From patchwork Mon Nov 12 10:24:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 10678433 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B1B1D13B5 for ; Mon, 12 Nov 2018 10:28:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9B09F29EE5 for ; Mon, 12 Nov 2018 10:28:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8EBD629EEF; Mon, 12 Nov 2018 10:28:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 310F229EE5 for ; Mon, 12 Nov 2018 10:28:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726912AbeKLUUv (ORCPT ); Mon, 12 Nov 2018 15:20:51 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:32735 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726161AbeKLUUu (ORCPT ); Mon, 12 Nov 2018 15:20:50 -0500 Received: from lhreml701-cah.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id DC31C541C4F98; Mon, 12 Nov 2018 10:28:10 +0000 (GMT) Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.153) by smtpsuk.huawei.com (10.201.108.42) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 12 Nov 2018 10:28:03 +0000 From: Roberto Sassu To: , , , CC: , , , , , Roberto Sassu Subject: [RFC][PATCH 01/12] mpi: introduce mpi_key_length() Date: Mon, 12 Nov 2018 11:24:12 +0100 Message-ID: <20181112102423.30415-2-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181112102423.30415-1-roberto.sassu@huawei.com> References: <20181112102423.30415-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.65.153] X-CFilter-Loop: Reflected Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 7cd1473c64a4..56187bb57c78 100644 --- a/include/linux/mpi.h +++ b/include/linux/mpi.h @@ -61,6 +61,8 @@ int mpi_resize(MPI a, unsigned nlimbs); /*-- mpicoder.c --*/ 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); MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len); void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign); diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index eead4b339466..207cb3b91a51 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -78,22 +78,41 @@ 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 *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);