SSL_SET_BIO
Section: OpenSSL (3)
Updated: 2021-03-26
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NAME
SSL_set_bio, SSL_set0_rbio, SSL_set0_wbio - connect the SSL object with a BIO
SYNOPSIS
#include <openssl/ssl.h>
void SSL_set_bio(SSL *ssl, BIO *rbio, BIO *wbio);
void SSL_set0_rbio(SSL *s, BIO *rbio);
void SSL_set0_wbio(SSL *s, BIO *wbio);
DESCRIPTION
SSL_set0_rbio() connects the
BIO rbio for the read operations of the
ssl
object. The
SSL engine inherits the behaviour of
rbio. If the
BIO is
nonblocking then the
ssl object will also have nonblocking behaviour. This
function transfers ownership of
rbio to
ssl. It will be automatically
freed using
BIO_free_all(3) when the
ssl is freed. On calling this
function, any existing
rbio that was previously set will also be freed via a
call to
BIO_free_all(3) (this includes the case where the
rbio is set to
the same value as previously).
SSL_set0_wbio() works in the same as SSL_set0_rbio() except that it connects
the BIO wbio for the write operations of the ssl object. Note that if the
rbio and wbio are the same then SSL_set0_rbio() and SSL_set0_wbio() each take
ownership of one reference. Therefore, it may be necessary to increment the
number of references available using BIO_up_ref(3) before calling the set0
functions.
SSL_set_bio() is similar to SSL_set0_rbio() and SSL_set0_wbio() except
that it connects both the rbio and the wbio at the same time, and
transfers the ownership of rbio and wbio to ssl according to
the following set of rules:
- •
-
If neither the rbio or wbio have changed from their previous values
then nothing is done.
- •
-
If the rbio and wbio parameters are different and both are different
to their
previously set values then one reference is consumed for the rbio and one
reference is consumed for the wbio.
- •
-
If the rbio and wbio parameters are the same and the rbio is not
the same as the previously set value then one reference is consumed.
- •
-
If the rbio and wbio parameters are the same and the rbio is the
same as the previously set value, then no additional references are consumed.
- •
-
If the rbio and wbio parameters are different and the rbio is the
same as the
previously set value then one reference is consumed for the wbio and no
references are consumed for the rbio.
- •
-
If the rbio and wbio parameters are different and the wbio is the
same as the previously set value and the old rbio and wbio values
were the same as each other then one reference is consumed for the rbio
and no references are consumed for the wbio.
- •
-
If the rbio and wbio parameters are different and the wbio
is the same as the
previously set value and the old rbio and wbio values were different
to each
other then one reference is consumed for the rbio and one reference
is consumed
for the wbio.
Because of this complexity, this function should be avoided;
use SSL_set0_rbio() and SSL_set0_wbio() instead.
RETURN VALUES
SSL_set_bio(),
SSL_set0_rbio() and
SSL_set0_wbio() cannot fail.
SEE ALSO
SSL_get_rbio(3),
SSL_connect(3),
SSL_accept(3),
SSL_shutdown(3),
ssl(7),
bio(7)
HISTORY
SSL_set0_rbio() and
SSL_set0_wbio() were added in OpenSSL 1.1.0.
COPYRIGHT
Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the ``License''). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.