5 ASN1_TIME_set, ASN1_UTCTIME_set, ASN1_GENERALIZEDTIME_set,
6 ASN1_TIME_adj, ASN1_UTCTIME_adj, ASN1_GENERALIZEDTIME_adj,
7 ASN1_TIME_check, ASN1_UTCTIME_check, ASN1_GENERALIZEDTIME_check,
8 ASN1_TIME_set_string, ASN1_UTCTIME_set_string, ASN1_GENERALIZEDTIME_set_string,
9 ASN1_TIME_set_string_X509,
12 ASN1_TIME_print, ASN1_UTCTIME_print, ASN1_GENERALIZEDTIME_print,
14 ASN1_TIME_cmp_time_t, ASN1_UTCTIME_cmp_time_t,
16 ASN1_TIME_to_generalizedtime - ASN.1 Time functions
20 ASN1_TIME *ASN1_TIME_set(ASN1_TIME *s, time_t t);
21 ASN1_UTCTIME *ASN1_UTCTIME_set(ASN1_UTCTIME *s, time_t t);
22 ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_set(ASN1_GENERALIZEDTIME *s,
25 ASN1_TIME *ASN1_TIME_adj(ASN1_TIME *s, time_t t, int offset_day,
27 ASN1_UTCTIME *ASN1_UTCTIME_adj(ASN1_UTCTIME *s, time_t t,
28 int offset_day, long offset_sec);
29 ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_adj(ASN1_GENERALIZEDTIME *s,
30 time_t t, int offset_day,
33 int ASN1_TIME_set_string(ASN1_TIME *s, const char *str);
34 int ASN1_TIME_set_string_X509(ASN1_TIME *s, const char *str);
35 int ASN1_UTCTIME_set_string(ASN1_UTCTIME *s, const char *str);
36 int ASN1_GENERALIZEDTIME_set_string(ASN1_GENERALIZEDTIME *s,
39 int ASN1_TIME_normalize(ASN1_TIME *s);
41 int ASN1_TIME_check(const ASN1_TIME *t);
42 int ASN1_UTCTIME_check(const ASN1_UTCTIME *t);
43 int ASN1_GENERALIZEDTIME_check(const ASN1_GENERALIZEDTIME *t);
45 int ASN1_TIME_print(BIO *b, const ASN1_TIME *s);
46 int ASN1_UTCTIME_print(BIO *b, const ASN1_UTCTIME *s);
47 int ASN1_GENERALIZEDTIME_print(BIO *b, const ASN1_GENERALIZEDTIME *s);
49 int ASN1_TIME_to_tm(const ASN1_TIME *s, struct tm *tm);
50 int ASN1_TIME_diff(int *pday, int *psec, const ASN1_TIME *from,
53 int ASN1_TIME_cmp_time_t(const ASN1_TIME *s, time_t t);
54 int ASN1_UTCTIME_cmp_time_t(const ASN1_UTCTIME *s, time_t t);
56 int ASN1_TIME_compare(const ASN1_TIME *a, const ASN1_TIME *b);
58 ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(ASN1_TIME *t,
59 ASN1_GENERALIZEDTIME **out);
63 The ASN1_TIME_set(), ASN1_UTCTIME_set() and ASN1_GENERALIZEDTIME_set()
64 functions set the structure B<s> to the time represented by the time_t
65 value B<t>. If B<s> is NULL a new time structure is allocated and returned.
67 The ASN1_TIME_adj(), ASN1_UTCTIME_adj() and ASN1_GENERALIZEDTIME_adj()
68 functions set the time structure B<s> to the time represented
69 by the time B<offset_day> and B<offset_sec> after the time_t value B<t>.
70 The values of B<offset_day> or B<offset_sec> can be negative to set a
71 time before B<t>. The B<offset_sec> value can also exceed the number of
72 seconds in a day. If B<s> is NULL a new structure is allocated
75 The ASN1_TIME_set_string(), ASN1_UTCTIME_set_string() and
76 ASN1_GENERALIZEDTIME_set_string() functions set the time structure B<s>
77 to the time represented by string B<str> which must be in appropriate ASN.1
78 time format (for example YYMMDDHHMMSSZ or YYYYMMDDHHMMSSZ). If B<s> is NULL
79 this function performs a format check on B<str> only. The string B<str>
82 ASN1_TIME_set_string_X509() sets ASN1_TIME structure B<s> to the time
83 represented by string B<str> which must be in appropriate time format
84 that RFC 5280 requires, which means it only allows YYMMDDHHMMSSZ and
85 YYYYMMDDHHMMSSZ (leap second is rejected), all other ASN.1 time format
86 are not allowed. If B<s> is NULL this function performs a format check
89 The ASN1_TIME_normalize() function converts an ASN1_GENERALIZEDTIME or
90 ASN1_UTCTIME into a time value that can be used in a certificate. It
91 should be used after the ASN1_TIME_set_string() functions and before
92 ASN1_TIME_print() functions to get consistent (i.e. GMT) results.
94 The ASN1_TIME_check(), ASN1_UTCTIME_check() and ASN1_GENERALIZEDTIME_check()
95 functions check the syntax of the time structure B<s>.
97 The ASN1_TIME_print(), ASN1_UTCTIME_print() and ASN1_GENERALIZEDTIME_print()
98 functions print the time structure B<s> to BIO B<b> in human readable
99 format. It will be of the format MMM DD HH:MM:SS YYYY [GMT], for example
100 "Feb 3 00:55:52 2015 GMT" it does not include a newline. If the time
101 structure has invalid format it prints out "Bad time value" and returns
102 an error. The output for generalized time may include a fractional part
103 following the second.
105 ASN1_TIME_to_tm() converts the time B<s> to the standard B<tm> structure.
106 If B<s> is NULL, then the current time is converted. The output time is GMT.
107 The B<tm_sec>, B<tm_min>, B<tm_hour>, B<tm_mday>, B<tm_wday>, B<tm_yday>,
108 B<tm_mon> and B<tm_year> fields of B<tm> structure are set to proper values,
109 whereas all other fields are set to 0. If B<tm> is NULL this function performs
110 a format check on B<s> only. If B<s> is in Generalized format with fractional
111 seconds, e.g. YYYYMMDDHHMMSS.SSSZ, the fractional seconds will be lost while
112 converting B<s> to B<tm> structure.
114 ASN1_TIME_diff() sets B<*pday> and B<*psec> to the time difference between
115 B<from> and B<to>. If B<to> represents a time later than B<from> then
116 one or both (depending on the time difference) of B<*pday> and B<*psec>
117 will be positive. If B<to> represents a time earlier than B<from> then
118 one or both of B<*pday> and B<*psec> will be negative. If B<to> and B<from>
119 represent the same time then B<*pday> and B<*psec> will both be zero.
120 If both B<*pday> and B<*psec> are non-zero they will always have the same
121 sign. The value of B<*psec> will always be less than the number of seconds
122 in a day. If B<from> or B<to> is NULL the current time is used.
124 The ASN1_TIME_cmp_time_t() and ASN1_UTCTIME_cmp_time_t() functions compare
125 the two times represented by the time structure B<s> and the time_t B<t>.
127 The ASN1_TIME_compare() function compares the two times represented by the
128 time structures B<a> and B<b>.
130 The ASN1_TIME_to_generalizedtime() function converts an ASN1_TIME to an
131 ASN1_GENERALIZEDTIME, regardless of year. If either B<out> or
132 B<*out> are NULL, then a new object is allocated and must be freed after use.
136 The ASN1_TIME structure corresponds to the ASN.1 structure B<Time>
137 defined in RFC5280 et al. The time setting functions obey the rules outlined
138 in RFC5280: if the date can be represented by UTCTime it is used, else
139 GeneralizedTime is used.
141 The ASN1_TIME, ASN1_UTCTIME and ASN1_GENERALIZEDTIME structures are represented
142 as an ASN1_STRING internally and can be freed up using ASN1_STRING_free().
144 The ASN1_TIME structure can represent years from 0000 to 9999 but no attempt
145 is made to correct ancient calendar changes (for example from Julian to
146 Gregorian calendars).
148 ASN1_UTCTIME is limited to a year range of 1950 through 2049.
150 Some applications add offset times directly to a time_t value and pass the
151 results to ASN1_TIME_set() (or equivalent). This can cause problems as the
152 time_t value can overflow on some systems resulting in unexpected results.
