NAME

       gnutls_certificate_set_retrieve_function - API function

SYNOPSIS

       #include <gnutls/gnutls.h>

       void            gnutls_certificate_set_retrieve_function(gnutls_certificate_credentials_t           cred,
       gnutls_certificate_retrieve_function * func);

ARGUMENTS

       gnutls_certificate_credentials_t cred
                   is a gnutls_certificate_credentials_t type.

       gnutls_certificate_retrieve_function * 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. You are advised
       to use gnutls_certificate_set_retrieve_function2() because it is much more efficient in the processing it
       requires from gnutls.

       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_retr2_st* st);

        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.

        st should contain the certificates and private keys.

       If  the  callback  function is provided then gnutls will call it, in the handshake, after the certificate
       request message has been received.

       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/

gnutls                                               3.4.10          gnutls_certificate_set_retrieve_function(3)