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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 345BBC433E0 for ; Fri, 31 Jul 2020 13:30:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1769222B49 for ; Fri, 31 Jul 2020 13:30:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731515AbgGaNaJ (ORCPT ); Fri, 31 Jul 2020 09:30:09 -0400 Received: from [216.24.177.18] ([216.24.177.18]:40508 "EHLO fornost.hmeau.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1727851AbgGaNaJ (ORCPT ); Fri, 31 Jul 2020 09:30:09 -0400 Received: from gwarestrin.arnor.me.apana.org.au ([192.168.0.7]) by fornost.hmeau.com with smtp (Exim 4.92 #5 (Debian)) id 1k1V6D-00016B-Mf; Fri, 31 Jul 2020 23:29:26 +1000 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Fri, 31 Jul 2020 23:29:25 +1000 Date: Fri, 31 Jul 2020 23:29:25 +1000 From: Herbert Xu To: Stephan =?iso-8859-1?Q?M=FCller?= Cc: linux-crypto@vger.kernel.org, Marcelo Cerri , Tianjia Zhang , ard.biesheuvel@linaro.org, nhorman@redhat.com, simo@redhat.com Subject: Re: [PATCH v3 0/5] DH: SP800-56A rev 3 compliant validation checks Message-ID: <20200731132925.GA14360@gondor.apana.org.au> References: <2543601.mvXUDI8C0e@positron.chronox.de> <5722559.lOV4Wx5bFT@positron.chronox.de> <2544426.mvXUDI8C0e@positron.chronox.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2544426.mvXUDI8C0e@positron.chronox.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Mon, Jul 20, 2020 at 07:05:45PM +0200, Stephan Müller wrote: > Hi, > > This patch set adds the required checks to make all aspects of > (EC)DH compliant with SP800-56A rev 3 assuming that all keys > are ephemeral. The use of static keys adds yet additional > validations which are hard to achieve in the kernel. > > SP800-56A rev 3 mandates various checks: > > - validation of remote public key defined in section 5.6.2.2.2 > is already implemented in: > > * ECC: crypto_ecdh_shared_secret with the call of > ecc_is_pubkey_valid_partial > > * FFC: dh_compute_val when the req->src is read and validated with > dh_is_pubkey_valid > > - validation of generated shared secret: The patch set adds the > shared secret validation as defined by SP800-56A rev 3. For > ECDH this only implies that the validation of the shared secret > is moved before the shared secret is returned to the caller. > > For DH, the validation is required to be performed against the prime > of the domain parameter set. > > This patch adds the MPI library file mpi_sub_ui that is required > to calculate P - 1 for the DH check. It would be possible, though > to simply set the LSB of the prime to 0 to obtain P - 1 (since > P is odd per definition) which implies that mpi_sub_ui would not > be needed. However, this would require a copy operation from > the existing prime MPI value into a temporary MPI where the > modification can be performed. Such copy operation is not available. > Therefore, the solution with the addition of mpi_sub_ui was chosen. > > NOTE: The function mpi_sub_ui is also added with the patch set > "[PATCH v5 2/8] lib/mpi: Extend the MPI library" currently sent > to the linux-crypto mailing list. > > - validation of the generated local public key: Patches 4 and 5 of > this patch set adds the required checks. > > Changes to v2: > > - add reference to GnuMP providing the basis for patch 2 and updating > the copyright note in patch 2 > > Changes to v1: > > - fix reference to Gnu MP as outlined by Ard Biesheuvel > - addition of patches 4 and 5 > > Marcelo Henrique Cerri (1): > lib/mpi: Add mpi_sub_ui() > > Stephan Mueller (4): > crypto: ECDH - check validity of Z before export > crypto: DH - check validity of Z before export > crypto: DH SP800-56A rev 3 local public key validation > crypto: ECDH SP800-56A rev 3 local public key validation > > crypto/dh.c | 38 +++++++++++++++++++++ > crypto/ecc.c | 42 +++++++++++++++++++++--- > crypto/ecc.h | 14 ++++++++ > include/linux/mpi.h | 3 ++ > lib/mpi/Makefile | 1 + > lib/mpi/mpi-sub-ui.c | 78 ++++++++++++++++++++++++++++++++++++++++++++ > 6 files changed, 172 insertions(+), 4 deletions(-) > create mode 100644 lib/mpi/mpi-sub-ui.c All applied. Thanks. -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt