Re: note metadata for files

[François Revol <revol@xxxxxxx>]

On 07/07/2014 00:32, shawn wilson wrote:
> So, I'm pushing this more into the realm of OT here (ie, this no
> longer has anything to do with zsh and for this reason and possibly
> others, this discussion might want to go offlist)
[...]
>> In case you're interested in the xattr compatibility issue, I've written
>> a paper about this:
>> http://dcevents.dublincore.org/IntConf/dc-2011/paper/view/53
>> Sadly it seems nobody cares.
> 
> Hmmmm, so how far has your research gone here? What software ignores
> xattr on which fs (how well does something like ncase deal with it)?

Well, even things like /bin/cp -p (--preserve) by default only preserves
mode,owner‐ship,timestamps but not xattr...

I think rsync supports the linux xattrs, probably not enabled by default
again, but I didn't try yet.

Don't know about ncase.

> What security mechanisms rely on EAs and have you tried to mangle them
> in order to bypass these mechanisms (either OS or application
> policies)?

I didn't really consider this question, given Samba alone already has a
hard time enough converting the ACLs.

Note, xattrs on Linux (and the now-withdrawn POSIX draft about xattrs)
have only been done on purpose of implementing ACLs atop.

> I'd be more interested in the networked ramifications of
> mangled EAs, but a copy from a thumb drive might be interesting as
> well (though I doubt that would be very fruitful since moving into a
> higher security realm is a bit harder in kernel space).

Besides, things like Samba and NTFS-3g differ (at least used to) on the
way the mangle named-stream inside xattrs...

François.