From patchwork Tue Jun 30 12:18:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 197553 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 E1E14C433DF for ; Tue, 30 Jun 2020 12:19:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C05FE20780 for ; Tue, 30 Jun 2020 12:19:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593519571; bh=EkM87xQP80yqnQSxLq/oLvhUOcXLgVR/GSO8f9UrIuE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yfZ9FvW15Cx/y0lDEZAIiYqPhzRNo7SonXzTjjb7es12NT7n85Gcx6sRKjrP3hWgt vzxrnP1i4aezDB6af5BditKPd5F6SoDndxVZdGNxtlz2VGdizQPUxWt4hg4h2gkm09 DoOvU5dLb6EkOtmTdQ+ziYBotbPHksCcyVhi/o7k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387619AbgF3MTb (ORCPT ); Tue, 30 Jun 2020 08:19:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:36302 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733295AbgF3MTa (ORCPT ); Tue, 30 Jun 2020 08:19:30 -0400 Received: from e123331-lin.nice.arm.com (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 AFB5220774; Tue, 30 Jun 2020 12:19:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593519569; bh=EkM87xQP80yqnQSxLq/oLvhUOcXLgVR/GSO8f9UrIuE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Df1paptExnRaOPBWRj/tLVQGWzPYBdJYSRq+6QSIeBu3FfyCTB2H2LMi7P7Afm213 KPvNtdMzaOISYK9mWv/gBtK8ZKOXsynPZ4jcmPNxa2BU4ss6GJ5SOlFY04dhl/Z71F tUPXJPDoOa7JXDNNP6L7gkCAzlKlWAHMb8p1mTlQ= From: Ard Biesheuvel To: linux-crypto@vger.kernel.org Cc: 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 , Tero Kristo , Matthias Brugger Subject: [PATCH v3 03/13] crypto: omap-aes - permit asynchronous skcipher as fallback Date: Tue, 30 Jun 2020 14:18:57 +0200 Message-Id: <20200630121907.24274-4-ardb@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200630121907.24274-1-ardb@kernel.org> References: <20200630121907.24274-1-ardb@kernel.org> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Even though the omap-aes driver implements asynchronous versions of ecb(aes), cbc(aes) and ctr(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/omap-aes.c | 35 ++++++++++---------- drivers/crypto/omap-aes.h | 3 +- 2 files changed, 19 insertions(+), 19 deletions(-) diff --git a/drivers/crypto/omap-aes.c b/drivers/crypto/omap-aes.c index b5aff20c5900..25154b74dcc6 100644 --- a/drivers/crypto/omap-aes.c +++ b/drivers/crypto/omap-aes.c @@ -548,20 +548,18 @@ static int omap_aes_crypt(struct skcipher_request *req, unsigned long mode) !!(mode & FLAGS_CBC)); if (req->cryptlen < aes_fallback_sz) { - 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); + 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); if (mode & FLAGS_ENCRYPT) - ret = crypto_skcipher_encrypt(subreq); + ret = crypto_skcipher_encrypt(&rctx->fallback_req); else - ret = crypto_skcipher_decrypt(subreq); - - skcipher_request_zero(subreq); + ret = crypto_skcipher_decrypt(&rctx->fallback_req); return ret; } dd = omap_aes_find_dev(rctx); @@ -590,11 +588,11 @@ static int omap_aes_setkey(struct crypto_skcipher *tfm, const u8 *key, memcpy(ctx->key, key, keylen); ctx->keylen = keylen; - 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); - ret = crypto_sync_skcipher_setkey(ctx->fallback, key, keylen); + ret = crypto_skcipher_setkey(ctx->fallback, key, keylen); if (!ret) return 0; @@ -640,15 +638,16 @@ static int omap_aes_init_tfm(struct crypto_skcipher *tfm) { const char *name = crypto_tfm_alg_name(&tfm->base); struct omap_aes_ctx *ctx = crypto_skcipher_ctx(tfm); - struct crypto_sync_skcipher *blk; + struct crypto_skcipher *blk; - blk = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK); + blk = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK); if (IS_ERR(blk)) return PTR_ERR(blk); ctx->fallback = blk; - crypto_skcipher_set_reqsize(tfm, sizeof(struct omap_aes_reqctx)); + crypto_skcipher_set_reqsize(tfm, sizeof(struct omap_aes_reqctx) + + crypto_skcipher_reqsize(blk)); ctx->enginectx.op.prepare_request = omap_aes_prepare_req; ctx->enginectx.op.unprepare_request = NULL; @@ -662,7 +661,7 @@ static void omap_aes_exit_tfm(struct crypto_skcipher *tfm) struct omap_aes_ctx *ctx = crypto_skcipher_ctx(tfm); if (ctx->fallback) - crypto_free_sync_skcipher(ctx->fallback); + crypto_free_skcipher(ctx->fallback); ctx->fallback = NULL; } diff --git a/drivers/crypto/omap-aes.h b/drivers/crypto/omap-aes.h index 2d111bf906e1..23d073e87bb8 100644 --- a/drivers/crypto/omap-aes.h +++ b/drivers/crypto/omap-aes.h @@ -97,7 +97,7 @@ struct omap_aes_ctx { int keylen; u32 key[AES_KEYSIZE_256 / sizeof(u32)]; u8 nonce[4]; - struct crypto_sync_skcipher *fallback; + struct crypto_skcipher *fallback; }; struct omap_aes_gcm_ctx { @@ -110,6 +110,7 @@ struct omap_aes_reqctx { unsigned long mode; u8 iv[AES_BLOCK_SIZE]; u32 auth_tag[AES_BLOCK_SIZE / sizeof(u32)]; + struct skcipher_request fallback_req; // keep at the end }; #define OMAP_AES_QUEUE_LENGTH 1