From patchwork Thu Dec 9 09:03:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolai Stange X-Patchwork-Id: 522599 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 18C2BC433EF for ; Thu, 9 Dec 2021 09:04:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235989AbhLIJIS (ORCPT ); Thu, 9 Dec 2021 04:08:18 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:35536 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235902AbhLIJIM (ORCPT ); Thu, 9 Dec 2021 04:08:12 -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-out2.suse.de (Postfix) with ESMTPS id 173A41FD50; Thu, 9 Dec 2021 09:04:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1639040678; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hA+GGZL+BK4ETMbAa98m16cIBCJHB9mGQ0QTimQ2P40=; b=S9hByI2jKya5MvyZxr20VYwxiVIoBLE20mjwjPa/0c2VvTGWZVw+PfuZxURf4utQx7n6WW CxQZiIz7v72iDA1g2UPz64Ji2DxWM93/ntJUYNBG79mje1t8JrMYoMmqGl7BzS7/fPjpHo cQzKduUEuVCSOcVO7+Z3hidv66tZIO4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1639040678; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hA+GGZL+BK4ETMbAa98m16cIBCJHB9mGQ0QTimQ2P40=; b=JwD/vyJM8SvU/u/DAv0HGryvMZZ+aIyp9UKdxEgIaHp7OJjxypEFAipiVz9AY2KDZ9EplZ LDMD3SexrJ6w7mCg== 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 F047813A86; Thu, 9 Dec 2021 09:04:37 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id TCzaOKXGsWHlaQAAMHmgww (envelope-from ); Thu, 09 Dec 2021 09:04:37 +0000 From: Nicolai Stange To: Herbert Xu , "David S. Miller" Cc: =?utf-8?q?Stephan_M=C3=BCller?= , Hannes Reinecke , 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, Nicolai Stange Subject: [PATCH v2 17/18] crypto: dh - try to match domain parameters to a known safe-prime group Date: Thu, 9 Dec 2021 10:03:57 +0100 Message-Id: <20211209090358.28231-18-nstange@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20211209090358.28231-1-nstange@suse.de> References: <20211209090358.28231-1-nstange@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org A subsequent patch will make the DH implementation to reject any input domain parameter set with ->group_id == DH_GROUP_ID_UNKNOWN in FIPS mode. However, as the keyctl(KEYCTL_DH_COMPUTE) implementation simply passes forward keys from userspace, it does not (and cannot) set ->group_id to anything else than DH_GROUP_ID_UNKNOWN. In order to still allow for keyctl(KEYCTL_DH_COMPUTE) to work on approved domain parameters passed in from userspace in FIPS mode, make crypto_dh_decode_key() to compare them against any of the known groups and set ->group_id upon having found a match, if any. Signed-off-by: Nicolai Stange Reviewed-by: Hannes Reinecke --- crypto/dh_helper.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c index ec9c4cdf57b2..b8a726b610a2 100644 --- a/crypto/dh_helper.c +++ b/crypto/dh_helper.c @@ -470,6 +470,36 @@ get_safe_prime_group(enum dh_group_id group_id) return NULL; } +static enum dh_group_id lookup_group_id(const char *g, size_t g_size, + const char *p, size_t p_size) +{ + int i; + + /* All safe-prime groups use a generator of g == 2. */ + while (g_size && !*g) { + ++g; + --g_size; + } + + if (g_size != 1 || *g != 2) + return DH_GROUP_ID_UNKNOWN; + + while (p_size && !*p) { + ++p; + --p_size; + } + + for (i = 0; i < ARRAY_SIZE(safe_prime_groups); ++i) { + if (safe_prime_groups[i].p_size != p_size) + continue; + + if (!memcmp(safe_prime_groups[i].p, p, p_size)) + return safe_prime_groups[i].group_id; + } + + return DH_GROUP_ID_UNKNOWN; +} + static inline u8 *dh_pack_data(u8 *dst, u8 *end, const void *src, size_t size) { if (!dst || size > end - dst) @@ -568,6 +598,9 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params) if (memchr_inv(params->p, 0, params->p_size) == NULL) return -EINVAL; + params->group_id = lookup_group_id(params->g, params->g_size, + params->p, params->p_size); + } else { const struct safe_prime_group *g;