.\" $OpenBSD: d2i_DHparams.3,v 1.8 2018/03/27 17:35:50 schwarze Exp $
.\" full merge up to: OpenSSL 61f805c1 Jan 16 01:01:46 2018 +0800
.\"
.\" This file was written by Ulf Moeller <ulf@openssl.org> and
.\" Dr. Stephen Henson <steve@openssl.org>.
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.Dd $Mdocdate: March 27 2018 $
.Dt D2I_DHPARAMS 3
.Os
.Sh NAME
.Nm d2i_DHparams ,
.Nm i2d_DHparams
.Nd PKCS#3 DH parameter functions
.Sh SYNOPSIS
.In openssl/dh.h
.Ft DH *
.Fo d2i_DHparams
.Fa "DH **a"
.Fa "unsigned char **pp"
.Fa "long length"
.Fc
.Ft int
.Fo i2d_DHparams
.Fa "DH *a"
.Fa "unsigned char **pp"
.Fc
.Sh DESCRIPTION
These functions decode and encode PKCS#3 DH parameters using the
DHparameter structure described in PKCS#3.
They otherwise behave in a way similar to
.Xr d2i_X509 3
and
.Xr i2d_X509 3 .
.Sh RETURN VALUES
.Fn d2i_DHparams
returns a
.Vt DH
object or
.Dv NULL
if an error occurs.
.Pp
.Fn i2d_DHparams
returns the number of bytes successfully encoded or a value <= 0
if an error occurs.
.Sh SEE ALSO
.Xr d2i_X509 3 ,
.Xr DH_new 3
.Sh HISTORY
.Fn d2i_DHparams
and
.Fn i2d_DHparams
first appeared in SSLeay 0.5.1 and have been available since
.Ox 2.4 .