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>
68 lines
1.6 KiB
C
68 lines
1.6 KiB
C
/* mpi-cmp.c - MPI functions
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* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
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*
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* This file is part of GnuPG.
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*
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* GnuPG is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* GnuPG is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*/
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#include "mpi-internal.h"
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int mpi_cmp_ui(MPI u, unsigned long v)
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{
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mpi_limb_t limb = v;
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mpi_normalize(u);
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if (!u->nlimbs && !limb)
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return 0;
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if (u->sign)
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return -1;
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if (u->nlimbs > 1)
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return 1;
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if (u->d[0] == limb)
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return 0;
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else if (u->d[0] > limb)
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return 1;
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else
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return -1;
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}
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int mpi_cmp(MPI u, MPI v)
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{
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mpi_size_t usize, vsize;
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int cmp;
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mpi_normalize(u);
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mpi_normalize(v);
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usize = u->nlimbs;
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vsize = v->nlimbs;
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if (!u->sign && v->sign)
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return 1;
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if (u->sign && !v->sign)
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return -1;
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if (usize != vsize && !u->sign && !v->sign)
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return usize - vsize;
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if (usize != vsize && u->sign && v->sign)
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return vsize + usize;
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if (!usize)
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return 0;
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cmp = mpihelp_cmp(u->d, v->d, usize);
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if (!cmp)
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return 0;
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if ((cmp < 0 ? 1 : 0) == (u->sign ? 1 : 0))
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return 1;
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return -1;
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}
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