1.\" $OpenBSD: SSL_get_version.3,v 1.6 2019/01/21 12:35:33 schwarze Exp $ 2.\" OpenSSL bb9ad09e Jun 6 00:43:05 2016 -0400 3.\" 4.\" This file was written by Lutz Jaenicke <jaenicke@openssl.org>. 5.\" Copyright (c) 2001, 2005, 2014 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: January 21 2019 $ 52.Dt SSL_GET_VERSION 3 53.Os 54.Sh NAME 55.Nm SSL_get_version , 56.Nm SSL_version 57.Nd get the protocol version of a connection 58.Sh SYNOPSIS 59.In openssl/ssl.h 60.Ft const char * 61.Fn SSL_get_version "const SSL *ssl" 62.Ft int 63.Fn SSL_version "const SSL *ssl" 64.Sh DESCRIPTION 65.Fn SSL_get_version 66returns the name of the protocol used for the connection 67.Fa ssl . 68.Pp 69.Fn SSL_version 70returns an integer constant representing that protocol. 71.Sh RETURN VALUES 72The following strings or integers can be returned: 73.Bl -tag -width Ds 74.It Qo TLSv1 Qc No or Dv TLS1_VERSION 75The connection uses the TLSv1.0 protocol. 76.It Qo TLSv1.1 Qc No or Dv TLS1_1_VERSION 77The connection uses the TLSv1.1 protocol. 78.It Qo TLSv1.2 Qc No or Dv TLS1_2_VERSION 79The connection uses the TLSv1.2 protocol. 80.It Qo TLSv1.3 Qc No or Dv TLS1_3_VERSION 81The connection uses the TLSv1.3 protocol. 82.It Qo DTLSv1 Qc No or Dv DTLS1_VERSION 83The connection uses the Datagram Transport Layer Security 1.0 protocol. 84.It Qq unknown 85This indicates that no version has been set (no connection established). 86.El 87.Sh SEE ALSO 88.Xr ssl 3 89.Sh HISTORY 90.Fn SSL_get_version 91and 92.Fn SSL_version 93first appeared in SSLeay 0.8.0 and have been available since 94.Ox 2.4 . 95