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 948EAC4332F for ; Fri, 10 Dec 2021 11:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240708AbhLJLlW (ORCPT ); Fri, 10 Dec 2021 06:41:22 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:33768 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240672AbhLJLlV (ORCPT ); Fri, 10 Dec 2021 06:41:21 -0500 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 8F35F210FE; Fri, 10 Dec 2021 11:37:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1639136265; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eb4zaX1qCjL7jijbTZCbjxJPZ9XZbK1lSdAhXFY9ulk=; b=bnwyLDqa55iGL0IUuSSQAYcks2Q2D6YlKHqOI42C/zkVfC8elX7w5vab2lVxpi9RER4lpK owPw+7SfA2N8ocAQfiz0bqEfmrglw9SEOBhLz7MWciT1Uqg5OqU44o3ES8/xZoCOsqeILo pR1fC7rfuyQ5gm/eiM7Bx7uwcYMld0c= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1639136265; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eb4zaX1qCjL7jijbTZCbjxJPZ9XZbK1lSdAhXFY9ulk=; b=qXaOTvCj7K4a7VUSeE94HhiaadYhcPfjsrL5pG0SdH5GYAMgKTYa+nPmPDkCW0QG20/ctv MDkAeHLsmF/kggDQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 7D25213DDE; Fri, 10 Dec 2021 11:37:45 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id Z51bHgk8s2EDcQAAMHmgww (envelope-from ); Fri, 10 Dec 2021 11:37:45 +0000 Subject: Re: [PATCH v2 18/18] crypto: dh - accept only approved safe-prime groups in FIPS mode To: Nicolai Stange , Herbert Xu , "David S. Miller" Cc: =?UTF-8?Q?Stephan_M=c3=bcller?= , Torsten Duwe , Zaibo Xu , Giovanni Cabiddu , David Howells , Jarkko Sakkinen , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, qat-linux@intel.com, keyrings@vger.kernel.org References: <20211209090358.28231-1-nstange@suse.de> <20211209090358.28231-19-nstange@suse.de> From: Hannes Reinecke Message-ID: Date: Fri, 10 Dec 2021 12:37:45 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <20211209090358.28231-19-nstange@suse.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On 12/9/21 10:03 AM, Nicolai Stange wrote: > SP800-56Arev3, sec. 5.5.2 ("Assurance of Domain-Parameter Validity") > asserts that an implementation needs to verify domain paramtere validity, > which boils down to either > - the domain parameters corresponding to some known safe-prime group > explicitly listed to be approved in the document or > - for parameters conforming to a "FIPS 186-type parameter-size set", > that the implementation needs to perform an explicit domain parameter > verification, which would require access to the "seed" and "counter" > values used in their generation. > > The latter is not easily feasible and moreover, SP800-56Arev3 states that > safe-prime groups are preferred and that FIPS 186-type parameter sets > should only be supported for backward compatibility, if it all. > > Make the dh implementations reject any domain parameters which don't > correspond to any of the approved safe-prime groups in FIPS mode. The > approved safe-prime groups are the ones specified in RFC 7919 and RFC 3526, > and given that all possible values of enum dh_group_id correspond to > either groups from these RFCs or to DH_GROUP_ID_UNKNOWN, it suffices to > make crypto_dh_decode_key() to reject any parameter set where > ->group_id == DH_GROUP_ID_UNKNOWN. > > As this change will effectively render the dh implementation unusable in > FIPS mode if neither of the CRYPTO_DH_GROUPS_RFC7919 or > CRYPTO_DH_GROUPS_RFC3526 Kconfig options enabled, make CRYPTO_DH imply > these two if CRYPTO_FIPS is set. > > Signed-off-by: Nicolai Stange > --- > crypto/Kconfig | 2 ++ > crypto/dh_helper.c | 4 ++++ > 2 files changed, 6 insertions(+) > Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), GF: Felix Imendörffer