.\" $OpenBSD: DSA_SIG_new.3,v 1.8 2019/06/10 14:58:48 schwarze Exp $
.\" full merge up to: OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100
.\"
.\" This file was written by Ulf Moeller <ulf@openssl.org>,
.\" Dr. Stephen Henson <steve@openssl.org>, and
.\" TJ Saunders <tj@castaglia.org>.
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.\"    "This product includes software developed by the OpenSSL Project
.\"    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
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.Dd $Mdocdate: June 10 2019 $
.Dt DSA_SIG_NEW 3
.Os
.Sh NAME
.Nm DSA_SIG_new ,
.Nm DSA_SIG_free ,
.Nm DSA_SIG_get0 ,
.Nm DSA_SIG_set0
.Nd manipulate DSA signature objects
.Sh SYNOPSIS
.In openssl/dsa.h
.Ft DSA_SIG *
.Fn DSA_SIG_new void
.Ft void
.Fo DSA_SIG_free
.Fa "DSA_SIG *sig"
.Fc
.Ft void
.Fo DSA_SIG_get0
.Fa "const DSA_SIG *sig"
.Fa "const BIGNUM **r"
.Fa "const BIGNUM **s"
.Fc
.Ft int
.Fo DSA_SIG_set0
.Fa "DSA_SIG *sig"
.Fa "BIGNUM *r"
.Fa "BIGNUM *s"
.Fc
.Sh DESCRIPTION
.Fn DSA_SIG_new
allocates an empty
.Vt DSA_SIG
structure.
.Pp
.Fn DSA_SIG_free
frees the
.Vt DSA_SIG
structure and its components.
The values are erased before the memory is returned to the system.
If
.Fa sig
is a
.Dv NULL
pointer, no action occurs.
.Pp
.Fn DSA_SIG_get0
retrieves internal pointers to the
.Fa r
and
.Fa s
values contained in
.Fa sig .
.Pp
The
.Fa r
and
.Fa s
values can be set by calling
.Fn DSA_SIG_set0 .
Calling this function transfers the memory management of the values to
.Fa sig ,
and therefore they should not be freed by the caller.
.Sh RETURN VALUES
If the allocation fails,
.Fn DSA_SIG_new
returns
.Dv NULL
and sets an error code that can be obtained by
.Xr ERR_get_error 3 .
Otherwise it returns a pointer to the newly allocated structure.
.Pp
.Fn DSA_SIG_set0
returns 1 on success or 0 on failure.
.Sh SEE ALSO
.Xr DSA_do_sign 3 ,
.Xr DSA_new 3
.Sh HISTORY
.Fn DSA_SIG_new
and
.Fn DSA_SIG_free
first appeared in OpenSSL 0.9.3 and have been available since
.Ox 2.6 .
.Pp
.Fn DSA_SIG_get0
and
.Fn DSA_SIG_set0
first appeared in OpenSSL 1.1.0 and have been available since
.Ox 6.3 .