Re: sshd: computer name's case must match?

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Feb 13 13:55, Bill Stewart wrote:
> On Wed, Feb 13, 2019 at 1:25 PM Corinna Vinschen
> <corinna-cygwin@cygwin.com> wrote:
> > > (a) Domain or computer name portion to the left of the "+" must always
> > > be uppercase
> >
> > No, the case must match the case of the domain or computername.
> >
> > > (b) Username after "+" sign (or username alone, without "+" sign) must
> > > match case exactly
> > >
> > > Questions:
> > >
> > > 1. Are the above two statements (a) and (b) complete/correct?
> > >
> > > 2. With regards to (a), are there any cases where the domain or
> > > computer name is not uppercase?
> >
> > Yes.  In my domain I have four machines using all-lowercase machine
> > name for no apparent reason.  One is a Linux machine, one is a
> > Windows 7 64 bit, the other two are Windows 8.1 32 and 64 bit machines.
> > All others, including the Windows 8 machines, are all uppercase.
> 
> The computer or domain name case inconsistency would seem to be a
> source of confusion, mainly because on the Windows side we are
> case-retentive but not case-sensitive, and it is not immediately
> obvious which case will apply in the case of a computer or domain
> name.
> 
> According to: http://pubs.opengroup.org/onlinepubs/9699919799/ -
> [...]
> >From this reference, it seems that a POSIX-compliant username cannot
> contain the + character?

*should*, not *must*.  It may be a portabiliy problem but it's not
strictly disallowed.  I'm also not sure what this has to do with the
matter at hand.

> So my suggestion is for Cygwin to convert the name part before the +
> automatically to upper (or lower) case.

The problem may be compatibility with existing scripts and OpenSSH
Match rules.

> Thoughts?

I'm in the process of discussing with the OpenSSH maintainers how to
proceed.


Corinna

-- 
Corinna Vinschen
Cygwin Maintainer

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