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mpi-genesis             1 /* mpi-mul.c  -  MPI functions
mpi_second_cut          2  * Modified by No Such Labs. (C) 2015. See README.
mpi-genesis             3  *
mpi_second_cut          4  * This file was originally part of Gnu Privacy Guard (GPG), ver. 1.4.10,
mpi_second_cut          5  * SHA256(gnupg-1.4.10.tar.gz):
mpi_second_cut          6  *        0bfd74660a2f6cedcf7d8256db4a63c996ffebbcdc2cf54397bfb72878c5a85a
mpi_second_cut          7  * (C) 1994-2005 Free Software Foundation, Inc.
mpi-genesis             8  *
mpi_second_cut          9  * This program is free software: you can redistribute it and/or modify
mpi-genesis            10  * it under the terms of the GNU General Public License as published by
mpi_second_cut         11  * the Free Software Foundation, either version 3 of the License, or
mpi-genesis            12  * (at your option) any later version.
mpi-genesis            13  *
mpi_second_cut         14  * This program is distributed in the hope that it will be useful,
mpi-genesis            15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
mpi-genesis            16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
mpi-genesis            17  * GNU General Public License for more details.
mpi-genesis            18  *
mpi-genesis            19  * You should have received a copy of the GNU General Public License
mpi_second_cut         20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
mpi-genesis            21  */
mpi-genesis            22 
mpi-genesis            23 #include <stdio.h>
mpi-genesis            24 #include <stdlib.h>
mpi_second_cut         25 
mpi_second_cut         26 #include "knobs.h"
mpi-genesis            27 #include "mpi-internal.h"
mpi-genesis            28 
mpi-genesis            29 
mpi-genesis            30 void
mpi-genesis            31 mpi_mul_ui( MPI prod, MPI mult, unsigned long small_mult )
mpi-genesis            32 {
mpi-genesis            33     mpi_size_t size, prod_size;
mpi-genesis            34     mpi_ptr_t  prod_ptr;
mpi-genesis            35     mpi_limb_t cy;
mpi-genesis            36     int sign;
mpi-genesis            37 
mpi-genesis            38     size = mult->nlimbs;
mpi-genesis            39     sign = mult->sign;
mpi-genesis            40 
mpi-genesis            41     if( !size || !small_mult ) {
mpi-genesis            42 	prod->nlimbs = 0;
mpi-genesis            43 	prod->sign = 0;
mpi-genesis            44 	return;
mpi-genesis            45     }
mpi-genesis            46 
mpi-genesis            47     prod_size = size + 1;
mpi-genesis            48     if( prod->alloced < prod_size )
mpi-genesis            49 	mpi_resize( prod, prod_size );
mpi-genesis            50     prod_ptr = prod->d;
mpi-genesis            51 
mpi-genesis            52     cy = mpihelp_mul_1( prod_ptr, mult->d, size, (mpi_limb_t)small_mult );
mpi-genesis            53     if( cy )
mpi-genesis            54 	prod_ptr[size++] = cy;
mpi-genesis            55     prod->nlimbs = size;
mpi-genesis            56     prod->sign = sign;
mpi-genesis            57 }
mpi-genesis            58 
mpi-genesis            59 
mpi-genesis            60 void
mpi-genesis            61 mpi_mul_2exp( MPI w, MPI u, unsigned long cnt)
mpi-genesis            62 {
mpi-genesis            63     mpi_size_t usize, wsize, limb_cnt;
mpi-genesis            64     mpi_ptr_t wp;
mpi-genesis            65     mpi_limb_t wlimb;
mpi-genesis            66     int usign, wsign;
mpi-genesis            67 
