Re: Microsoft Accounts (was Re: Problem with "None" Group on Non-Domain Members)

[Ken Brown <kbrown at cornell dot edu>]

On 5/8/2014 7:17 PM, Robert Pendell wrote:
> On Thu, May 8, 2014 at 4:09 PM, Corinna Vinschen wrote:
> > On May  7 16:46, Corinna Vinschen wrote:
> > > On May  7 10:09, Chris J. Breisch wrote:
> > > > Corinna Vinschen wrote:
> > > > > And here's a problem which I'm not sure how to solve at all:
> > > > >
> > > > > When calling the latest mkpasswd, the primary group of the local
> > > > > user account backing the Microsoft Account will *still* be "None".
> > > > >
> > > > > The reason is that the local account is just the same old account
> > > > > as usual.  Its default primary group *is* "None".
> > > > >
> > > > > Only when logging in via the Micosoft Account email address, the
> > > > > user token will not reflect what's stored in the local SAM, but
> > > > > will have been changed by the OS as outlined in this thread.
> > > > >
> > > > > So, when a user decides to create a passwd file rather than using
> > > > > the SAM/DB code in Cygwin, the information generated by mkpasswd
> > > > > will not match the user token, and the primary group stored in
> > > > > /etc/passwd will not even be available at all in the user token.
> > > > >
> > > > > I have not the faintest idea how to workaround this schizophrenia.
> > > > >
> > > > >
> > > > > Corinna
> > > > Oh wow. It took me two reads of this to understand it. Caffeine is
> > > > finally kicking in, I guess. Unless you just want to hard code the
> > > > primary group that mkpasswd generates to "Users" for any account
> > > > that it would tend to want to set as "None". That would be some
> > > > smelly code though.
> > >
> > > Hmm, but it might fix a couple of problems.  If we go ahead and
> > > always convert the "None" primary group to "Users", we'd have a
> > > pretty stable state, which works nicely for local accounts,
> > > independently of habving logged in as normal account or as Microsoft
> > > Account.  This might be the easiest workaound, in fact.
> >
> > I created a new snapshot on http://cygwin.com/snapshots/ which
> > introduces the following behaviour, which is a bit less intrusive:
> >
> > If a local account is connected to a Microsoft Account, the primary
> > group defaults to "Users".  If it's a normal local accout it defaults
> > to "None", as usual.  This also covers mkpasswd from the snapshot.
> >
> > This does not work if you continue to use an already existing
> > /etc/passwd file.  I have no good solution for this sccenario, other
> > than a (yet to be written) FAQ entry.
> >
> > Hope that helps nevertheless.
> >
> >
> > Corinna
>
> Thanks for all the effort you have put forth on this issue Corinna.  I
> checked the snapshot today and found the behavior to be matching what
> you described.  An expected side effect right now is that old files
> still have the group SID set to the user SID as well as all the other
> installed files placed by the OS however there isn't much we can do
> there beyond changing the group manually for the files.
>
> On that note I used the larger inst package (to get updates to
> mkpasswd and the like) and noticed that there is a /usr/lib and
> /usr/bin folder with the updated files however cygwin mounts /lib and
> /bin on top of the respective folders making any files installed there
> inaccessible in a normal cygwin run.

This doesn't happen if you install the snapshot by the method suggested 
in the FAQ:

  http://cygwin.com/faq.html#faq.setup.snapshots

Ken

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