--- Forwarded from Steffen Nurpmeso <stef...@sdaoden.eu> ---
Date: Wed, 06 Mar 2024 23:43:00 +0100
Author: Steffen Nurpmeso <stef...@sdaoden.eu>
From: Steffen Nurpmeso <stef...@sdaoden.eu>
...
Subject: Re: [..] Recommendation for dkim signing
Message-ID: <20240306224300.AvxERJ7Z@steffen%sdaoden.eu>
...
One. Last. Message. Of mine.
And sorry for all this mostly off-topic noise.
Steffen Nurpmeso wrote in
<20240306214948.V5gSjSiU@steffen%sdaoden.eu>:
...
|So now that i have DKIM myself i tested.
|And *no* verification software i can reach actually supports
|Ed25519-sha256 as of RFC 8463 from September 2018!
|It is even *worse* than that.
...
| - Microsoft: fails the DKIM test if a RFC 8463 signature is
| present, no matter whether first or last!!!
| Is this *really* true? That is really bad.
+ It even actively fails SHA1 DKIM signatures.
I know these are deprecated, but if i use a rsa-sha1 and
a rsa-sha256 signature in that order:
Authentication-Results: spf=pass (sender IP is 217.144.132.164)
smtp.mailfrom=sdaoden.eu; dkim=fail (body hash did not verify)
header.d=sdaoden.eu;dmarc=bestguesspass action=none
header.from=sdaoden.eu;compauth=pass reason=109
The *very*same* message/-checkum passes Google:
Authentication-Results: mx.google.com;
dkim=pass (test mode) header.i=@sdaoden.eu header.s=lemon
header.b=meYlPkTE;
dkim=pass (test mode) header.i=@sdaoden.eu header.s=citron
header.b=Cehr1W9z;
spf=pass (google.com: domain of stef...@sdaoden.eu designates
217.144.132.164 as permitted sender) smtp.mailfrom=stef...@sdaoden.eu
Looking at that. Say, the Microsoft
Authentication-Results: does not denote its own domain
name, no? Ie i could not strip it. I have not read RFC
8601 for very too long to know, though.
They do not look at the h=sha1 of the DNS record, do they.
They do not look at the a= of the DKIM signature.
...
| - Place a single signature.
|
| - It must be RSA-sha256.
And exactly only that.
|RFC 6376 surely would have deserved something better.
Good night, greetings, and
Ciao from Germany,
-- End forward <20240306224300.AvxERJ7Z@steffen%sdaoden.eu>
--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)
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