On Thursday 19 February 2009, Robin H. Johnson wrote:
> On Thu, Feb 19, 2009 at 10:47:33AM +0100, Robert Buchholz wrote:
> > > Your count of needing to attack two boxes presently is wrong.
> > > Just pick some community rsyncNN.CC.gentoo.org that also hosts
> > > distfiles via HTTP/FTP, and attack that box, replacing both a
> > > Manifest and the distfile.
> >
> > The rsync attack can be avoided by using the signed tree tarballs.
> > The DIST hash attack can't.
>
> Err, unless I'm missing something, the signed-tree stuff (as tarballs
> or MetaManifest per my GLEPs) does prevent the DIST hash issue as
> well. For a signed tree (where the Manifests and full tree contents
> are verifiable), I don't see how you would subvert a distfile and NOT
> have it detected (short of defeating the hash functions).

Maybe I should have been clearer. By the "DIST hash attack" I meant an 
attack on the original location of the distfile where you would need to 
run a man-in-the-middle attack on the developer and either the 
distfiles master or the user downloading the file. That's why I said 
right now you need to attack two boxes, and by removing DIST entries 
from Manifest this would be reduced to one.


Robert