Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932771AbaFIOGI (ORCPT ); Mon, 9 Jun 2014 10:06:08 -0400 Received: from mail-we0-f169.google.com ([74.125.82.169]:57834 "EHLO mail-we0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750720AbaFIOGF (ORCPT ); Mon, 9 Jun 2014 10:06:05 -0400 MIME-Version: 1.0 In-Reply-To: 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 17:06:02 +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 16:58, Dmitry Kasatkin wrote: > 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 > > There is no reason to have advanced bloated implementation for unsure, may be never coming use-cases. It is always very easy to make new patches for the future cases. - Dmitry >> Mimi >> -- 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/