Re: [openpgp] Encrypted emails with cleartext copies [was: Re: use of .well-known in WKD and HKP]

Bart Butler <bart+ietf@pm.me> Thu, 02 November 2023 11:39 UTC

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Date: Thu, 02 Nov 2023 11:38:49 +0000
To: Wiktor Kwapisiewicz <wiktor@metacode.biz>
From: Bart Butler <bart+ietf@pm.me>
Cc: Daniel Huigens <d.huigens=40protonmail.com@dmarc.ietf.org>, openpgp@ietf.org
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Archived-At: <https://mailarchive.ietf.org/arch/msg/openpgp/n-IGf3yvykKfd16LGkzGrpcT_yc>
Subject: Re: [openpgp] Encrypted emails with cleartext copies [was: Re: use of .well-known in WKD and HKP]
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Hi Wiktor,

As an aside to the main discussion here, I agree with you that rewriting From is not great, but most mailing lists do it because they have to. Either the original email has an enforcing DMARC policy but only SPF aligned (which is terrible but it happens--I would love to mandate aligned DKIM given it's 2023), or, less forgivably, the list modifies the body content and breaks the aligned DKIM signature.

In some cases it's stupid optional stuff like with footers which should go extinct. But even if you turn all that off, software like Mailman (any version) simply does not support forwarding along the raw email without breaking DKIM in some cases, which I discovered to my horror a month or two back. 


-Bart

On Thursday, November 2nd, 2023 at 12:26 PM, Wiktor Kwapisiewicz <wiktor@metacode.biz> wrote:

> I think it works like that because the Mailing List software rewrites
> From. If I sent you e-mail directly and CC'd the list then you'd get
> two copies of the same e-mail: one with From me and one with rewritten From.
> 

> I'm not a big fan of rewriting e-mails. This sounds like a workaround
> instead of addressing the problem where it originated from (e.g. for
> DMARC signatures some mailing lists don't modify From e-mails and only
> append List-* headers. List-Unsubscribe exists and this plays well with
> DMARC).