mirror of
https://github.com/Fishwaldo/Star64_linux.git
synced 2025-06-21 14:11:20 +00:00
crypto: GnuPG based MPI lib - source files (part 1)
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>
This commit is contained in:
Dmitry Kasatkin
parent
1ea6b8f489
commit
cdec9cb516
14 changed files with 2681 additions and 0 deletions
323
lib/mpi/mpi-pow.c
Normal file
323
lib/mpi/mpi-pow.c
Normal file
|
|
@ -0,0 +1,323 @@
|
|||
/* mpi-pow.c - MPI functions
|
||||
* Copyright (C) 1994, 1996, 1998, 2000 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 <linux/string.h>
|
||||
#include "mpi-internal.h"
|
||||
#include "longlong.h"
|
||||
|
||||
/****************
|
||||
* RES = BASE ^ EXP mod MOD
|
||||
*/
|
||||
int mpi_powm(MPI res, MPI base, MPI exp, MPI mod)
|
||||
{
|
||||
mpi_ptr_t mp_marker = NULL, bp_marker = NULL, ep_marker = NULL;
|
||||
mpi_ptr_t xp_marker = NULL;
|
||||
mpi_ptr_t tspace = NULL;
|
||||
mpi_ptr_t rp, ep, mp, bp;
|
||||
mpi_size_t esize, msize, bsize, rsize;
|
||||
int esign, msign, bsign, rsign;
|
||||
mpi_size_t size;
|
||||
int mod_shift_cnt;
|
||||
int negative_result;
|
||||
int assign_rp = 0;
|
||||
mpi_size_t tsize = 0; /* to avoid compiler warning */
|
||||
/* fixme: we should check that the warning is void */
|
||||
int rc = -ENOMEM;
|
||||
|
||||
esize = exp->nlimbs;
|
||||
msize = mod->nlimbs;
|
||||
size = 2 * msize;
|
||||
esign = exp->sign;
|
||||
msign = mod->sign;
|
||||
|
||||
rp = res->d;
|
||||
ep = exp->d;
|
||||
|
||||
if (!msize)
|
||||
msize = 1 / msize; /* provoke a signal */
|
||||
|
||||
if (!esize) {
|
||||
/* Exponent is zero, result is 1 mod MOD, i.e., 1 or 0
|
||||
* depending on if MOD equals 1. */
|
||||
rp[0] = 1;
|
||||
res->nlimbs = (msize == 1 && mod->d[0] == 1) ? 0 : 1;
|
||||
res->sign = 0;
|
||||
goto leave;
|
||||
}
|
||||
|
||||
/* Normalize MOD (i.e. make its most significant bit set) as required by
|
||||
* mpn_divrem. This will make the intermediate values in the calculation
|
||||
* slightly larger, but the correct result is obtained after a final
|
||||
* reduction using the original MOD value. */
|
||||
mp = mp_marker = mpi_alloc_limb_space(msize);
|
||||
if (!mp)
|
||||
goto enomem;
|
||||
count_leading_zeros(mod_shift_cnt, mod->d[msize - 1]);
|
||||
if (mod_shift_cnt)
|
||||
mpihelp_lshift(mp, mod->d, msize, mod_shift_cnt);
|
||||
else
|
||||
MPN_COPY(mp, mod->d, msize);
|
||||
|
||||
bsize = base->nlimbs;
|
||||
bsign = base->sign;
|
||||
if (bsize > msize) { /* The base is larger than the module. Reduce it. */
|
||||
/* Allocate (BSIZE + 1) with space for remainder and quotient.
