From patchwork Tue Jun 30 12:19:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11633867 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 776316C1 for ; Tue, 30 Jun 2020 12:20:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 605E62078B for ; Tue, 30 Jun 2020 12:20:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593519609; bh=z47aA9KxWozhyQQe5M0Dd9poj8oy6PNGecaY82Ab64Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PaivkaG/rZYDDj6M1PcVXG4zsu4ABESglpx96SNGFE+lX6X2itJeKrP4AZuIj4o9f qgHtKc9GbGYfQ0tb2LmuCiezPijs8DnHktB3qRhaEP/2CkNDBHK2jewX/nOS0yayyS apqVDscT44upQVN9mnfhFsoCNpeb+0zLDjeCErr8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387622AbgF3MUI (ORCPT ); Tue, 30 Jun 2020 08:20:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:36652 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732804AbgF3MUH (ORCPT ); Tue, 30 Jun 2020 08:20:07 -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 F299220672; Tue, 30 Jun 2020 12:20:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593519606; bh=z47aA9KxWozhyQQe5M0Dd9poj8oy6PNGecaY82Ab64Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qUO8KsiXamHHCRbFl/vWqQ5bObrN/D1SF6lJ6o26i3foXYEMYMUwqUhnjGfLLGQ9h +o6Xnu6KlfvAcYTxe4tRnWF9ojV99uygHGIqLexIYLyvKBhrA7zAp4JDXDJGj0Tl6q VQYJEeOIsBkzV7MVKNLSuHre0hlVXvYc98vlzV/8= 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 11/13] crypto: qce - permit asynchronous skcipher as fallback Date: Tue, 30 Jun 2020 14:19:05 +0200 Message-Id: <20200630121907.24274-12-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 qce driver implements asynchronous versions of ecb(aes), cbc(aes)and xts(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. While at it, remove the pointless memset() from qce_skcipher_init(), and remove the unnecessary call to it from qce_skcipher_init_fallback(). Signed-off-by: Ard Biesheuvel --- drivers/crypto/qce/cipher.h | 3 +- drivers/crypto/qce/skcipher.c | 42 ++++++++++---------- 2 files changed, 24 insertions(+), 21 deletions(-) diff --git a/drivers/crypto/qce/cipher.h b/drivers/crypto/qce/cipher.h index 7770660bc853..cffa9fc628ff 100644 --- a/drivers/crypto/qce/cipher.h +++ b/drivers/crypto/qce/cipher.h @@ -14,7 +14,7 @@ struct qce_cipher_ctx { u8 enc_key[QCE_MAX_KEY_SIZE]; unsigned int enc_keylen; - struct crypto_sync_skcipher *fallback; + struct crypto_skcipher *fallback; }; /** @@ -43,6 +43,7 @@ struct qce_cipher_reqctx { struct sg_table src_tbl; struct scatterlist *src_sg; unsigned int cryptlen; + struct skcipher_request fallback_req; // keep at the end }; static inline struct qce_alg_template *to_cipher_tmpl(struct crypto_skcipher *tfm) diff --git a/drivers/crypto/qce/skcipher.c b/drivers/crypto/qce/skcipher.c index 9412433f3b21..a8147381b774 100644 --- a/drivers/crypto/qce/skcipher.c +++ b/drivers/crypto/qce/skcipher.c @@ -178,7 +178,7 @@ static int qce_skcipher_setkey(struct crypto_skcipher *ablk, const u8 *key, break; } - ret = crypto_sync_skcipher_setkey(ctx->fallback, key, keylen); + ret = crypto_skcipher_setkey(ctx->fallback, key, keylen); if (!ret) ctx->enc_keylen = keylen; return ret; @@ -235,16 +235,15 @@ static int qce_skcipher_crypt(struct skcipher_request *req, int encrypt) req->cryptlen <= aes_sw_max_len) || (IS_XTS(rctx->flags) && req->cryptlen > QCE_SECTOR_SIZE && req->cryptlen % QCE_SECTOR_SIZE))) { - 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); - ret = encrypt ? crypto_skcipher_encrypt(subreq) : - crypto_skcipher_decrypt(subreq); - skcipher_request_zero(subreq); + 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); + ret = encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) : + crypto_skcipher_decrypt(&rctx->fallback_req); return ret; } @@ -263,10 +262,9 @@ static int qce_skcipher_decrypt(struct skcipher_request *req) static int qce_skcipher_init(struct crypto_skcipher *tfm) { - struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm); - - memset(ctx, 0, sizeof(*ctx)); - crypto_skcipher_set_reqsize(tfm, sizeof(struct qce_cipher_reqctx)); + /* take the size without the fallback skcipher_request at the end */ + crypto_skcipher_set_reqsize(tfm, offsetof(struct qce_cipher_reqctx, + fallback_req)); return 0; } @@ -274,17 +272,21 @@ static int qce_skcipher_init_fallback(struct crypto_skcipher *tfm) { struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm); - qce_skcipher_init(tfm); - ctx->fallback = crypto_alloc_sync_skcipher(crypto_tfm_alg_name(&tfm->base), - 0, CRYPTO_ALG_NEED_FALLBACK); - return PTR_ERR_OR_ZERO(ctx->fallback); + ctx->fallback = crypto_alloc_skcipher(crypto_tfm_alg_name(&tfm->base), + 0, CRYPTO_ALG_NEED_FALLBACK); + if (IS_ERR(ctx->fallback)) + return PTR_ERR(ctx->fallback); + + crypto_skcipher_set_reqsize(tfm, sizeof(struct qce_cipher_reqctx) + + crypto_skcipher_reqsize(ctx->fallback)); + return 0; } static void qce_skcipher_exit(struct crypto_skcipher *tfm) { struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm); - crypto_free_sync_skcipher(ctx->fallback); + crypto_free_skcipher(ctx->fallback); } struct qce_skcipher_def {