From patchwork Thu Jun 11 19:05:38 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tadeusz Struk X-Patchwork-Id: 6591271 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: X-Original-To: patchwork-linux-crypto@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0331CC0020 for ; Thu, 11 Jun 2015 19:06:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 00FD82062C for ; Thu, 11 Jun 2015 19:06:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCBE320616 for ; Thu, 11 Jun 2015 19:06:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754663AbbFKTFk (ORCPT ); Thu, 11 Jun 2015 15:05:40 -0400 Received: from mga09.intel.com ([134.134.136.24]:41319 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753219AbbFKTFg (ORCPT ); Thu, 11 Jun 2015 15:05:36 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 11 Jun 2015 12:05:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,596,1427785200"; d="scan'208";a="745132778" Received: from tstruk-mobl1.jf.intel.com (HELO [127.0.1.1]) ([134.134.171.161]) by orsmga002.jf.intel.com with ESMTP; 11 Jun 2015 12:05:37 -0700 Subject: [PATCH RFC v4 1/4] MPILIB: add mpi_read_buf(), mpi_copy() and mpi_get_size() helpers From: Tadeusz Struk To: herbert@gondor.apana.org.au Cc: linux-kernel@vger.kernel.org, keescook@chromium.org, jwboyer@redhat.com, richard@nod.at, tadeusz.struk@intel.com, steved@redhat.com, qat-linux@intel.com, dhowells@redhat.com, linux-crypto@vger.kernel.org, james.l.morris@oracle.com, jkosina@suse.cz, zohar@linux.vnet.ibm.com, davem@davemloft.net, vgoyal@redhat.com Date: Thu, 11 Jun 2015 12:05:38 -0700 Message-ID: <20150611190538.31826.97258.stgit@tstruk-mobl1> In-Reply-To: <20150611190533.31826.13956.stgit@tstruk-mobl1> References: <20150611190533.31826.13956.stgit@tstruk-mobl1> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Added a mpi_read_buf() helper function to export MPI to a buf provided by the user, and a mpi_get_size() helper, that tells the user how big the buf is. Implemented mpi_copy(), which was declared in mpi.h, but never implemented. Signed-off-by: Tadeusz Struk --- include/linux/mpi.h | 3 ++ lib/mpi/mpicoder.c | 86 ++++++++++++++++++++++++++++++++++++++++----------- lib/mpi/mpiutil.c | 47 ++++++++++++++++++++++++++++ 3 files changed, 117 insertions(+), 19 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/include/linux/mpi.h b/include/linux/mpi.h index 5af1b81..5e55fd0 100644 --- a/include/linux/mpi.h +++ b/include/linux/mpi.h @@ -73,6 +73,7 @@ int mpi_set_ui(MPI w, ulong u); MPI mpi_alloc_set_ui(unsigned long u); void mpi_m_check(MPI a); void mpi_swap(MPI a, MPI b); +unsigned int mpi_get_size(MPI a); /*-- mpicoder.c --*/ MPI do_encode_md(const void *sha_buffer, unsigned nbits); @@ -81,6 +82,8 @@ MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread); int mpi_fromstr(MPI val, const char *str); u32 mpi_get_keyid(MPI a, u32 *keyid); void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign); +int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, + int *sign); void *mpi_get_secure_buffer(MPI a, unsigned *nbytes, int *sign); int mpi_set_buffer(MPI a, const void *buffer, unsigned nbytes, int sign); diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index 4cc6442..f48b028 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -128,28 +128,36 @@ leave: } EXPORT_SYMBOL_GPL(mpi_read_from_buffer); -/**************** - * Return an allocated buffer with the MPI (msb first). - * NBYTES receives the length of this buffer. Caller must free the - * return string (This function does return a 0 byte buffer with NBYTES - * set to zero if the value of A is zero. If sign is not NULL, it will - * be set to the sign of the A. +/** + * mpi_read_buffer() - read MPI to a bufer provided by user (msb