mpi-genesis            68     usize = u->nlimbs;
mpi-genesis            69     usign = u->sign;
mpi-genesis            70 
mpi-genesis            71     if( !usize ) {
mpi-genesis            72 	w->nlimbs = 0;
mpi-genesis            73 	w->sign = 0;
mpi-genesis            74 	return;
mpi-genesis            75     }
mpi-genesis            76 
mpi-genesis            77     limb_cnt = cnt / BITS_PER_MPI_LIMB;
mpi-genesis            78     wsize = usize + limb_cnt + 1;
mpi-genesis            79     if( w->alloced < wsize )
mpi-genesis            80 	mpi_resize(w, wsize );
mpi-genesis            81     wp = w->d;
mpi-genesis            82     wsize = usize + limb_cnt;
mpi-genesis            83     wsign = usign;
mpi-genesis            84 
mpi-genesis            85     cnt %= BITS_PER_MPI_LIMB;
mpi-genesis            86     if( cnt ) {
mpi-genesis            87 	wlimb = mpihelp_lshift( wp + limb_cnt, u->d, usize, cnt );
mpi-genesis            88 	if( wlimb ) {
mpi-genesis            89 	    wp[wsize] = wlimb;
mpi-genesis            90 	    wsize++;
mpi-genesis            91 	}
mpi-genesis            92     }
mpi-genesis            93     else {
mpi-genesis            94 	MPN_COPY_DECR( wp + limb_cnt, u->d, usize );
mpi-genesis            95     }
mpi-genesis            96 
mpi-genesis            97     /* Zero all whole limbs at low end.  Do it here and not before calling
mpi-genesis            98      * mpn_lshift, not to lose for U == W.  */
mpi-genesis            99     MPN_ZERO( wp, limb_cnt );
mpi-genesis           100 
mpi-genesis           101     w->nlimbs = wsize;
mpi-genesis           102     w->sign = wsign;
mpi-genesis           103 }
mpi-genesis           104 
mpi-genesis           105 
mpi-genesis           106 
mpi-genesis           107 void
mpi-genesis           108 mpi_mul( MPI w, MPI u, MPI v)
mpi-genesis           109 {
mpi-genesis           110     mpi_size_t usize, vsize, wsize;
mpi-genesis           111     mpi_ptr_t up, vp, wp;
mpi-genesis           112     mpi_limb_t cy;
mpi-genesis           113     int usign, vsign, usecure, vsecure, sign_product;
mpi-genesis           114     int assign_wp=0;
mpi-genesis           115     mpi_ptr_t tmp_limb=NULL;
mpi-genesis           116 
mpi-genesis           117 
mpi-genesis           118     if( u->nlimbs < v->nlimbs ) { /* Swap U and V. */
mpi-genesis           119 	usize = v->nlimbs;
mpi-genesis           120 	usign = v->sign;
mpi-genesis           121 	usecure = mpi_is_secure(v);
mpi-genesis           122 	up    = v->d;
mpi-genesis           123 	vsize = u->nlimbs;
mpi-genesis           124 	vsign = u->sign;
mpi-genesis           125 	vsecure = mpi_is_secure(u);
mpi-genesis           126 	vp    = u->d;
mpi-genesis           127     }
mpi-genesis           128     else {
mpi-genesis           129 	usize = u->nlimbs;
mpi-genesis           130 	usign = u->sign;
mpi-genesis           131 	usecure = mpi_is_secure(u);
mpi-genesis           132 	up    = u->d;
mpi-genesis           133 	vsize = v->nlimbs;
mpi-genesis           134 	vsign = v->sign;
mpi-genesis           135 	vsecure = mpi_is_secure(v);
mpi-genesis           136 	vp    = v->d;
mpi-genesis           137     }
mpi-genesis           138     sign_product = usign ^ vsign;
mpi-genesis           139     wp = w->d;
mpi-genesis           140 
mpi-genesis           141     /* Ensure W has space enough to store the result.  */
mpi-genesis           142     wsize = usize + vsize;
mpi-genesis           143     if ( !mpi_is_secure (w) && (mpi_is_secure (u) || mpi_is_secure (v)) ) {
