From patchwork Thu Oct 1 20:28:56 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tadeusz Struk X-Patchwork-Id: 7311211 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: X-Original-To: patchwork-linux-crypto@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 2EA0D9F302 for ; Thu, 1 Oct 2015 20:31:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 21E7C20600 for ; Thu, 1 Oct 2015 20:31:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED316205BD for ; Thu, 1 Oct 2015 20:31:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756403AbbJAUbD (ORCPT ); Thu, 1 Oct 2015 16:31:03 -0400 Received: from mga14.intel.com ([192.55.52.115]:22285 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753419AbbJAUbB (ORCPT ); Thu, 1 Oct 2015 16:31:01 -0400 Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP; 01 Oct 2015 13:31:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,619,1437462000"; d="scan'208";a="572348102" Received: from tstruk-mobl1.jf.intel.com (HELO [127.0.1.1]) ([134.134.171.56]) by FMSMGA003.fm.intel.com with ESMTP; 01 Oct 2015 13:31:02 -0700 Subject: [PATCH v4 2/3] lib/mpi: Add mpi sgl helpers From: Tadeusz Struk To: herbert@gondor.apana.org.au Cc: linux-crypto@vger.kernel.org, qat-linux@intel.com, tadeusz.struk@intel.com Date: Thu, 01 Oct 2015 13:28:56 -0700 Message-ID: <20151001202856.7193.94775.stgit@tstruk-mobl1> In-Reply-To: <20151001202845.7193.51602.stgit@tstruk-mobl1> References: <20151001202845.7193.51602.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 Add mpi_read_raw_from_sgl and mpi_write_to_sgl helpers. Signed-off-by: Tadeusz Struk --- include/linux/mpi.h | 4 + lib/mpi/mpicoder.c | 194 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 198 insertions(+) -- 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 641b7d6..8b8269f 100644 --- a/include/linux/mpi.h +++ b/include/linux/mpi.h @@ -31,6 +31,7 @@ #define G10_MPI_H #include +#include /* DSI defines */ @@ -78,6 +79,7 @@ void mpi_swap(MPI a, MPI b); MPI do_encode_md(const void *sha_buffer, unsigned nbits); MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes); MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread); +MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len); 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); @@ -85,6 +87,8 @@ 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); +int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned *nbytes, + int *sign); #define log_mpidump g10_log_mpidump diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index 95c52a9..10ffef4 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -319,3 +319,197 @@ int mpi_set_buffer(MPI a, const void *xbuffer, unsigned nbytes, int sign) return 0; } EXPORT_SYMBOL_GPL(mpi_set_buffer); + +/** + * mpi_write_to_sgl() - Funnction exports MPI to an sgl (msb first) + * + * This function works in the same way as the mpi_read_buffer, but it + * takes an sgl instead of u8 * buf. + * + * @a: a multi precision integer + * @sgl: scatterlist to write to. Needs to be at least + * mpi_get_size(a) long. + * @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 + */ +int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, + int *sign) +{ + u8 *p, *p2; + mpi_limb_t alimb, alimb2; + unsigned int n = mpi_get_size(a), sglen = sg_len(sgl); + int i, x, y = 0, lzeros = 0, buf_len; + + if (sglen < n || !nbytes) + return -EINVAL; + + if (sign) + *sign = a->sign; + + p = (void *)&a->d[a->nlimbs] - 1; + + for (i = a->nlimbs * sizeof(alimb) - 1; i >= 0; i--, p--) { + if (!*p) + lzeros++; + else + break; + } + + *nbytes = n - lzeros; + buf_len = sgl->length; + p2 = sg_virt(sgl); + + for (i = a->nlimbs - 1; i >= 0; i--) { + alimb = a->d[i]; + p = (u8 *)&alimb2; +#if BYTES_PER_MPI_LIMB == 4 + *p++ = alimb >> 24; + *p++ = alimb >> 16; + *p++ = alimb >> 8; + *p++ = alimb; +#elif BYTES_PER_MPI_LIMB == 8 + *p++ = alimb >> 56; + *p++ = alimb >> 48; + *p++ = alimb >> 40; + *p++ = alimb >> 32; + *p++ = alimb >> 24; + *p++ = alimb >> 16; + *p++ = alimb >> 8; + *p++ = alimb; +#else +#error please implement for this limb size. +#endif + if (lzeros > 0) { + if (lzeros >= sizeof(alimb)) { + p -= sizeof(alimb); + continue; + } else { + mpi_limb_t *limb1 = (void *)p - sizeof(alimb); + mpi_limb_t *limb2 = (void *)p - sizeof(alimb) + + lzeros; + *limb1 = *limb2; + p -= lzeros; + y = lzeros; + } + lzeros -= sizeof(alimb); + } + + p = p - (sizeof(alimb) - y); + + for (x = 0; x < sizeof(alimb) - y; x++) { + if (!buf_len) { + sgl = sg_next(sgl); + buf_len = sgl->length; + p2 = sg_virt(sgl); + } + *p2++ = *p++; + buf_len--; + } + y = 0; + } + return 0; +} +EXPORT_SYMBOL_GPL(mpi_write_to_sgl); + +/* + * mpi_read_raw_from_sgl() - Function allocates an MPI and populates it with + * data from the sgl + * + * This function works in the same way as the mpi_read_raw_data, but it + * takes an sgl instead of void * buffer. i.e. it allocates + * a new MPI and reads the content of the sgl to the MPI. + * + * @sgl: scatterlist to read from + * @len: number of bytes to read + * + * Return: Pointer to a new MPI or NULL on error + */ +MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len) +{ + struct scatterlist *sg; + int x, i, j, z, lzeros, ents; + unsigned int nbits, nlimbs, nbytes; + mpi_limb_t a; + MPI val = NULL; + + if (len > sg_len(sgl)) + return NULL; + + lzeros = 0; + ents = sg_nents(sgl); + + for_each_sg(sgl, sg, ents, i) { + const u8 *buff = sg_virt(sg); + int len = sg->length; + + while (len-- && !*buff++) + lzeros++; + + if (len && *buff) + break; + + ents--; + lzeros = 0; + } + + sgl = sg; + + if (!ents) + nbytes = 0; + else + nbytes = len - lzeros; + + nbits = nbytes * 8; + if (nbits > MAX_EXTERN_MPI_BITS) { + pr_info("MPI: mpi too large (%u bits)\n", nbits); + return NULL; + } + + if (nbytes > 0) + nbits -= count_leading_zeros(*(u8 *)(sg_virt(sgl) + lzeros)); + else + nbits = 0; + + nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB); + val = mpi_alloc(nlimbs); + if (!val) + return NULL; + + val->nbits = nbits; + val->sign = 0; + val->nlimbs = nlimbs; + + if (nbytes == 0) + return val; + + j = nlimbs - 1; + a = 0; + z = 0; + x = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; + x %= BYTES_PER_MPI_LIMB; + + for_each_sg(sgl, sg, ents, i) { + const u8 *buffer = sg_virt(sg) + lzeros; + int len = sg->length - lzeros; + int buf_shift = x; + + if (sg_is_last(sg) && (len % BYTES_PER_MPI_LIMB)) + len += BYTES_PER_MPI_LIMB - (len % BYTES_PER_MPI_LIMB); + + for (; x < len + buf_shift; x++) { + a <<= 8; + a |= *buffer++; + if (((z + x + 1) % BYTES_PER_MPI_LIMB) == 0) { + val->d[j--] = a; + a = 0; + } + } + z += x; + x = 0; + lzeros = 0; + } + return val; +} +EXPORT_SYMBOL_GPL(mpi_read_raw_from_sgl);