open == file considered harmful (Re: [Python-Dev] RE: rexec.pyunuseable)

Luke Kenneth Casson Leighton lkcl at lkcl.net
Wed Dec 17 14:40:32 EST 2003


> Are you aware of the original issue, which is that as soon as you have
> a file *instance* (which might have been given to you by a very
> restrictive open() variant), you can always get to the file *class*
> using the __class__ attribute?  Access to the __class__ attribute is
> useful for all sorts of reasons.

that is why i am proposing that ACLs be added to every "Entity"
in language - functions, modules, attributes etc.

[even if the implementation is such that they aren't _actually_
 every-object-in-python-has-another-damn-pointer]

in this way, you would have one ACL on the open() function which
restricts it to file-read-only, another ACL on the open.__class__
attribute which would be, for the sake of argument
[("all functions", DENY, ABSOLUTELY_EVERYTHING)]

etc.

l.




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