1.\" $OpenBSD: SSL_get_fd.3,v 1.6 2018/03/27 17:35:50 schwarze Exp $ 2.\" 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, 2005, 2013 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: March 27 2018 $ 52.Dt SSL_GET_FD 3 53.Os 54.Sh NAME 55.Nm SSL_get_fd , 56.Nm SSL_get_rfd , 57.Nm SSL_get_wfd 58.Nd get file descriptor linked to an SSL object 59.Sh SYNOPSIS 60.In openssl/ssl.h 61.Ft int 62.Fn SSL_get_fd "const SSL *ssl" 63.Ft int 64.Fn SSL_get_rfd "const SSL *ssl" 65.Ft int 66.Fn SSL_get_wfd "const SSL *ssl" 67.Sh DESCRIPTION 68.Fn SSL_get_fd 69returns the file descriptor which is linked to 70.Fa ssl . 71.Fn SSL_get_rfd 72and 73.Fn SSL_get_wfd 74return the file descriptors for the read or the write channel, 75which can be different. 76If the read and the write channel are different, 77.Fn SSL_get_fd 78will return the file descriptor of the read channel. 79.Sh RETURN VALUES 80The following return values can occur: 81.Bl -tag -width Ds 82.It \(mi1 83The operation failed, because the underlying 84.Vt BIO 85is not of the correct type (suitable for file descriptors). 86.It \(>=0 87The file descriptor linked to 88.Fa ssl . 89.El 90.Sh SEE ALSO 91.Xr BIO_new 3 , 92.Xr ssl 3 , 93.Xr SSL_set_fd 3 94.Sh HISTORY 95.Fn SSL_get_fd 96appeared in SSLeay 0.4 or earlier and has been available since 97.Ox 2.4 . 98.Pp 99.Fn SSL_get_rfd 100and 101.Fn SSL_get_wfd 102first appeared in OpenSSL 0.9.6c and have been available since 103.Ox 3.2 . 104