|
||||
* (The quotient is (bsize - msize + 1) limbs.) */
|
||||
bp = bp_marker = mpi_alloc_limb_space(bsize + 1);
|
||||
if (!bp)
|
||||
goto enomem;
|
||||
MPN_COPY(bp, base->d, bsize);
|
||||
/* We don't care about the quotient, store it above the remainder,
|
||||
* at BP + MSIZE. */
|
||||
mpihelp_divrem(bp + msize, 0, bp, bsize, mp, msize);
|
||||
bsize = msize;
|
||||
/* Canonicalize the base, since we are going to multiply with it
|
||||
* quite a few times. */
|
||||
MPN_NORMALIZE(bp, bsize);
|
||||
} else
|
||||
bp = base->d;
|
||||
|
||||
if (!bsize) {
|
||||
res->nlimbs = 0;
|
||||
res->sign = 0;
|
||||
goto leave;
|
||||
}
|
||||
|
||||
if (res->alloced < size) {
|
||||
/* We have to allocate more space for RES. If any of the input
|
||||
* parameters are identical to RES, defer deallocation of the old
|
||||
* space. */
|
||||
if (rp == ep || rp == mp || rp == bp) {
|
||||
rp = mpi_alloc_limb_space(size);
|
||||
if (!rp)
|
||||
goto enomem;
|
||||
assign_rp = 1;
|
||||
} else {
|
||||
if (mpi_resize(res, size) < 0)
|
||||
goto enomem;
|
||||
rp = res->d;
|
||||
}
|
||||
} else { /* Make BASE, EXP and MOD not overlap with RES. */
|
||||
if (rp == bp) {
|
||||
/* RES and BASE are identical. Allocate temp. space for BASE. */
|
||||
BUG_ON(bp_marker);
|
||||
bp = bp_marker = mpi_alloc_limb_space(bsize);
|
||||
if (!bp)
|
||||
goto enomem;
|
||||
MPN_COPY(bp, rp, bsize);
|
||||
}
|
||||
if (rp == ep) {
|
||||
/* RES and EXP are identical. Allocate temp. space for EXP. */
|
||||
ep = ep_marker = mpi_alloc_limb_space(esize);
|
||||
if (!ep)
|
||||
goto enomem;
|
||||
MPN_COPY(ep, rp, esize);
|
||||
}
|
||||
if (rp == mp) {
|
||||
/* RES and MOD are identical. Allocate temporary space for MOD. */
|
||||
BUG_ON(mp_marker);
|
||||
mp = mp_marker = mpi_alloc_limb_space(msize);
|
||||
if (!mp)
|
||||
goto enomem;
|
||||
MPN_COPY(mp, rp, msize);
|
||||
}
|
||||
}
|
||||
|
||||
MPN_COPY(rp, bp, bsize);
|
||||
rsize = bsize;
|
||||
rsign = bsign;
|
||||
|
||||
{
|
||||
mpi_size_t i;
|
||||
mpi_ptr_t xp;
|
||||
int c;
|
||||
mpi_limb_t e;
|
||||
mpi_limb_t carry_limb;
|
||||
struct karatsuba_ctx karactx;
|
||||
|
||||
xp = xp_marker = mpi_alloc_limb_space(2 * (msize + 1));
|
||||
if (!xp)
|
||||
goto enomem;
|
||||
|
||||
memset(&karactx, 0, sizeof karactx);
|
||||
negative_result = (ep[0] & 1) && base->sign;
|
||||
|
||||
i = esize - 1;
|
||||
e = ep[i];
|
||||
count_leading_zeros(c, e);
|
||||
e = (e << c) << 1; /* shift the exp bits to the left, lose msb */
|
||||
c = BITS_PER_MPI_LIMB - 1 - c;
|
||||
|
||||
/* Main loop.
|
||||
*
|
||||
* Make the result be pointed to alternately by XP and RP. This
|
||||
* helps us avoid block copying, which would otherwise be necessary
|
||||
* with the overlap restrictions of mpihelp_divmod. With 50% probability
|
||||
* the result after this loop will be in the area originally pointed
|
||||
* by RP (==RES->d), and with 50% probability in the area originally
|
||||
* pointed to by XP.
