Subject: Re: thoughts on a possible "pre-upload" hook

From: "Shawn O. Pearce" <[email-masked]>
Date: Tue, 22 Sep 2009 09:17:25 -0700

Matthieu Moy <[email-masked]> wrote:
> >>>>>> "Sitaram" == Sitaram Chamarty <[email-masked]> writes:
> > Sitaram> As git is used more and more in corporate-type environments, at some
> > Sitaram> point it becomes convenient to have *branches* (or more accurately,
> > Sitaram> refs) that are not readable.
> 
> But that alone would make it rather painfull for the user : "git
> clone" would fail if any branch in the repository is not readable, for
> example.

No, what Sitaram is asking for is to have upload-pack not advertise
the hidden branches.  By not advertising them, the client cannot
send a "want" request for them, and they won't appear in the list
that clone believes exists when it creates the new local repository.
Thus, clone would succeed.
 
> Also, don't forget that branches are just references, which means that
> if you prevent reference A from being uploaded, then another reference
> B may point to the same commits as A, and then you can bypass the
> safety hook on A by using B.

Yes.  But this is no different than having two different git
repositories, A.git and B.git.  Pushing commits from A.git into B.git
allows someone to bypass A.git's filesystem read access control by
instead reading those commits from B.git.

IOW, those who have access to the data must protect it.  You can't
do it entirely in software, especially when you don't control the
user's computer.

-- 
Shawn.