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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CEC5C433EF for ; Mon, 21 Feb 2022 02:21:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343544AbiBUCWD (ORCPT ); Sun, 20 Feb 2022 21:22:03 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:40780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343540AbiBUCWC (ORCPT ); Sun, 20 Feb 2022 21:22:02 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A14B7658B; Sun, 20 Feb 2022 18:21:39 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 28B2561055; Mon, 21 Feb 2022 02:21:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 357A5C340E8; Mon, 21 Feb 2022 02:21:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645410098; bh=kGIeWEaq/5UzKoe9nNUsyzDA3N0lfQIYAcHCE2Et33Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Qkme+nn2X2Y4RINHEWEoRSLt9y7wLpMTzVJejfvOaJsNfUcZy6SNfwy+gVGdLvM3C k0Tv6KaOkEJhYoNHIqHJAar6Otdb+52kzKIp5Brx55DVYYbuT2bQgl/wF6ZQU7ByHW DEJUAYQnrzoKofyw6fZcU6K0tGQDOaiEv2/DB5xMvZjV0pD2s2Yi5ih8SlLP56dug6 mH/yWxyaFALXHOxOEr5z/EkZdoB2vFa4nRcaEkPTMJXyqKzaI9I1a3Rzybv0KejXC5 tTSAe7GUpzZT4q1y8BgjNl9T4AZ7U+3+jvA/mEIBBFfojlVS9z6CgWbjUj04SBwsMR gZTmVTuv7YUuw== Date: Sun, 20 Feb 2022 18:21:36 -0800 From: Eric Biggers To: Jarkko Sakkinen Cc: keyrings@vger.kernel.org, David Howells , linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org, Stefan Berger , Gilad Ben-Yossef , Tianjia Zhang , Vitaly Chikunov , Mimi Zohar , stable@vger.kernel.org Subject: Re: [PATCH 2/2] KEYS: asymmetric: properly validate hash_algo and encoding Message-ID: References: <20220201003414.55380-1-ebiggers@kernel.org> <20220201003414.55380-3-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Mon, Feb 21, 2022 at 02:46:26AM +0100, Jarkko Sakkinen wrote: > On Mon, Jan 31, 2022 at 04:34:14PM -0800, Eric Biggers wrote: > > From: Eric Biggers > > > > It is insecure to allow arbitrary hash algorithms and signature > > encodings to be used with arbitrary signature algorithms. Notably, > > ECDSA, ECRDSA, and SM2 all sign/verify raw hash values and don't > > disambiguate between different hash algorithms like RSA PKCS#1 v1.5 > > padding does. Therefore, they need to be restricted to certain sets of > > hash algorithms (ideally just one, but in practice small sets are used). > > Additionally, the encoding is an integral part of modern signature > > algorithms, and is not supposed to vary. > > > > Therefore, tighten the checks of hash_algo and encoding done by > > software_key_determine_akcipher(). > > > > Also rearrange the parameters to software_key_determine_akcipher() to > > put the public_key first, as this is the most important parameter and it > > often determines everything else. > > > > Fixes: 299f561a6693 ("x509: Add support for parsing x509 certs with ECDSA keys") > > Fixes: 215525639631 ("X.509: support OSCCA SM2-with-SM3 certificate verification") > > Fixes: 0d7a78643f69 ("crypto: ecrdsa - add EC-RDSA (GOST 34.10) algorithm") > > Cc: stable@vger.kernel.org > > Signed-off-by: Eric Biggers > > --- > > crypto/asymmetric_keys/public_key.c | 111 +++++++++++++++++++--------- > > 1 file changed, 76 insertions(+), 35 deletions(-) > > > > diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c > > index aba7113d86c76..a603ee8afdb8d 100644 > > --- a/crypto/asymmetric_keys/public_key.c > > +++ b/crypto/asymmetric_keys/public_key.c > > @@ -60,39 +60,83 @@ static void public_key_destroy(void *payload0, void *payload3) > > } > > > > /* > > - * Determine the crypto algorithm name. > > + * Given a public_key, and an encoding and hash_algo to be used for signing > > + * and/or verification with that key, determine the name of the corresponding > > + * akcipher algorithm. Also check that encoding and hash_algo are allowed. > > */ > > -static > > -int software_key_determine_akcipher(const char *encoding, > > - const char *hash_algo, > > - const struct public_key *pkey, > > - char alg_name[CRYPTO_MAX_ALG_NAME]) > > +static int > > +software_key_determine_akcipher(const struct public_key *pkey, > > + const char *encoding, const char *hash_algo, > > + char alg_name[CRYPTO_MAX_ALG_NAME]) > > Why is changing parameter order necessary? > It's mentioned in the commit message. It's obviously not necessary but this way makes much more sense IMO. - Eric