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=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C073CC433ED for ; Tue, 27 Apr 2021 23:46:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CF98600CC for ; Tue, 27 Apr 2021 23:46:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236805AbhD0XrQ (ORCPT ); Tue, 27 Apr 2021 19:47:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:58890 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236015AbhD0XrP (ORCPT ); Tue, 27 Apr 2021 19:47:15 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 336D9613F8; Tue, 27 Apr 2021 23:46:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619567191; bh=/4zboaigQcqYojznpGGzY09/dRMU6IDja/PWMwP5n+M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y9iA/XRswGCDCKC50UbwA8lkm7lfebRYhGls2FTXo9CylIQZNfFg25xJwg+CEk30w soy4BsrPWTvRf6njOcMTGe1Ms3/L1RWyDhjVzbRpvl9bL+lrc5fZL84EUGF92Xtwvz +NI3j6/1khzFlEIihSje6VFwyhobBd1C+jGcf9qzOeZNVSkoUxfSiNGQyVl2Yir+Qt bVlau2kfmPkr8DEZmm6BioIX48TOZwDmuGqXlPEMxRspEmSIslMzqj3mVkOEU1xtat r26hiTZB+uZOqyvAGhrjOAcwBaw1LFjdkF0+oAB1T+YQ3bWX3CvKo2SJd9RYMiELfL 0DdYqlWggKXng== Date: Wed, 28 Apr 2021 02:46:29 +0300 From: Jarkko Sakkinen To: Stefan Berger Cc: jeyu@kernel.org, keyrings@vger.kernel.org, dhowells@redhat.com, zohar@linux.ibm.com, nayna@linux.ibm.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/2] certs: Add support for using elliptic curve keys for signing modules Message-ID: References: <20210421194319.1489291-1-stefanb@linux.ibm.com> <20210421194319.1489291-3-stefanb@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210421194319.1489291-3-stefanb@linux.ibm.com> Precedence: bulk List-ID: On Wed, Apr 21, 2021 at 03:43:19PM -0400, Stefan Berger wrote: > Add support for using elliptic curve keys for signing modules. It uses > a NIST P384 (secp384r1) key if the user chooses an elliptic curve key > and will have ECDSA support built into the kernel. > > Note: A developer choosing an ECDSA key for signing modules should still > delete the signing key (rm certs/signing_key.*) when building an older > version of a kernel that only supports RSA keys. Unless kbuild automati- > cally detects and generates a new kernel module key, ECDSA-signed kernel > modules will fail signature verification. > > Signed-off-by: Stefan Berger Looks good to me. Acked-by: Jarkko Sakkinen /Jarkko > > --- > v3: > - added missing OIDs for ECDSA signed hashes to pkcs7_sig_note_pkey_algo > - added recommendation to use string hash to Kconfig help text > > v2: > - check for ECDSA key by id-ecPublicKey from output line > 'Public Key Algorithm: id-ecPublicKey'. > --- > certs/Kconfig | 26 ++++++++++++++++++++++++++ > certs/Makefile | 9 +++++++++ > crypto/asymmetric_keys/pkcs7_parser.c | 8 ++++++++ > 3 files changed, 43 insertions(+) > > diff --git a/certs/Kconfig b/certs/Kconfig > index 48675ad319db..d58f16c9f2d9 100644 > --- a/certs/Kconfig > +++ b/certs/Kconfig > @@ -15,6 +15,32 @@ config MODULE_SIG_KEY > then the kernel will automatically generate the private key and > certificate as described in Documentation/admin-guide/module-signing.rst > > +choice > + prompt "Type of module signing key to be generated" > + default MODULE_SIG_KEY_TYPE_RSA > + help > + The type of module signing key type to generate. This option > + does not apply if a #PKCS11 URI is used. > + > +config MODULE_SIG_KEY_TYPE_RSA > + bool "RSA" > + depends on MODULE_SIG || IMA_APPRAISE_MODSIG > + help > + Use an RSA key for module signing. > + > +config MODULE_SIG_KEY_TYPE_ECDSA > + bool "ECDSA" > + select CRYPTO_ECDSA > + depends on MODULE_SIG || IMA_APPRAISE_MODSIG > + help > + Use an elliptic curve key (NIST P384) for module signing. Consider > + using a strong hash like sha256 or sha384 for hashing modules. > + > + Note: Remove all ECDSA signing keys, e.g. certs/signing_key.pem, > + when falling back to building Linux 5.11 and older kernels. > + > +endchoice > + > config SYSTEM_TRUSTED_KEYRING > bool "Provide system-wide ring of trusted keys" > depends on KEYS > diff --git a/certs/Makefile b/certs/Makefile > index f64bc89ccbf1..c2fabc288550 100644 > --- a/certs/Makefile > +++ b/certs/Makefile > @@ -62,7 +62,15 @@ ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem") > > X509TEXT=$(shell openssl x509 -in $(CONFIG_MODULE_SIG_KEY) -text) > > +# Support user changing key type > +ifdef CONFIG_MODULE_SIG_KEY_TYPE_ECDSA > +keytype_openssl = -newkey ec -pkeyopt ec_paramgen_curve:secp384r1 > +$(if $(findstring id-ecPublicKey,$(X509TEXT)),,$(shell rm -f $(CONFIG_MODULE_SIG_KEY))) > +endif > + > +ifdef CONFIG_MODULE_SIG_KEY_TYPE_RSA > $(if $(findstring rsaEncryption,$(X509TEXT)),,$(shell rm -f $(CONFIG_MODULE_SIG_KEY))) > +endif > > $(obj)/signing_key.pem: $(obj)/x509.genkey > @$(kecho) "###" > @@ -77,6 +85,7 @@ $(obj)/signing_key.pem: $(obj)/x509.genkey > -batch -x509 -config $(obj)/x509.genkey \ > -outform PEM -out $(obj)/signing_key.pem \ > -keyout $(obj)/signing_key.pem \ > + $(keytype_openssl) \ > $($(quiet)redirect_openssl) > @$(kecho) "###" > @$(kecho) "### Key pair generated." > diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c > index 967329e0a07b..6592279d839a 100644 > --- a/crypto/asymmetric_keys/pkcs7_parser.c > +++ b/crypto/asymmetric_keys/pkcs7_parser.c > @@ -269,6 +269,14 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen, > ctx->sinfo->sig->pkey_algo = "rsa"; > ctx->sinfo->sig->encoding = "pkcs1"; > break; > + case OID_id_ecdsa_with_sha1: > + case OID_id_ecdsa_with_sha224: > + case OID_id_ecdsa_with_sha256: > + case OID_id_ecdsa_with_sha384: > + case OID_id_ecdsa_with_sha512: > + ctx->sinfo->sig->pkey_algo = "ecdsa"; > + ctx->sinfo->sig->encoding = "x962"; > + break; > default: > printk("Unsupported pkey algo: %u\n", ctx->last_oid); > return -ENOPKG; > -- > 2.29.2 > >