[tahoe-dev] Tahoe and restricting uploads

[Brian Warner]

On Tue, 07 Oct 2008 16:18:19 -0400
Benjamin R Welton <benjamin.r.welton at wmich.edu> wrote:

> Hello Everyone,

Welcome!

> I am pretty new to tahoe and i am looking at using it in one of the
> projects that i am doing. One of the big questions that i have about tahoe
> is whether or not there is a way to limit who can upload to the storage
> grid? I would like to keep downloads unrestricted but leave uploads
> restricted to a certain set of nodes.
> 
> Is something like this possible to do for an entire grid? If its not
> possible to do on the entire grid can it be done on the storage nodes
> individually?

Not yet, unfortunately. The goal of the "Accounting" project is to provide
this sort of control. When this is done, users who have the authority to
upload files (i.e. to consume storage space) will have a special "storage
authority". This will take the form of a "blessed" private key (i.e. a
private key and a signed certificate that grants it storage authority). Each
storage server will be configured with a public key that delgates storage
authority outwards: the user gets to upload files if there is a certificate
chain that spans from the server's public key to the user's private one.

It will also be possible for the storage servers to delegate this decision to
some other centralized key. Allmydata.com will use this by having the storage
servers delegate to our account manager key, then all customer keys will be
signed by the account manager key. Customer nodes will present the
manager->customer certificate and their own signed upload request, and the
manager->server would accept it because of the two-hop chain.


This is one of the remaining "Big Ticket" items for Tahoe: I don't really
consider Tahoe to be complete until this is implemented. But it's been
falling behind our other current big priorities: repair and signed
introductions. We're hoping to get it done in the next couple of months.

Please take a look at the following tickets and wiki pages for more
information about our Accounting plans:

 http://allmydata.org/trac/tahoe/wiki/AccountingDesign
 #468: design+build the Usage/Aggregator service
       http://allmydata.org/trac/tahoe/ticket/468
 http://allmydata.org/trac/tahoe/wiki/QuotaManagement
 #467: change peer-selection to prepare for rights-amplification step
       http://allmydata.org/trac/tahoe/ticket/467


cheers,
 -Brian