153 New applications should use ASN1_TIME_adj() instead and pass the offset value
154 in the B<offset_sec> and B<offset_day> parameters instead of directly
155 manipulating a time_t value.
157 ASN1_TIME_adj() may change the type from ASN1_GENERALIZEDTIME to ASN1_UTCTIME,
158 or vice versa, based on the resulting year. The ASN1_GENERALIZEDTIME_adj() and
159 ASN1_UTCTIME_adj() functions will not modify the type of the return structure.
161 It is recommended that functions starting with ASN1_TIME be used instead of
162 those starting with ASN1_UTCTIME or ASN1_GENERALIZEDTIME. The functions
163 starting with ASN1_UTCTIME and ASN1_GENERALIZEDTIME act only on that specific
164 time format. The functions starting with ASN1_TIME will operate on either
169 ASN1_TIME_print(), ASN1_UTCTIME_print() and ASN1_GENERALIZEDTIME_print()
170 do not print out the time zone: it either prints out "GMT" or nothing. But all
171 certificates complying with RFC5280 et al use GMT anyway.
173 Use the ASN1_TIME_normalize() function to normalize the time value before
174 printing to get GMT results.
178 Set a time structure to one hour after the current time and print it out:
181 #include <openssl/asn1.h>
188 tm = ASN1_TIME_adj(NULL, t, 0, 60 * 60);
189 b = BIO_new_fp(stdout, BIO_NOCLOSE);
190 ASN1_TIME_print(b, tm);
191 ASN1_STRING_free(tm);
194 Determine if one time is later or sooner than the current time:
198 if (!ASN1_TIME_diff(&day, &sec, NULL, to))
199 /* Invalid time format */
201 if (day > 0 || sec > 0)
203 else if (day < 0 || sec < 0)
210 ASN1_TIME_set(), ASN1_UTCTIME_set(), ASN1_GENERALIZEDTIME_set(), ASN1_TIME_adj(),
211 ASN1_UTCTIME_adj and ASN1_GENERALIZEDTIME_set return a pointer to a time structure
212 or NULL if an error occurred.
214 ASN1_TIME_set_string(), ASN1_UTCTIME_set_string(), ASN1_GENERALIZEDTIME_set_string()
215 ASN1_TIME_set_string_X509() return 1 if the time value is successfully set and 0 otherwise.
217 ASN1_TIME_normalize() returns 1 on success, and 0 on error.
219 ASN1_TIME_check(), ASN1_UTCTIME_check and ASN1_GENERALIZEDTIME_check() return 1
220 if the structure is syntactically correct and 0 otherwise.
222 ASN1_TIME_print(), ASN1_UTCTIME_print() and ASN1_GENERALIZEDTIME_print() return 1
223 if the time is successfully printed out and 0 if an error occurred (I/O error or
224 invalid time format).
226 ASN1_TIME_to_tm() returns 1 if the time is successfully parsed and 0 if an
227 error occurred (invalid time format).
229 ASN1_TIME_diff() returns 1 for success and 0 for failure. It can fail if the
230 passed-in time structure has invalid syntax, for example.
232 ASN1_TIME_cmp_time_t() and ASN1_UTCTIME_cmp_time_t() return -1 if B<s> is
233 before B<t>, 0 if B<s> equals B<t>, or 1 if B<s> is after B<t>. -2 is returned
236 ASN1_TIME_compare() returns -1 if B<a> is before B<b>, 0 if B<a> equals B<b>, or 1 if B<a> is after B<b>. -2 is returned on error.
238 ASN1_TIME_to_generalizedtime() returns a pointer to
239 the appropriate time structure on success or NULL if an error occurred.
243 The ASN1_TIME_to_tm() function was added in OpenSSL 1.1.1.
244 The ASN1_TIME_set_string_X509() function was added in OpenSSL 1.1.1.
245 The ASN1_TIME_normalize() function was added in OpenSSL 1.1.1.
246 The ASN1_TIME_cmp_time_t() function was added in OpenSSL 1.1.1.
247 The ASN1_TIME_compare() function was added in OpenSSL 1.1.1.
251 Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
253 Licensed under the Apache License 2.0 (the "License"). You may not use
254 this file except in compliance with the License. You can obtain a copy
255 in the file LICENSE in the source distribution or at
256 L<https://www.openssl.org/source/license.html>.