We are implementing Duo on some Linux systems that do not have internet access, and that work through a gateway that also does not have internet access. I’ve set up a proxy on the gateway and on another machine that does have internet access. The gateway machine has a proxy that then proxies to the second machine.
We are using pam_duo, and it is failing. I tried the trick of configuring login_duo and then trying “login_duo -d”, and it gives the error:
 Failsafe Duo login for ‘’: Couldn’t connect to api-.duosecurity.com: wrong version number
I’ve tried the double-proxy setup by setting https_proxy, and I’m able to curl https websites just fine, so the proxies are working. I temporarily allowed internet access for the gateway, and when I do that, duo_login works fine.
Does anyone know what the “wrong version number” error is from?