.\"	$OpenBSD: SSL_get_fd.3,v 1.6 2018/03/27 17:35:50 schwarze Exp $
.\"	OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100
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.Dd $Mdocdate: March 27 2018 $
.Dt SSL_GET_FD 3
.Os
.Sh NAME
.Nm SSL_get_fd ,
.Nm SSL_get_rfd ,
.Nm SSL_get_wfd
.Nd get file descriptor linked to an SSL object
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft int
.Fn SSL_get_fd "const SSL *ssl"
.Ft int
.Fn SSL_get_rfd "const SSL *ssl"
.Ft int
.Fn SSL_get_wfd "const SSL *ssl"
.Sh DESCRIPTION
.Fn SSL_get_fd
returns the file descriptor which is linked to
.Fa ssl .
.Fn SSL_get_rfd
and
.Fn SSL_get_wfd
return the file descriptors for the read or the write channel,
which can be different.
If the read and the write channel are different,
.Fn SSL_get_fd
will return the file descriptor of the read channel.
.Sh RETURN VALUES
The following return values can occur:
.Bl -tag -width Ds
.It \(mi1
The operation failed, because the underlying
.Vt BIO
is not of the correct type (suitable for file descriptors).
.It \(>=0
The file descriptor linked to
.Fa ssl .
.El
.Sh SEE ALSO
.Xr BIO_new 3 ,
.Xr ssl 3 ,
.Xr SSL_set_fd 3
.Sh HISTORY
.Fn SSL_get_fd
appeared in SSLeay 0.4 or earlier and has been available since
.Ox 2.4 .
.Pp
.Fn SSL_get_rfd
and
.Fn SSL_get_wfd
first appeared in OpenSSL 0.9.6c and have been available since
.Ox 3.2 .