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