From patchwork Tue Jun 30 12:19:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11633859 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 67FEE138C for ; Tue, 30 Jun 2020 12:19:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51F6A207E8 for ; Tue, 30 Jun 2020 12:19:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593519590; bh=IfoJQfcz0Zm1QSESqy4YEJnncc0TZMao0pTV9CEAQXY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BfxXiyTDfTK1Bxng8/ONRL8elkCT6NdWptRB+ydjpt2T91+BLV1h2BJFLe5SNUajf c9FUXEjZKs8DvGlbZ9ozyPwCQsccv8emSRJr0kOxD6r1vqw9tm+fNK1P7fgpj5bgDW 0slEBmyedekTXNEcyHJ4uVhOtZGpEjrbKLCKKI/Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733295AbgF3MTt (ORCPT ); Tue, 30 Jun 2020 08:19:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:36470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732804AbgF3MTt (ORCPT ); Tue, 30 Jun 2020 08:19:49 -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 A28D22078B; Tue, 30 Jun 2020 12:19:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593519588; bh=IfoJQfcz0Zm1QSESqy4YEJnncc0TZMao0pTV9CEAQXY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j4X5hH9JDfbmAeZfa2/fyP0zXglsPjkv9wiGHgaNG1BL/E56bJK6oCqNRmLAHeUa7 bAD9dM77S9ePFXZaFwDKxhzC8rKgRjC5F9WbqVgNyxOFPjzHU2NRUhTHZ01EdX9cCp bmozy4olQWBU+9SxMBUHkwQq48chAyjpZ7ZIFo1Y= 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 07/13] crypto: ccp - permit asynchronous skcipher as fallback Date: Tue, 30 Jun 2020 14:19:01 +0200 Message-Id: <20200630121907.24274-8-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 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 --- drivers/crypto/ccp/ccp-crypto-aes-xts.c | 33 ++++++++++---------- drivers/crypto/ccp/ccp-crypto.h | 4 ++- 2 files changed, 19 insertions(+), 18 deletions(-) diff --git a/drivers/crypto/ccp/ccp-crypto-aes-xts.c b/drivers/crypto/ccp/ccp-crypto-aes-xts.c index 04b2517df955..959168a7ac59 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; } @@ -221,7 +220,7 @@ static void ccp_aes_xts_exit_tfm(struct crypto_skcipher *tfm) { struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm); - crypto_free_sync_skcipher(ctx->u.aes.tfm_skcipher); + crypto_free_skcipher(ctx->u.aes.tfm_skcipher); } static int ccp_register_aes_xts_alg(struct list_head *head, 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 {