[E-Lang] draft statement of consensus

Bill Frantz frantz@pwpconsult.com
Tue, 6 Feb 2001 22:35:17 -0800


At 12:29 PM -0800 2/6/01, Mark S. Miller wrote:
>>Bill wrote:
>>> I would love to set up a MLS system where code downloaded by my web
>>browser
>>> was restricted.  Some restrictions I would like include:
>>>
>>> * No way can it read my address book.  (Ditto for email messages.)
>>> * No way can it schedule system startup tasks.
>>> * No way can the code be executed outside these restrictions.
>
>At 11:14 AM Tuesday 2/6/01, Marc Stiegler wrote:
>>My Capzilla browser, when launching caplets, already achieves these goals,
>>and I don't even know what MLS is :-) So if this is a good example, then I'd
>>guess you can do it with pure capabilities :-)
>
>
>This is an excellent example of the problem I've had understanding what MLS
>is *for*.  All the non governmental examples seem like stuff you can do with
>just capabilities, without ever thinking "MLS".

At 12:14:00 -0700 2/6/01, Marc Stiegler wrote:
>My Capzilla browser, when launching caplets, already achieves these goals,
>and I don't even know what MLS is :-) So if this is a good example, then I'd
>guess you can do it with pure capabilities :-)

Do note that Key Logic designed a MLS system using a pure capability system
as a mechanism.  We were working on getting a B2, until we found out how
much it would cost.


I think when the MLS ideas were developed, the designers had the Unix
system as their model.  They assumed that programs ran with the full
authority of their users, so you needed some mandatory mechanism to keep
the program from using it's (full) authority to provide access in excess of
the mandatory policy.  My web browser example attempted to describe the
essence of this mind set.

Cheers - Bill


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