Re: [art] Argh!!!! onto https://www.rfc-editor.org/errata.php

[Steffen Nurpmeso <[e-mail]>]

Hello.

John Levine wrote in
 <[e-mail]>:
 |It appears that Steffen Nurpmeso  <[e-mail]> said:
 |>All i wanted to report is that for RFC 6376, section 3.4.2, the
 |>reality of software (Google, "Microsoft", Amavis.., rspamd, and
 |>what not) is that in the three items ...
 |>
 |>WSP has to be replaced with "WSP, CR and LF", unless something
 |>more lengthy is desired.
 |
 |No, it's correct as is.
 |
 |The first bullet on page 16 says to unfold all the lines, so the CR/LF
 |are gone before it does anything with WSP.

But *that* unfolding refers to exactly CRLF alone, because only
this combination is allowed by RFC 5322.
I .. now you make me a bit unsure, but i really think i did test
both, removing lone CR and LF, as well as treating them literally.
Both did not work out.  The LF really has to be treated as
whitespace to make the algorithm work.  I would have to test this
again to be very sure.
But ok, shall that be right, then the unfolding algorithm

   o  Unfold all header field continuation lines as described in
      [RFC5322]; in particular, lines with terminators embedded in
      continued header field values (that is, CRLF sequences followed by
      WSP) MUST be interpreted without the CRLF.  Implementations MUST
      NOT remove the CRLF at the end of the header field value.

would have to be changed to "unfold..as described in.., except
that lone CR and LF characters must be treated like CRLF", or
something similar.

...

So now i have looked into what OpenDKIM does (in the past i looked
what dkimpy does, but likely lots of Python code *must* come into
play before, "thus"..), and there i see (WSP+style changes):

  dkim_canon_header_string(..){
  ..
    /* skip all spaces before first word */
    while (*p != '\0' && DKIM_ISWSP(*p))
    ..
    for ( ; *p != '\0'; p++){
      if (isascii(*p) && isspace(*p)){
         /* mark that there was a space and continue */
         space = TRUE;
         continue;

That isspace(3) includes the isblank(3) that RFC 5322 asks for,
but also LF and CR and more.  So that goes more in line with
changing the three paragraphs; also beyond the milter protocol.

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)