#442: p1: BWS

Mark Nottingham <mnot@mnot.net> Fri, 19 April 2013 11:47 UTC

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From: Mark Nottingham <mnot@mnot.net>
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Date: Fri, 19 Apr 2013 21:46:57 +1000
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Subject: #442: p1: BWS
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Tracking this in:
  http://trac.tools.ietf.org/wg/httpbis/trac/ticket/442


On 18/04/2013, at 11:18 AM, Mark Nottingham <mnot@mnot.net> wrote:

> p1 3.2.3 says:
> 
>>   BWS is used where the grammar allows optional whitespace, for
>>   historical reasons, but senders SHOULD NOT generate it in messages;
>>   recipients MUST accept such bad optional whitespace and remove it
>>   before interpreting the field value or forwarding the message
>>   downstream.
> 
>  http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-22#section-3.2.3
> 
> Throughout our specs, BWS is used at the end of header fields:
>     header-field   = field-name ":" OWS field-value BWS
> 
> and in transfer-codings:
>     transfer-parameter = attribute BWS "=" BWS value
> 
> and in Expect headers:
>  expectation  = expect-name [ BWS "=" BWS expect-value]
>                             *( OWS ";" [ OWS expect-param ] )
>  expect-param = expect-name [ BWS "=" BWS expect-value ]
> 
> and, finally, in auth-params on challenges and credentials:
>  auth-param     = token BWS "=" BWS ( token / quoted-string )
> 
> Is this whitespace really "bad" enough to MUST-require that intermediaries (including load balancers and other hardware!) remove it before forwarding the message?
> 
> Cheers,
> 
> --
> Mark Nottingham   http://www.mnot.net/
> 
> 
> 
> 

--
Mark Nottingham   http://www.mnot.net/