gnutls_x509_crt_check_hostname2(3) gnutls gnutls_x509_crt_check_hostname2(3)

NAME         top

       gnutls_x509_crt_check_hostname2 - API function

SYNOPSIS         top

       #include <gnutls/x509.h>

       unsigned gnutls_x509_crt_check_hostname2(gnutls_x509_crt_t cert,
       const char * hostname, unsigned int flags);

ARGUMENTS         top

       gnutls_x509_crt_t cert
                   should contain an gnutls_x509_crt_t type

       const char * hostname
                   A null terminated string that contains a DNS name

       unsigned int flags

DESCRIPTION         top

       This function will check if the given certificate's subject matches
       the given hostname.  This is a basic implementation of the matching
       described in RFC6125, and takes into account wildcards, and the
       DNSName/IPAddress subject alternative name PKIX extension.

       IPv4 addresses are accepted by this function in the dotted-decimal
       format (e.g, ddd.ddd.ddd.ddd), and IPv6 addresses in the hexadecimal
       x:x:x:x:x:x:x:x format. For them the IPAddress subject alternative
       name extension is consulted. Previous versions to 3.6.0 of GnuTLS in
       case of a non-match would consult (in a non-standard extension) the
       DNSname and CN fields. This is no longer the case.

       When the flag GNUTLS_VERIFY_DO_NOT_ALLOW_WILDCARDS is specified no
       wildcards are considered. Otherwise they are only considered if the
       domain name consists of three components or more, and the wildcard
       starts at the leftmost position.  When the flag
       GNUTLS_VERIFY_DO_NOT_ALLOW_IP_MATCHES is specified, the input will be
       treated as a DNS name, and matching of textual IP addresses against
       the IPAddress part of the alternative name will not be allowed.

       The function gnutls_x509_crt_check_ip() is available for matching IP

RETURNS         top

       non-zero for a successful match, and zero on failure.

SINCE         top


REPORTING BUGS         top

       Report bugs to <>.
       Home page:

COPYRIGHT         top

       Copyright © 2001-2019 Free Software Foundation, Inc., and others.
       Copying and distribution of this file, with or without modification,
       are permitted in any medium without royalty provided the copyright
       notice and this notice are preserved.

SEE ALSO         top

       The full documentation for gnutls is maintained as a Texinfo manual.
       If the /usr/share/doc/gnutls/ directory does not contain the HTML
       form visit 

COLOPHON         top

       This page is part of the GnuTLS (GnuTLS Transport Layer Security
       Library) project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, send it to  This page was obtained from the
       tarball gnutls-3.6.6.tar.xz fetched from
       ⟨⟩ on 2019-03-06.  If you discover
       any rendering problems in this HTML version of the page, or you
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gnutls                              3.6.5 gnutls_x509_crt_check_hostname2(3)