Re: draft-ietf-httpbis-header-structure: handling multiple field values

Julian Reschke <julian.reschke@gmx.de> Tue, 12 May 2020 20:20 UTC

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To: Poul-Henning Kamp <phk@phk.freebsd.dk>
Cc: Ian Clelland <iclelland@google.com>, Willy Tarreau <w@1wt.eu>, HTTP Working Group <ietf-http-wg@w3.org>
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From: Julian Reschke <julian.reschke@gmx.de>
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Date: Tue, 12 May 2020 22:17:39 +0200
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Subject: Re: draft-ietf-httpbis-header-structure: handling multiple field values
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On 12.05.2020 21:34, Poul-Henning Kamp wrote:
> --------
> In message <4045931b-06b3-9b76-106f-773499b8374b@gmx.de>de>, Julian Reschke writes:
>
>> Going back to the SH spec: I'm afraid that the spec *disallows* to fail
>> early on garbage - is this *really* the intent?
>
> Ehhh... what ?
>
> 	1.1.  Intentionally Strict Processing
>
> 	   This specification intentionally defines strict parsing and
> 	   serialisation behaviours using step-by-step algorithms; the only
> 	   error handling defined is to fail the operation altogether.
>
> Since the only failure is total failure, why or even how would you go
> about postponing it ?

The issue here is that combining

   Foo: "a

and

   Foo: b"

into

   Foo: "a, b"

*hides* an issue, and no failure will occur. Furthermore, we not only
get no failure, but the resulting string may vary depending on how the
fields were combined.

I get that it's unavoidable that this *can* happen, but does this mean
we should *disallow* failing for that input?

Best regards, Julian