Automatically generated by Pod::Man 4.14 (Pod::Simple 3.42)

Standard preamble:
========================================================================
..

..

.. Set up some character translations and predefined strings. \*(-- will
give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
double quote, and \*(R" will give a right double quote. \*(C+ will
give a nicer C++. Capital omega is used to do unbreakable dashes and
therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
nothing in troff, for use with C<>.
.tr \(*W- . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\}
Escape single quotes in literal strings from groff's Unicode transform.

If the F register is >0, we'll generate index entries on stderr for
titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
entries marked with X<> in POD. Of course, you'll have to process the
output yourself in some meaningful fashion.

Avoid warning from groff about undefined register 'F'.
.. .nr rF 0 . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF Fear. Run. Save yourself. No user-serviceable parts.
. \" fudge factors for nroff and troff . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] .\} . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents . \" corrections for vroff . \" for low resolution devices (crt and lpr) \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} ========================================================================

Title "BIO 7ossl" For nroff, turn off justification. Always turn off hyphenation; it makes
way too many mistakes in technical documents.
bio - Basic I/O abstraction Header "SYNOPSIS" .Vb 1 #include <openssl/bio.h> .Ve Header "DESCRIPTION" A \s-1BIO\s0 is an I/O abstraction, it hides many of the underlying I/O details from an application. If an application uses a \s-1BIO\s0 for its I/O it can transparently handle \s-1SSL\s0 connections, unencrypted network connections and file I/O.

There are two types of \s-1BIO,\s0 a source/sink \s-1BIO\s0 and a filter \s-1BIO.\s0

As its name implies a source/sink \s-1BIO\s0 is a source and/or sink of data, examples include a socket \s-1BIO\s0 and a file \s-1BIO.\s0

A filter \s-1BIO\s0 takes data from one \s-1BIO\s0 and passes it through to another, or the application. The data may be left unmodified (for example a message digest \s-1BIO\s0) or translated (for example an encryption \s-1BIO\s0). The effect of a filter \s-1BIO\s0 may change according to the I/O operation it is performing: for example an encryption \s-1BIO\s0 will encrypt data if it is being written to and decrypt data if it is being read from.

BIOs can be joined together to form a chain (a single \s-1BIO\s0 is a chain with one component). A chain normally consists of one source/sink \s-1BIO\s0 and one or more filter BIOs. Data read from or written to the first \s-1BIO\s0 then traverses the chain to the end (normally a source/sink \s-1BIO\s0).

Some BIOs (such as memory BIOs) can be used immediately after calling \fBBIO_new(). Others (such as file BIOs) need some additional initialization, and frequently a utility function exists to create and initialize such BIOs.

If BIO_free() is called on a \s-1BIO\s0 chain it will only free one \s-1BIO\s0 resulting in a memory leak.

Calling BIO_free_all() on a single \s-1BIO\s0 has the same effect as calling \fBBIO_free() on it other than the discarded return value.

Normally the type argument is supplied by a function which returns a pointer to a \s-1BIO_METHOD.\s0 There is a naming convention for such functions: a source/sink \s-1BIO\s0 typically starts with BIO_s_ and a filter \s-1BIO\s0 with BIO_f_.

Header "EXAMPLES" Create a memory \s-1BIO:\s0

.Vb 1 BIO *mem = BIO_new(BIO_s_mem()); .Ve

Header "SEE ALSO" \fBBIO_ctrl\|(3), \fBBIO_f_base64\|(3), BIO_f_buffer\|(3), \fBBIO_f_cipher\|(3), BIO_f_md\|(3), \fBBIO_f_null\|(3), BIO_f_ssl\|(3), \fBBIO_f_readbuffer\|(3), \fBBIO_find_type\|(3), BIO_new\|(3), \fBBIO_new_bio_pair\|(3), \fBBIO_push\|(3), BIO_read_ex\|(3), \fBBIO_s_accept\|(3), BIO_s_bio\|(3), \fBBIO_s_connect\|(3), BIO_s_fd\|(3), \fBBIO_s_file\|(3), BIO_s_mem\|(3), \fBBIO_s_null\|(3), BIO_s_socket\|(3), \fBBIO_set_callback\|(3), \fBBIO_should_retry\|(3) Header "COPYRIGHT" Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.