summaryrefslogtreecommitdiff
path: root/plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-pow.c
diff options
context:
space:
mode:
Diffstat (limited to 'plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-pow.c')
-rw-r--r--plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-pow.c326
1 files changed, 0 insertions, 326 deletions
diff --git a/plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-pow.c b/plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-pow.c
deleted file mode 100644
index ca7ead0285..0000000000
--- a/plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-pow.c
+++ /dev/null
@@ -1,326 +0,0 @@
-/* mpi-pow.c - MPI functions for exponentiation
- * Copyright (C) 1994, 1996, 1998, 2000, 2002
- * 2003 Free Software Foundation, Inc.
- *
- * This file is part of Libgcrypt.
- *
- * Libgcrypt is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as
- * published by the Free Software Foundation; either version 2.1 of
- * the License, or (at your option) any later version.
- *
- * Libgcrypt 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 Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this program; if not, see <http://www.gnu.org/licenses/>.
- *
- * 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.
- */
-
-#include <config.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "mpi-internal.h"
-#include "longlong.h"
-
-
-/****************
- * RES = BASE ^ EXPO mod MOD
- */
-void
-gcry_mpi_powm (gcry_mpi_t res,
- gcry_mpi_t base, gcry_mpi_t expo, gcry_mpi_t mod)
-{
- /* Pointer to the limbs of the arguments, their size and signs. */
- mpi_ptr_t rp, ep, mp, bp;
- mpi_size_t esize, msize, bsize, rsize;
- int msign, bsign, rsign;
- /* Flags telling the secure allocation status of the arguments. */
- int esec, msec, bsec, rsec;
- /* Size of the result including space for temporary values. */
- mpi_size_t size;
- /* Helper. */
- int mod_shift_cnt;
- int negative_result;
- mpi_ptr_t mp_marker = NULL;
- mpi_ptr_t bp_marker = NULL;
- mpi_ptr_t ep_marker = NULL;
- mpi_ptr_t xp_marker = NULL;
- unsigned int mp_nlimbs = 0;
- unsigned int bp_nlimbs = 0;
- unsigned int ep_nlimbs = 0;
- unsigned int xp_nlimbs = 0;
- mpi_ptr_t tspace = NULL;
- mpi_size_t tsize = 0;
-
-
- esize = expo->nlimbs;
- msize = mod->nlimbs;
- size = 2 * msize;
- msign = mod->sign;
-
- esec = mpi_is_secure(expo);
- msec = mpi_is_secure(mod);
- bsec = mpi_is_secure(base);
- rsec = mpi_is_secure(res);
-
- rp = res->d;
- ep = expo->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_nlimbs = msec? msize:0;
- mp = mp_marker = mpi_alloc_limb_space(msize, msec);
- count_leading_zeros (mod_shift_cnt, mod->d[msize-1]);
- if (mod_shift_cnt)
- _gcry_mpih_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_nlimbs = bsec ? (bsize + 1):0;
- bp = bp_marker = mpi_alloc_limb_space( bsize + 1, bsec );
- MPN_COPY ( bp, base->d, bsize );
- /* We don't care about the quotient, store it above the
- * remainder, at BP + MSIZE. */
- _gcry_mpih_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;
- }
-
-
- /* Make BASE, EXPO and MOD not overlap with RES. */
- if ( rp == bp )
- {
- /* RES and BASE are identical. Allocate temp. space for BASE. */
- gcry_assert (!bp_marker);
- bp_nlimbs = bsec? bsize:0;
- bp = bp_marker = mpi_alloc_limb_space( bsize, bsec );
