Re: [art] not an erratum in RFC 6376, was Argh!!!! onto https://www.rfc-editor.org/errata.php

[Steffen Nurpmeso <[e-mail]>]

Murray S. Kucherawy wrote in
 <[e-mail]>:
 |On Thu, Mar 21, 2024 at 8:30 AM Steffen Nurpmeso <[e-mail]> \
 |wrote:
 |> But .. that is what happens in real life software?  Maybe one
 |> should even add a paragraph stating that, and mention the Sendmail
 |> milter protocol, which possibly is the culprit of what happens.
 |> (Though _why_ that is, since the other possibilities would have
 |> worked out just equally well?  Ie, literal bytes or simple
 |> stripping.  I cannot tell, i was not around anything email around
 |> 2006-2011 when that seems to have been developed.)
 |>
 |> I did ask on -dkim@ and implemented as written and said, but DKIM
 |> verification fails for such multiline headers from milter
 |> communication if RFC 6376 is followed exactly.  (Thankfully DKIM
 |> has a certificate test mode built-in, otherwise some reputation
 |> downgrade (if at all possible in my case) would surely have kicked
 |> in!  It is a great standard!)
 |>
 |
 |milter provides multiline headers separated by LFs, not CRLFs.  I don't
 |recall why it was done this way, but that's how it's been since the
 |beginning.  This is in the milter API documentation, which is (or used to
 |be) packaged in the sendmail source tarball.  You can find it online too;
 |for example:
 |
 |https://www.ibm.com/docs/en/aix/7.2?topic=functions-xxfi-header-callback\
 |-function

Well i actually had that around all the time, it is in the FreeBSD
source code that i track.  But i myself used the plain text
document  $Id: milter-protocol.txt,v 1.6 2004/08/04 16:27:50 tvierling Exp $
which does not mention this.

But *regardless* of all that.
If you do not treat LF as whitespace, you get failing signatures,
unless i am now totally confused.
Btw i posted OpenDKIM code of a canonicalization function which
does *not* do what you say this very evening, but it uses
isspace(3) on header field body content?!?

Good night from Germany,

--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)