gnutls_certificate_client_set_retrieve_function - API function

       #include <gnutls/compat.h>

       cred, gnutls_certificate_client_retrieve_function * func);

       gnutls_certificate_credentials_t cred
                   is a gnutls_certificate_credentials_t structure.

       gnutls_certificate_client_retrieve_function * func
                   is the callback function

       This function sets a callback to be called in order to retrieve the
       certificate to be used in the handshake.  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_retr_st* st);

        req_ca_cert is only used in X.509 certificates.  Contains a list with
       the CA names that the server considers trusted.  Normally we should send
       a certificate that is signed by one of these CAs. These names are DER
       encoded. To get a more meaningful value use the function

        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, if a certificate is requested by the server (and after the
       certificate request message has been received).

       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.

       Report bugs to <>.
       Home page:

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       permitted in any medium without royalty provided the copyright notice and
       this notice are preserved.

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gnutls                        gnutls_certificate_client_set_retrieve_function(3)