Re: [Technical Errata Reported] RFC7230 (5257)

The #element production in RFC 7230 matches a lone comma and a value 
beginning with two commas, both of which this proposed change would 
cause it to reject. A more correct improvement would be to move leading 
OWS out of the repeatable subexpression, thereby eliminating the need to 
special-case an initial comma:

#element => [ element OWS ] *( "," OWS [ element OWS ] )

On 02/07/2018 06:20 PM, RFC Errata System wrote:
> The following errata report has been submitted for RFC7230,
> "Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing".
>
> --------------------------------------
> You may review the report below and at:
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.rfc-2Deditor.org_errata_eid5257&d=DwIBaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=-o8MJF7i0TzXAJRB0ncfTVfWKSyTG7nl_iTLU_A2B7c&m=zQjlOYino3rJYW4JoSmEaFILD08XL2uMjejcqr140FU&s=glP3zQBZzlydq72gdMb9gIXPknE1jsRwB6m7Hq-jjDs&e=
>
> --------------------------------------
> Type: Technical
> Reported by: Erwin Pe <erwin.pe@baesystems.com>
>
> Section: 7
>
> Original Text
> -------------
> For compatibility with legacy list rules, a recipient MUST parse and
> ignore a reasonable number of empty list elements: enough to handle
> common mistakes by senders that merge values, but not so much that
> they could be used as a denial-of-service mechanism.  In other words,
> a recipient MUST accept lists that satisfy the following syntax:
>
>    #element => [ ( "," / element ) *( OWS "," [ OWS element ] ) ]
>
>    1#element => *( "," OWS ) element *( OWS "," [ OWS element ] )
>
> Corrected Text
> --------------
> For compatibility with legacy list rules, a recipient MUST parse and
> ignore a reasonable number of empty list elements: enough to handle
> common mistakes by senders that merge values, but not so much that
> they could be used as a denial-of-service mechanism.  In other words,
> a recipient MUST accept lists that satisfy the following syntax:
>
>    #element => [ ( ("," OWS element) / element ) *( OWS "," [ OWS
>      element ] ) ]
>
>    1#element => *( "," OWS ) element *( OWS "," [ OWS element ] )
>
> Notes
> -----
> With the current ABNF rule for #element, and using token as an element, the construction:
>
>      ",     foobar"
>
> cannot be derived from #element, but can be derived from 1#element. (legacy list rule)
> Since #element is meant to be a superset of 1#element, lists derived from 1#element should satisfy the #element rule as well.
>
> Instructions:
> -------------
> This erratum is currently posted as "Reported". If necessary, please
> use "Reply All" to discuss whether it should be verified or
> rejected. When a decision is reached, the verifying party
> can log in to change the status and edit the report, if necessary.
>
> --------------------------------------
> RFC7230 (draft-ietf-httpbis-p1-messaging-26)
> --------------------------------------
> Title               : Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
> Publication Date    : June 2014
> Author(s)           : R. Fielding, Ed., J. Reschke, Ed.
> Category            : PROPOSED STANDARD
> Source              : Hypertext Transfer Protocol Bis APP
> Area                : Applications
> Stream              : IETF
> Verifying Party     : IESG
>

Received on Thursday, 8 February 2018 04:05:20 UTC