ASN1_TIME_set, ASN1_UTCTIME_set, ASN1_GENERALIZEDTIME_set, ASN1_TIME_adj,
ASN1_UTCTIME_adj, ASN1_GENERALIZEDTIME_adj, ASN1_TIME_check,
ASN1_UTCTIME_check, ASN1_GENERALIZEDTIME_check, ASN1_TIME_set_string,
ASN1_UTCTIME_set_string, ASN1_GENERALIZEDTIME_set_string,
ASN1_TIME_set_string_X509, ASN1_TIME_normalize, ASN1_TIME_to_tm,
ASN1_TIME_print, ASN1_TIME_print_ex, ASN1_UTCTIME_print,
ASN1_GENERALIZEDTIME_print, ASN1_TIME_diff, ASN1_TIME_cmp_time_t,
ASN1_UTCTIME_cmp_time_t, ASN1_TIME_compare, ASN1_TIME_to_generalizedtime,
ASN1_TIME_dup, ASN1_UTCTIME_dup, ASN1_GENERALIZEDTIME_dup - ASN.1 Time
functions
ASN1_TIME *ASN1_TIME_set(ASN1_TIME *s, time_t t);
ASN1_UTCTIME *ASN1_UTCTIME_set(ASN1_UTCTIME *s, time_t t);
ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_set(ASN1_GENERALIZEDTIME *s,
time_t t);
ASN1_TIME *ASN1_TIME_adj(ASN1_TIME *s, time_t t, int offset_day,
long offset_sec);
ASN1_UTCTIME *ASN1_UTCTIME_adj(ASN1_UTCTIME *s, time_t t,
int offset_day, long offset_sec);
ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_adj(ASN1_GENERALIZEDTIME *s,
time_t t, int offset_day,
long offset_sec);
int ASN1_TIME_set_string(ASN1_TIME *s, const char *str);
int ASN1_TIME_set_string_X509(ASN1_TIME *s, const char *str);
int ASN1_UTCTIME_set_string(ASN1_UTCTIME *s, const char *str);
int ASN1_GENERALIZEDTIME_set_string(ASN1_GENERALIZEDTIME *s,
const char *str);
int ASN1_TIME_normalize(ASN1_TIME *s);
int ASN1_TIME_check(const ASN1_TIME *t);
int ASN1_UTCTIME_check(const ASN1_UTCTIME *t);
int ASN1_GENERALIZEDTIME_check(const ASN1_GENERALIZEDTIME *t);
int ASN1_TIME_print(BIO *b, const ASN1_TIME *s);
int ASN1_TIME_print_ex(BIO *bp, const ASN1_TIME *tm, unsigned long flags);
int ASN1_UTCTIME_print(BIO *b, const ASN1_UTCTIME *s);
int ASN1_GENERALIZEDTIME_print(BIO *b, const ASN1_GENERALIZEDTIME *s);
int ASN1_TIME_to_tm(const ASN1_TIME *s, struct tm *tm);
int ASN1_TIME_diff(int *pday, int *psec, const ASN1_TIME *from,
const ASN1_TIME *to);
int ASN1_TIME_cmp_time_t(const ASN1_TIME *s, time_t t);
int ASN1_UTCTIME_cmp_time_t(const ASN1_UTCTIME *s, time_t t);
int ASN1_TIME_compare(const ASN1_TIME *a, const ASN1_TIME *b);
ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(ASN1_TIME *t,
ASN1_GENERALIZEDTIME **out);
ASN1_TIME *ASN1_TIME_dup(const ASN1_TIME *t);
ASN1_UTCTIME *ASN1_UTCTIME_dup(const ASN1_UTCTIME *t);
ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_dup(const ASN1_GENERALIZEDTIME *t);
The
ASN1_TIME_set(),
ASN1_UTCTIME_set() and
ASN1_GENERALIZEDTIME_set() functions set the structure
s to the
time represented by the time_t value
t. If
s is NULL a new time
structure is allocated and returned.
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 NULL a new structure is allocated and returned.
The
ASN1_TIME_set_string(),
ASN1_UTCTIME_set_string() and
ASN1_GENERALIZEDTIME_set_string() functions set the time structure
s to the time represented by string
str which must be in
appropriate ASN.1 time format (for example YYMMDDHHMMSSZ or YYYYMMDDHHMMSSZ).
If
s is NULL this function performs a format check on
str only.
The string
str is copied into
s.
ASN1_TIME_set_string_X509() sets
ASN1_TIME structure
s to
the time represented by string
str which must be in appropriate time
format that RFC 5280 requires, which means it only allows YYMMDDHHMMSSZ and
YYYYMMDDHHMMSSZ (leap second is rejected), all other ASN.1 time format are not
allowed. If
s is NULL this function performs a format check on
str only.
The
ASN1_TIME_normalize() function converts an
ASN1_GENERALIZEDTIME or
ASN1_UTCTIME into a time value that can
be used in a certificate. It should be used after the
ASN1_TIME_set_string() functions and before
ASN1_TIME_print()
functions to get consistent (i.e. GMT) 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 BIO
b in human readable format. It will be of the format
MMM DD HH:MM:SS YYYY [GMT], for example "Feb 3 00:55:52 2015 GMT",
which does not include a newline. If the time structure has invalid format it
prints out "Bad time value" and returns an error. The output for
generalized time may include a fractional part following the second.
