From nobody Fri May 21 10:25:02 2021 Return-Path: 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 E83123A18A2 for ; Fri, 21 May 2021 10:25:00 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -1.306 X-Spam-Level: X-Spam-Status: No, score=-1.306 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, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=neutral reason="invalid (unsupported algorithm ed25519-sha256)" header.d=fifthhorseman.net header.b=jSlEySFc; dkim=pass (2048-bit key) header.d=fifthhorseman.net header.b=R4eOZu/7 Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id V9I1jZ6JUWzE for ; Fri, 21 May 2021 10:24:55 -0700 (PDT) Received: from che.mayfirst.org (unknown [162.247.75.117]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 7CFE23A18A0 for ; Fri, 21 May 2021 10:24:55 -0700 (PDT) DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/simple; d=fifthhorseman.net; i=@fifthhorseman.net; q=dns/txt; s=2019; t=1621617893; h=from : to : subject : date : message-id : mime-version : content-type : from; bh=JizpHl2zx3/nUz1aLdHRZKSCDVql6BVffr+zML2BRY4=; b=jSlEySFcPrRCNvQZ+RvG00/TF+3y3kjP47cz780AjOn6IOiepkSjbb65XpwELq0inja8w spUZcsM60Atkkb5Aw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=fifthhorseman.net; i=@fifthhorseman.net; q=dns/txt; s=2019rsa; t=1621617893; h=from : to : subject : date : message-id : mime-version : content-type : from; bh=JizpHl2zx3/nUz1aLdHRZKSCDVql6BVffr+zML2BRY4=; b=R4eOZu/7VTWr9pHDy4xn1e/ZwAYmh/9PuP9xWHZ/QrlcyDZt+RkHLBUtfU06P33PWWOZn 78NbzrtYjWHPFFptTkSdUfOGrKuUTRie6tCSUlbncMh/zLVnADEcC9tLpEsrs7kHfY6Lf2R 7OG7pNxwgHnCc/31sQOuvTlx/heYOgYRWe5wo6mbbU99rSXCpjhkwil3yrg69UB/SU0T5aC DhS8tFetW5aQxLUH9fTZPjse0CRGlGRbd3pcBklAXLuHv9RMRpX9eE9gDOb/lnmE291KG4K /hBRIoT2SGCDAhzFugdFoAJ55xaZA5Bqo3+46ImeUpgIVMJJk4O0Dzn1vcuQ== Received: from fifthhorseman.net (lair.fifthhorseman.net [108.58.6.98]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by che.mayfirst.org (Postfix) with ESMTPSA id 05D95F9A5 for ; Fri, 21 May 2021 13:24:52 -0400 (EDT) Received: by fifthhorseman.net (Postfix, from userid 1000) id 72CA721272; Fri, 21 May 2021 13:24:49 -0400 (EDT) From: Daniel Kahn Gillmor To: openpgp@ietf.org Autocrypt: addr=dkg@fifthhorseman.net; prefer-encrypt=mutual; keydata= mDMEX+i03xYJKwYBBAHaRw8BAQdACA4xvL/xI5dHedcnkfViyq84doe8zFRid9jW7CC9XBiI0QQf FgoAgwWCX+i03wWJBZ+mAAMLCQcJEOCS6zpcoQ26RxQAAAAAAB4AIHNhbHRAbm90YXRpb25zLnNl cXVvaWEtcGdwLm9yZ/tr8E9NA10HvcAVlSxnox6z62KXCInWjZaiBIlgX6O5AxUKCAKbAQIeARYh BMKfigwB81402BaqXOCS6zpcoQ26AADZHQD/Zx9nc3N2kj13AUsKMr/7zekBtgfSIGB3hRCU74Su G44A/34Yp6IAkndewLxb1WdRSokycnaCVyrk0nb4imeAYyoPtBc8ZGtnQGZpZnRoaG9yc2VtYW4u bmV0PojRBBMWCgCDBYJf6LTfBYkFn6YAAwsJBwkQ4JLrOlyhDbpHFAAAAAAAHgAgc2FsdEBub3Rh dGlvbnMuc2VxdW9pYS1wZ3Aub3JnL0Gwxvypz2tu1IPG+yu1zPjkiZwpscsitwrVvzN3bbADFQoI ApsBAh4BFiEEwp+KDAHzXjTYFqpc4JLrOlyhDboAAPkXAP0Z29z7jW+YzLzPTQML4EQLMbkHOfU4 +s+ki81Czt0WqgD/SJ8RyrqDCtEP8+E4ZSR01ysKqh+MUAsTaJlzZjehiQ24MwRf6LTfFgkrBgEE AdpHDwEBB0DkKHOW2kmqfAK461+acQ49gc2Z6VoXMChRqobGP0ubb4kBiAQYFgoBOgWCX+i03wWJ BZ+mAAkQ4JLrOlyhDbpHFAAAAAAAHgAgc2FsdEBub3RhdGlvbnMuc2VxdW9pYS1wZ3Aub3Jnfvo+ nHoxDwaLaJD8XZuXiaqBNZtIGXIypF1udBBRoc0CmwICHgG+oAQZFgoAbwWCX+i03wkQPp1xc3He VlxHFAAAAAAAHgAgc2FsdEBub3RhdGlvbnMuc2VxdW9pYS1wZ3Aub3JnaheiqE7Pfi3Atb3GGTw+ jFcBGOaobgzEJrhEuFpXREEWIQQttUkcnfDcj0MoY88+nXFzcd5WXAAAvrsBAIJ5sBg8Udocv25N stN/zWOiYpnjjvOjVMLH4fV3pWE1AP9T6hzHz7hRnAA8d01vqoxOlQ3O6cb/kFYAjqx3oMXSBhYh BMKfigwB81402BaqXOCS6zpcoQ26AADX7gD/b83VObe14xrNP8xcltRrBZF5OE1rQSPkMNy+eWpk eCwA/1hxiS8ZxL5/elNjXiWuHXEvUGnRoVj745Vl48sZPVYMuDgEX+i03xIKKwYBBAGXVQEFAQEH QIGex1WZbH6xhUBve5mblScGYU+Y8QJOomXH+rr5tMsMAwEICYjJBBgWCgB7BYJf6LTfBYkFn6YA CRDgkus6XKENukcUAAAAAAAeACBzYWx0QG5vdGF0aW9ucy5zZXF1b2lhLXBncC5vcmcEAx9vTD3b J0SXkhvcRcCr6uIDJwic3KFKxkH1m4QW0QKbDAIeARYhBMKfigwB81402BaqXOCS6zpcoQ26AAAX mwD8CWmukxwskU82RZLMk5fm1wCgMB5z8dA50KLw3rgsCykBAKg1w/Y7XpBS3SlXEegIg1K1e6dR fRxL7Z37WZXoH8AH Date: Fri, 21 May 2021 13:24:48 -0400 Message-ID: <87bl94dmov.fsf@fifthhorseman.net> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Archived-At: Subject: [openpgp] OpenPGP certificate structure: multiple binding signatures on subkeys? (MR 43) X-BeenThere: openpgp@ietf.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Ongoing discussion of OpenPGP issues." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 May 2021 17:25:01 -0000 --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi OpenPGP folks-- in https://gitlab.com/openpgp-wg/rfc4880bis/-/merge_requests/43 and https://gitlab.com/openpgp-wg/rfc4880bis/-/issues/25 vanitasvitae suggests that the structure for OpenPGP certificates (aka "Transferable Public Keys", aka "keyblocks") is wrong. He recommends this change: =2D-- a/crypto-refresh.md +++ b/crypto-refresh.md @@ -2914,8 +2914,8 @@ The format of an OpenPGP V4 key that uses multiple pu= blic keys is similar except User ID [Signature ...] [User ID [Signature ...] ...] [User Attribute [Signature ...] ...] =2D [[Subkey [Binding-Signature-Revocation] =2D Primary-Key-Binding-Signature] ...] + [[Subkey [Binding-Signature-Revocation ...] + Subkey-Binding-Signature ...] ...] =20 A subkey always has a single signature after it that is issued using the p= rimary key to tie the two keys together. This binding signature may be in either V3 or V4 format, but SHOULD be V4. There are two things happening here: - the binding signature is correctly identified as a Subkey-Binding-Signature, not a Primary-Key-Binding-Signature. (the primary-key-binding signature (the "cross-sig") is, where appropriate, expected to be embedded in the subkey-binding-signature itself) - there can be more than one binding sig revocation, and more than one subkey binding signature This matches my understanding of how OpenPGP certificates are structured, and I believe most implementations work this way. I've opened https://gitlab.com/sequoia-pgp/openpgp-interoperability-test-suite/-/issues= /52 to request a test for this, but it may not be necessary if the WG has consensus that this is correct. I note that if the change in the structure is correct, then the text below it should also be changed (it should not say "has a single signature after it=E2=80=A6") --dkg --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEARYIAB0WIQQttUkcnfDcj0MoY88+nXFzcd5WXAUCYKfs4QAKCRA+nXFzcd5W XCDjAP9aQL2RKlutl1MutM4EbCd/LV4i19Wo4uup/b134Vm9igEA1uxGHW581UYu Op75Iqd3WmfcRzyQuIQamrStmA+fMw8= =Hq14 -----END PGP SIGNATURE----- --=-=-=--