From patchwork Thu Jun 25 07:18:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 197596 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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 48AB1C433DF for ; Thu, 25 Jun 2020 07:18:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C2732084D for ; Thu, 25 Jun 2020 07:18:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593069505; bh=VVayIPQ+HSNieft1cfa6TV5fPDX6pY3vykjJAQPAILw=; h=From:To:Cc:Subject:Date:List-ID:From; b=SIZL4Q6Wbu28GOmxfJsLmYbs4Ems7LpCF5GB0k5IQNy/G+cUm/VmoaLY/CURZOBIa 5A2AXyWshtRUZ2jtFFhrqjCihYD87XJSiJ2twypHR2IUKfYUDmy/8VMH7gsmLtnawq gp4qKaZnzFYEge858kbUypu396ZgpOWD4xzu/2a4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728725AbgFYHSY (ORCPT ); Thu, 25 Jun 2020 03:18:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:43882 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726149AbgFYHSX (ORCPT ); Thu, 25 Jun 2020 03:18:23 -0400 Received: from localhost.localdomain (lfbn-nic-1-188-42.w2-15.abo.wanadoo.fr [2.15.37.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BCF0E20720; Thu, 25 Jun 2020 07:18:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593069502; bh=VVayIPQ+HSNieft1cfa6TV5fPDX6pY3vykjJAQPAILw=; h=From:To:Cc:Subject:Date:From; b=raqQzJAKcGM3djhKR/Lbsgip7zTWnkrCf2K2FKAgxReu0zJU8wBIEwKegebzFcBEd mCqOz39qA8/Z+VvNcjRrVH6aUa6NJOKSS9zJI92LXTzVuQMS+G4VE6jwq3VHNI7Reu jNZttVcbynf2oPq50rfRU/lV0/rxl37ToRpxB54k= From: Ard Biesheuvel To: netdev@vger.kernel.org Cc: linux-crypto@vger.kernel.org, Ard Biesheuvel , Antoine Tenart , Andrew Lunn , Florian Fainelli , Heiner Kallweit , "David S. Miller" , Jakub Kicinski , stable@vger.kernel.org, Eric Biggers Subject: [PATCH v2] net: phy: mscc: avoid skcipher API for single block AES encryption Date: Thu, 25 Jun 2020 09:18:16 +0200 Message-Id: <20200625071816.1739528-1-ardb@kernel.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org The skcipher API dynamically instantiates the transformation object on request that implements the requested algorithm optimally on the given platform. This notion of optimality only matters for cases like bulk network or disk encryption, where performance can be a bottleneck, or in cases where the algorithm itself is not known at compile time. In the mscc case, we are dealing with AES encryption of a single block, and so neither concern applies, and we are better off using the AES library interface, which is lightweight and safe for this kind of use. Note that the scatterlist API does not permit references to buffers that are located on the stack, so the existing code is incorrect in any case, but avoiding the skcipher and scatterlist APIs entirely is the most straight-forward approach to fixing this. Cc: Antoine Tenart Cc: Andrew Lunn Cc: Florian Fainelli Cc: Heiner Kallweit Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Fixes: 28c5107aa904e ("net: phy: mscc: macsec support") Reviewed-by: Eric Biggers Signed-off-by: Ard Biesheuvel --- v2: - select CRYPTO_LIB_AES only if MACSEC is enabled - add Eric's R-b drivers/net/phy/Kconfig | 3 +- drivers/net/phy/mscc/mscc_macsec.c | 40 +++++--------------- 2 files changed, 10 insertions(+), 33 deletions(-) diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig index f25702386d83..e351d65533aa 100644 --- a/drivers/net/phy/Kconfig +++ b/drivers/net/phy/Kconfig @@ -480,8 +480,7 @@ config MICROCHIP_T1_PHY config MICROSEMI_PHY tristate "Microsemi PHYs" depends on MACSEC || MACSEC=n - select CRYPTO_AES - select CRYPTO_ECB + select CRYPTO_LIB_AES if MACSEC help Currently supports VSC8514, VSC8530, VSC8531, VSC8540 and VSC8541 PHYs diff --git a/drivers/net/phy/mscc/mscc_macsec.c b/drivers/net/phy/mscc/mscc_macsec.c index b4d3dc4068e2..d53ca884b5c9 100644 --- a/drivers/net/phy/mscc/mscc_macsec.c +++ b/drivers/net/phy/mscc/mscc_macsec.c @@ -10,7 +10,7 @@ #include #include -#include +#include #include @@ -500,39 +500,17 @@ static u32 vsc8584_macsec_flow_context_id(struct macsec_flow *flow) static int vsc8584_macsec_derive_key(const u8 key[MACSEC_KEYID_LEN], u16 key_len, u8 hkey[16]) { - struct crypto_skcipher *tfm = crypto_alloc_skcipher("ecb(aes)", 0, 0); - struct skcipher_request *req = NULL; - struct scatterlist src, dst; - DECLARE_CRYPTO_WAIT(wait); - u32 input[4] = {0}; + const u8 input[AES_BLOCK_SIZE] = {0}; + struct crypto_aes_ctx ctx; int ret; - if (IS_ERR(tfm)) - return PTR_ERR(tfm); - - req = skcipher_request_alloc(tfm, GFP_KERNEL); - if (!req) { - ret = -ENOMEM; - goto out; - } - - skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | - CRYPTO_TFM_REQ_MAY_SLEEP, crypto_req_done, - &wait); - ret = crypto_skcipher_setkey(tfm, key, key_len); - if (ret < 0) - goto out; - - sg_init_one(&src, input, 16); - sg_init_one(&dst, hkey, 16); - skcipher_request_set_crypt(req, &src, &dst, 16, NULL); - - ret = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); + ret = aes_expandkey(&ctx, key, key_len); + if (ret) + return ret; -out: - skcipher_request_free(req); - crypto_free_skcipher(tfm); - return ret; + aes_encrypt(&ctx, hkey, input); + memzero_explicit(&ctx, sizeof(ctx)); + return 0; } static int vsc8584_macsec_transformation(struct phy_device *phydev,