1.\" $OpenBSD: SSL_get_peer_certificate.3,v 1.6 2021/06/26 17:36:28 tb Exp $ 2.\" full merge up to: OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100 3.\" 4.\" This file was written by Lutz Jaenicke <jaenicke@openssl.org>. 5.\" Copyright (c) 2000, 2001, 2005 The OpenSSL Project. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in 16.\" the documentation and/or other materials provided with the 17.\" distribution. 18.\" 19.\" 3. All advertising materials mentioning features or use of this 20.\" software must display the following acknowledgment: 21.\" "This product includes software developed by the OpenSSL Project 22.\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 23.\" 24.\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 25.\" endorse or promote products derived from this software without 26.\" prior written permission. For written permission, please contact 27.\" openssl-core@openssl.org. 28.\" 29.\" 5. Products derived from this software may not be called "OpenSSL" 30.\" nor may "OpenSSL" appear in their names without prior written 31.\" permission of the OpenSSL Project. 32.\" 33.\" 6. Redistributions of any form whatsoever must retain the following 34.\" acknowledgment: 35.\" "This product includes software developed by the OpenSSL Project 36.\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" 37.\" 38.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 39.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 40.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 41.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 42.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 43.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 44.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 45.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 46.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 47.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 48.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 49.\" OF THE POSSIBILITY OF SUCH DAMAGE. 50.\" 51.Dd $Mdocdate: June 26 2021 $ 52.Dt SSL_GET_PEER_CERTIFICATE 3 53.Os 54.Sh NAME 55.Nm SSL_get_peer_certificate 56.Nd get the X509 certificate of the peer 57.Sh SYNOPSIS 58.In openssl/ssl.h 59.Ft X509 * 60.Fn SSL_get_peer_certificate "const SSL *ssl" 61.Sh DESCRIPTION 62.Fn SSL_get_peer_certificate 63returns a pointer to the X509 certificate the peer presented. 64If the peer did not present a certificate, 65.Dv NULL 66is returned. 67.Pp 68Due to the protocol definition, a TLS/SSL server will always send a 69certificate, if present. 70A client will only send a certificate when explicitly requested to do so by the 71server (see 72.Xr SSL_CTX_set_verify 3 ) . 73If an anonymous cipher is used, no certificates are sent. 74.Pp 75That a certificate is returned does not indicate information about the 76verification state. 77Use 78.Xr SSL_get_verify_result 3 79to check the verification state. 80.Pp 81The reference count of the 82.Vt X509 83object is incremented by one, so that it will not be destroyed when the session 84containing the peer certificate is freed. 85The 86.Vt X509 87object must be explicitly freed using 88.Xr X509_free 3 . 89.Sh RETURN VALUES 90The following return values can occur: 91.Bl -tag -width Ds 92.It Dv NULL 93No certificate was presented by the peer or no connection was established. 94.It Pointer to an X509 certificate 95The return value points to the certificate presented by the peer. 96.El 97.Sh SEE ALSO 98.Xr ssl 3 , 99.Xr SSL_CTX_set_verify 3 , 100.Xr SSL_get0_peername 3 , 101.Xr SSL_get_verify_result 3 102.Sh HISTORY 103.Fn SSL_get_peer_certificate 104appeared in SSLeay 0.4 or earlier and has been available since 105.Ox 2.4 . 106