AnonymousFox

//opt/cpanel/ea-openssl11/share/man/man7/bio.7

.\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" 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 C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    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\}
.el\{\
.    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.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is turned on, 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'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{
.    if \nF \{
.        de IX
.        tm Index:\\$1\t\\n%\t"\\$2"
..
.        if !\nF==2 \{
.            nr % 0
.            nr F 2
.        \}
.    \}
.\}
.rr rF
.\"
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
.    \" fudge factors for nroff and troff
.if n \{\
.    ds #H 0
.    ds #V .8m
.    ds #F .3m
.    ds #[ \f1
.    ds #] \fP
.\}
.if t \{\
.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
.    ds #V .6m
.    ds #F 0
.    ds #[ \&
.    ds #] \&
.\}
.    \" simple accents for nroff and troff
.if n \{\
.    ds ' \&
.    ds ` \&
.    ds ^ \&
.    ds , \&
.    ds ~ ~
.    ds /
.\}
.if t \{\
.    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
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
.    \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
.    \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
.    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
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "BIO 7"
.TH BIO 7 "2023-09-11" "1.1.1w" "OpenSSL"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
bio \- Basic I/O abstraction
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/bio.h>
.Ve
.SH "DESCRIPTION"
.IX 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.
.PP
There are two type of \s-1BIO,\s0 a source/sink \s-1BIO\s0 and a filter \s-1BIO.\s0
.PP
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
.PP
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.
.PP
BIOs can be joined together to form a chain (a single \s-1BIO\s0 is a chain
with one component). A chain normally consist 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).
.PP
Some BIOs (such as memory BIOs) can be used immediately after calling
\&\fIBIO_new()\fR. Others (such as file BIOs) need some additional initialization,
and frequently a utility function exists to create and initialize such BIOs.
.PP
If \fIBIO_free()\fR is called on a \s-1BIO\s0 chain it will only free one \s-1BIO\s0 resulting
in a memory leak.
.PP
Calling \fIBIO_free_all()\fR on a single \s-1BIO\s0 has the same effect as calling
\&\fIBIO_free()\fR on it other than the discarded return value.
.PP
Normally the \fBtype\fR 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 is normally called BIO_s_*() and a filter \s-1BIO\s0
BIO_f_*();
.SH "EXAMPLES"
.IX Header "EXAMPLES"
Create a memory \s-1BIO:\s0
.PP
.Vb 1
\& BIO *mem = BIO_new(BIO_s_mem());
.Ve
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fIBIO_ctrl\fR\|(3),
\&\fIBIO_f_base64\fR\|(3), \fIBIO_f_buffer\fR\|(3),
\&\fIBIO_f_cipher\fR\|(3), \fIBIO_f_md\fR\|(3),
\&\fIBIO_f_null\fR\|(3), \fIBIO_f_ssl\fR\|(3),
\&\fIBIO_find_type\fR\|(3), \fIBIO_new\fR\|(3),
\&\fIBIO_new_bio_pair\fR\|(3),
\&\fIBIO_push\fR\|(3), \fIBIO_read_ex\fR\|(3),
\&\fIBIO_s_accept\fR\|(3), \fIBIO_s_bio\fR\|(3),
\&\fIBIO_s_connect\fR\|(3), \fIBIO_s_fd\fR\|(3),
\&\fIBIO_s_file\fR\|(3), \fIBIO_s_mem\fR\|(3),
\&\fIBIO_s_null\fR\|(3), \fIBIO_s_socket\fR\|(3),
\&\fIBIO_set_callback\fR\|(3),
\&\fIBIO_should_retry\fR\|(3)
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2000\-2019 The OpenSSL Project Authors. All Rights Reserved.
.PP
Licensed under the OpenSSL license (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>.