[REBOL] Re: overwriting the secure dialect
From: lmecir:mbox:vol:cz at: 29-Nov-2002 16:50
Hi Alban,
----- Original Message -----
From: "Alban Gabillon"
> 'secure is used to define the access control policy. Then rebol grants or
> denies access to ressources based on this policy.
> What I would like to do is to define my own access control policy language
> which would be more expressive than 'secure. I give you an example: I
would
> like the language to be able to express authorization rules separately
> addressing the file existence and the file content. Consequently,
regarding
> a given file, one may have the permission to see it but not to consult its
> content. One may also be forbidden to both see it and consult it.
>
> So my question is: Is there a way to make rebol to apply the policy
defined
> with my custom language ?
>
> > > Is there a possibility to overwrite the native secure dialect with a
> > custom one ?
> > >
> > > Thanks in advance
> > >
> > > AG
your problem isn't the custom language. In Rebol it is trivial to write any
custom language, a.k.a. dialect. The trouble is, what to do with it. The
SECURE function clearly affects data built to the interpreter. These data
are accessed by native functions manipulating files, network resources, etc.
If you wanted to change security policies of the natives, you might have to
rewrite the natives (probably in C), i.e. build a new version of the
interpreter.
The reason, why you cannot access security data from Rebol is simple:
otherwise there would have been no security at all.
This means, that you can write your own dialect, but you are unable to
change the behaviour of the natives.
Hope it will be clear now
-L
