From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98022C433EF for ; Sat, 16 Oct 2021 20:18:33 +0000 (UTC) Received: from mail.server123.net (mail.server123.net [78.46.64.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 03FFF61073 for ; Sat, 16 Oct 2021 20:18:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 03FFF61073 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=wagner.name Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=saout.de X-Virus-Scanned: amavisd-new at saout.de Received-SPF: None (mailfrom) identity=mailfrom; client-ip=84.19.178.47; helo=v1.tansi.org; envelope-from=arno@wagner.name; receiver= Received: from v1.tansi.org (mail.tansi.org [84.19.178.47]) by mail.server123.net (Postfix) with ESMTP for ; Sat, 16 Oct 2021 22:15:42 +0200 (CEST) Received: from gatewagner.dyndns.org (81-6-44-245.init7.net [81.6.44.245]) by v1.tansi.org (Postfix) with ESMTPA id 84D82140116 for ; Sat, 16 Oct 2021 22:15:39 +0200 (CEST) Received: by gatewagner.dyndns.org (Postfix, from userid 1000) id B33AD17A279; Sat, 16 Oct 2021 22:15:41 +0200 (CEST) Date: Sat, 16 Oct 2021 22:15:41 +0200 From: Arno Wagner To: dm-crypt@saout.de Message-ID: <20211016201541.GA18893@tansi.org> Mail-Followup-To: dm-crypt@saout.de References: <6c699b29-90ac-49c9-894f-3f9050cf9037@localhost> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <6c699b29-90ac-49c9-894f-3f9050cf9037@localhost> User-Agent: Mutt/1.10.1 (2018-07-13) Message-ID-Hash: Q7X26AS3BF4JZDBZEWQ3WKTUPVXD4SGT X-Message-ID-Hash: Q7X26AS3BF4JZDBZEWQ3WKTUPVXD4SGT X-MailFrom: arno@wagner.name X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-dm-crypt.saout.de-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header X-Mailman-Version: 3.3.2 Precedence: list Subject: [dm-crypt] Re: reg: Question on LUKS device's content exposure List-Id: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable On Thu, Oct 14, 2021 at 21:56:06 CEST, Michael Kj=F6rling wrote: > On 13 Oct 2021 08:41 +0000, from samsapi01@protonmail.ch (sami0l): > > Suppose my VPS provider wants to view contents of > > /mnt/sdb1_crypt_files, will they be able to mount the device file > > /dev/sda to view the contents at /dev/mapper/sdb1_crypt or > > /mnt/sdb1_crypt_files? Meaning, since /dev/mapper/sdb1_crypt, > > /dev/sdb1 or /mnt/sdb1_crypt_files are *within* the main or root > > /dev/sda will they get access to the files which is within the LUKS > > device (and decrypted at /dev/mapper/sdb1_crypt) too? >=20 > Anyone who is in control of the hypervisor will be able to inspect the > VM's portion of the host's RAM, and extract from it anything they > wish, including cryptographic keys or other relevant material (or just > copy it wholesale). [...]=20 I completely agree. =20 You cannot protect a VM against the hypervisor it is running under=20 and you cannot protect against the admin of that hypervisor.=20 Even things like CPUs encrypting RAM only serve to protect against other VMs on the same hardware, not against the hypervisor.=20 As to the idea with a dedicated, alerted rack, I know of real-world installations that do exectly that. This will fail with a competent attacker as well though, as physical locks and tamper-detection=20 switches are not that secure as well. Regards, Arno --=20 Arno Wagner, Dr. sc. techn., Dipl. Inform., Email: arno@wagner.name GnuPG: ID: CB5D9718 FP: 12D6 C03B 1B30 33BB 13CF B774 E35C 5FA1 CB5D 9718 ---- A good decision is based on knowledge and not on numbers. -- Plato If it's in the news, don't worry about it. The very definition of=20 "news" is "something that hardly ever happens." -- Bruce Schneier _______________________________________________ dm-crypt mailing list -- dm-crypt@saout.de To unsubscribe send an email to dm-crypt-leave@saout.de