mpi-genesis           144         /* w is not allocated in secure space but u or v is.  To make sure
mpi-genesis           145          * that no temporray results are stored in w, we temporary use 
mpi-genesis           146          * a newly allocated limb space for w */
mpi-genesis           147         wp = mpi_alloc_limb_space( wsize, 1 );
mpi-genesis           148         assign_wp = 2; /* mark it as 2 so that we can later copy it back to
mpi-genesis           149                         * mormal memory */
mpi-genesis           150     }
mpi-genesis           151     else if( w->alloced < wsize ) {
mpi-genesis           152 	if( wp == up || wp == vp ) {
mpi-genesis           153 	    wp = mpi_alloc_limb_space( wsize, mpi_is_secure(w) );
mpi-genesis           154 	    assign_wp = 1;
mpi-genesis           155 	}
mpi-genesis           156 	else {
mpi-genesis           157 	    mpi_resize(w, wsize );
mpi-genesis           158 	    wp = w->d;
mpi-genesis           159 	}
mpi-genesis           160     }
mpi-genesis           161     else { /* Make U and V not overlap with W.	*/
mpi-genesis           162 	if( wp == up ) {
mpi-genesis           163 	    /* W and U are identical.  Allocate temporary space for U.	*/
mpi-genesis           164 	    up = tmp_limb = mpi_alloc_limb_space( usize, usecure  );
mpi-genesis           165 	    /* Is V identical too?  Keep it identical with U.  */
mpi-genesis           166 	    if( wp == vp )
mpi-genesis           167 		vp = up;
mpi-genesis           168 	    /* Copy to the temporary space.  */
mpi-genesis           169 	    MPN_COPY( up, wp, usize );
mpi-genesis           170 	}
mpi-genesis           171 	else if( wp == vp ) {
mpi-genesis           172 	    /* W and V are identical.  Allocate temporary space for V.	*/
mpi-genesis           173 	    vp = tmp_limb = mpi_alloc_limb_space( vsize, vsecure );
mpi-genesis           174 	    /* Copy to the temporary space.  */
mpi-genesis           175 	    MPN_COPY( vp, wp, vsize );
mpi-genesis           176 	}
mpi-genesis           177     }
mpi-genesis           178 
mpi-genesis           179     if( !vsize )
mpi-genesis           180 	wsize = 0;
mpi-genesis           181     else {
mpi-genesis           182 	cy = mpihelp_mul( wp, up, usize, vp, vsize );
mpi-genesis           183 	wsize -= cy? 0:1;
mpi-genesis           184     }
mpi-genesis           185 
mpi-genesis           186     if( assign_wp ) {
mpi-genesis           187         if (assign_wp == 2) {
mpi-genesis           188             /* copy the temp wp from secure memory back to normal memory */
mpi-genesis           189 	    mpi_ptr_t tmp_wp = mpi_alloc_limb_space (wsize, 0);
mpi-genesis           190 	    MPN_COPY (tmp_wp, wp, wsize);
mpi-genesis           191             mpi_free_limb_space (wp);
mpi-genesis           192             wp = tmp_wp;
mpi-genesis           193         }
mpi-genesis           194 	mpi_assign_limb_space( w, wp, wsize );
mpi-genesis           195     }
mpi-genesis           196     w->nlimbs = wsize;
mpi-genesis           197     w->sign = sign_product;
mpi-genesis           198     if( tmp_limb )
mpi-genesis           199 	mpi_free_limb_space( tmp_limb );
mpi-genesis           200 }
mpi-genesis           201 
mpi-genesis           202 
mpi-genesis           203 void
mpi-genesis           204 mpi_mulm( MPI w, MPI u, MPI v, MPI m)
mpi-genesis           205 {
mpi-genesis           206     mpi_mul(w, u, v);
mpi-genesis           207     mpi_fdiv_r( w, w, m );
mpi-genesis           208 }
mpi-genesis           209