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 X-Spam-Level: X-Spam-Status: No, score=-23.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 321E8C4338F for ; Wed, 28 Jul 2021 11:31:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0EBDF60724 for ; Wed, 28 Jul 2021 11:31:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236075AbhG1LbK (ORCPT ); Wed, 28 Jul 2021 07:31:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:37610 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234517AbhG1LbJ (ORCPT ); Wed, 28 Jul 2021 07:31:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C8BB960724; Wed, 28 Jul 2021 11:31:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627471868; bh=GrTwMapp7eNH+1uVmCWGuecyOBz6cQ7nTF/0BCD/PFg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=bNOYbnfQHcgpwd2cb+INWPFsKF6j5ddWbkqduDV+sfL5Mo1TcWRcdZq5Q0qdEQkeQ MTjv7RKzZnYD/DaG7NhfiV02mjHtek9OEp8IjuhnC8jQwApDf99enFN35c8wpRRk/c Nn5GiEPD7Btb81RTR98NZPn7cKCrw6ydvR2SjFDYc73B9EwM3eYsnUGaBaAhkxx5WA BDk+1OcUckNp5Oal/UPuRB3yW/7QrP6PRW12aKIrjQpQXIA/kNhWk9R4dxZT2y+XT+ hDsywHF4PXdRaoyTJenNhODSrnh+MldMYYmotT9xfrzsd9prcHZKyK5Pf64dLiTjQh 3ZqCO0ft6hHkw== Date: Wed, 28 Jul 2021 13:31:02 +0200 From: Mauro Carvalho Chehab To: Roberto Sassu Cc: , , , , , , Subject: Re: [RFC][PATCH v2 02/12] diglim: Basic definitions Message-ID: <20210728133102.339c7b8e@coco.lan> In-Reply-To: <20210726163700.2092768-3-roberto.sassu@huawei.com> References: <20210726163700.2092768-1-roberto.sassu@huawei.com> <20210726163700.2092768-3-roberto.sassu@huawei.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, 26 Jul 2021 18:36:50 +0200 Roberto Sassu escreveu: > Introduce the basic definitions, exported to user space, to use digest > lists. The definitions, added to include/uapi/linux/diglim.h, are > documented in Documentation/security/diglim/implementation.rst. > > Signed-off-by: Roberto Sassu > --- > .../security/diglim/implementation.rst | 97 +++++++++++++++++++ > Documentation/security/diglim/index.rst | 1 + > MAINTAINERS | 2 + > include/uapi/linux/diglim.h | 51 ++++++++++ > 4 files changed, 151 insertions(+) > create mode 100644 Documentation/security/diglim/implementation.rst > create mode 100644 include/uapi/linux/diglim.h > > diff --git a/Documentation/security/diglim/implementation.rst b/Documentation/security/diglim/implementation.rst > new file mode 100644 > index 000000000000..59a180b3bb3f > --- /dev/null > +++ b/Documentation/security/diglim/implementation.rst > @@ -0,0 +1,97 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +Implementation > +============== > + > +This section describes the implementation of DIGLIM. > + > + > +Basic Definitions > +----------------- > + > +This section introduces the basic definitions required to use DIGLIM. > + > + > +Compact Digest List Format > +~~~~~~~~~~~~~~~~~~~~~~~~~~ > + > +.. kernel-doc:: include/uapi/linux/diglim.h > + :identifiers: compact_list_hdr > + > +Compact Types > +............. > + > +Digests can be of different types: > + > +- ``COMPACT_PARSER``: digests of executables which are given the ability to > + parse digest lists not in the compact format and to upload to the kernel > + the digest list converted to the compact format; > +- ``COMPACT_FILE``: digests of regular files; > +- ``COMPACT_METADATA``: digests of file metadata (e.g. the digest > + calculated by EVM to verify a portable signature); > +- ``COMPACT_DIGEST_LIST``: digests of digest lists (only used internally by > + the kernel). > + > +Different users of DIGLIM might query digests with different compact types. > +For example, IMA would be interested in COMPACT_FILE, as it deals with > +regular files, while EVM would be interested in COMPACT_METADATA, as it > +verifies file metadata. > + > + > +Compact Modifiers > +................. > + > +Digests can also have specific attributes called modifiers (bit position): > + > +- ``COMPACT_MOD_IMMUTABLE``: file content or metadata should not be > + modifiable. > + > +IMA might use this information to deny open for writing, or EVM to deny > +setxattr operations. > + > + > +Actions > +....... > + > +This section defines a set of possible actions that have been executed on > +the digest lists (bit position): > + > +- ``COMPACT_ACTION_IMA_MEASURED``: