From: Gary R Hook Subject: [PATCH v2 3/4] crypto: ccp - Rework the unit-size check for XTS-AES Date: Fri, 21 Jul 2017 14:05:07 -0500 Message-ID: <150066390692.49973.8816619065422606698.stgit@sosxen.amd.com> References: <150066355075.49973.1565434199212056832.stgit@sosxen.amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: thomas.lendacky@amd.com, herbert@gondor.apana.org.au, davem@davemloft.net To: linux-crypto@vger.kernel.org Return-path: Received: from mail-by2nam03on0067.outbound.protection.outlook.com ([104.47.42.67]:27395 "EHLO NAM03-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754141AbdGUTFN (ORCPT ); Fri, 21 Jul 2017 15:05:13 -0400 In-Reply-To: <150066355075.49973.1565434199212056832.stgit@sosxen.amd.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: The CCP supports a limited set of unit-size values. Change the check for this parameter such that acceptable values match the enumeration. Then clarify the conditions under which we must use the fallback implementation. Signed-off-by: Gary R Hook --- drivers/crypto/ccp/ccp-crypto-aes-xts.c | 75 ++++++++++++++----------------- 1 file changed, 35 insertions(+), 40 deletions(-) diff --git a/drivers/crypto/ccp/ccp-crypto-aes-xts.c b/drivers/crypto/ccp/ccp-crypto-aes-xts.c index 4a313f62dbea..3c37794ffe2d 100644 --- a/drivers/crypto/ccp/ccp-crypto-aes-xts.c +++ b/drivers/crypto/ccp/ccp-crypto-aes-xts.c @@ -1,8 +1,9 @@ /* * AMD Cryptographic Coprocessor (CCP) AES XTS crypto API support * - * Copyright (C) 2013 Advanced Micro Devices, Inc. + * Copyright (C) 2013,2017 Advanced Micro Devices, Inc. * + * Author: Gary R Hook * Author: Tom Lendacky * * This program is free software; you can redistribute it and/or modify @@ -38,46 +39,26 @@ struct ccp_unit_size_map { u32 value; }; -static struct ccp_unit_size_map unit_size_map[] = { +static struct ccp_unit_size_map xts_unit_sizes[] = { { - .size = 4096, - .value = CCP_XTS_AES_UNIT_SIZE_4096, - }, - { - .size = 2048, - .value = CCP_XTS_AES_UNIT_SIZE_2048, - }, - { - .size = 1024, - .value = CCP_XTS_AES_UNIT_SIZE_1024, + .size = 16, + .value = CCP_XTS_AES_UNIT_SIZE_16, }, { - .size = 512, + .size = 512, .value = CCP_XTS_AES_UNIT_SIZE_512, }, { - .size = 256, - .value = CCP_XTS_AES_UNIT_SIZE__LAST, - }, - { - .size = 128, - .value = CCP_XTS_AES_UNIT_SIZE__LAST, - }, - { - .size = 64, - .value = CCP_XTS_AES_UNIT_SIZE__LAST, - }, - { - .size = 32, - .value = CCP_XTS_AES_UNIT_SIZE__LAST, + .size = 1024, + .value = CCP_XTS_AES_UNIT_SIZE_1024, }, { - .size = 16, - .value = CCP_XTS_AES_UNIT_SIZE_16, + .size = 2048, + .value = CCP_XTS_AES_UNIT_SIZE_2048, }, { - .size = 1, - .value = CCP_XTS_AES_UNIT_SIZE__LAST, + .size = 4096, + .value = CCP_XTS_AES_UNIT_SIZE_4096, }, }; @@ -124,7 +105,9 @@ static int ccp_aes_xts_crypt(struct ablkcipher_request *req, { struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm); struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req); + unsigned int fallback = 0; unsigned int unit; + u32 block_size; u32 unit_size; int ret; @@ -137,18 +120,30 @@ static int ccp_aes_xts_crypt(struct ablkcipher_request *req, if (!req->info) return -EINVAL; + /* Check conditions under which the CCP can fulfill a request. The + * device can handle input plaintext of a length that is a multiple + * of the unit_size, bug the crypto implementation only supports + * the unit_size being equal to the input length. This limits the + * number of scenarios we can handle. Also validate the key length. + */ + block_size = 0; unit_size = CCP_XTS_AES_UNIT_SIZE__LAST; - if (req->nbytes <= unit_size_map[0].size) { - for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++) { - if (!(req->nbytes & (unit_size_map[unit].size - 1))) { - unit_size = unit_size_map[unit].value; - break; - } + for (unit = 0; unit < ARRAY_SIZE(xts_unit_sizes); unit++) { + if (req->nbytes == xts_unit_sizes[unit].size) { + unit_size = unit; + block_size = xts_unit_sizes[unit].size; + break; } } - - if ((unit_size == CCP_XTS_AES_UNIT_SIZE__LAST) || - (ctx->u.aes.key_len != AES_KEYSIZE_128)) { + /* The CCP has restrictions on block sizes. Also, a version 3 device + * only supports AES-128 operations; version 5 CCPs support both + * AES-128 and -256 operations. + */ + if (unit_size == CCP_XTS_AES_UNIT_SIZE__LAST) + fallback = 1; + if (ctx->u.aes.key_len != AES_KEYSIZE_128) + fallback = 1; + if (fallback) { SKCIPHER_REQUEST_ON_STACK(subreq, ctx->u.aes.tfm_skcipher); /* Use the fallback to process the request for any