Adduser devel - Nov 2010 - Bug#604242: [patch] Allow dots in username by default

Package: adduser
Version: 3.112

I don''t think there''s a reason not to allow usernames to
contain dots
(.), as they are also allowed to contain underscores (_) and dashes (-).
useradd accepts this.

Attached is a patch that makes dots be allowed just as other special
chars. One could also add the point in this line in /etc/adduser.conf:
#NAME_REGEX="^[a-z][-a-z0-9_]*\$"
but providing a patch for that makes the change harder to perform! ;-)


This fix would be appreciated for the gnome-system-tools, because
currently users-admin says dots are accepted, and this is false on
Debian. Saying dots are not allowed would be an issue because other
platforms allow for them, which means Debian should carry a specific
patch...

Original report in Ubuntu:
https://bugs.launchpad.net/ubuntu/+source/gnome-system-tools/+bug/677929


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This one time, at band camp, Milan Bouchet-Valat said:
> I don''t think there''s a reason not to allow usernames to
contain dots
> (.), as they are also allowed to contain underscores (_) and dashes (-).
> useradd accepts this.
> 
> Attached is a patch that makes dots be allowed just as other special
> chars. One could also add the point in this line in /etc/adduser.conf:
> #NAME_REGEX="^[a-z][-a-z0-9_]*\$"
> but providing a patch for that makes the change harder to perform! ;-)
> 
> 
> This fix would be appreciated for the gnome-system-tools, because
> currently users-admin says dots are accepted, and this is false on
> Debian. Saying dots are not allowed would be an issue because other
> platforms allow for them, which means Debian should carry a specific
> patch...
-  $configref->{"name_regex"} = "^[a-z][-a-z0-9_]*\$";
-  $configref->{"name_regex_system"} =
"^[A-Za-z][-A-Za-z0-9_]*\$";
+  $configref->{"name_regex"} = "^[a-z][-a-z0-9_.]*\$";
+  $configref->{"name_regex_system"} =
"^[A-Za-z][-A-Za-z0-9_.]*\$";

That''s a regex, so a bare . is almost certainly not what you want
there.

Why does users-admin use adduser instead of useradd?  It''s not that
it shouldn''t, but adduser is primarily designed as a policy compliant
method for maintainers to interface in a policy compliant way with user
management in maintainer scripts - extending it to be a general purpose
user management script for all manner of environments isn''t what
it''s
aimed at, and I''m not convinced it will be a good thing to make it
general purpose.  I think before changing the naming policy of adduser,
it does make sense to stop for a moment and check if you''re using the
right tool for the job.

Cheers,
-- 
 -----------------------------------------------------------------
|   ,''''`.                                            Stephen
Gran |
|  : :'' :                                        sgran at debian.org |
|  `. `''                        Debian user, admin, and developer |
|    `-                                     http://www.debian.org |
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Le dimanche 21 novembre 2010 ? 17:42 +0000, Stephen Gran a ?crit
:
> -  $configref->{"name_regex"} =
"^[a-z][-a-z0-9_]*\$";
> -  $configref->{"name_regex_system"} =
"^[A-Za-z][-A-Za-z0-9_]*\$";
> +  $configref->{"name_regex"} =
"^[a-z][-a-z0-9_.]*\$";
> +  $configref->{"name_regex_system"} =
"^[A-Za-z][-A-Za-z0-9_.]*\$";
>
> That''s a regex, so a bare . is almost certainly not what you want
there.
Indeed, kind of silly. Of course, we need to escape it...
> Why does users-admin use adduser instead of useradd?  It''s not
that
> it shouldn''t, but adduser is primarily designed as a policy
compliant
> method for maintainers to interface in a policy compliant way with user
> management in maintainer scripts - extending it to be a general purpose
> user management script for all manner of environments isn''t what
it''s
> aimed at, and I''m not convinced it will be a good thing to make it
> general purpose.  I think before changing the naming policy of adduser,
> it does make sense to stop for a moment and check if you''re using
the
> right tool for the job.
AFAIK, users-admin has always used adduser on Debian systems, I guess
with the idea that it will more likely to what the admin wants, since
settings from /etc/adduser.conf will be used. But this also brings many
issues, because we can never be sure what adduser is going to do, nor if
it will fail (the present bug being a good example).

Anyway, users-admin is being replaced with accounts-dialog in GNOME, so
I''m not going to change the way it works. And accounts-dialog uses
useradd (it was mainly designed for Fedora originally), and I guess
that''s what we''ll want to keep for Debian too, but that
creates other
problems (like: how do you choose where to create home directories? what
if people create accounts using adduser once, and accounts-dialog the
other?).

The current bug should also IMHO be fixed for adduser itself,
disregarding the fact that users-admin needs it. I can''t find a reason
why dots shouldn''t be allowed, and they can be pretty convenient for
some naming conventions (e.g. firstname.lastname)

severity 604242 wishlist
thanks

On Sun, Nov 21, 2010 at 07:14:36PM +0100, Milan Bouchet-Valat
wrote:
> The current bug should also IMHO be fixed for adduser itself,
> disregarding the fact that users-admin needs it. I can''t find a
reason
> why dots shouldn''t be allowed, and they can be pretty convenient
for
> some naming conventions (e.g. firstname.lastname)
Having dots in the user name creates some issues with scipts using
chown, which still accepts dots as separator between user name and
group name. If chown still accepts dots, there will be scripts using
this notation, which will break if a user name contains a dot.

I would recommend keeping the current default (which can be
overwritten by local configuration) until chown has stopped accepting
dots as separator.

IMO, chown compatibility and not breaking third-party scripts is more
important than being consistent with some graphical front-end''s
documentation.

Greetings
Marc

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Processing commands for control at bugs.debian.org:
> severity 604242 wishlist
Bug #604242 [adduser] [patch] Allow dots in username by default
Severity set to ''wishlist'' from ''normal''
> thanks
Stopping processing here.

Please contact me if you need assistance.
-- 
604242: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=604242
Debian Bug Tracking System
Contact owner at bugs.debian.org with problems

users-admin has been replaced with a gnome-control-center applet in
GNOME 3, and it uses useradd, so I don''t really care now. Feel free to
close the bug.

(Note though that useradd seems to allow dots in usernames on most
platforms, which probably suffer from the same potential problems as
Debian.)