the digest list has been measured by > + IMA; > +- ``COMPACT_ACTION_IMA_APPRAISED``: the digest list has been successfully > + appraised by IMA; > +- ``COMPACT_ACTION_IMA_APPRAISED_DIGSIG``: the digest list has been > + successfully appraised by IMA by verifying a digital signature. > + > +This information might help users of DIGLIM to decide whether to use the > +result of a queried digest. > + > +For example, if a digest belongs to a digest list that was not measured > +before, IMA should ignore the result of the query, as the measurement list > +sent to remote verifiers would lack which digests have been uploaded to the > +kernel. > + > + > +Compact Digest List Example > +........................... > + > +:: > + > + version: 1, type: 2, modifiers: 0 algo: 4, count: 3, datalen: 96 > + > + version: 1, type: 3, modifiers: 1 algo: 6, count: 2, datalen: 128 > + > + > +This digest list consists of two blocks. The first block contains three > +SHA256 digests of regular files. The second block contains two SHA512 > +digests of immutable metadata. > + > + > +Compact Digest List Operations > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + > +Finally, this section defines the possible operations that can be performed > +with digest lists: > + > +- ``DIGEST_LIST_ADD``: the digest list is being added; > +- ``DIGEST_LIST_DEL``: the digest list is being deleted. > diff --git a/Documentation/security/diglim/index.rst b/Documentation/security/diglim/index.rst > index 0fc5ab019bc0..4771134c2f0d 100644 > --- a/Documentation/security/diglim/index.rst > +++ b/Documentation/security/diglim/index.rst > @@ -9,3 +9,4 @@ Digest Lists Integrity Module (DIGLIM) > > introduction > architecture > + implementation > diff --git a/MAINTAINERS b/MAINTAINERS > index c914dadd7e65..f61f5239468a 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -5458,8 +5458,10 @@ L: linux-integrity@vger.kernel.org > S: Supported > T: git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git > F: Documentation/security/diglim/architecture.rst > +F: Documentation/security/diglim/implementation.rst > F: Documentation/security/diglim/index.rst > F: Documentation/security/diglim/introduction.rst > +F: include/uapi/linux/diglim.h > > DIOLAN U2C-12 I2C DRIVER > M: Guenter Roeck > diff --git a/include/uapi/linux/diglim.h b/include/uapi/linux/diglim.h > new file mode 100644 > index 000000000000..8a33d1f0fefb > --- /dev/null > +++ b/include/uapi/linux/diglim.h > @@ -0,0 +1,51 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +/* > + * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH > + * > + * Author: Roberto Sassu > + * > + * DIGLIM definitions exported to user space, useful for generating digest > + * lists. > + */ > + > +#ifndef _UAPI__LINUX_DIGLIM_H > +#define _UAPI__LINUX_DIGLIM_H > + > +#include > +#include > + > +enum compact_types { COMPACT_KEY, COMPACT_PARSER, COMPACT_FILE, > + COMPACT_METADATA, COMPACT_DIGEST_LIST, COMPACT__LAST }; > + > +enum compact_modifiers { COMPACT_MOD_IMMUTABLE, COMPACT_MOD__LAST }; > + > +enum compact_actions { COMPACT_ACTION_IMA_MEASURED, > + COMPACT_ACTION_IMA_APPRAISED, > + COMPACT_ACTION_IMA_APPRAISED_DIGSIG, > + COMPACT_ACTION__LAST }; > + > +enum ops { DIGEST_LIST_ADD, DIGEST_LIST_DEL, DIGEST_LIST_OP__LAST }; > + > +/** > + * struct compact_list_hdr - header of the following concatenated digests > + * @version: version of the digest list > + * @_reserved: field reserved for future use > + * @type: type of digest list among enum compact_types > + * @modifiers: additional attributes among (1 << enum compact_modifiers) > + * @algo: digest algorithm > + * @count: number of digests > + * @datalen: length of concatenated digests > + * > + * A digest list is a set of blocks composed by struct compact_list_hdr and > + * the following concatenated digests. > + */ > +struct compact_list_hdr { > + __u8 version; > + __u8 _reserved; > + __le16 type; > + __le16 modifiers; > + __le16 algo; > + __le32 count; > + __le32 datalen; > +} __packed; > +#endif /*_UAPI__LINUX_DIGLIM_H*/ Besides Greg's notes, I'm wondering why to enforce a particular endness here. I mean, this is uAPI. I would expect it to use the CPU endianness instead, in order to avoid uneeded conversions. Thanks, Mauro