Allow disabling OTP for selected users

[Keruspe]

This allows enforcing OTP for "privileged" users while disabling it for "guest" users

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[Keruspe]

@googlebot I signed it!

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[ThomasHabets]

Does this not belong in the PAM config?

Something like:

auth [success=1,default=ok] pam_listfile.so item=user sense=deny file=/etc/otp_disabled 

That way users can't "opt out" of OTP. And if they can opt out, then this option is the same as having nullok in your config, no?

[Keruspe]

Hmm, it seems I misunderstood how nullok worked here, it's sufficient for what I want, thanks!