OpenSSL::PKey::EC::Point#mul

static VALUE ossl_ec_point_mul(int argc, VALUE *argv, VALUE self)
{
    EC_POINT *point_self, *point_result;
    const EC_GROUP *group;
    VALUE group_v = rb_attr_get(self, id_i_group);
    VALUE arg1, arg2, arg3, result;
    const BIGNUM *bn_g = NULL;

    GetECPoint(self, point_self);
    GetECGroup(group_v, group);

    result = rb_obj_alloc(cEC_POINT);
    ossl_ec_point_initialize(1, &group_v, result);
    GetECPoint(result, point_result);

    rb_scan_args(argc, argv, "12", &arg1, &arg2, &arg3);
    if (RB_TYPE_P(arg1, T_ARRAY) || argc > 2)
        rb_raise(rb_eNotImpError, "OpenSSL::PKey::EC::Point#mul with arrays " \
                 "is no longer supported");

    BIGNUM *bn = GetBNPtr(arg1);
    if (!NIL_P(arg2))
        bn_g = GetBNPtr(arg2);
    if (EC_POINT_mul(group, point_result, bn_g, point_self, bn, ossl_bn_ctx) != 1)
        ossl_raise(eEC_POINT, NULL);

    return result;
}