Welcome back.
As you know, Centrify provides MFA for UNIX, Linux, Windows, our Vault and more (all you need is a tenant, sign-up using the "Try it now" button.
If you need help on PAM chaining, we suggest you check with the PAM_RADIUS maintainer or your MFA provider.
Here are a few references (you may be able to infer what to do from here):
- Setting-up MFA with SecurID (with PAM chaining): https://community.centrify.com/t5/TechBlog/Review-Integrating-DirectControl-with-RSA-SecurID-to-Achieve/ba-p/23814
- Setting-up Centrify MFA with Express for UNIX/Linux: https://community.centrify.com/t5/TechBlog/HOWTO-Implement-MFA-on-Centrify-Express-for-UNIX-Linux/ba-p/23695 (just in case you decide to use us).
- Using Centrify MFA with others as the RADIUS Server: https://community.centrify.com/t5/TechBlog/Configuring-RADIUS-MFA-to-work-for-DUO-RSA-SecurID-SecureAuth-or/ba-p/25858
R.P