Standard preamble:
========================================================================
..
.... Set up some character translations and predefined strings. \*(-- will
give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
double quote, and \*(R" will give a right double quote. \*(C+ will
give a nicer C++. Capital omega is used to do unbreakable dashes and
therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
nothing in troff, for use with C<>.
.tr \(*W- . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\}
Escape single quotes in literal strings from groff's Unicode transform.
If the F register is >0, we'll generate index entries on stderr for
titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
entries marked with X<> in POD. Of course, you'll have to process the
output yourself in some meaningful fashion.
Avoid warning from groff about undefined register 'F'.
.. .nr rF 0 . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF
Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
Fear. Run. Save yourself. No user-serviceable parts.
. \" fudge factors for nroff and troff . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] .\} . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents . \" corrections for vroff . \" for low resolution devices (crt and lpr) \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} ========================================================================
Title "ASN1_TIME_SET 3"
way too many mistakes in technical documents.
The ASN1_TIME_adj(), ASN1_UTCTIME_adj() and ASN1_GENERALIZEDTIME_adj() functions set the time structure s to the time represented by the time offset_day and offset_sec after the time_t value t. The values of offset_day or offset_sec can be negative to set a time before t. The offset_sec value can also exceed the number of seconds in a day. If s is \s-1NULL\s0 a new structure is allocated and returned.
The ASN1_TIME_set_string(), ASN1_UTCTIME_set_string() and \fBASN1_GENERALIZEDTIME_set_string() functions set the time structure s to the time represented by string str which must be in appropriate \s-1ASN.1\s0 time format (for example \s-1YYMMDDHHMMSSZ\s0 or \s-1YYYYMMDDHHMMSSZ\s0). If s is \s-1NULL\s0 this function performs a format check on str only. The string str is copied into s.
\fBASN1_TIME_set_string_X509() sets \s-1ASN1_TIME\s0 structure s to the time represented by string str which must be in appropriate time format that \s-1RFC 5280\s0 requires, which means it only allows \s-1YYMMDDHHMMSSZ\s0 and \s-1YYYYMMDDHHMMSSZ\s0 (leap second is rejected), all other \s-1ASN.1\s0 time format are not allowed. If s is \s-1NULL\s0 this function performs a format check on str only.
The ASN1_TIME_normalize() function converts an \s-1ASN1_GENERALIZEDTIME\s0 or \fB\s-1ASN1_UTCTIME\s0 into a time value that can be used in a certificate. It should be used after the ASN1_TIME_set_string() functions and before \fBASN1_TIME_print() functions to get consistent (i.e. \s-1GMT\s0) results.
The ASN1_TIME_check(), ASN1_UTCTIME_check() and ASN1_GENERALIZEDTIME_check() functions check the syntax of the time structure s.
The ASN1_TIME_print(), ASN1_UTCTIME_print() and ASN1_GENERALIZEDTIME_print() functions print the time structure s to \s-1BIO\s0 b in human readable format. It will be of the format \s-1MMM DD HH:MM:SS YYYY\s0 [\s-1GMT\s0], for example \*(L"Feb 3 00:55:52 2015 \s-1GMT\*(R",\s0 which does not include a newline. If the time structure has invalid format it prints out \*(L"Bad time value\*(R" and returns an error. The output for generalized time may include a fractional part following the second.
\fBASN1_TIME_print_ex() provides flags to specify the output format of the datetime. This can be either \s-1ASN1_DTFLGS_RFC822\s0 or \s-1ASN1_DTFLGS_ISO8601\s0.
\fBASN1_TIME_to_tm() converts the time s to the standard tm structure. If s is \s-1NULL,\s0 then the current time is converted. The output time is \s-1GMT.\s0 The tm_sec, tm_min, tm_hour, tm_mday, tm_wday, tm_yday, \fItm_mon and tm_year fields of tm structure are set to proper values, whereas all other fields are set to 0. If tm is \s-1NULL\s0 this function performs a format check on s only. If s is in Generalized format with fractional seconds, e.g. \s-1YYYYMMDDHHMMSS.SSSZ,\s0 the fractional seconds will be lost while converting s to tm structure.
\fBASN1_TIME_diff() sets *pday and *psec to the time difference between \fIfrom and to. If to represents a time later than from then one or both (depending on the time difference) of *pday and *psec will be positive. If to represents a time earlier than from then one or both of *pday and *psec will be negative. If to and from represent the same time then *pday and *psec will both be zero. If both *pday and *psec are nonzero they will always have the same sign. The value of *psec will always be less than the number of seconds in a day. If from or to is \s-1NULL\s0 the current time is used.
The ASN1_TIME_cmp_time_t() and ASN1_UTCTIME_cmp_time_t() functions compare the two times represented by the time structure s and the time_t t.
The ASN1_TIME_compare() function compares the two times represented by the time structures a and b.
