1=pod 2 3=head1 NAME 4 5SSL_set_fd, SSL_set_rfd, SSL_set_wfd - connect the SSL object with a file descriptor 6 7=head1 SYNOPSIS 8 9 #include <openssl/ssl.h> 10 11 int SSL_set_fd(SSL *ssl, int fd); 12 int SSL_set_rfd(SSL *ssl, int fd); 13 int SSL_set_wfd(SSL *ssl, int fd); 14 15=head1 DESCRIPTION 16 17SSL_set_fd() sets the file descriptor B<fd> as the input/output facility 18for the TLS/SSL (encrypted) side of B<ssl>. B<fd> will typically be the 19socket file descriptor of a network connection. 20 21When performing the operation, a B<socket BIO> is automatically created to 22interface between the B<ssl> and B<fd>. The BIO and hence the SSL engine 23inherit the behaviour of B<fd>. If B<fd> is nonblocking, the B<ssl> will 24also have nonblocking behaviour. 25 26If there was already a BIO connected to B<ssl>, BIO_free() will be called 27(for both the reading and writing side, if different). 28 29SSL_set_rfd() and SSL_set_wfd() perform the respective action, but only 30for the read channel or the write channel, which can be set independently. 31 32=head1 RETURN VALUES 33 34The following return values can occur: 35 36=over 4 37 38=item Z<>0 39 40The operation failed. Check the error stack to find out why. 41 42=item Z<>1 43 44The operation succeeded. 45 46=back 47 48=head1 NOTES 49 50On Windows, a socket handle is a 64-bit data type (UINT_PTR), which leads to a 51compiler warning (conversion from 'SOCKET' to 'int', possible loss of data) when 52passing the socket handle to SSL_set_*fd(). For the time being, this warning can 53safely be ignored, because although the Microsoft documentation claims that the 54upper limit is INVALID_SOCKET-1 (2^64 - 2), in practice the current socket() 55implementation returns an index into the kernel handle table, the size of which 56is limited to 2^24. 57 58 59=head1 SEE ALSO 60 61L<SSL_get_fd(3)>, L<SSL_set_bio(3)>, 62L<SSL_connect(3)>, L<SSL_accept(3)>, 63L<SSL_shutdown(3)>, L<ssl(7)> , L<bio(7)> 64 65=head1 COPYRIGHT 66 67Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved. 68 69Licensed under the Apache License 2.0 (the "License"). You may not use 70this file except in compliance with the License. You can obtain a copy 71in the file LICENSE in the source distribution or at 72L<https://www.openssl.org/source/license.html>. 73 74=cut 75