From patchwork Thu Jun 25 12:42:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11625075 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 6AC0F6C1 for ; Thu, 25 Jun 2020 12:43:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 531F42072E for ; Thu, 25 Jun 2020 12:43:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593089029; bh=wGffz0ZawEaorm/Ljcec1lJrVUrfVxGLZbekPHv2K80=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i3o6VHQbrppF4PVfmxx0/9Mkn3ex2EJyhJdOepYpqTl/WqYrjagOabnUnkFpBpM2l YVl1jmns3SR8e7p1glCvS7Hc6dh0q1Yadu13ZRE7al9ITvVgoMoQfcXvwXFusEa7zB KgR6knfaEk9qh9gN9j0yp0IiVGgAsl1QsIZKyaX8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404775AbgFYMns (ORCPT ); Thu, 25 Jun 2020 08:43:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:46130 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404285AbgFYMns (ORCPT ); Thu, 25 Jun 2020 08:43:48 -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 CD956206BE; Thu, 25 Jun 2020 12:43:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593089027; bh=wGffz0ZawEaorm/Ljcec1lJrVUrfVxGLZbekPHv2K80=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MmwesvC+7kD10YqfQO/nPFbYUFpC7XeU11gAUcw3j/N/E6Ffqnx/faL0B/oJyiqoq UzW7VOQjL9KDjDU8aCn/pE2m18ZVENw0zuOGBIJ+2sVy4wdjXUdEeX6EQPphXhnaiK YjosleV9OLAFL1GVLhL77uJ8LvDbm00pVMqh6YRk= 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 07/12] crypto: ccp - permit asynchronous skcipher as fallback Date: Thu, 25 Jun 2020 14:42:48 +0200 Message-Id: <20200625124253.1906557-8-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 ccp driver implements an asynchronous version of xts(aes), the fallback it allocates is 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 Reported-by: kernel test robot --- drivers/crypto/ccp/ccp-crypto-aes-xts.c | 31 ++++++++++---------- drivers/crypto/ccp/ccp-crypto.h | 4 ++- 2 files changed, 18 insertions(+), 17 deletions(-) diff --git a/drivers/crypto/ccp/ccp-crypto-aes-xts.c b/drivers/crypto/ccp/ccp-crypto-aes-xts.c index 04b2517df955..e0fb4e8f22fb 100644 --- a/drivers/crypto/ccp/ccp-crypto-aes-xts.c +++ b/drivers/crypto/ccp/ccp-crypto-aes-xts.c @@ -98,7 +98,7 @@ static int ccp_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key, ctx->u.aes.key_len = key_len / 2; sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len); - return crypto_sync_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len); + return crypto_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len); } static int ccp_aes_xts_crypt(struct skcipher_request *req, @@ -145,20 +145,19 @@ static int ccp_aes_xts_crypt(struct skcipher_request *req, (ctx->u.aes.key_len != AES_KEYSIZE_256)) fallback = 1; if (fallback) { - SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, - ctx->u.aes.tfm_skcipher); - /* Use the fallback to process the request for any * unsupported unit sizes or key sizes */ - skcipher_request_set_sync_tfm(subreq, ctx->u.aes.tfm_skcipher); - skcipher_request_set_callback(subreq, req->base.flags, - NULL, NULL); - skcipher_request_set_crypt(subreq, req->src, req->dst, - req->cryptlen, req->iv); - ret = encrypt ? crypto_skcipher_encrypt(subreq) : - crypto_skcipher_decrypt(subreq); - skcipher_request_zero(subreq); + skcipher_request_set_tfm(&rctx->fallback_req, + ctx->u.aes.tfm_skcipher); + 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); + ret = encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) : + crypto_skcipher_decrypt(&rctx->fallback_req); return ret; } @@ -198,13 +197,12 @@ static int ccp_aes_xts_decrypt(struct skcipher_request *req) static int ccp_aes_xts_init_tfm(struct crypto_skcipher *tfm) { struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm); - struct crypto_sync_skcipher *fallback_tfm; + struct crypto_skcipher *fallback_tfm; ctx->complete = ccp_aes_xts_complete; ctx->u.aes.key_len = 0; - fallback_tfm = crypto_alloc_sync_skcipher("xts(aes)", 0, - CRYPTO_ALG_ASYNC | + fallback_tfm = crypto_alloc_skcipher("xts(aes)", 0, CRYPTO_ALG_NEED_FALLBACK); if (IS_ERR(fallback_tfm)) { pr_warn("could not load fallback driver xts(aes)\n"); @@ -212,7 +210,8 @@ static int ccp_aes_xts_init_tfm(struct crypto_skcipher *tfm) } ctx->u.aes.tfm_skcipher = fallback_tfm; - crypto_skcipher_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx)); + crypto_skcipher_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx) + + crypto_skcipher_reqsize(fallback_tfm)); return 0; } diff --git a/drivers/crypto/ccp/ccp-crypto.h b/drivers/crypto/ccp/ccp-crypto.h index 90a009e6b5c1..aed3d2192d01 100644 --- a/drivers/crypto/ccp/ccp-crypto.h +++ b/drivers/crypto/ccp/ccp-crypto.h @@ -89,7 +89,7 @@ static inline struct ccp_crypto_ahash_alg * /***** AES related defines *****/ struct ccp_aes_ctx { /* Fallback cipher for XTS with unsupported unit sizes */ - struct crypto_sync_skcipher *tfm_skcipher; + struct crypto_skcipher *tfm_skcipher; enum ccp_engine engine; enum ccp_aes_type type; @@ -121,6 +121,8 @@ struct ccp_aes_req_ctx { u8 rfc3686_iv[AES_BLOCK_SIZE]; struct ccp_cmd cmd; + + struct skcipher_request fallback_req; // keep at the end }; struct ccp_aes_cmac_req_ctx {