---
title: "Unsupported OneSpan Authentication Server Features and Limitiations"
slug: "oas-pg-unsupported-onespan-authentication-server-features-and-limitiations-3-28"
updated: 2025-07-04T10:04:31Z
published: 2025-07-07T13:58:12Z
canonical: "docs.onespan.com/oas-pg-unsupported-onespan-authentication-server-features-and-limitiations-3-28"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.onespan.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Unsupported OneSpan Authentication Server Features and Limitiations

When using an HSM with OneSpan Authentication Server, certain standard features are not supported and certain limitations apply.

The following standard features are not supported with HSM:

- OATH-based authenticators
- Generation of offline authentication data for Digipass Authentication for Windows Logon

The following RADIUS protocols are not supported with HSM:

- CHAP
- MS-CHAP
- MS-CHAP v2