openssh unix dev - Mar 2014 - SSH_PRIVSEP_USER configurable at runtime?

Hi,


Right now, the unprivileged account for privilege separation is only
configurable at compile time (SSH_PRIVSEP_USER).  I'd like to ask if it
would be acceptable to have the account runtime configurable by adding
something like

  PrivilegeSeparationAccount foo

to sshd_config.

The reason I'm asking is this.  I'm working on a long overdue change to
Cygwin which is supposed to get rid of the /etc/passwd and /etc/group
files.  Rather, the Windows account databases (SAM and AD)are asked
directly for account information, and UID/GID values as well as
usernames are dynamic.

For instance, assuming you have a domain member machine MACH103, which
is member of the domain DOM1.  Assuming the machine as well as DOM1
and another dmain, DOM2, all have a user called "sshd", the
automatically
generated Cygwin usernames will be

  MACH103+sshd     for the local account
  sshd             for the account in domain DOM1
  DOM2+sshd        for the account in domain DOM2.

Additionally, the admin can decide if the domain name gets prepended
every time, which results in "DOM1+sshd" as username in DOM1, and the
domain separator character can be chosen freely as well, for instance
a backslash (MACH103\sshd).

With domainnames being part of the username, this allows for so many
variations of the actual username, that a fixed name "sshd" or just
a compile time option will become a problem.

Any chance to get such a sshd_config option?


Thanks,
Corinna

-- 
Corinna Vinschen
Cygwin Maintainer
Red Hat
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On Mon, 31 Mar 2014, Corinna Vinschen wrote:
> For instance, assuming you have a domain member machine MACH103, which
> is member of the domain DOM1.  Assuming the machine as well as DOM1
> and another dmain, DOM2, all have a user called "sshd", the
automatically
> generated Cygwin usernames will be
> 
>   MACH103+sshd     for the local account
>   sshd             for the account in domain DOM1
>   DOM2+sshd        for the account in domain DOM2.
> 
> Additionally, the admin can decide if the domain name gets prepended
> every time, which results in "DOM1+sshd" as username in DOM1, and
the
> domain separator character can be chosen freely as well, for instance
> a backslash (MACH103\sshd).
> 
> With domainnames being part of the username, this allows for so many
> variations of the actual username, that a fixed name "sshd" or
just
> a compile time option will become a problem.
> 
> Any chance to get such a sshd_config option?
I'm really loathe to add an option for this. Is there any way that
sshd could figure out which account automatically? e.g. by having
ssh-host-config ensure that ${machine}/sshd exists and is appropriately
configured

-d