[Top] [All Lists]

Re: ABNF experts sought for OpenPGP header definition

2005-05-21 01:42:36

Simon Josefsson wrote:

We would like help with improving the ABNF

Above all bookmark <>

The various provisions of RFC 2045 apply.

Amended by RfC 2231, you get some pretty obscure stuff with
2231, e.g. parameter names must be unique.  Okay, you have
that already.

   id-or-url := id / url
   id        := *HEXDIG

Like zero digits ?

   url       := absoluteURI  ; Defined in RFC 2396.

Obsoleted by STD 66 (3986).  If you ckeck an RfC number at
<> you get the status + updates.

for one it doesn't include CFWS at the necessary spots.

Add [CFWS} after the colon, before and after the "=", and
before the CRLF.  Just an idea.  Check out RfC 3834, it's
my favourite example for "how stuff works".

Further, it doesn't permit quoting, such as:

OpenPGP: "B565716F"

Do you need / want this ?  How long can it be ?  Less than
998 doesn't need folding, unless it's an encoded word (but
it's not).

OpenPGP: "";

Here RfC 2231 won't help you for excessively long URLs.

OpenPGP: url="";

Here it could, in theory.  Another observation might help,
an URI never contains any FWS.  Therefore you can insert
folding white space when needed (again for the 998 limit),
and later remove it to get the unfolded URL.

For a pretty simple application see RfC 2017.  Any credits
for every single bit I said here should go to Bruce Lilly
and Bill Fenner (unless I screwed up of course ;-)

See also draft-lilly-field-specification-03

Suggestions for only partial improvements are appreciated.

Bill proposed a nicer way to import rules:  use prose-val,
as defined in 2234bis.
                      Bye, Frank

<Prev in Thread] Current Thread [Next in Thread>