Re: [9fans] Venti and the hash / public key in plan9

["Lluís Batlle" <viriketo@gmail.com>]

2006/2/6, Russ Cox <rsc@swtch.com>:
> > Hi...  I've been reading the papers about Venti.  There is an
> > explanation about the low probability of the repetition of a hash
> > string in a normal-sized nowadays hard disk.  Anyway I've don't
> > understood what does Venti do when a hash is found in the stored
> > blocks, and the contents of the blocks are different (the
> > low-probability case).  I imagine there is some code which does not
> > give a data-loss...  Can someone give a small explanation about that?
>
> It responds to the write RPC with an error.
So what should manage that error? The application? Maybe it try a
different write size?
In fact there should be another application layer between 9p and the
RPC for venti, isn't it? (which?)

>
> > And also about public key management in plan9 for (at least) 9p
> > connections.  I've seen in the paper regarding Security that there's
> > used only Shared-key authentication (p9sk1).  Maybe there's something
> > new in the actual distribution of plan9.
>
> p9sk1 is only an authentication protocol.
>
> Some 9P sessions are encrypted using TLS/SSL.
> We just match the SHA1 hash of the remote public key against
> a local list of okayed hashes.  There is no attempt to
> delve into the whole key hierarchy.  This is discussed
> in the Security paper.
Ok, I'll keep on reading it (I didn't finish).
>
> Russ
>
Thanks a lot!