[svn] gcry - r1363 - in trunk: cipher mpi
svn author wk
cvs at cvs.gnupg.org
Tue Dec 2 12:38:43 CET 2008
Author: wk
Date: 2008-12-02 12:38:43 +0100 (Tue, 02 Dec 2008)
New Revision: 1363
Modified:
trunk/cipher/dsa.c
trunk/mpi/ChangeLog
trunk/mpi/mpi-pow.c
Log:
Re-indented some code.
Modified: trunk/mpi/ChangeLog
===================================================================
--- trunk/mpi/ChangeLog 2008-11-28 19:10:15 UTC (rev 1362)
+++ trunk/mpi/ChangeLog 2008-12-02 11:38:43 UTC (rev 1363)
@@ -1,3 +1,7 @@
+2008-12-02 Werner Koch <wk at g10code.com>
+
+ * mpi-pow.c (gcry_mpi_powm): Re-indent.
+
2008-08-20 Werner Koch <wk at g10code.com>
* mpi-bit.c (gcry_mpi_lshift): Actually implement.
Modified: trunk/cipher/dsa.c
===================================================================
--- trunk/cipher/dsa.c 2008-11-28 19:10:15 UTC (rev 1362)
+++ trunk/cipher/dsa.c 2008-12-02 11:38:43 UTC (rev 1363)
@@ -15,8 +15,7 @@
* 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ * License along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
Modified: trunk/mpi/mpi-pow.c
===================================================================
--- trunk/mpi/mpi-pow.c 2008-11-28 19:10:15 UTC (rev 1362)
+++ trunk/mpi/mpi-pow.c 2008-12-02 11:38:43 UTC (rev 1363)
@@ -1,5 +1,6 @@
-/* mpi-pow.c - MPI functions
- * Copyright (C) 1994, 1996, 1998, 2000, 2002, 2003 Free Software Foundation, Inc.
+/* 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.
*
@@ -14,8 +15,7 @@
* 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ * 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
@@ -37,265 +37,298 @@
* 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)
+gcry_mpi_powm (gcry_mpi_t res,
+ gcry_mpi_t base, gcry_mpi_t expo, gcry_mpi_t mod)
{
- mpi_ptr_t rp, ep, mp, bp;
- mpi_size_t esize, msize, bsize, rsize;
- int msign, bsign, rsign;
- int esec, msec, bsec, rsec;
- mpi_size_t size;
- int mod_shift_cnt;
- int negative_result;
- mpi_ptr_t mp_marker=NULL, bp_marker=NULL, ep_marker=NULL;
- mpi_ptr_t xp_marker=NULL;
- unsigned int mp_nlimbs = 0, bp_nlimbs = 0, ep_nlimbs = 0;
- unsigned int xp_nlimbs = 0;
- int assign_rp = 0;
- mpi_ptr_t tspace = NULL;
- mpi_size_t tsize=0; /* to avoid compiler warning */
- /* fixme: we should check that the warning is void*/
+ mpi_ptr_t rp, ep, mp, bp;
+ mpi_size_t esize, msize, bsize, rsize;
+ int msign, bsign, rsign;
+ int esec, msec, bsec, rsec;
+ mpi_size_t size;
+ 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;
+ int assign_rp = 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);
+ 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;
+ rp = res->d;
+ ep = expo->d;
- if( !msize )
- msize = 1 / msize; /* provoke a signal */
+ 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;
+ 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 );
+ /* 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 );
+ 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;
+ else
+ bp = base->d;
- if( !bsize ) {
- res->nlimbs = 0;
- res->sign = 0;
- goto leave;
+ 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 ) {
+ 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, rsec );
assign_rp = 1;
- }
- else {
+ }
+ else
+ {
mpi_resize( res, size );
rp = res->d;
- }
+ }
}
- else { /* 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);
+ else
+ {
+ /* 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 == 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);
+ 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);
}
}
+
+ 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_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;
- MPN_COPY( rp, bp, bsize );
- rsize = bsize;
- rsign = bsign;
+ /* 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);
+ }
- {
- mpi_size_t i;
- mpi_ptr_t xp;
- int c;
- mpi_limb_t e;
- mpi_limb_t carry_limb;
- struct karatsuba_ctx karactx;
+ xsize = 2 * rsize;
+ if ( xsize > msize )
+ {
+ _gcry_mpih_divrem(xp + msize, 0, xp, xsize, mp, msize);
+ xsize = msize;
+ }
- xp_nlimbs = msec? (2 * (msize + 1)):0;
- xp = xp_marker = mpi_alloc_limb_space( 2 * (msize + 1), msec );
+ tp = rp; rp = xp; xp = tp;
+ rsize = xsize;
- memset( &karactx, 0, sizeof karactx );
- negative_result = (ep[0] & 1) && base->sign;
+ 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 = 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;
+ i--;
+ if ( i < 0 )
+ break;
+ e = ep[i];
+ c = BITS_PER_MPI_LIMB;
+ }
- /* 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.
- */
+ /* We shifted MOD, the modulo reduction argument, left
+ MOD_SHIFT_CNT steps. Adjust the result by reducing it with the
+ original MOD.
- for(;;) {
- while( c ) {
- mpi_ptr_t tp;
- mpi_size_t xsize;
+ 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
+ {
+ MPN_COPY( res->d, rp, rsize);
+ rp = res->d;
+ }
- /*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 );
- }
+ if ( rsize >= msize )
+ {
+ _gcry_mpih_divrem(rp + msize, 0, rp, rsize, mp, msize);
+ rsize = msize;
+ }
- xsize = 2 * rsize;
- if( xsize > msize ) {
- _gcry_mpih_divrem(xp + msize, 0, xp, xsize, mp, msize);
- xsize = 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 );
+ }
- 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 {
- 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 );
+ 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);
}
-
- 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);
- }
- res->nlimbs = rsize;
- res->sign = rsign;
-
- leave:
- if( assign_rp ) _gcry_mpi_assign_limb_space( res, rp, size );
- 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 );
+ res->nlimbs = rsize;
+ res->sign = rsign;
+
+ leave:
+ if (assign_rp)
+ _gcry_mpi_assign_limb_space( res, rp, size );
+ 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 );
}
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