`completion' and `context' arguments must be set by the application. */
int (*key_agreement)(SilcClient client, SilcClientConnection conn,
SilcClientEntry client_entry, const char *hostname,
`completion' and `context' arguments must be set by the application. */
int (*key_agreement)(SilcClient client, SilcClientConnection conn,
SilcClientEntry client_entry, const char *hostname,