Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2552C433F5 for ; Tue, 11 Jan 2022 18:04:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345350AbiAKSEB (ORCPT ); Tue, 11 Jan 2022 13:04:01 -0500 Received: from frasgout.his.huawei.com ([185.176.79.56]:4389 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345158AbiAKSDv (ORCPT ); Tue, 11 Jan 2022 13:03:51 -0500 Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4JYJPq0CrVz67cQc; Wed, 12 Jan 2022 02:00:15 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Tue, 11 Jan 2022 19:03:47 +0100 From: Roberto Sassu To: , , , CC: , , , , , , , Roberto Sassu Subject: [PATCH 01/14] mpi: Introduce mpi_key_length() Date: Tue, 11 Jan 2022 19:03:05 +0100 Message-ID: <20220111180318.591029-2-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220111180318.591029-1-roberto.sassu@huawei.com> References: <20220111180318.591029-1-roberto.sassu@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhreml754-chm.china.huawei.com (10.201.108.204) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Introduce the new function to get the number of bits and bytes from an MPI. Signed-off-by: Roberto Sassu --- include/linux/mpi.h | 2 ++ lib/mpi/mpicoder.c | 33 ++++++++++++++++++++++++++------- 2 files changed, 28 insertions(+), 7 deletions(-) diff --git a/include/linux/mpi.h b/include/linux/mpi.h index eb0d1c1db208..a7dd4c9d8120 100644 --- a/include/linux/mpi.h +++ b/include/linux/mpi.h @@ -90,6 +90,8 @@ enum gcry_mpi_format { }; MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes); +int mpi_key_length(const void *xbuffer, unsigned int ret_nread, + unsigned int *nbits_arg, unsigned int *nbytes_arg); MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread); int mpi_fromstr(MPI val, const char *str); MPI mpi_scanval(const char *string); diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index 39c4c6731094..cd10ae9968b7 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -79,22 +79,41 @@ MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes) } EXPORT_SYMBOL_GPL(mpi_read_raw_data); -MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) +int mpi_key_length(const void *xbuffer, unsigned int ret_nread, + unsigned int *nbits_arg, unsigned int *nbytes_arg) { const uint8_t *buffer = xbuffer; - unsigned int nbits, nbytes; - MPI val; + unsigned int nbits; - if (*ret_nread < 2) - return ERR_PTR(-EINVAL); + if (ret_nread < 2) + return -EINVAL; nbits = buffer[0] << 8 | buffer[1]; if (nbits > MAX_EXTERN_MPI_BITS) { pr_info("MPI: mpi too large (%u bits)\n", nbits); - return ERR_PTR(-EINVAL); + return -EINVAL; } - nbytes = DIV_ROUND_UP(nbits, 8); + if (nbits_arg) + *nbits_arg = nbits; + if (nbytes_arg) + *nbytes_arg = DIV_ROUND_UP(nbits, 8); + + return 0; +} +EXPORT_SYMBOL_GPL(mpi_key_length); + +MPI mpi_read_from_buffer(const void *xbuffer, unsigned int *ret_nread) +{ + const uint8_t *buffer = xbuffer; + unsigned int nbytes; + MPI val; + int ret; + + ret = mpi_key_length(xbuffer, *ret_nread, NULL, &nbytes); + if (ret < 0) + return ERR_PTR(ret); + if (nbytes + 2 > *ret_nread) { pr_info("MPI: mpi larger than buffer nbytes=%u ret_nread=%u\n", nbytes, *ret_nread); -- 2.32.0