.\"	$OpenBSD: SSL_CTX_add_extra_chain_cert.3,v 1.2 2016/11/30 12:55:25 schwarze Exp $
.\"	OpenSSL f0d6ee6be Feb 15 07:41:42 2002 +0000
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.\" This file was written by Lutz Jaenicke <jaenicke@openssl.org> and
.\" Dr. Stephen Henson <steve@openssl.org>.
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.Dd $Mdocdate: November 30 2016 $
.Dt SSL_CTX_ADD_EXTRA_CHAIN_CERT 3
.Os
.Sh NAME
.Nm SSL_CTX_add_extra_chain_cert ,
.Nm SSL_CTX_clear_extra_chain_certs
.Nd add or clear extra chain certificates
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft long
.Fn SSL_CTX_add_extra_chain_cert "SSL_CTX *ctx" "X509 *x509"
.Ft long
.Fn SSL_CTX_clear_extra_chain_certs "SSL_CTX *ctx"
.Sh DESCRIPTION
.Fn SSL_CTX_add_extra_chain_cert
adds the certificate
.Fa x509
to the extra chain certificates associated with
.Fa ctx .
Several certificates can be added one after another.
.Pp
.Fn SSL_CTX_clear_extra_chain_certs
clears all extra chain certificates associated with
.Fa ctx .
.Pp
These functions are implemented as macros.
.Pp
When sending a certificate chain, extra chain certificates are sent
in order following the end entity certificate.
.Pp
If no chain is specified, the library will try to complete the chain from the
available CA certificates in the trusted CA storage, see
.Xr SSL_CTX_load_verify_locations 3 .
.Pp
The x509 certificate provided to
.Fn SSL_CTX_add_extra_chain_cert
will be freed by the library when the
.Vt SSL_CTX
is destroyed.
An application should not free the
.Fa x509
object.
.Sh RETURN VALUES
.Fn SSL_CTX_add_extra_chain_cert
and
.Fn SSL_CTX_clear_extra_chain_certs
return 1 on success or 0 for failure.
Check out the error stack to find out the reason for failure.
.Sh SEE ALSO
.Xr ssl 3 ,
.Xr SSL_CTX_load_verify_locations 3 ,
.Xr SSL_CTX_set_client_cert_cb 3 ,
.Xr SSL_CTX_use_certificate 3
.Sh CAVEATS
Only one set of extra chain certificates can be specified per
.Vt SSL_CTX
structure.
Different chains for different certificates (for example if both
RSA and DSA certificates are specified by the same server) or
different SSL structures with the same parent
.Vt SSL_CTX
cannot be specified using this function.