Re: Why is the default user group "users"? and: rights and access to /var/mail

[Nils Gillmann <ng0@n0.is>]

Nils Gillmann transcribed 1.3K bytes:
> Hi,
> 
> can someone tell me why in gnu/system/shadow module you thought
> it would be a good idea to default to "users" as a shared group
> for all accounts created as normal user profiles?
> 
> Reason why I'm asking has a second question attached:
> Why does our opensmtpd-service (and dovecot?) create
> /var/mail world readable, owned by root:root?
> I'm working on integration of mailx (package done, debugging its
> runtime currently[1]), though I think my concern is not exclusive to
> mailx: I want users to be able to read mailboxes inside /var/mail
> by their name (/var/mail/$username) and which are set to be r+w
> only for $username:$username. If you want to list the content of
> the folder you would need to be part of the wheel/sudo group,
> otherwise you are just able to access your mailbox with your
> mailreader.
> $username:$username was what I learned as good and secure usage
> for user accounts. Why GuixSD uses $username:users is beyond me.
> I know recently the default chmod of the user $home was changed
> (last year?) so I can no longer read other users homes, but I'm
> still questioning the choice.
> Some explanation on this would be good.

I think I can achieve what I want with different settings and services.
root:root might still be a problem, but I need test more with this.

On $username:users, I was told that $username:$username is quiet
recent and new development in how defaults are set for Unix users.
With every user in one group we just need to watch chmod. So I guess
the decision was made when this one user group was still dominant.

> 
> [1] Not sure if this is something you want to see in Guix master,
> as a package and as integration. If you are, I'll work it into
> my Guix repo when I'm done with it.
>