NAME

       gnutls_x509_crt_get_subject_alt_name - API function

SYNOPSIS

       #include <gnutls/x509.h>

       int  gnutls_x509_crt_get_subject_alt_name(gnutls_x509_crt_t  cert, unsigned int seq, void * san, size_t *
       san_size, unsigned int * critical);

ARGUMENTS

       gnutls_x509_crt_t cert
                   should contain a gnutls_x509_crt_t type

       unsigned int seq
                   specifies the sequence number of the alt name (0 for the first one, 1 for the second etc.)

       void * san  is the place where the alternative name will be copied to

       size_t * san_size
                   holds the size of san.

       unsigned int * critical
                   will be non-zero if the extension is marked as critical (may be null)

DESCRIPTION

       This function retrieves the Alternative Name (2.5.29.17), contained  in  the  given  certificate  in  the
       X509v3 Certificate Extensions.

       When  the  SAN  type  is  otherName,  it  will  extract  the  data  in  the  otherName's value field, and
       GNUTLS_SAN_OTHERNAME is returned.  You may use gnutls_x509_crt_get_subject_alt_othername_oid() to get the
       corresponding OID and the "virtual" SAN types (e.g., GNUTLS_SAN_OTHERNAME_XMPP).

       If an otherName OID is known, the data will be decoded.  Otherwise the returned data will be DER encoded,
       and you will have to decode it yourself.  Currently, only the RFC 3920 id-on-xmppAddr SAN is recognized.

RETURNS

       the alternative subject name type on success, one of the enumerated  gnutls_x509_subject_alt_name_t.   It
       will  return  GNUTLS_E_SHORT_MEMORY_BUFFER  if   san_size is not large enough to hold the value.  In that
       case  san_size will be updated with the required size.  If the certificate does not have  an  Alternative
       name with the specified sequence number then GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE is returned.

REPORTING BUGS

       Report bugs to <bugs@gnutls.org>.
       Home page: http://www.gnutls.org

COPYRIGHT

       Copyright © 2001-2022 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

       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

       http://www.gnutls.org/manual/