From patchwork Sat Jun 27 08:36:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11629403 X-Patchwork-Delegate: herbert@gondor.apana.org.au 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 DE51414E3 for ; Sat, 27 Jun 2020 08:36:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C8615212CC for ; Sat, 27 Jun 2020 08:36:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593247010; bh=7g45QWyrYUg0An4TDCghUfvpEHV1X2Se+dPPjGObVdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Zn4zvkkvlitmjdDoP8aJF4HIcRUhrtetMt0wbhEv3Yj/vfqc2e+c5d3/N0RA9N/Ep qrxQZnnEnnRBL+3+T79W5oOG5l6168Ye3ru2SaLHSn0CZFxIAyG5KCL95unnYwp2yY rkSSTYVCyPnvjFWI4a8k8s8ppTaUsL7f29FbnXFY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726337AbgF0Igu (ORCPT ); Sat, 27 Jun 2020 04:36:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:60884 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726086AbgF0Igt (ORCPT ); Sat, 27 Jun 2020 04:36:49 -0400 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 1071F208C7; Sat, 27 Jun 2020 08:36:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593247009; bh=7g45QWyrYUg0An4TDCghUfvpEHV1X2Se+dPPjGObVdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m/ajGB074NYPLnbD44erR6c0f/YJu/AftljLUMwznn2XTvzylJ57vf9p77ozT+oMH LnD5P55AI7sAnQiCyMDNQOkzTrkruxcyc0jQAiYMgNHRmip/V38nDze6evPOeL1pLE IE0r1GnBuZ0T4ZicvAT81K/AIf0R2ONMInASwX58= 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 , Tero Kristo , Matthias Brugger Subject: [PATCH v2 03/13] crypto: omap-aes - permit asynchronous skcipher as fallback Date: Sat, 27 Jun 2020 10:36:13 +0200 Message-Id: <20200627083623.2428333-4-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 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