.\" $OpenBSD: SSL_get_peer_certificate.3,v 1.6 2021/06/26 17:36:28 tb Exp $ .\" full merge up to: OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100 .\" .\" This file was written by Lutz Jaenicke . .\" Copyright (c) 2000, 2001, 2005 The OpenSSL Project. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in .\" the documentation and/or other materials provided with the .\" distribution. .\" .\" 3. All advertising materials mentioning features or use of this .\" software must display the following acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" .\" .\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to .\" endorse or promote products derived from this software without .\" prior written permission. For written permission, please contact .\" openssl-core@openssl.org. .\" .\" 5. Products derived from this software may not be called "OpenSSL" .\" nor may "OpenSSL" appear in their names without prior written .\" permission of the OpenSSL Project. .\" .\" 6. Redistributions of any form whatsoever must retain the following .\" acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" .\" .\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY .\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: June 26 2021 $ .Dt SSL_GET_PEER_CERTIFICATE 3 .Os .Sh NAME .Nm SSL_get_peer_certificate .Nd get the X509 certificate of the peer .Sh SYNOPSIS .In openssl/ssl.h .Ft X509 * .Fn SSL_get_peer_certificate "const SSL *ssl" .Sh DESCRIPTION .Fn SSL_get_peer_certificate returns a pointer to the X509 certificate the peer presented. If the peer did not present a certificate, .Dv NULL is returned. .Pp Due to the protocol definition, a TLS/SSL server will always send a certificate, if present. A client will only send a certificate when explicitly requested to do so by the server (see .Xr SSL_CTX_set_verify 3 ) . If an anonymous cipher is used, no certificates are sent. .Pp That a certificate is returned does not indicate information about the verification state. Use .Xr SSL_get_verify_result 3 to check the verification state. .Pp The reference count of the .Vt X509 object is incremented by one, so that it will not be destroyed when the session containing the peer certificate is freed. The .Vt X509 object must be explicitly freed using .Xr X509_free 3 . .Sh RETURN VALUES The following return values can occur: .Bl -tag -width Ds .It Dv NULL No certificate was presented by the peer or no connection was established. .It Pointer to an X509 certificate The return value points to the certificate presented by the peer. .El .Sh SEE ALSO .Xr ssl 3 , .Xr SSL_CTX_set_verify 3 , .Xr SSL_get0_peername 3 , .Xr SSL_get_verify_result 3 .Sh HISTORY .Fn SSL_get_peer_certificate appeared in SSLeay 0.4 or earlier and has been available since .Ox 2.4 .