[cap-talk] More Heresey: ACLs not inherently bad

[John Carlson]

On Sep 10, 2008, at 3:30 AM, Jonathan S. Shapiro wrote:

> On Tue, 2008-09-09 at 20:30 -0700, Charles Landau wrote:
>> Jed Donnelley wrote:
>>> Sorry - I was clear on that.  I shouldn't have included the leaf
>>> object in the above <> (see below as to what I was thinking).  What
>>> I don't understand is how such a directory-like object distinguishes
>>> between a fetch by the "new process" from a fetch by some other
>>> process (old process).  Are you imagining some Horton-like mechanism
>>> where the relevant processes get different capabilities to the
>>> directory-like object so that the directory-like object can
>>> distinguish the fetches?
>>
>> Each time you pass a different set of capabilities to a process, you
>> construct a new directory-like object that will give access to that  
>> set.
>> So in general, different processes will receive capabilities to
>> different directory-like objects. It needn't use Horton.
>
> This is precisely the operation that is both performance prohibitive  
> and
> (human) complexity prohibitive. It will turn out that humans can't  
> make
> the necessary decisions to decide what goes in to those directories.

If you use search as a way to create a directory, you can store your  
search terms and a swiss number for the namespace you are searching in  
your object referred to by your capability.  If you are passing  
capabilities as data, you can seal the capability, so that you know  
that when you get the capability back, you can unseal it and know you  
are the originator.

To define the search terms, you may use any method you choose:  
keywords, SQL, XML, etc. etc.

I realize that this has been shot down in the past.  I guess I don't  
get why this is so against the capabilities community idea of a secure  
system.  What is wrong with a query as a capability?  Why must I use a  
method?

If you want a method, store the method name (say as a swiss number)  
along with search terms somewhere and use the method name when you are  
communicating.  I don't really see the difference.  Is there a  
difference?

It really is as simple as what Jed describes in his Managing Domains  
paper.

John