mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 10:40:15 +02:00
2a598d0b28
As lib/mpi is mostly used by crypto code, move it under lib/crypto so that patches touching it get directed to the right mailing list. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
44 lines
1.3 KiB
C
44 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* mpihelp-mul_1.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_mul_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;
|
|
|
|
/* The loop counter and index J goes from -S1_SIZE to -1. This way
|
|
* the loop becomes faster. */
|
|
j = -s1_size;
|
|
|
|
/* Offset the base pointers to compensate for the negative indices. */
|
|
s1_ptr -= j;
|
|
res_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;
|
|
res_ptr[j] = prod_low;
|
|
} while (++j);
|
|
|
|
return cy_limb;
|
|
}
|