[Python-Dev] capabilities & proxies (python-dev Summary for 2003-03-01 through 2003-03-15)

[M.-A. Lemburg]

Ben Laurie wrote:
> Brett Cannon wrote:
> 
>> Capabilities can loosely be thought of like bound methods.  Security with
>> capabilities is done based on possession; if you hold a reference to an
>> object you can use that object.
> 
> 
> This confusion is my fault: I just happened to like using bound methods 
> as the basis for capabilities, but objects can also be used, so long as 
> access to them is appropriately restricted. This is explained in detail 
> in the PEP I am writing (with help from others, I should note).
> 
>> Proxies are a wrapper around objects that restrict access to the object.
>> This restriction extends all the way to the core; even core code can't 
>> get
>> access to parts of a proxied object that it doesn't want any object to 
>> get
>> a hold of.
> 
> Its not clear to me what you mean by "core code" - certainly anything 
> written in C can slice through a proxy without any problems (or, indeed, 
> a capability).

That's certainly true...

BTW, just in case you aren't aware of it, mxProxy implements pretty
much what Brett summarized here for proxies. You may want to have
a look.

-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Software directly from the Source  (#1, Mar 18 2003)
 >>> Python/Zope Products & Consulting ...         http://www.egenix.com/
 >>> mxODBC, mxDateTime, mxTextTools ...        http://python.egenix.com/
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