OpenSSL::BN#mod_inverse

static VALUE
ossl_bn_mod_inverse(VALUE self, VALUE other)
{
    BIGNUM *bn1, *bn2 = GetBNPtr(other), *result;
    VALUE obj;
    GetBN(self, bn1);
    obj = NewBN(rb_obj_class(self));
    if (!(result = BN_mod_inverse(NULL, bn1, bn2, ossl_bn_ctx)))
        ossl_raise(eBNError, "BN_mod_inverse");
    SetBN(obj, result);
    return obj;
}