From patchwork Thu Jun 25 12:42:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 211319 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, 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 A0670C433E0 for ; Thu, 25 Jun 2020 12:44:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 763FB206BE for ; Thu, 25 Jun 2020 12:44:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593089060; bh=1mKbpa4I4Sh07AGQPoHxLj1RNd0nCGZ8qWt4DEk3uDw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mz0jbLdmTBaEz7cbbIp+AkfLeOylI8iCad7D1Uzk+fGByhH8fSMLlhbPp6Sle1Okl bdPgeb9e+bPW2/2lmwPaacquSS9L5Whbtz0gTuks5/2iwhhXW7kYj1lbBP/z3yVDA5 7TmXhEnJQScb8FPH2lDL7JqfeSuvRRjnCbDGo22A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404792AbgFYMoM (ORCPT ); Thu, 25 Jun 2020 08:44:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:46520 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404755AbgFYMoI (ORCPT ); Thu, 25 Jun 2020 08:44:08 -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 03531206BE; Thu, 25 Jun 2020 12:44:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593089047; bh=1mKbpa4I4Sh07AGQPoHxLj1RNd0nCGZ8qWt4DEk3uDw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EtSqpxr5/UQ9Ntco1uUPIcviLv6ya5Mu71Nnggl7PMTeIeA0sjbtLYU14mpmVEN2o EbvVdfOb4JRPemi3FcNe2EsCV3/iZIaUYEiLW3bo1H/2x3PuvrMrV5O80eNtBL46o7 zWfXGJzR0Od3k+p6GdnIBmGt1X8YSZHg5+uk1HDo= From: Ard Biesheuvel To: linux-crypto@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-amlogic@lists.infradead.org, Ard Biesheuvel , Corentin Labbe , Herbert Xu , "David S. Miller" , Maxime Ripard , Chen-Yu Tsai , Tom Lendacky , Ayush Sawal , Vinay Kumar Yadav , Rohit Maheshwari , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Jamie Iles , Eric Biggers Subject: [PATCH 12/12] crypto: sahara - permit asynchronous skcipher as fallback Date: Thu, 25 Jun 2020 14:42:53 +0200 Message-Id: <20200625124253.1906557-13-ardb@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200625124253.1906557-1-ardb@kernel.org> References: <20200625124253.1906557-1-ardb@kernel.org> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org Even though the sahara driver implements asynchronous versions of ecb(aes) and cbc(aes), the fallbacks it allocates are required to be synchronous. Given that SIMD based software implementations are usually asynchronous as well, even though they rarely complete asynchronously (this typically only happens in cases where the request was made from softirq context, while SIMD was already in use in the task context that it interrupted), these implementations are disregarded, and either the generic C version or another table based version implemented in assembler is selected instead. Since falling back to synchronous AES is not only a performance issue, but potentially a security issue as well (due to the fact that table based AES is not time invariant), let's fix this, by allocating an ordinary skcipher as the fallback, and invoke it with the completion routine that was given to the outer request. Signed-off-by: Ard Biesheuvel --- drivers/crypto/sahara.c | 96 +++++++++----------- 1 file changed, 45 insertions(+), 51 deletions(-) diff --git a/drivers/crypto/sahara.c b/drivers/crypto/sahara.c index 466e30bd529c..0c8cb23ae708 100644 --- a/drivers/crypto/sahara.c +++ b/drivers/crypto/sahara.c @@ -146,11 +146,12 @@ struct sahara_ctx { /* AES-specific context */ int keylen; u8 key[AES_KEYSIZE_128]; - struct crypto_sync_skcipher *fallback; + struct crypto_skcipher *fallback; }; struct sahara_aes_reqctx { unsigned long mode; + struct skcipher_request fallback_req; // keep at the end }; /* @@ -617,10 +618,10 @@ static int sahara_aes_setkey(struct crypto_skcipher *tfm, const u8 *key, /* * The requested key size is not supported by HW, do a fallback. */ - crypto_sync_skcipher_clear_flags(ctx->fallback, CRYPTO_TFM_REQ_MASK); - crypto_sync_skcipher_set_flags(ctx->fallback, tfm->base.crt_flags & + crypto_skcipher_clear_flags(ctx->fallback, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(ctx->fallback, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK); - return crypto_sync_skcipher_setkey(ctx->fallback, key, keylen); + return crypto_skcipher_setkey(ctx->fallback, key, keylen); } static int sahara_aes_crypt(struct skcipher_request *req, unsigned long mode) @@ -651,21 +652,19 @@ static int sahara_aes_crypt(struct skcipher_request *req, unsigned long mode) static int sahara_aes_ecb_encrypt(struct skcipher_request *req) { + struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req); struct sahara_ctx *ctx = crypto_skcipher_ctx( crypto_skcipher_reqtfm(req)); - int err; if (unlikely(ctx->keylen != AES_KEYSIZE_128)) { - SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback); - - skcipher_request_set_sync_tfm(subreq, ctx->fallback); - skcipher_request_set_callback(subreq, req->base.flags, - NULL, NULL); - skcipher_request_set_crypt(subreq, req->src, req->dst, - req->cryptlen, req->iv); - err = crypto_skcipher_encrypt(subreq); - skcipher_request_zero(subreq); - return err; + skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback); + skcipher_request_set_callback(&rctx->fallback_req, + req->base.flags, + req->base.complete, + req->base.data); + skcipher_request_set_crypt(&rctx->fallback_req, req->src, + req->dst, req->cryptlen, req->iv); + return crypto_skcipher_encrypt(&rctx->fallback_req); } return sahara_aes_crypt(req, FLAGS_ENCRYPT); @@ -673,21 +672,19 @@ static int sahara_aes_ecb_encrypt(struct skcipher_request *req) static int sahara_aes_ecb_decrypt(struct skcipher_request *req) { + struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req); struct sahara_ctx *ctx = crypto_skcipher_ctx( crypto_skcipher_reqtfm(req)); - int err; if (unlikely(ctx->keylen != AES_KEYSIZE_128)) { - SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback); - - skcipher_request_set_sync_tfm(subreq, ctx->fallback); - skcipher_request_set_callback(subreq, req->base.flags, - NULL, NULL); - skcipher_request_set_crypt(subreq, req->src, req->dst, - req->cryptlen, req->iv); - err = crypto_skcipher_decrypt(subreq); - skcipher_request_zero(subreq); - return err; + skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback); + skcipher_request_set_callback(&rctx->fallback_req, + req->base.flags, + req->base.complete, + req->base.data); + skcipher_request_set_crypt(&rctx->fallback_req, req->src, + req->dst, req->cryptlen, req->iv); + return crypto_skcipher_decrypt(&rctx->fallback_req); } return sahara_aes_crypt(req, 0); @@ -695,21 +692,19 @@ static int sahara_aes_ecb_decrypt(struct skcipher_request *req) static int sahara_aes_cbc_encrypt(struct skcipher_request *req) { + struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req); struct sahara_ctx *ctx = crypto_skcipher_ctx( crypto_skcipher_reqtfm(req)); - int err; if (unlikely(ctx->keylen != AES_KEYSIZE_128)) { - SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback); - - skcipher_request_set_sync_tfm(subreq, ctx->fallback); - skcipher_request_set_callback(subreq, req->base.flags, - NULL, NULL); - skcipher_request_set_crypt(subreq, req->src, req->dst, - req->cryptlen, req->iv); - err = crypto_skcipher_encrypt(subreq); - skcipher_request_zero(subreq); - return err; + skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback); + skcipher_request_set_callback(&rctx->fallback_req, + req->base.flags, + req->base.complete, + req->base.data); + skcipher_request_set_crypt(&rctx->fallback_req, req->src, + req->dst, req->cryptlen, req->iv); + return crypto_skcipher_encrypt(&rctx->fallback_req); } return sahara_aes_crypt(req, FLAGS_ENCRYPT | FLAGS_CBC); @@ -717,21 +712,19 @@ static int sahara_aes_cbc_encrypt(struct skcipher_request *req) static int sahara_aes_cbc_decrypt(struct skcipher_request *req) { + struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req); struct sahara_ctx *ctx = crypto_skcipher_ctx( crypto_skcipher_reqtfm(req)); - int err; if (unlikely(ctx->keylen != AES_KEYSIZE_128)) { - SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback); - - skcipher_request_set_sync_tfm(subreq, ctx->fallback); - skcipher_request_set_callback(subreq, req->base.flags, - NULL, NULL); - skcipher_request_set_crypt(subreq, req->src, req->dst, - req->cryptlen, req->iv); - err = crypto_skcipher_decrypt(subreq); - skcipher_request_zero(subreq); - return err; + skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback); + skcipher_request_set_callback(&rctx->fallback_req, + req->base.flags, + req->base.complete, + req->base.data); + skcipher_request_set_crypt(&rctx->fallback_req, req->src, + req->dst, req->cryptlen, req->iv); + return crypto_skcipher_decrypt(&rctx->fallback_req); } return sahara_aes_crypt(req, FLAGS_CBC); @@ -742,14 +735,15 @@ static int sahara_aes_init_tfm(struct crypto_skcipher *tfm) const char *name = crypto_tfm_alg_name(&tfm->base); struct sahara_ctx *ctx = crypto_skcipher_ctx(tfm); - ctx->fallback = crypto_alloc_sync_skcipher(name, 0, + ctx->fallback = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK); if (IS_ERR(ctx->fallback)) { pr_err("Error allocating fallback algo %s\n", name); return PTR_ERR(ctx->fallback); } - crypto_skcipher_set_reqsize(tfm, sizeof(struct sahara_aes_reqctx)); + crypto_skcipher_set_reqsize(tfm, sizeof(struct sahara_aes_reqctx) + + crypto_skcipher_reqsize(ctx->fallback)); return 0; } @@ -758,7 +752,7 @@ static void sahara_aes_exit_tfm(struct crypto_skcipher *tfm) { struct sahara_ctx *ctx = crypto_skcipher_ctx(tfm); - crypto_free_sync_skcipher(ctx->fallback); + crypto_free_skcipher(ctx->fallback); } static u32 sahara_sha_init_hdr(struct sahara_dev *dev,