AlkantarClanX12
Your IP : 3.144.93.34
.\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35)
.\"
.\" 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 >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'.
.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 "SSL_CTX_SET_RECORD_PADDING_CALLBACK 3"
.TH SSL_CTX_SET_RECORD_PADDING_CALLBACK 3 "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"
SSL_CTX_set_record_padding_callback, SSL_set_record_padding_callback, SSL_CTX_set_record_padding_callback_arg, SSL_set_record_padding_callback_arg, SSL_CTX_get_record_padding_callback_arg, SSL_get_record_padding_callback_arg, SSL_CTX_set_block_padding, SSL_set_block_padding \- install callback to specify TLS 1.3 record padding
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/ssl.h>
\&
\& void SSL_CTX_set_record_padding_callback(SSL_CTX *ctx, size_t (*cb)(SSL *s, int type, size_t len, void *arg));
\& void SSL_set_record_padding_callback(SSL *ssl, size_t (*cb)(SSL *s, int type, size_t len, void *arg));
\&
\& void SSL_CTX_set_record_padding_callback_arg(SSL_CTX *ctx, void *arg);
\& void *SSL_CTX_get_record_padding_callback_arg(const SSL_CTX *ctx);
\&
\& void SSL_set_record_padding_callback_arg(SSL *ssl, void *arg);
\& void *SSL_get_record_padding_callback_arg(const SSL *ssl);
\&
\& int SSL_CTX_set_block_padding(SSL_CTX *ctx, size_t block_size);
\& int SSL_set_block_padding(SSL *ssl, size_t block_size);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
\&\fBSSL_CTX_set_record_padding_callback()\fR or \fBSSL_set_record_padding_callback()\fR
can be used to assign a callback function \fIcb\fR to specify the padding
for \s-1TLS 1.3\s0 records. The value set in \fBctx\fR is copied to a new \s-1SSL\s0 by \fBSSL_new()\fR.
.PP
\&\fBSSL_CTX_set_record_padding_callback_arg()\fR and \fBSSL_set_record_padding_callback_arg()\fR
assign a value \fBarg\fR that is passed to the callback when it is invoked. The value
set in \fBctx\fR is copied to a new \s-1SSL\s0 by \fBSSL_new()\fR.
.PP
\&\fBSSL_CTX_get_record_padding_callback_arg()\fR and \fBSSL_get_record_padding_callback_arg()\fR
retrieve the \fBarg\fR value that is passed to the callback.
.PP
\&\fBSSL_CTX_set_block_padding()\fR and \fBSSL_set_block_padding()\fR pads the record to a multiple
of the \fBblock_size\fR. A \fBblock_size\fR of 0 or 1 disables block padding. The limit of
\&\fBblock_size\fR is \s-1SSL3_RT_MAX_PLAIN_LENGTH.\s0
.PP
The callback is invoked for every record before encryption.
The \fBtype\fR parameter is the \s-1TLS\s0 record type that is being processed; may be
one of \s-1SSL3_RT_APPLICATION_DATA, SSL3_RT_HANDSHAKE,\s0 or \s-1SSL3_RT_ALERT.\s0
The \fBlen\fR parameter is the current plaintext length of the record before encryption.
The \fBarg\fR parameter is the value set via \fBSSL_CTX_set_record_padding_callback_arg()\fR
or \fBSSL_set_record_padding_callback_arg()\fR.
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
The \fBSSL_CTX_get_record_padding_callback_arg()\fR and \fBSSL_get_record_padding_callback_arg()\fR
functions return the \fBarg\fR value assigned in the corresponding set functions.
.PP
The \fBSSL_CTX_set_block_padding()\fR and \fBSSL_set_block_padding()\fR functions return 1 on success
or 0 if \fBblock_size\fR is too large.
.PP
The \fBcb\fR returns the number of padding bytes to add to the record. A return of 0
indicates no padding will be added. A return value that causes the record to
exceed the maximum record size (\s-1SSL3_RT_MAX_PLAIN_LENGTH\s0) will pad out to the
maximum record size.
.SH "NOTES"
.IX Header "NOTES"
The default behavior is to add no padding to the record.
.PP
A user-supplied padding callback function will override the behavior set by
\&\fBSSL_set_block_padding()\fR or \fBSSL_CTX_set_block_padding()\fR. Setting the user-supplied
callback to \s-1NULL\s0 will restore the configured block padding behavior.
.PP
These functions only apply to \s-1TLS 1.3\s0 records being written.
.PP
Padding bytes are not added in constant-time.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBssl\fR\|(7), \fBSSL_new\fR\|(3)
.SH "HISTORY"
.IX Header "HISTORY"
The record padding \s-1API\s0 was added for \s-1TLS 1.3\s0 support in OpenSSL 1.1.1.
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2017\-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>.