OpenVPN client configuration for passing MFA static challenge response

robross0606

3/13/24, 1:40 PM

I have site-to-site tunnel configuration set up on a Linux router which has worked for several years with typical OpenVPN authentication (certs, U/P auth, etc.). In this setup, my Linux router is the client side of the site-to-site tunnel. Recently the server end of this enabled mandatory multi-factor authentication (MFA) using a one-time password (OTP):

static-challenge "Enter Authenticator Code" 1

I have been able to set up the OTP generator part of this so that I can access the correct OTP generated response code from a script. However, I cannot seem to figure out how to set up the OpenVPN client (cli) automated scripting to pass this response during client authentication with the remote server. All my searching yields many articles and threads about how to set up the server side of MFA on OpenVPN, but very little to nothing about how to pass it on the client side from the command line. All the articles seem to assume the client side will be using one of the GUI apps (Windows, MacOS, etc.) with live challenge/response. Any help or ideas here would be much appreciated!

380

0 + 1

openvpn

vpn-client

totp

Greg Askew

3/13/24, 1:53 PM

Multifactor authentication such as this is 99.999% intended for interactive use cases. Those that aren't use hardware HSM modules and a truckload of OS and application code. That's why there isn't much information available. For example, both AWS and Azure have HSM solutions. Of course that doesn't mean that something can't be cobbled together. That is known as "wish it were Multifactor".

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: OpenVPN client configuration for passing MFA static challenge response

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.