The ASN1_TIME_to_generalizedtime() function converts an \s-1ASN1_TIME\s0 to an \fB\s-1ASN1_GENERALIZEDTIME\s0, regardless of year. If either out or \fI*out are \s-1NULL,\s0 then a new object is allocated and must be freed after use.
The ASN1_TIME_dup(), ASN1_UTCTIME_dup() and ASN1_GENERALIZEDTIME_dup() functions duplicate the time structure t and return the duplicated result correspondingly.
The \s-1ASN1_TIME\s0, \s-1ASN1_UTCTIME\s0 and \s-1ASN1_GENERALIZEDTIME\s0 structures are represented as an \s-1ASN1_STRING\s0 internally and can be freed up using \fBASN1_STRING_free().
The \s-1ASN1_TIME\s0 structure can represent years from 0000 to 9999 but no attempt is made to correct ancient calendar changes (for example from Julian to Gregorian calendars).
\fB\s-1ASN1_UTCTIME\s0 is limited to a year range of 1950 through 2049.
Some applications add offset times directly to a time_t value and pass the results to ASN1_TIME_set() (or equivalent). This can cause problems as the time_t value can overflow on some systems resulting in unexpected results. New applications should use ASN1_TIME_adj() instead and pass the offset value in the offset_sec and offset_day parameters instead of directly manipulating a time_t value.
\fBASN1_TIME_adj() may change the type from \s-1ASN1_GENERALIZEDTIME\s0 to \fB\s-1ASN1_UTCTIME\s0, or vice versa, based on the resulting year. \fBASN1_GENERALIZEDTIME_adj() and ASN1_UTCTIME_adj() will not modify the type of the return structure.
It is recommended that functions starting with \s-1ASN1_TIME\s0 be used instead of those starting with \s-1ASN1_UTCTIME\s0 or \s-1ASN1_GENERALIZEDTIME\s0. The functions starting with \s-1ASN1_UTCTIME\s0 and \s-1ASN1_GENERALIZEDTIME\s0 act only on that specific time format. The functions starting with \s-1ASN1_TIME\s0 will operate on either format.
\fBASN1_TIME_print(), ASN1_TIME_print_ex(), ASN1_UTCTIME_print() and \fBASN1_GENERALIZEDTIME_print() do not distinguish if they fail because of an I/O error or invalid time format.
Use the ASN1_TIME_normalize() function to normalize the time value before printing to get \s-1GMT\s0 results.
\fBASN1_TIME_set_string(), ASN1_UTCTIME_set_string(), \fBASN1_GENERALIZEDTIME_set_string() and ASN1_TIME_set_string_X509() return 1 if the time value is successfully set and 0 otherwise.
\fBASN1_TIME_normalize() returns 1 on success, and 0 on error.
\fBASN1_TIME_check(), ASN1_UTCTIME_check and ASN1_GENERALIZEDTIME_check() return 1 if the structure is syntactically correct and 0 otherwise.
\fBASN1_TIME_print(), ASN1_UTCTIME_print() and ASN1_GENERALIZEDTIME_print() return 1 if the time is successfully printed out and 0 if an I/O error occurred an error occurred (I/O error or invalid time format).
\fBASN1_TIME_to_tm() returns 1 if the time is successfully parsed and 0 if an error occurred (invalid time format).
\fBASN1_TIME_diff() returns 1 for success and 0 for failure. It can fail if the passed-in time structure has invalid syntax, for example.
\fBASN1_TIME_cmp_time_t() and ASN1_UTCTIME_cmp_time_t() return -1 if s is before t, 0 if s equals t, or 1 if s is after t. -2 is returned on error.
\fBASN1_TIME_compare() returns -1 if a is before b, 0 if a equals b, or 1 if a is after b. -2 is returned on error.
\fBASN1_TIME_to_generalizedtime() returns a pointer to the appropriate time structure on success or \s-1NULL\s0 if an error occurred.
\fBASN1_TIME_dup(), ASN1_UTCTIME_dup() and ASN1_GENERALIZEDTIME_dup() return a pointer to a time structure or \s-1NULL\s0 if an error occurred.
.Vb 2 #include <time.h> #include <openssl/asn1.h> \& ASN1_TIME *tm; time_t t; BIO *b; \& t = time(NULL); tm = ASN1_TIME_adj(NULL, t, 0, 60 * 60); b = BIO_new_fp(stdout, BIO_NOCLOSE); ASN1_TIME_print(b, tm); ASN1_STRING_free(tm); BIO_free(b); .Ve
Determine if one time is later or sooner than the current time:
.Vb 1 int day, sec; \& if (!ASN1_TIME_diff(&day, &sec, NULL, to)) /* Invalid time format */ \& if (day > 0 || sec > 0) printf("Later\en"); else if (day < 0 || sec < 0) printf("Sooner\en"); else printf("Same\en"); .Ve
Licensed under the Apache License 2.0 (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.