gnutls_x509_crt_get_subject_alt_name - API function

       #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);

       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)

       This function retrieves the Alternative Name (, 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.,

       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.

       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.

       Report bugs to <>.
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gnutls                               3.6.gnutls_x509_crt_get_subject_alt_name(3)