void ssl_set_rng( ssl_context *ssl,
                  int (*f_rng)(void *, unsigned char *, size_t),
                  void *p_rng )
{
    ssl->f_rng      = f_rng;
    ssl->p_rng      = p_rng;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.