cdec9cb516
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. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
57 lines
2.0 KiB
C
57 lines
2.0 KiB
C
/* mpihelp-sub.c - MPI helper functions
|
|
* Copyright (C) 1994, 1996 Free Software Foundation, Inc.
|
|
* Copyright (C) 1998, 1999, 2000, 2001 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
|
|
*
|
|
* 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"
|
|
|
|
/****************
|
|
* Compare OP1_PTR/OP1_SIZE with OP2_PTR/OP2_SIZE.
|
|
* There are no restrictions on the relative sizes of
|
|
* the two arguments.
|
|
* Return 1 if OP1 > OP2, 0 if they are equal, and -1 if OP1 < OP2.
|
|
*/
|
|
int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size)
|
|
{
|
|
mpi_size_t i;
|
|
mpi_limb_t op1_word, op2_word;
|
|
|
|
for (i = size - 1; i >= 0; i--) {
|
|
op1_word = op1_ptr[i];
|
|
op2_word = op2_ptr[i];
|
|
if (op1_word != op2_word)
|
|
goto diff;
|
|
}
|
|
return 0;
|
|
|
|
diff:
|
|
/* This can *not* be simplified to
|
|
* op2_word - op2_word
|
|
* since that expression might give signed overflow. */
|
|
return (op1_word > op2_word) ? 1 : -1;
|
|
}
|