Re: [apps-discuss] seeking pragmatic guidelines for content-type'structure': when to go top-level?

"t.petch" <ietfc@btconnect.com> Fri, 11 November 2011 19:57 UTC

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From: "t.petch" <ietfc@btconnect.com>
To: "Ned Freed" <ned.freed@mrochek.com>
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Cc: dcrocker@bbiw.net, Apps Discuss <apps-discuss@ietf.org>
Subject: Re: [apps-discuss] seeking pragmatic guidelines for content-type'structure': when to go top-level?
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----- Original Message -----
From: "Ned Freed" <ned.freed@mrochek.com>
To: "t.petch" <ietfc@btconnect.com>
Cc: <dcrocker@bbiw.net>et>; "Apps Discuss" <apps-discuss@ietf.org>
Sent: Friday, November 11, 2011 1:46 AM
> > ----- Original Message -----
> > From: "Dave CROCKER" <dhc@dcrocker.net>
> > To: "Apps Discuss" <apps-discuss@ietf.org>
> > Sent: Thursday, November 10, 2011 7:59 AM
> > > Folks,
> > >
<snip>

> In other words, you changed the file extension to one that your application
> knows is associated with a font of some kind. So it tried to process it
> as such and got an error.
>
> And again, to the extent this has anything to do with top-level types, you
have
> just shown your application to be capable of handling previously unknown ones
> without falling over. And that's all you have shown.
>
> But if you want to actually perform a more complete test, you should have
tried
> to add a font/* entry to your application's media type tables and then tested
> with content having that label. I've done that lots of times and previously
> unknown top-level types have never been a problem.
>
> > I think we need to know this for commonly deployed platforms before we can
say
> > it is not dangerous.
>
> If you regard the behavior you describe as dangerous, well, we appear to be
> working from very different definitions of the word "dangerous".

On the contrary, it suggested to me that the top level type was ignored and so
it did not matter what it was; ie the behaviour I see is safe, not dangerous.
If there is a danger, it might lie in cleverer software that took more notice of
the top level typ.

Just to be clear, I tried a variety of combinations, including ones where the
type was one I would expect the MUA to understand, eg 'image', with a filename
of eg .ttf, and the MUA preferred the file name extension to the type.  Or
perhaps it treats everything not text the same.

Tom Petch



>
> Ned
>
>