.\" $OpenBSD: ASN1_TIME_set.3,v 1.2 2016/11/10 15:08:13 jmc Exp $ .\" OpenSSL 99d63d46 Mon Jun 6 00:43:05 2016 -0400 .\" .\" This file was written by Dr. Stephen Henson. .\" Copyright (c) 2015 The OpenSSL Project. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in .\" the documentation and/or other materials provided with the .\" distribution. .\" .\" 3. All advertising materials mentioning features or use of this .\" software must display the following acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit. 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IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: November 10 2016 $ .Dt ASN1_TIME_SET 3 .Os .Sh NAME .Nm ASN1_TIME_set , .Nm ASN1_TIME_adj , .Nm ASN1_TIME_set_string , .Nm ASN1_TIME_check , .Nm ASN1_TIME_print .Nd ASN.1 Time functions .Sh SYNOPSIS .Ft ASN1_TIME * .Fo ASN1_TIME_set .Fa "ASN1_TIME *s" .Fa "time_t t" .Fc .Ft ASN1_TIME * .Fo ASN1_TIME_adj .Fa "ASN1_TIME *s" .Fa "time_t t" .Fa "int offset_day" .Fa "long offset_sec" .Fc .Ft int .Fo ASN1_TIME_set_string .Fa "ASN1_TIME *s" .Fa "const char *str" .Fc .Ft int .Fo ASN1_TIME_check .Fa "const ASN1_TIME *t" .Fc .Ft int .Fo ASN1_TIME_print .Fa "BIO *b" .Fa "const ASN1_TIME *s" .Fc .Sh DESCRIPTION The function .Fn ASN1_TIME_set sets the .Vt ASN1_TIME structure .Fa s to the time represented by the .Vt time_t value .Fa t . If .Fa s is .Dv NULL , a new .Vt ASN1_TIME structure is allocated and returned. .Pp .Fn ASN1_TIME_adj sets the .Vt ASN1_TIME structure .Fa s to the time represented by the time .Fa offset_day and .Fa offset_sec after the .Vt time_t value .Fa t . The values of .Fa offset_day or .Fa offset_sec can be negative to set a time before .Fa t . The .Fa offset_sec value can also exceed the number of seconds in a day. If .Fa s is .Dv NULL , a new .Vt ASN1_TIME structure is allocated and returned. .Pp .Fn ASN1_TIME_set_string sets the .Vt ASN1_TIME structure .Fa s to the time represented by the string .Fa str , which must be in appropriate ASN.1 time format (for example YYMMDDHHMMSSZ or YYYYMMDDHHMMSSZ). .Pp .Fn ASN1_TIME_check checks the syntax of the .Vt ASN1_TIME structure .Fa s . .Pp .Fn ASN1_TIME_print prints out the time .Fa s to .Vt BIO .Fa 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". It does not include a newline. If the time structure has an invalid format, it prints out "Bad time value" and returns an error. .Pp The .Vt ASN1_TIME structure corresponds to the ASN.1 structure .Sy Time defined in RFC 5280 et al. The time setting functions obey the rules outlined in RFC 5280: if the date can be represented by UTCTime it is used, otherwise GeneralizedTime is used. .Pp The .Vt ASN1_TIME structure is represented as an .Vt ASN1_STRING internally and can be freed up using .Xr ASN1_STRING_free 3 . .Pp The .Vt 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). .Sh RETURN VALUES .Fn ASN1_TIME_set and .Fn ASN1_TIME_adj return a pointer to an .Vt ASN1_TIME structure or .Dv NULL if an error occurred. .Pp .Fn ASN1_TIME_set_string returns 1 if the time value is successfully set or 0 otherwise. .Pp .Fn ASN1_TIME_check returns 1 if the structure is syntactically correct or 0 otherwise. .Pp .Fn ASN1_TIME_print returns 1 if the time is successfully printed out or 0 if an error occurred (I/O error or invalid time format). .Sh EXAMPLES Set a time structure to one hour after the current time and print it out: .Bd -literal -offset indent #include #include 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); .Ed .Sh CAVEATS Some applications add offset times directly to a .Vt time_t value and pass the results to .Fn ASN1_TIME_set (or equivalent). This can cause problems as the .Vt time_t value can overflow on some systems resulting in unexpected results. New applications should use .Fn ASN1_TIME_adj instead and pass the offset value in the .Fa offset_sec and .Fa offset_day parameters instead of directly manipulating a .Vt time_t value. .Sh BUGS .Fn ASN1_TIME_print currently does not print out the time zone: it either prints out "GMT" or nothing. But all certificates complying with RFC 5280 et al use GMT anyway.