static void x509_start_chain(const br_x509_class **ctx,
                             const char *server_name)
{
  struct x509_context *x509 = (struct x509_context *)ctx;

  if(!x509->verifyhost)
    server_name = NULL;
  x509->minimal.vtable->start_chain(&x509->minimal.vtable, server_name);
}
static void x509_start_chain(const br_x509_class **ctx,
                             const char *server_name)
{
  struct x509_context *x509 = (struct x509_context *)ctx;

  if(!x509->verifyhost)
    server_name = NULL;
  x509->minimal.vtable->start_chain(&x509->minimal.vtable, server_name);
}