Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932709AbaFIN6u (ORCPT ); Mon, 9 Jun 2014 09:58:50 -0400 Received: from mail-wi0-f182.google.com ([209.85.212.182]:40963 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754873AbaFIN6s (ORCPT ); Mon, 9 Jun 2014 09:58:48 -0400 MIME-Version: 1.0 In-Reply-To: <1402321691.7064.31.camel@dhcp-9-2-203-236.watson.ibm.com> References: <1401818318-15780-1-git-send-email-zohar@linux.vnet.ibm.com> <1401818318-15780-5-git-send-email-zohar@linux.vnet.ibm.com> <5395A4F9.1020205@samsung.com> <1402318294.7064.19.camel@dhcp-9-2-203-236.watson.ibm.com> <5395B125.8010503@samsung.com> <1402321691.7064.31.camel@dhcp-9-2-203-236.watson.ibm.com> Date: Mon, 9 Jun 2014 16:58:46 +0300 Message-ID: Subject: Re: [RFC PATCH v5 4/4] KEYS: define an owner trusted keyring From: Dmitry Kasatkin To: Mimi Zohar Cc: Dmitry Kasatkin , linux-security-module , David Howells , Josh Boyer , keyrings , linux-kernel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9 June 2014 16:48, Mimi Zohar wrote: > On Mon, 2014-06-09 at 16:05 +0300, Dmitry Kasatkin wrote: >> On 09/06/14 15:51, Mimi Zohar wrote: >> > On Mon, 2014-06-09 at 15:13 +0300, Dmitry Kasatkin wrote: >> >> On 03/06/14 20:58, Mimi Zohar wrote: >> >>> Instead of allowing public keys, with certificates signed by any >> >>> key on the system trusted keyring, to be added to a trusted >> >>> keyring, this patch further restricts the certificates to those >> >>> signed by a particular key on the system keyring. >> >>> >> >>> When the UEFI secure boot keys are added to the system keyring, the >> >>> platform owner will be able to load their key in one of the UEFI DBs >> >>> (eg. Machine Owner Key(MOK) list) and select their key, without >> >>> having to rebuild the kernel. >> >>> >> >>> This patch defines an owner trusted keyring, a new boot command >> >>> line option 'keys_ownerid=', and defines a new function >> >>> get_system_or_owner_trusted_keyring(). >> >> Hello, >> >> >> >> The functionality of this entire patch can be replaced by only ~2 lines >> >> of code in x509_request_asymmetric_key() >> >> >> >> if (keys_ownerid || strcmp(keys_ownerid, id)) >> >> return -EPERM; >> >> >> >> Right? >> > Are you suggesting only add the one matching key to the system keyring? >> >> No. I am not suggesting this. >> >> All built in keys are allocated with KEY_ALLOC_TRUSTED flag and >> prep.trusted is set to "true". >> >> So the following statement has no effect. > > Ok, so it has no affect on adding builtin keys to the system keyring. > >> >> #ifdef CONFIG_SYSTEM_TRUSTED_KEYRING >> ret = x509_validate_trust(cert, system_trusted_keyring); >> if (!ret) >> prep->trusted = 1; >> #endif > > The last patch set changes the test to: > ret = x509_validate_trust(cert, get_system_or_owner_trusted_keyring()); > It does not really mater. I just copied original code to my response. >> Keys which come from user-space will check for >> >> if (keys_ownerid && strcmp(keys_ownerid, id)) >> return -EPERM; >> >> >> So 2 lines patch works fine.. > > It works based on the assumption, that you would ever only want a single > key on the 'owner' keyring, which is probably not the case. > There is no any assumption here. I am discussing functionality of this patch. That is exactly what this patch does - loads single key on the owners keyring. There is no need for additional keyring for a single key. That is just enough to limit verification to the owners key id. - Dmitry > Mimi > > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Thanks, Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/