.\" $OpenBSD: SSL_set1_param.3,v 1.6 2022/09/10 10:22:46 jsg Exp $
.\" full merge up to:
.\" OpenSSL man3/SSL_CTX_get0_param 99d63d46 Oct 26 13:56:48 2016 -0400
.\"
.\" This file was written by Dr. Stephen Henson <steve@openssl.org>.
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.Dd $Mdocdate: September 10 2022 $
.Dt SSL_SET1_PARAM 3
.Os
.Sh NAME
.Nm SSL_CTX_get0_param ,
.Nm SSL_get0_param ,
.Nm SSL_CTX_set1_param ,
.Nm SSL_set1_param
.Nd get and set verification parameters
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft X509_VERIFY_PARAM *
.Fo SSL_CTX_get0_param
.Fa "SSL_CTX *ctx"
.Fc
.Ft X509_VERIFY_PARAM *
.Fo SSL_get0_param
.Fa "SSL *ssl"
.Fc
.Ft int
.Fo SSL_CTX_set1_param
.Fa "SSL_CTX *ctx"
.Fa "X509_VERIFY_PARAM *vpm"
.Fc
.Ft int
.Fo SSL_set1_param
.Fa "SSL *ssl"
.Fa "X509_VERIFY_PARAM *vpm"
.Fc
.Sh DESCRIPTION
.Fn SSL_CTX_get0_param
and
.Fn SSL_get0_param
retrieve an internal pointer to the verification parameters for
.Fa ctx
or
.Fa ssl ,
respectively.
The returned pointer must not be freed by the calling application,
but the application can modify the parameters pointed to,
to suit its needs: for example to add a hostname check.
.Pp
.Fn SSL_CTX_set1_param
and
.Fn SSL_set1_param
set the verification parameters to
.Fa vpm
for
.Fa ctx
or
.Fa ssl .
.Sh RETURN VALUES
.Fn SSL_CTX_get0_param
and
.Fn SSL_get0_param
return a pointer to an
.Vt X509_VERIFY_PARAM
structure.
.Pp
.Fn SSL_CTX_set1_param
and
.Fn SSL_set1_param
return 1 for success or 0 for failure.
.Sh EXAMPLES
Check that the hostname matches
.Pa www.foo.com
in the peer certificate:
.Bd -literal -offset indent
X509_VERIFY_PARAM *vpm = SSL_get0_param(ssl);
X509_VERIFY_PARAM_set1_host(vpm, "www.foo.com", 0);
.Ed
.Sh SEE ALSO
.Xr ssl 3 ,
.Xr X509_VERIFY_PARAM_set_flags 3
.Sh HISTORY
.Fn SSL_CTX_set1_param
and
.Fn SSL_set1_param
first appeared in OpenSSL 1.0.0 and have been available since
.Ox 4.9 .
.Pp
.Fn SSL_CTX_get0_param
and
.Fn SSL_get0_param
first appeared in OpenSSL 1.0.2 and have been available since
.Ox 6.3 .