#147: header-specific canonicalisation

This has been discussed on-list and in meetings sporadically, but I don't think we've ever focused on it exclusively.

<http://trac.tools.ietf.org/wg/httpbis/trac/ticket/147>


Current text at <http://tools.ietf.org/html/draft-ietf-httpbis-p6-cache-08#section-2.6>:

>    The selecting request-headers from two requests are defined to match
>    if and only if the selecting request-headers in the first request can
>    be transformed to the selecting request-headers in the second request
>    by adding or removing linear white space [[anchor8: [
> ref
> ]]] at places
>    where this is allowed by the corresponding ABNF, and/or combining
>    multiple message-header fields with the same field name following the
>    rules about header fields in 
> Section 3.2 of [Part1].

Proposed replacement:

  The selecting request-headers from two requests are defined to match
  if and only if those in the first request can be transformed to those in the
  second request by applying any of the following:
    - adding or removing whitespace, where allowed in the headers' ABNF
    - combining multiple message-header fields with the same field name (see
       Section 3.2 of [Part1])
    - canonicalising both headers' values in a way that is known to have identical
       semantics, according to the headers' specification (e.g., re-ordering field values
      when order is not significant; case-normalisation, where values are defined to be
      case-insensitive)


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

Received on Wednesday, 3 March 2010 06:00:30 UTC