????
Your IP : 3.17.175.191
.\" 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_SET1_HOST 3"
.TH SSL_SET1_HOST 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_set1_host, SSL_add1_host, SSL_set_hostflags, SSL_get0_peername \- SSL server verification parameters
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/ssl.h>
\&
\& int SSL_set1_host(SSL *s, const char *hostname);
\& int SSL_add1_host(SSL *s, const char *hostname);
\& void SSL_set_hostflags(SSL *s, unsigned int flags);
\& const char *SSL_get0_peername(SSL *s);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
These functions configure server hostname checks in the \s-1SSL\s0 client.
.PP
\&\fBSSL_set1_host()\fR sets the expected \s-1DNS\s0 hostname to \fBname\fR clearing
any previously specified hostname or names. If \fBname\fR is \s-1NULL,\s0
or the empty string the list of hostnames is cleared, and name
checks are not performed on the peer certificate. When a nonempty
\&\fBname\fR is specified, certificate verification automatically checks
the peer hostname via \fBX509_check_host\fR\|(3) with \fBflags\fR as specified
via \fBSSL_set_hostflags()\fR. Clients that enable \s-1DANE TLSA\s0 authentication
via \fBSSL_dane_enable\fR\|(3) should leave it to that function to set
the primary reference identifier of the peer, and should not call
\&\fBSSL_set1_host()\fR.
.PP
\&\fBSSL_add1_host()\fR adds \fBname\fR as an additional reference identifier
that can match the peer's certificate. Any previous names set via
\&\fBSSL_set1_host()\fR or \fBSSL_add1_host()\fR are retained, no change is made
if \fBname\fR is \s-1NULL\s0 or empty. When multiple names are configured,
the peer is considered verified when any name matches. This function
is required for \s-1DANE TLSA\s0 in the presence of service name indirection
via \s-1CNAME, MX\s0 or \s-1SRV\s0 records as specified in \s-1RFC7671, RFC7672\s0 or
\&\s-1RFC7673.\s0
.PP
\&\fBSSL_set_hostflags()\fR sets the \fBflags\fR that will be passed to
\&\fBX509_check_host\fR\|(3) when name checks are applicable, by default
the \fBflags\fR value is 0. See \fBX509_check_host\fR\|(3) for the list
of available flags and their meaning.
.PP
\&\fBSSL_get0_peername()\fR returns the \s-1DNS\s0 hostname or subject CommonName
from the peer certificate that matched one of the reference
identifiers. When wildcard matching is not disabled, the name
matched in the peer certificate may be a wildcard name. When one
of the reference identifiers configured via \fBSSL_set1_host()\fR or
\&\fBSSL_add1_host()\fR starts with \*(L".\*(R", which indicates a parent domain prefix
rather than a fixed name, the matched peer name may be a sub-domain
of the reference identifier. The returned string is allocated by
the library and is no longer valid once the associated \fBssl\fR handle
is cleared or freed, or a renegotiation takes place. Applications
must not free the return value.
.PP
\&\s-1SSL\s0 clients are advised to use these functions in preference to
explicitly calling \fBX509_check_host\fR\|(3). Hostname checks may be out
of scope with the \s-1RFC7671 \fBDANE\-EE\s0\fR\|(3) certificate usage, and the
internal check will be suppressed as appropriate when \s-1DANE\s0 is
enabled.
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
\&\fBSSL_set1_host()\fR and \fBSSL_add1_host()\fR return 1 for success and 0 for
failure.
.PP
\&\fBSSL_get0_peername()\fR returns \s-1NULL\s0 if peername verification is not
applicable (as with \s-1RFC7671 \fBDANE\-EE\s0\fR\|(3)), or no trusted peername was
matched. Otherwise, it returns the matched peername. To determine
whether verification succeeded call \fBSSL_get_verify_result\fR\|(3).
.SH "EXAMPLES"
.IX Header "EXAMPLES"
Suppose \*(L"smtp.example.com\*(R" is the \s-1MX\s0 host of the domain \*(L"example.com\*(R".
The calls below will arrange to match either the \s-1MX\s0 hostname or the
destination domain name in the \s-1SMTP\s0 server certificate. Wildcards
are supported, but must match the entire label. The actual name
matched in the certificate (which might be a wildcard) is retrieved,
and must be copied by the application if it is to be retained beyond
the lifetime of the \s-1SSL\s0 connection.
.PP
.Vb 5
\& SSL_set_hostflags(ssl, X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS);
\& if (!SSL_set1_host(ssl, "smtp.example.com"))
\& /* error */
\& if (!SSL_add1_host(ssl, "example.com"))
\& /* error */
\&
\& /* XXX: Perform SSL_connect() handshake and handle errors here */
\&
\& if (SSL_get_verify_result(ssl) == X509_V_OK) {
\& const char *peername = SSL_get0_peername(ssl);
\&
\& if (peername != NULL)
\& /* Name checks were in scope and matched the peername */
\& }
.Ve
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBX509_check_host\fR\|(3),
\&\fBSSL_get_verify_result\fR\|(3).
\&\fBSSL_dane_enable\fR\|(3).
.SH "HISTORY"
.IX Header "HISTORY"
These functions were added in OpenSSL 1.1.0.
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2016\-2020 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>.