|
||||
*/
|
||||
|
||||
for (;;) {
|
||||
while (c) {
|
||||
mpi_ptr_t tp;
|
||||
mpi_size_t xsize;
|
||||
|
||||
/*if (mpihelp_mul_n(xp, rp, rp, rsize) < 0) goto enomem */
|
||||
if (rsize < KARATSUBA_THRESHOLD)
|
||||
mpih_sqr_n_basecase(xp, rp, rsize);
|
||||
else {
|
||||
if (!tspace) {
|
||||
tsize = 2 * rsize;
|
||||
tspace =
|
||||
mpi_alloc_limb_space(tsize);
|
||||
if (!tspace)
|
||||
goto enomem;
|
||||
} else if (tsize < (2 * rsize)) {
|
||||
mpi_free_limb_space(tspace);
|
||||
tsize = 2 * rsize;
|
||||
tspace =
|
||||
mpi_alloc_limb_space(tsize);
|
||||
if (!tspace)
|
||||
goto enomem;
|
||||
}
|
||||
mpih_sqr_n(xp, rp, rsize, tspace);
|
||||
}
|
||||
|
||||
xsize = 2 * rsize;
|
||||
if (xsize > msize) {
|
||||
mpihelp_divrem(xp + msize, 0, xp, xsize,
|
||||
mp, msize);
|
||||
xsize = msize;
|
||||
}
|
||||
|
||||
tp = rp;
|
||||
rp = xp;
|
||||
xp = tp;
|
||||
rsize = xsize;
|
||||
|
||||
if ((mpi_limb_signed_t) e < 0) {
|
||||
/*mpihelp_mul( xp, rp, rsize, bp, bsize ); */
|
||||
if (bsize < KARATSUBA_THRESHOLD) {
|
||||
mpi_limb_t tmp;
|
||||
if (mpihelp_mul
|
||||
(xp, rp, rsize, bp, bsize,
|
||||
&tmp) < 0)
|
||||
goto enomem;
|
||||
} else {
|
||||
if (mpihelp_mul_karatsuba_case
|
||||
(xp, rp, rsize, bp, bsize,
|
||||
&karactx) < 0)
|
||||
goto enomem;
|
||||
}
|
||||
|
||||
xsize = rsize + bsize;
|
||||
if (xsize > msize) {
|
||||
mpihelp_divrem(xp + msize, 0,
|
||||
xp, xsize, mp,
|
||||
msize);
|
||||
xsize = msize;
|
||||
}
|
||||
|
||||
tp = rp;
|
||||
rp = xp;
|
||||
xp = tp;
|
||||
rsize = xsize;
|
||||
}
|
||||
e <<= 1;
|
||||
c--;
|
||||
}
|
||||
|
||||
i--;
|
||||
if (i < 0)
|
||||
break;
|
||||
e = ep[i];
|
||||
c = BITS_PER_MPI_LIMB;
|
||||
}
|
||||
|
||||
/* We shifted MOD, the modulo reduction argument, left MOD_SHIFT_CNT
|
||||
* steps. Adjust the result by reducing it with the original MOD.
|
||||
*
|
||||
* Also make sure the result is put in RES->d (where it already
|
||||
* might be, see above).
|
||||
*/
|
||||
if (mod_shift_cnt) {
|
||||
carry_limb =
|
||||
mpihelp_lshift(res->d, rp, rsize, mod_shift_cnt);
|
||||
rp = res->d;
|
||||
if (carry_limb) {
|
||||
rp[rsize] = carry_limb;
|
||||
rsize++;
|
||||
}
|
||||
} else {
|
||||
MPN_COPY(res->d, rp, rsize);
|
||||
rp = res->d;
|
||||
}
|
||||
|
||||
if (rsize >= msize) {
|
||||
mpihelp_divrem(rp + msize, 0, rp, rsize, mp, msize);
|
||||
rsize = msize;
|
||||
}
|
||||
|
||||
/* Remove any leading zero words from the result. */
|
||||
if (mod_shift_cnt)
|
||||
mpihelp_rshift(rp, rp, rsize, mod_shift_cnt);
|
||||
MPN_NORMALIZE(rp, rsize);
|
||||
|
||||
mpihelp_release_karatsuba_ctx(&karactx);
|
||||
}
|
||||
|
||||
if (negative_result && rsize) {
|
||||
if (mod_shift_cnt)
|
||||
mpihelp_rshift(mp, mp, msize, mod_shift_cnt);
|
||||
mpihelp_sub(rp, mp, msize, rp, rsize);
|
||||
rsize = msize;
|
||||
rsign = msign;
|
||||
MPN_NORMALIZE(rp, rsize);
|
||||
}
|
||||
res->nlimbs = rsize;
|
||||
res->sign = rsign;
|
||||
|
||||
leave:
|
||||
rc = 0;
|
||||
enomem:
|
||||
if (assign_rp)
|
||||
mpi_assign_limb_space(res, rp, size);
|
||||
if (mp_marker)
|
||||
mpi_free_limb_space(mp_marker);
|
||||
if (bp_marker)
|
||||
mpi_free_limb_space(bp_marker);
|
||||
if (ep_marker)
|
||||
mpi_free_limb_space(ep_marker);
|
||||
if (xp_marker)
|
||||
mpi_free_limb_space(xp_marker);
|
||||
if (tspace)
|
||||
mpi_free_limb_space(tspace);
|
||||
return rc;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(mpi_powm);
|
||||
Loading…
Add table
Add a link
Reference in a new issue