From patchwork Sat Jun 27 08:36:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11629499 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9D038618 for ; Sat, 27 Jun 2020 08:41:52 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 75C3A207FC for ; Sat, 27 Jun 2020 08:41:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="zZlFwkRi"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="HciL4sMm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75C3A207FC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=RHbX7z9aqReQ4aVivwVR741hBn+cRSJCa4xhewsk6cs=; b=zZlFwkRiRudIBxkARqg961R7t 3jh5hhkFKppMfwpT/eik5qY9j+eB/0vqDjNc9VCEnmqEFSBAHk0Hx0++1oWEPjmwyhGvz3CSV0FrI vjZWspFc5ouGQ7FAUw/CW0+O/v8n0yx+wkzAKz7tDcoVO7G0O2Aw77v0B8nSav1Kh3mCAIh10dwUP I9o9dPlyLxQ6adYd9G1bsWsL+4gelCMlDwZ/bEXPfHxBNcFs1L6om+zxE5riUgirtBz2fGxvHL63U tj3kJa0xO8KVh+xpSAsDisLUl88l7tW9/456iix1gtEkRbvgX6xYNrCLt0MZMkIY05YNnwkX/mu/I Kbf+7q3LQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jp6Ml-0000FH-Dd; Sat, 27 Jun 2020 08:39:19 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jp6L4-0007ss-8c; Sat, 27 Jun 2020 08:37:32 +0000 Received: from dogfood.home (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 0B600207FC; Sat, 27 Jun 2020 08:37:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593247049; bh=1mKbpa4I4Sh07AGQPoHxLj1RNd0nCGZ8qWt4DEk3uDw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HciL4sMmgPCTWYfKn8WHC8Cev4c1ptta+YmLvQ1IjcYaB/cqNTB6GUa0rVz+wVnw/ n+tjZSG2qpgKjR00nqqKhrUGl7HDg6Y418OH41PBjrMwBnx+0EbPbWNToCoBEH5FU8 qvFtVw0AnHDBYYYAt+IPmOWLuFUvtFM7L6nBxWaM= From: Ard Biesheuvel To: linux-crypto@vger.kernel.org Subject: [PATCH v2 12/13] crypto: sahara - permit asynchronous skcipher as fallback Date: Sat, 27 Jun 2020 10:36:22 +0200 Message-Id: <20200627083623.2428333-13-ardb@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200627083623.2428333-1-ardb@kernel.org> References: <20200627083623.2428333-1-ardb@kernel.org> MIME-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -5.2 (-----) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-5.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [198.145.29.99 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eric Biggers , Corentin Labbe , Ayush Sawal , Jamie Iles , Fabio Estevam , Ard Biesheuvel , Herbert Xu , Rohit Maheshwari , Chen-Yu Tsai , NXP Linux Team , Tom Lendacky , Sascha Hauer , Vinay Kumar Yadav , Maxime Ripard , Matthias Brugger , linux-amlogic@lists.infradead.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Tero Kristo , Pengutronix Kernel Team , Shawn Guo , "David S. Miller" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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,