sshd boolean option parsing is excessively case-sensitive

[nmarques]

Dear People,

The field 'PasswordAuthentication' unlike all the others requires no capitalization in order for the ssh daemon to start properly!

While this works:

PasswordAuthentication yes

The following doesn't work for this field (though works for other fields):

PasswordAuthentication Yes

This is most likely an issue to bring up to upstream project. Could we have a fix so that configuration can be done in a consistent way and the daemon doesn't break because of capitalization of a given parameter (it works on the other fields using [Yy] or [Nn]).

This is a reality in 14.04 and 16.04.

Thanks for your time.

[Colin Watson (cjwatson)]

This is true of all the purely yes/no flags; I agree that there are some multi-state options that behave differently.

I've raised this upstream, and linked the bug here. Thanks for your report. I should warn you in advance that a backport to 14.04/16.04 is rather unlikely, but if fixed upstream then it'll make its way into later Ubuntu releases.

[nmarques (nmo-marques)]

Hi Collin, thanks for the input. I've spoken to upstream also about this, and they informed me that some options are parsed with a more advanced parser than others (the last being yes/no).

Their advice was to follow the comments spec.

[Launchpad Janitor (janitor)]

This bug was fixed in the package openssh - 1:7.7p1-2

---------------
openssh (1:7.7p1-2) unstable; urgency=medium

  * Fix parsing of DebianBanner option (closes: #894730).

 -- Colin Watson <email address hidden> Wed, 04 Apr 2018 00:47:29 +0100