finish

static VALUE
rb_digest_base_finish(VALUE self)
{
    rb_digest_metadata_t *algo;
    void *pctx;
    VALUE str;

    algo = get_digest_base_metadata(rb_obj_class(self));

    TypedData_Get_Struct(self, void, &digest_type, pctx);

    str = rb_str_new(0, algo->digest_len);
    algo->finish_func(pctx, (unsigned char *)RSTRING_PTR(str));

    /* avoid potential coredump caused by use of a finished context */
    algo_init(algo, pctx);

    return str;
}