.\"	$OpenBSD: BN_set_negative.3,v 1.6 2021/12/06 19:45:27 schwarze Exp $
.\"
.\" Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: December 6 2021 $
.Dt BN_SET_NEGATIVE 3
.Os
.Sh NAME
.Nm BN_set_negative ,
.Nm BN_is_negative
.Nd change and inspect the sign of a BIGNUM
.Sh SYNOPSIS
.In openssl/bn.h
.Ft void
.Fo BN_set_negative
.Fa "BIGNUM *b"
.Fa "int n"
.Fc
.Ft int
.Fo BN_is_negative
.Fa "const BIGNUM *b"
.Fc
.Sh DESCRIPTION
.Fn BN_set_negative
sets
.Fa b
to negative if both
.Fa b
and
.Fa n
are non-zero, otherwise it sets it to positive.
.Pp
.Fn BN_is_negative
tests the sign of
.Fa b .
.Sh RETURN VALUES
.Fn BN_is_negative
returns 1 if
.Fa b
is negative or 0 otherwise.
.Sh SEE ALSO
.Xr BN_add 3 ,
.Xr BN_new 3 ,
.Xr BN_set_bit 3 ,
.Xr BN_zero 3
.Sh HISTORY
.Fn BN_set_negative
and
.Fn BN_is_negative
first appeared in OpenSSL 0.9.8 and have been available since
.Ox 4.5 .