crypto/bn/old/bn_mul.c.works

   1 /* crypto/bn/bn_mul.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include "cryptlib.h"
  61 #include "bn_lcl.h"
  62
  63 int bn_mm(BIGNUM *m,BIGNUM *A,BIGNUM *B, BIGNUM *sk,BN_CTX *ctx);
  64
  65 /* r must be different to a and b */
  66 int BN_mul(r, a, b)
  67 BIGNUM *r;
  68 BIGNUM *a;
  69 BIGNUM *b;
  70         {
  71         BN_ULONG *ap,*bp,*rp;
  72         BIGNUM *sk;
  73         int i,n,ret;
  74         int max,al,bl;
  75         BN_CTX ctx;
  76
  77         bn_check_top(a);
  78         bn_check_top(b);
  79
  80         al=a->top;
  81         bl=b->top;
  82         if ((al == 0) || (bl == 0))
  83                 {
  84                 r->top=0;
  85                 return(1);
  86                 }
  87 #ifdef BN_MUL_DEBUG
  88 printf("BN_mul(%d,%d)\n",a->top,b->top);
  89 #endif
  90
  91 #ifdef BN_RECURSION
  92         if (    (bn_limit_bits > 0) &&
  93                 (bl > bn_limit_num) && (al > bn_limit_num))
  94                 {
  95                 n=(BN_num_bits_word(al|bl)-bn_limit_bits);
  96                 n*=2;
  97                 sk=(BIGNUM *)Malloc(sizeof(BIGNUM)*n);
  98                 memset(sk,0,sizeof(BIGNUM)*n);
  99                 memset(&ctx,0,sizeof(ctx));
 100
 101                 ret=bn_mm(r,a,b,&(sk[0]),&ctx);
 102                 for (i=0; i<n; i+=2)
 103                         {
 104                         BN_clear_free(&sk[i]);
 105                         BN_clear_free(&sk[i+1]);
 106                         }
 107                 Free(sk);
 108                 return(ret);
 109                 }
 110 #endif
 111
 112         max=(al+bl);
 113         if (bn_wexpand(r,max) == NULL) return(0);
 114         r->top=max;
 115         r->neg=a->neg^b->neg;
 116         ap=a->d;
 117         bp=b->d;
 118         rp=r->d;
 119
 120 #ifdef BN_RECURSION
 121         if ((al == bl) && (al == 8))
 122                 {
 123                 bn_mul_comba8(rp,ap,bp);
 124                 }
 125         else
 126 #endif
 127                 {
 128                 rp[al]=bn_mul_words(rp,ap,al,*(bp++));
 129                 rp++;
 130                 for (i=1; i<bl; i++)
 131                         {
 132                         rp[al]=bn_mul_add_words(rp,ap,al,*(bp++));
 133                         rp++;
 134                         }
 135                 }
 136         if ((max > 0) && (r->d[max-1] == 0)) r->top--;
 137         return(1);
 138         }
 139
 140 #ifdef BN_RECURSION
 141
 142 #define ahal    (sk[0])
 143 #define blbh    (sk[1])
 144
 145 /* r must be different to a and b */
 146 int bn_mm(m, A, B, sk,ctx)
 147 BIGNUM *m,*A,*B;
 148 BIGNUM *sk;
 149 BN_CTX *ctx;
 150         {
 151         int n,num,sqr=0;
 152         int an,bn;
 153         BIGNUM ah,al,bh,bl;
 154
 155         an=A->top;
 156         bn=B->top;
 157 #ifdef BN_MUL_DEBUG
 158 printf("bn_mm(%d,%d)\n",A->top,B->top);
 159 #endif
 160
 161         if (A == B) sqr=1;
 162         num=(an>bn)?an:bn;
 163         n=(num+1)/2;
 164         /* Are going to now chop things into 'num' word chunks. */
 165
 166         BN_init(&ah);
 167         BN_init(&al);
 168         BN_init(&bh);
 169         BN_init(&bl);
 170
 171         bn_set_low (&al,A,n);
 172         bn_set_high(&ah,A,n);
 173         bn_set_low (&bl,B,n);
 174         bn_set_high(&bh,B,n);
 175
 176         BN_sub(&ahal,&ah,&al);
 177         BN_sub(&blbh,&bl,&bh);
 178
 179         if (num <= (bn_limit_num+bn_limit_num))
 180                 {
 181                 BN_mul(m,&ahal,&blbh);
 182                 if (sqr)
 183                         {
 184                         BN_sqr(&ahal,&al,ctx);
 185                         BN_sqr(&blbh,&ah,ctx);
 186                         }
 187                 else
 188                         {
 189                         BN_mul(&ahal,&al,&bl);
 190                         BN_mul(&blbh,&ah,&bh);
 191                         }
 192                 }
 193         else
 194                 {
 195                 bn_mm(m,&ahal,&blbh,&(sk[2]),ctx);
 196                 bn_mm(&ahal,&al,&bl,&(sk[2]),ctx);
 197                 bn_mm(&blbh,&ah,&bh,&(sk[2]),ctx);
 198                 }
 199
 200         BN_add(m,m,&ahal);
 201         BN_add(m,m,&blbh);
 202
 203         BN_lshift(m,m,n*BN_BITS2);
 204         BN_lshift(&blbh,&blbh,n*BN_BITS2*2);
 205
 206         BN_add(m,m,&ahal);
 207         BN_add(m,m,&blbh);
 208
 209         m->neg=A->neg^B->neg;
 210         return(1);
 211         }
 212 #undef ahal     (sk[0])
 213 #undef blbh     (sk[1])
 214
 215 #include "bn_low.c"
 216 #include "bn_high.c"
 217 #include "f.c"
 218
 219 #endif