- MPN_COPY(bp, rp, bsize);
- }
- if ( rp == ep )
- {
- /* RES and EXPO are identical. Allocate temp. space for EXPO. */
- ep_nlimbs = esec? esize:0;
- ep = ep_marker = mpi_alloc_limb_space( esize, esec );
- MPN_COPY(ep, rp, esize);
- }
- if ( rp == mp )
- {
- /* RES and MOD are identical. Allocate temporary space for MOD.*/
- gcry_assert (!mp_marker);
- mp_nlimbs = msec?msize:0;
- mp = mp_marker = mpi_alloc_limb_space( msize, msec );
- MPN_COPY(mp, rp, msize);
- }
-
- /* Copy base to the result. */
- if (res->alloced < size)
- {
- mpi_resize (res, size);
- rp = res->d;
- }
- MPN_COPY ( rp, bp, bsize );
- rsize = bsize;
- rsign = bsign;
-
- /* Main processing. */
- {
- mpi_size_t i;
- mpi_ptr_t xp;
- int c;
- mpi_limb_t e;
- mpi_limb_t carry_limb;
- struct karatsuba_ctx karactx;
-
- xp_nlimbs = msec? (2 * (msize + 1)):0;
- xp = xp_marker = mpi_alloc_limb_space( 2 * (msize + 1), msec );
-
- 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 expo 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
- _gcry_mpih_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;
-
- /*mpih_mul_n(xp, rp, rp, rsize);*/
- if ( rsize < KARATSUBA_THRESHOLD )
- _gcry_mpih_sqr_n_basecase( xp, rp, rsize );
- else
- {
- if ( !tspace )
- {
- tsize = 2 * rsize;
- tspace = mpi_alloc_limb_space( tsize, 0 );
- }
- else if ( tsize < (2*rsize) )
- {
- _gcry_mpi_free_limb_space (tspace, 0);
- tsize = 2 * rsize;
- tspace = mpi_alloc_limb_space (tsize, 0 );
- }
- _gcry_mpih_sqr_n (xp, rp, rsize, tspace);
- }
-
- xsize = 2 * rsize;
- if ( xsize > msize )
- {
- _gcry_mpih_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 )
- {
- /*mpih_mul( xp, rp, rsize, bp, bsize );*/
- if( bsize < KARATSUBA_THRESHOLD )
- _gcry_mpih_mul ( xp, rp, rsize, bp, bsize );
- else
- _gcry_mpih_mul_karatsuba_case (xp, rp, rsize, bp, bsize,
- &karactx);
-
- xsize = rsize + bsize;
- if ( xsize > msize )
- {
- _gcry_mpih_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 = _gcry_mpih_lshift( res->d, rp, rsize, mod_shift_cnt);
- rp = res->d;
- if ( carry_limb )
- {
- rp[rsize] = carry_limb;
- rsize++;
- }
- }
- else if (res->d != rp)
- {
- MPN_COPY (res->d, rp, rsize);
- rp = res->d;
- }
-
- if ( rsize >= msize )
- {
- _gcry_mpih_divrem(rp + msize, 0, rp, rsize, mp, msize);
- rsize = msize;
- }
-
- /* Remove any leading zero words from the result. */
- if ( mod_shift_cnt )
- _gcry_mpih_rshift( rp, rp, rsize, mod_shift_cnt);
- MPN_NORMALIZE (rp, rsize);
-
- _gcry_mpih_release_karatsuba_ctx (&karactx );
- }
-
- /* Fixup for negative results. */
- if ( negative_result && rsize )
- {
- if ( mod_shift_cnt )
- _gcry_mpih_rshift( mp, mp, msize, mod_shift_cnt);
- _gcry_mpih_sub( rp, mp, msize, rp, rsize);
- rsize = msize;
- rsign = msign;
- MPN_NORMALIZE(rp, rsize);
- }
- gcry_assert (res->d == rp);
- res->nlimbs = rsize;
- res->sign = rsign;
-
- leave:
- if (mp_marker)
- _gcry_mpi_free_limb_space( mp_marker, mp_nlimbs );
- if (bp_marker)
- _gcry_mpi_free_limb_space( bp_marker, bp_nlimbs );
- if (ep_marker)
- _gcry_mpi_free_limb_space( ep_marker, ep_nlimbs );
- if (xp_marker)
- _gcry_mpi_free_limb_space( xp_marker, xp_nlimbs );
- if (tspace)
- _gcry_mpi_free_limb_space( tspace, 0 );
-}
-
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-10 12:56:35 +0000