More OpenSSH hacking. I'm trying to figure out why the new(ish) PAM chauthtok via keyboard-interactive code displays the PAM messages properly on some platforms (Redhat, AIX) but doesn't on others (Solaris, HP-UX). I added some instrumentation to the PAM code to help debug it and spent some time poking sshd with a debugger, but without definitive results. It seems to be related to to message "style" set by PAM when responding to the request, but needs more investigation.
I also noticed a problem whereby the if the PAM authentication thread dies without completing the authentication (either success or failure), sshd will block indefinitely for that session. I have a fix for that, which will go in once a few style nits are sorted out.
Spent a little time looking at dropbear, another SSH2 server implementation. While fiddling with it I got it running on HP-UX, fixed what I suspect was a bug and sent the patch for both back to the author.