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.IX Title "bio 3"
.TH bio 3 2019-12-20 1.0.2u OpenSSL
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.SH NAME
bio \- I/O abstraction
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/bio.h>
.Ve
.PP
TBA
.SH DESCRIPTION
.IX Header "DESCRIPTION"
A BIO is an I/O abstraction, it hides many of the underlying I/O
details from an application. If an application uses a BIO for its
I/O it can transparently handle SSL connections, unencrypted network
connections and file I/O.
.PP
There are two type of BIO, a source/sink BIO and a filter BIO.
.PP
As its name implies a source/sink BIO is a source and/or sink of data,
examples include a socket BIO and a file BIO.
.PP
A filter BIO takes data from one BIO and passes it through to
another, or the application. The data may be left unmodified (for
example a message digest BIO) or translated (for example an
encryption BIO). The effect of a filter BIO may change according
to the I/O operation it is performing: for example an encryption
BIO will encrypt data if it is being written to and decrypt data
if it is being read from.
.PP
BIOs can be joined together to form a chain (a single BIO is a chain
with one component). A chain normally consist of one source/sink
BIO and one or more filter BIOs. Data read from or written to the
first BIO then traverses the chain to the end (normally a source/sink
BIO).
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBBIO_ctrl\fR\|(3),
\&\fBBIO_f_base64\fR\|(3), \fBBIO_f_buffer\fR\|(3),
\&\fBBIO_f_cipher\fR\|(3), \fBBIO_f_md\fR\|(3),
\&\fBBIO_f_null\fR\|(3), \fBBIO_f_ssl\fR\|(3),
\&\fBBIO_find_type\fR\|(3), \fBBIO_new\fR\|(3),
\&\fBBIO_new_bio_pair\fR\|(3),
\&\fBBIO_push\fR\|(3), \fBBIO_read\fR\|(3),
\&\fBBIO_s_accept\fR\|(3), \fBBIO_s_bio\fR\|(3),
\&\fBBIO_s_connect\fR\|(3), \fBBIO_s_fd\fR\|(3),
\&\fBBIO_s_file\fR\|(3), \fBBIO_s_mem\fR\|(3),
\&\fBBIO_s_null\fR\|(3), \fBBIO_s_socket\fR\|(3),
\&\fBBIO_set_callback\fR\|(3),
\&\fBBIO_should_retry\fR\|(3)