checkday(date, len); if(wdaynum != -1) found = TRUE; } if(!found && (monnum == -1)) { monnum = checkmonth(date, len); if(monnum != -1) found = TRUE; } if(!found && (tzoff == -1)) { /* this must be a time zone string */ tzoff = checktz(date, len); if(tzoff != -1) found = TRUE; } } if(!found) return PARSEDATE_FAIL; /* bad string */ date += len; } else if(ISDIGIT(*date)) { /* a digit */ unsigned int val; char *end; if((secnum == -1) && match_time(date, &hournum, &minnum, &secnum, &end)) { /* time stamp */ date = end; } else { curl_off_t lval; int num_digits = 0; const char *p = date; if(curlx_str_number(&p, &lval, 99999999)) return PARSEDATE_FAIL; /* we know num_digits cannot be larger than 8 */ num_digits = (int)(p - date); val = (unsigned int)lval; if((tzoff == -1) && (num_digits == 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; } else if((num_digits == 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 = p; } } part++; } if(secnum == -1) secnum = minnum = hournum = 0; /* no time, make it zero */ if((mdaynum == -1) || (monnum == -1) || (yearnum == -1)) /* 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 a 64 bits '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)(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 *unused) { time_t parsed = -1; int rc = parsedate(p, &parsed); (void)unused; /* legacy argument from the past that we ignore */ if(rc == PARSEDATE_OK) { if(parsed == (time_t)-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. Returns non-zero on error. */ int Curl_getdate_capped(const char *p, time_t *tp) { int rc = parsedate(p, tp); return (rc == PARSEDATE_FAIL); }