mirror of
https://github.com/joel16/android_kernel_sony_msm8994.git
synced 2024-11-27 06:01:12 +00:00
5ce3e312ec
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>
123 lines
3.3 KiB
C
123 lines
3.3 KiB
C
/* mpi-inline.h - Internal to the Multi Precision Integers
|
|
* Copyright (C) 1994, 1996, 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
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#ifndef G10_MPI_INLINE_H
|
|
#define G10_MPI_INLINE_H
|
|
|
|
#ifndef G10_MPI_INLINE_DECL
|
|
#define G10_MPI_INLINE_DECL extern inline
|
|
#endif
|
|
|
|
G10_MPI_INLINE_DECL mpi_limb_t
|
|
mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
|
|
mpi_size_t s1_size, mpi_limb_t s2_limb)
|
|
{
|
|
mpi_limb_t x;
|
|
|
|
x = *s1_ptr++;
|
|
s2_limb += x;
|
|
*res_ptr++ = s2_limb;
|
|
if (s2_limb < x) { /* sum is less than the left operand: handle carry */
|
|
while (--s1_size) {
|
|
x = *s1_ptr++ + 1; /* add carry */
|
|
*res_ptr++ = x; /* and store */
|
|
if (x) /* not 0 (no overflow): we can stop */
|
|
goto leave;
|
|
}
|
|
return 1; /* return carry (size of s1 to small) */
|
|
}
|
|
|
|
leave:
|
|
if (res_ptr != s1_ptr) { /* not the same variable */
|
|
mpi_size_t i; /* copy the rest */
|
|
for (i = 0; i < s1_size - 1; i++)
|
|
res_ptr[i] = s1_ptr[i];
|
|
}
|
|
return 0; /* no carry */
|
|
}
|
|
|
|
G10_MPI_INLINE_DECL mpi_limb_t
|
|
mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
|
|
mpi_ptr_t s2_ptr, mpi_size_t s2_size)
|
|
{
|
|
mpi_limb_t cy = 0;
|
|
|
|
if (s2_size)
|
|
cy = mpihelp_add_n(res_ptr, s1_ptr, s2_ptr, s2_size);
|
|
|
|
if (s1_size - s2_size)
|
|
cy = mpihelp_add_1(res_ptr + s2_size, s1_ptr + s2_size,
|
|
s1_size - s2_size, cy);
|
|
return cy;
|
|
}
|
|
|
|
G10_MPI_INLINE_DECL mpi_limb_t
|
|
mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
|
|
mpi_size_t s1_size, mpi_limb_t s2_limb)
|
|
{
|
|
mpi_limb_t x;
|
|
|
|
x = *s1_ptr++;
|
|
s2_limb = x - s2_limb;
|
|
*res_ptr++ = s2_limb;
|
|
if (s2_limb > x) {
|
|
while (--s1_size) {
|
|
x = *s1_ptr++;
|
|
*res_ptr++ = x - 1;
|
|
if (x)
|
|
goto leave;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
leave:
|
|
if (res_ptr != s1_ptr) {
|
|
mpi_size_t i;
|
|
for (i = 0; i < s1_size - 1; i++)
|
|
res_ptr[i] = s1_ptr[i];
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
G10_MPI_INLINE_DECL mpi_limb_t
|
|
mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
|
|
mpi_ptr_t s2_ptr, mpi_size_t s2_size)
|
|
{
|
|
mpi_limb_t cy = 0;
|
|
|
|
if (s2_size)
|
|
cy = mpihelp_sub_n(res_ptr, s1_ptr, s2_ptr, s2_size);
|
|
|
|
if (s1_size - s2_size)
|
|
cy = mpihelp_sub_1(res_ptr + s2_size, s1_ptr + s2_size,
|
|
s1_size - s2_size, cy);
|
|
return cy;
|
|
}
|
|
|
|
#endif /*G10_MPI_INLINE_H */
|