From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- lib/crypto/mpi/generic_mpih-mul3.c | 48 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 lib/crypto/mpi/generic_mpih-mul3.c (limited to 'lib/crypto/mpi/generic_mpih-mul3.c') diff --git a/lib/crypto/mpi/generic_mpih-mul3.c b/lib/crypto/mpi/generic_mpih-mul3.c new file mode 100644 index 000000000..ccdbab412 --- /dev/null +++ b/lib/crypto/mpi/generic_mpih-mul3.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* mpihelp-mul_3.c - MPI helper functions + * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * Note: This code is heavily based on the GNU MP Library. + * Actually it's the same code with only minor changes in the + * way the data is stored; this is to support the abstraction + * of an optional secure memory allocation which may be used + * to avoid revealing of sensitive data due to paging etc. + * The GNU MP Library itself is published under the LGPL; + * however I decided to publish this code under the plain GPL. + */ + +#include "mpi-internal.h" +#include "longlong.h" + +mpi_limb_t +mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, + mpi_size_t s1_size, mpi_limb_t s2_limb) +{ + mpi_limb_t cy_limb; + mpi_size_t j; + mpi_limb_t prod_high, prod_low; + mpi_limb_t x; + + /* The loop counter and index J goes from -SIZE to -1. This way + * the loop becomes faster. */ + j = -s1_size; + res_ptr -= j; + s1_ptr -= j; + + cy_limb = 0; + do { + umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb); + + prod_low += cy_limb; + cy_limb = (prod_low < cy_limb ? 1 : 0) + prod_high; + + x = res_ptr[j]; + prod_low = x - prod_low; + cy_limb += prod_low > x ? 1 : 0; + res_ptr[j] = prod_low; + } while (++j); + + return cy_limb; +} -- cgit v1.2.3