mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-18 17:54:13 +08:00
7e8dec918e
Adds the multi-precision-integer maths library which was originally taken from GnuPG and ported to the kernel by (among others) David Howells. This version is taken from Fedora kernel 2.6.32-71.14.1.el6. The difference is that checkpatch reported errors and warnings have been fixed. This library is used to implemenet RSA digital signature verification used in IMA/EVM integrity protection subsystem. Due to patch size limitation, the patch is divided into 4 parts. This code is unnecessary for RSA digital signature verification, but for completeness it is included here and can be compiled, if CONFIG_MPILIB_EXTRA is enabled. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
69 lines
1.6 KiB
C
69 lines
1.6 KiB
C
/* mpi-cmp.c - MPI functions
|
|
* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
|
|
*
|
|
* This file is part of GnuPG.
|
|
*
|
|
* GnuPG is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* GnuPG is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
|
|
*/
|
|
|
|
#include "mpi-internal.h"
|
|
|
|
int mpi_cmp_ui(MPI u, unsigned long v)
|
|
{
|
|
mpi_limb_t limb = v;
|
|
|
|
mpi_normalize(u);
|
|
if (!u->nlimbs && !limb)
|
|
return 0;
|
|
if (u->sign)
|
|
return -1;
|
|
if (u->nlimbs > 1)
|
|
return 1;
|
|
|
|
if (u->d[0] == limb)
|
|
return 0;
|
|
else if (u->d[0] > limb)
|
|
return 1;
|
|
else
|
|
return -1;
|
|
}
|
|
|
|
int mpi_cmp(MPI u, MPI v)
|
|
{
|
|
mpi_size_t usize, vsize;
|
|
int cmp;
|
|
|
|
mpi_normalize(u);
|
|
mpi_normalize(v);
|
|
usize = u->nlimbs;
|
|
vsize = v->nlimbs;
|
|
if (!u->sign && v->sign)
|
|
return 1;
|
|
if (u->sign && !v->sign)
|
|
return -1;
|
|
if (usize != vsize && !u->sign && !v->sign)
|
|
return usize - vsize;
|
|
if (usize != vsize && u->sign && v->sign)
|
|
return vsize + usize;
|
|
if (!usize)
|
|
return 0;
|
|
cmp = mpihelp_cmp(u->d, v->d, usize);
|
|
if (!cmp)
|
|
return 0;
|
|
if ((cmp < 0 ? 1 : 0) == (u->sign ? 1 : 0))
|
|
return 1;
|
|
return -1;
|
|
}
|