W3C home > Mailing lists > Public > ietf-http-wg@w3.org > July to September 2009

Re: Issue 194: restricting allowed characters in quoted-pair

From: Roy T. Fielding <fielding@gbiv.com>
Date: Sun, 27 Sep 2009 15:33:11 -0700
Message-Id: <F5AD6A03-E56A-4D21-A026-5F063208C580@gbiv.com>
Cc: HTTP Working Group <ietf-http-wg@w3.org>
To: Julian Reschke <julian.reschke@gmx.de>

On Sep 27, 2009, at 4:16 AM, Julian Reschke wrote:

> Henrik Nordstrom wrote:
>> fre 2009-09-25 klockan 14:40 +0200 skrev Julian Reschke:
>>> - whether that's purely advisory or a requirement (SHOULD?), I  
>>> lean to the former, and
>> SHOULD == RECOMMENDED.
>> \ quoting more than needed is not an error, but not recommended as  
>> some
>> applications may not understand \ quoting...
>>> - where exactly to state it, as quoted-pair is used both inside  
>>> quoted-string and comment, and the characters that need escaping  
>>> thus differ; one way to fix this would be to change the ABNF so  
>>> "comment" gets it's own quoted-cpair rule.
>> Just a general statement that the producer SHOULD NOT \ quote other
>> characters than the reserved ones for the type of data produced  
>> (comment
>> or quoted-string).
>> There is no need to overdo this, and absolutely no reason to  
>> complicate
>> the BNF for it.
>> ...
>
> OK, then.
>
> So I have added the SHOULD NOT in both places, and -- to make  
> things less confusing with respect to quoted-pair -- added quoted- 
> cpair for use in comments (it's the same grammar, but comes with  
> different prose).
>
> See <http://trac.tools.ietf.org/wg/httpbis/trac/changeset/702>
>
> The actual text:
>
>    A string of text is parsed as a single word if it is quoted using
>    double-quote marks.
>
>      quoted-string  = DQUOTE *( qdtext / quoted-pair ) DQUOTE
>      qdtext         = OWS / %x21 / %x23-5B / %x5D-7E / obs-text
>                     ; OWS / <VCHAR except DQUOTE and "\"> / obs-text
>      obs-text       = %x80-FF
>
>    The backslash character ("\") can be used as a single-character
>    quoting mechanism only within quoted-string constructs:

remove "only"

>      quoted-pair    = "\" ( WSP / VCHAR / obs-text )
>
>    Producers SHOULD NOT escape characters that do not require escaping
>    (DQUOTE and the backslash character).

that should be "(i.e., other than DQUOTE and backslash)".

Same fix applies to the comment section.

....Roy
Received on Sunday, 27 September 2009 22:33:50 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 27 April 2012 06:51:10 GMT