NAME

       gnutls_certificate_set_retrieve_function2 - API function

SYNOPSIS

       #include <gnutls/abstract.h>

       void    gnutls_certificate_set_retrieve_function2(gnutls_certificate_credentials_t   cred,
       gnutls_certificate_retrieve_function2 * func);

ARGUMENTS

       gnutls_certificate_credentials_t cred
                   is a gnutls_certificate_credentials_t type.

       gnutls_certificate_retrieve_function2 * func
                   is the callback function

DESCRIPTION

       This function sets a callback to be called in order to retrieve the certificate to be used
       in the handshake. The callback will take control only if a certificate is requested by the
       peer.

       The  callback's   function   prototype   is:   int   (*callback)(gnutls_session_t,   const
       gnutls_datum_t*   req_ca_dn,   int   nreqs,  const  gnutls_pk_algorithm_t*  pk_algos,  int
       pk_algos_length, gnutls_pcert_st** pcert, unsigned int *pcert_length,  gnutls_privkey_t  *
       pkey);

        req_ca_dn is only used in X.509 certificates.  Contains a list with the CA names that the
       server considers trusted.  This  is  a  hint  and  typically  the  client  should  send  a
       certificate  that  is  signed  by  one  of these CAs. These names, when available, are DER
       encoded. To get a more meaningful value use the function gnutls_x509_rdn_get().

        pk_algos contains a list with server's acceptable signature algorithms.  The  certificate
       returned should support the server's given algorithms.

        pcert should contain a single certificate and public key or a list of them.

        pcert_length is the size of the previous list.

        pkey is the private key.

       If the callback function is provided then gnutls will call it, in the handshake, after the
       certificate request message has been received.  All the provided by  the  callback  values
       will not be released or modified by gnutls.

       In server side pk_algos and req_ca_dn are NULL.

       The callback function should set the certificate list to be sent, and return 0 on success.
       If no certificate was selected then the number of certificates should be set to zero.  The
       value  (-1) indicates error and the handshake will be terminated. If both certificates are
       set in the credentials and a callback is available, the callback takes predence.

SINCE

       3.0

REPORTING BUGS

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

COPYRIGHT

       Copyright © 2001-2021 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/