ASN1_TIME_print_ex() provides
flags to specify the output format
of the datetime. This can be either
ASN1_DTFLGS_RFC822 or
ASN1_DTFLGS_ISO8601.
ASN1_TIME_to_tm() converts the time
s to the standard
tm
structure. If
s is NULL, then the current time is converted. The output
time is GMT. The
tm_sec,
tm_min,
tm_hour,
tm_mday,
tm_wday,
tm_yday,
tm_mon and
tm_year fields of
tm structure are set to proper values, whereas all other fields are set
to 0. If
tm is NULL this function performs a format check on
s
only. If
s is in Generalized format with fractional seconds, e.g.
YYYYMMDDHHMMSS.SSSZ, the fractional seconds will be lost while converting
s to
tm structure.
ASN1_TIME_diff() sets
*pday and
*psec to the time
difference between
from 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 NULL 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
ASN1_TIME
to an
ASN1_GENERALIZEDTIME, regardless of year. If either
out or
*out are NULL, 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
ASN1_TIME structure corresponds to the ASN.1 structure
Time
defined in RFC5280 et al. The time setting functions obey the rules outlined
in RFC5280: if the date can be represented by UTCTime it is used, else
GeneralizedTime is used.
The
ASN1_TIME,
ASN1_UTCTIME and
ASN1_GENERALIZEDTIME
structures are represented as an
ASN1_STRING internally and can be
freed up using
ASN1_STRING_free().
The
ASN1_TIME 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).
ASN1_UTCTIME 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.
ASN1_TIME_adj() may change the type from
ASN1_GENERALIZEDTIME to
ASN1_UTCTIME, or vice versa, based on the resulting year.
ASN1_GENERALIZEDTIME_adj() and
ASN1_UTCTIME_adj() will not
modify the type of the return structure.
It is recommended that functions starting with
ASN1_TIME be used instead
of those starting with
ASN1_UTCTIME or
ASN1_GENERALIZEDTIME. The
functions starting with
ASN1_UTCTIME and
ASN1_GENERALIZEDTIME
act only on that specific time format. The functions starting with
ASN1_TIME will operate on either format.
ASN1_TIME_print(),
ASN1_UTCTIME_print() and
ASN1_GENERALIZEDTIME_print() do not print out the timezone: it either
prints out "GMT" or nothing. But all certificates complying with
RFC5280 et al use GMT anyway.
ASN1_TIME_print(),
ASN1_TIME_print_ex(),
ASN1_UTCTIME_print() and
ASN1_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 GMT results.
ASN1_TIME_set(),
ASN1_UTCTIME_set(),
ASN1_GENERALIZEDTIME_set(),
ASN1_TIME_adj(),
ASN1_UTCTIME_adj() and
ASN1_GENERALIZEDTIME_set() return a
pointer to a time structure or NULL if an error occurred.
ASN1_TIME_set_string(),
ASN1_UTCTIME_set_string(),
ASN1_GENERALIZEDTIME_set_string() and
ASN1_TIME_set_string_X509() return 1 if the time value is successfully
set and 0 otherwise.
ASN1_TIME_normalize() returns 1 on success, and 0 on error.
ASN1_TIME_check(), ASN1_UTCTIME_check and
ASN1_GENERALIZEDTIME_check() return 1 if the structure is syntactically
correct and 0 otherwise.
ASN1_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).
ASN1_TIME_to_tm() returns 1 if the time is successfully parsed and 0 if
an error occurred (invalid time format).
ASN1_TIME_diff() returns 1 for success and 0 for failure. It can fail if
the passed-in time structure has invalid syntax, for example.
ASN1_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.
ASN1_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.
ASN1_TIME_to_generalizedtime() returns a pointer to the appropriate time
structure on success or NULL if an error occurred.
ASN1_TIME_dup(),
ASN1_UTCTIME_dup() and
ASN1_GENERALIZEDTIME_dup() return a pointer to a time structure or NULL
if an error occurred.
Set a time structure to one hour after the current time and print it out:
#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);
Determine if one time is later or sooner than the current time:
int day, sec;
if (!ASN1_TIME_diff(&day, &sec, NULL, to))
/* Invalid time format */
if (day > 0 || sec > 0)
printf("Later\n");
else if (day < 0 || sec < 0)
printf("Sooner\n");
else
printf("Same\n");
The
ASN1_TIME_to_tm() function was added in OpenSSL 1.1.1. The
ASN1_TIME_set_string_X509() function was added in OpenSSL 1.1.1. The
ASN1_TIME_normalize() function was added in OpenSSL 1.1.1. The
ASN1_TIME_cmp_time_t() function was added in OpenSSL 1.1.1. The
ASN1_TIME_compare() function was added in OpenSSL 1.1.1.
Copyright 2015-2021 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy in the
file LICENSE in the source distribution or at
<
https://www.openssl.org/source/license.html>.