[openpgp] Re: Splitting replacement keys subpacket into related keys and trust equivalence?

Andrew Gallagher <andrewg@andrewg.com> Fri, 13 September 2024 09:02 UTC

Return-Path: <andrewg@andrewg.com>
X-Original-To: openpgp@ietfa.amsl.com
Delivered-To: openpgp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 3D635C1840FF; Fri, 13 Sep 2024 02:02:12 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.108
X-Spam-Level:
X-Spam-Status: No, score=-2.108 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_ZEN_BLOCKED_OPENDNS=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01, URIBL_DBL_BLOCKED_OPENDNS=0.001, URIBL_ZEN_BLOCKED_OPENDNS=0.001] autolearn=unavailable autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=andrewg.com
Received: from mail.ietf.org ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id uhU8n-r2-b3t; Fri, 13 Sep 2024 02:02:06 -0700 (PDT)
Received: from fum.andrewg.com (fum.andrewg.com [IPv6:2a01:4f9:c011:23ad::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 6E1A5C1CAE8E; Fri, 13 Sep 2024 02:02:05 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=andrewg.com; s=andrewg-com; t=1726218123; bh=3IQWHb6Av80oKDkFPvWxSQrHGuNqRYcFJv7QakYn/l0=; h=From:Subject:Date:References:Cc:In-Reply-To:To:From; b=lZJLjkZjWCM9goLSA0RsqNS+lVNZ+E0grz4VYBuuozemf/cezEh0D2FvDoYHPuqOV 45uYKQKtwLhnKw/uhVwj5uqMGiyuS35aBB8pUVc89AkQd79kC78XoAGI08UcTFCZ7x TcK86/c1JKUh6gY0Ye1gAS/QygxLCIWUsnr4NQiXXBfihMXRNa9z0tLucgmp1Hb993 nbABAvDt8OIpF/zzQRLj5FHsdPqL03uSbQ88kHreHqwDRnkXNbLrWfn39PDdIJ4TBo VO7CRpjIpRdzsn8VaXY9u7WXG81L4l0COtFzdWQcOgv+sWNkKjwIyv5yRdYa4r3ZMz 5Utw0KfXfgUrA==
Received: from smtpclient.apple (unknown [176.61.115.103]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by fum.andrewg.com (Postfix) with ESMTPSA id 6EBE75DFD5; Fri, 13 Sep 2024 09:02:03 +0000 (UTC)
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
From: Andrew Gallagher <andrewg@andrewg.com>
Mime-Version: 1.0 (1.0)
Date: Fri, 13 Sep 2024 10:01:52 +0100
Message-Id: <5ED82E08-5973-4C4D-8726-49B24646DF2D@andrewg.com>
References: <I1AVKcpZIk0c47n7JbfpMHn0RmQv7YTkXvRC7JbH_MRPfKvd4V6jn50E0pIcaANbAZ4-khxFgIGLk5D1rDsJgPTQgvNoqbPzbj5WEd5rUc0=@protonmail.com>
In-Reply-To: <I1AVKcpZIk0c47n7JbfpMHn0RmQv7YTkXvRC7JbH_MRPfKvd4V6jn50E0pIcaANbAZ4-khxFgIGLk5D1rDsJgPTQgvNoqbPzbj5WEd5rUc0=@protonmail.com>
To: Daniel Huigens <d.huigens@protonmail.com>
X-Mailer: iPhone Mail (21G93)
Message-ID-Hash: IVJ2X4XW7WZ6VY4RQ5CEELVJD7LWTET3
X-Message-ID-Hash: IVJ2X4XW7WZ6VY4RQ5CEELVJD7LWTET3
X-MailFrom: andrewg@andrewg.com
X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-openpgp.ietf.org-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header
CC: Andrew Gallagher <andrewg=40andrewg.com@dmarc.ietf.org>, Bart Butler <bart+ietf@pm.me>, Daniel Huigens <d.huigens=40protonmail.com@dmarc.ietf.org>, Justus Winter <justus@sequoia-pgp.org>, draft-ietf-openpgp-replacementkey@ietf.org, "openpgp\\\\@ietf.org" <openpgp@ietf.org>
X-Mailman-Version: 3.3.9rc4
Precedence: list
Subject: [openpgp] Re: Splitting replacement keys subpacket into related keys and trust equivalence?
List-Id: "Ongoing discussion of OpenPGP issues." <openpgp.ietf.org>
Archived-At: <https://mailarchive.ietf.org/arch/msg/openpgp/ZRvWuFRA4z7e6L6Eh6JI9mZgX3A>
List-Archive: <https://mailarchive.ietf.org/arch/browse/openpgp>
List-Help: <mailto:openpgp-request@ietf.org?subject=help>
List-Owner: <mailto:openpgp-owner@ietf.org>
List-Post: <mailto:openpgp@ietf.org>
List-Subscribe: <mailto:openpgp-join@ietf.org>
List-Unsubscribe: <mailto:openpgp-leave@ietf.org>

On 13 Sep 2024, at 08:42, Daniel Huigens <d.huigens@protonmail.com> wrote:
> 
> In the email case specifically, you _could_ take it as a signal to say,
> "oh there's a replacement key, but I don't know where/which it is,
> so I need to go fetch this contact's keys again (by email address)".

Sure, but I’m thinking specifically of the cases where lookup by email address isn’t efficient, e.g. if there is no WKD on the domain and there are a number of fake keys on the keyservers. If we compare with the design goal of trying to match the behaviour of subkeys as much as possible, leaving out fingerprints does complicate the lookup process in the general case. 

A