[http-state] BNF notation differences, was: Comments on draft-ietf-httpstate-cookie-08.txt (1 - 4.1.2.)

[Julian Reschke <[e-mail]>]

On 31.05.2010 18:25, Adam Barth wrote:
> ...
>> Copying the rfc1123-date grammar from draft-ietf-httpbis-p1-messaging-09
>> into an appendix would probably be the best solution as differences with
>> case-sensitivity and white space would then no longer be a source of
>> confusion. Otherwise there simply should be a reminder that the grammar
>> notation is different from RFC 2616 and care must be taken to apply the
>> right rules for imported symbols.
>
> I've add the following text near the use of 1123-date:
>
> [[
> sane-cookie-date  =<rfc1123-date, as defined in RFC 2616>
>                      ; Note that RFC 2616 uses a different grammatical notation
>                      ; than this document (which uses ABNF from RFC5234).
> ]]
>
> Hopefully that addresses your concerns.
> ...

The current ABNF is:


set-cookie-header = "Set-Cookie:" SP set-cookie-string
set-cookie-string = cookie-pair *( ";" SP cookie-av )
cookie-pair       = cookie-name "=" cookie-value
cookie-name       = token
cookie-value      = token
token             = <token, defined in [RFC 2616], Section 2.2>

cookie-av         = expires-av / max-age-av / domain-av /
                     path-av / secure-av / httponly-av /
                     extension-av
expires-av        = "Expires=" sane-cookie-date
sane-cookie-date  = <rfc1123-date, defined in [RFC 2616], Section 3.3.1>
                     ; Note that RFC 2616 uses a different grammatical
                     ; notation than this document (which uses ABNF
                     ; from [RFC5234]).
max-age-av        = "Max-Age=" 1*DIGIT
domain-av         = "Domain=" domain-value
domain-value      = <subdomain, defined in [RFC 1034], Section 3.5>
path-av           = "Path=" path-value
path-value        = <any CHAR except CTLs or ";">
secure-av         = "Secure"
httponly-av       = "HttpOnly"
extension-av      = <any CHAR except CTLs or ";">


So the comment was applied to sane-cookie-date, but it also applies to 
token. Furthermore, the ABNF for domain-value (RFC 1034) uses yet 
another syntax. So maybe it would be better to remove the comment again, 
and just to add a prose warning that these three productions inherited 
from other specs are defined in different variants of ABNF.

Also, re:

   <any CHAR except CTLs or ";">

I think it would be good to avoid prose productions. In this case, an 
alternative would be:

   0x20-3A / 0x3C-7E
   ; any CHAR except CTLs or ";"

Best regards, Julian