first) + * + * @a: a multi precision integer + * @buf: bufer to which the output will be written to. Needs to be at + * leaset mpi_get_size(a) long. + * @buf_len: size of the buf. + * @nbytes: receives the actual length of the data written. + * @sign: if not NULL, it will be set to the sign of a. + * + * Return: 0 on success or error code in case of error */ -void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign) +int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, + int *sign) { - uint8_t *p, *buffer; + uint8_t *p; mpi_limb_t alimb; + unsigned int n = mpi_get_size(a); int i; - unsigned int n; + + if (buf_len < n || !buf) + return -EINVAL; if (sign) *sign = a->sign; - *nbytes = n = a->nlimbs * BYTES_PER_MPI_LIMB; - if (!n) - n++; /* avoid zero length allocation */ - p = buffer = kmalloc(n, GFP_KERNEL); - if (!p) - return NULL; + + if (nbytes) + *nbytes = n; + + p = buf; for (i = a->nlimbs - 1; i >= 0; i--) { alimb = a->d[i]; @@ -171,15 +179,55 @@ void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign) #error please implement for this limb size. #endif } + return 0; +} +EXPORT_SYMBOL_GPL(mpi_read_buffer); + +/* + * mpi_get_buffer() - Returns an allocated buffer with the MPI (msb first). + * Caller must free the return string. + * This function does return a 0 byte buffer with nbytes set to zero if the + * value of A is zero. + * + * @a: a multi precision integer. + * @nbytes: receives the length of this buffer. + * @sign: if not NULL, it will be set to the sign of the a. + * + * Return: Pointer to MPI buffer or NULL on error + */ +void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign) +{ + uint8_t *buf, *p; + int n, ret; + + if (!nbytes) + return NULL; + + n = mpi_get_size(a); + + if (!n) + n++; + + buf = kmalloc(n, GFP_KERNEL); + + if (!buf) + return NULL; + + ret = mpi_read_buffer(a, buf, n, nbytes, sign); + + if (ret) { + kfree(buf); + return NULL; + } /* this is sub-optimal but we need to do the shift operation * because the caller has to free the returned buffer */ - for (p = buffer; !*p && *nbytes; p++, --*nbytes) + for (p = buf; !*p && *nbytes; p++, --*nbytes) ; - if (p != buffer) - memmove(buffer, p, *nbytes); + if (p != buf) + memmove(buf, p, *nbytes); - return buffer; + return buf; } EXPORT_SYMBOL_GPL(mpi_get_buffer); diff --git a/lib/mpi/mpiutil.c b/lib/mpi/mpiutil.c index bf076d2..ee078e2 100644 --- a/lib/mpi/mpiutil.c +++ b/lib/mpi/mpiutil.c @@ -54,6 +54,40 @@ MPI mpi_alloc(unsigned nlimbs) } EXPORT_SYMBOL_GPL(mpi_alloc); +/** + * mpi_copy() - allocates a new MPI as exact copy of a. + * + * @copy: pointer to an MPI in which the copy will be stored + * @a: A multi precision integer for which we want to do a copy + * + * Return: 0 on success or err + */ +int mpi_copy(MPI *copy, MPI a) +{ + int ret = 0; + + if (!copy) + return -EINVAL; + + if (a) { + *copy = mpi_alloc(a->nlimbs); + if (*copy) { + memcpy((*copy)->d, a->d, a->nlimbs * + sizeof(mpi_limb_t)); + (*copy)->nlimbs = a->nlimbs; + (*copy)->sign = a->sign; + (*copy)->flags = a->flags; + (*copy)->nbits = a->nbits; + } else { + ret = -ENOMEM; + } + } else { + *copy = NULL; + } + return ret; +} +EXPORT_SYMBOL_GPL(mpi_copy); + mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs) { size_t len = nlimbs * sizeof(mpi_limb_t); @@ -122,5 +156,18 @@ void mpi_free(MPI a) } EXPORT_SYMBOL_GPL(mpi_free); +/** + * mpi_get_size() - returns max size required to store the number + * + * @a: A multi precision integer for which we want to allocate a bufer + * + * Return: size required to store the number + */ +unsigned int mpi_get_size(MPI a) +{ + return a->nlimbs * BYTES_PER_MPI_LIMB; +} +EXPORT_SYMBOL_GPL(mpi_get_size); + MODULE_DESCRIPTION("Multiprecision maths library"); MODULE_LICENSE("GPL");