crypto/bn/bn_mulw.c

   1 /* crypto/bn/bn_mulw.c */
   2 /* Copyright (C) 1995-1997 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 #ifdef BN_LLONG
  64
  65 BN_ULONG bn_mul_add_word(rp,ap,num,w)
  66 BN_ULONG *rp,*ap;
  67 int num;
  68 BN_ULONG w;
  69         {
  70         BN_ULONG c1=0;
  71
  72         for (;;)
  73                 {
  74                 mul_add(rp[0],ap[0],w,c1);
  75                 if (--num == 0) break;
  76                 mul_add(rp[1],ap[1],w,c1);
  77                 if (--num == 0) break;
  78                 mul_add(rp[2],ap[2],w,c1);
  79                 if (--num == 0) break;
  80                 mul_add(rp[3],ap[3],w,c1);
  81                 if (--num == 0) break;
  82                 ap+=4;
  83                 rp+=4;
  84                 }
  85
  86         return(c1);
  87         }
  88
  89 BN_ULONG bn_mul_word(rp,ap,num,w)
  90 BN_ULONG *rp,*ap;
  91 int num;
  92 BN_ULONG w;
  93         {
  94         BN_ULONG c1=0;
  95
  96         for (;;)
  97                 {
  98                 mul(rp[0],ap[0],w,c1);
  99                 if (--num == 0) break;
 100                 mul(rp[1],ap[1],w,c1);
 101                 if (--num == 0) break;
 102                 mul(rp[2],ap[2],w,c1);
 103                 if (--num == 0) break;
 104                 mul(rp[3],ap[3],w,c1);
 105                 if (--num == 0) break;
 106                 ap+=4;
 107                 rp+=4;
 108                 }
 109         return(c1);
 110         }
 111
 112 void bn_sqr_words(r,a,n)
 113 BN_ULONG *r,*a;
 114 int n;
 115         {
 116         for (;;)
 117                 {
 118                 BN_ULLONG t;
 119
 120                 t=(BN_ULLONG)(a[0])*(a[0]);
 121                 r[0]=Lw(t); r[1]=Hw(t);
 122                 if (--n == 0) break;
 123
 124                 t=(BN_ULLONG)(a[1])*(a[1]);
 125                 r[2]=Lw(t); r[3]=Hw(t);
 126                 if (--n == 0) break;
 127
 128                 t=(BN_ULLONG)(a[2])*(a[2]);
 129                 r[4]=Lw(t); r[5]=Hw(t);
 130                 if (--n == 0) break;
 131
 132                 t=(BN_ULLONG)(a[3])*(a[3]);
 133                 r[6]=Lw(t); r[7]=Hw(t);
 134                 if (--n == 0) break;
 135
 136                 a+=4;
 137                 r+=8;
 138                 }
 139         }
 140
 141 #else
 142
 143 BN_ULONG bn_mul_add_word(rp,ap,num,w)
 144 BN_ULONG *rp,*ap;
 145 int num;
 146 BN_ULONG w;
 147         {
 148         BN_ULONG c=0;
 149         BN_ULONG bl,bh;
 150
 151         bl=LBITS(w);
 152         bh=HBITS(w);
 153
 154         for (;;)
 155                 {
 156                 mul_add(rp[0],ap[0],bl,bh,c);
 157                 if (--num == 0) break;
 158                 mul_add(rp[1],ap[1],bl,bh,c);
 159                 if (--num == 0) break;
 160                 mul_add(rp[2],ap[2],bl,bh,c);
 161                 if (--num == 0) break;
 162                 mul_add(rp[3],ap[3],bl,bh,c);
 163                 if (--num == 0) break;
 164                 ap+=4;
 165                 rp+=4;
 166                 }
 167         return(c);
 168         }
 169
 170 BN_ULONG bn_mul_word(rp,ap,num,w)
 171 BN_ULONG *rp,*ap;
 172 int num;
 173 BN_ULONG w;
 174         {
 175         BN_ULONG carry=0;
 176         BN_ULONG bl,bh;
 177
 178         bl=LBITS(w);
 179         bh=HBITS(w);
 180
 181         for (;;)
 182                 {
 183                 mul(rp[0],ap[0],bl,bh,carry);
 184                 if (--num == 0) break;
 185                 mul(rp[1],ap[1],bl,bh,carry);
 186                 if (--num == 0) break;
 187                 mul(rp[2],ap[2],bl,bh,carry);
 188                 if (--num == 0) break;
 189                 mul(rp[3],ap[3],bl,bh,carry);
 190                 if (--num == 0) break;
 191                 ap+=4;
 192                 rp+=4;
 193                 }
 194         return(carry);
 195         }
 196
 197 void bn_sqr_words(r,a,n)
 198 BN_ULONG *r,*a;
 199 int n;
 200         {
 201         for (;;)
 202                 {
 203                 sqr64(r[0],r[1],a[0]);
 204                 if (--n == 0) break;
 205
 206                 sqr64(r[2],r[3],a[1]);
 207                 if (--n == 0) break;
 208
 209                 sqr64(r[4],r[5],a[2]);
 210                 if (--n == 0) break;
 211
 212                 sqr64(r[6],r[7],a[3]);
 213                 if (--n == 0) break;
 214
 215                 a+=4;
 216                 r+=8;
 217                 }
 218         }
 219
 220 #endif
 221
 222 #if defined(BN_LLONG) && defined(BN_DIV2W)
 223
 224 BN_ULONG bn_div64(h,l,d)
 225 BN_ULONG h,l,d;
 226         {
 227         return((BN_ULONG)(((((BN_ULLONG)h)<<BN_BITS2)|l)/(BN_ULLONG)d));
 228         }
 229
 230 #else
 231
 232 /* Divide h-l by d and return the result. */
 233 /* I need to test this some more :-( */
 234 BN_ULONG bn_div64(h,l,d)
 235 BN_ULONG h,l,d;
 236         {
 237         BN_ULONG dh,dl,q,ret=0,th,tl,t;
 238         int i,count=2;
 239
 240         if (d == 0) return(BN_MASK2);
 241
 242         i=BN_num_bits_word(d);
 243         if ((i != BN_BITS2) && (h > (BN_ULONG)1<<i))
 244                 {
 245 #ifndef WIN16
 246                 fprintf(stderr,"Division would overflow (%d)\n",i);
 247 #endif
 248                 abort();
 249                 }
 250         i=BN_BITS2-i;
 251         if (h >= d) h-=d;
 252
 253         if (i)
 254                 {
 255                 d<<=i;
 256                 h=(h<<i)|(l>>(BN_BITS2-i));
 257                 l<<=i;
 258                 }
 259         dh=(d&BN_MASK2h)>>BN_BITS4;
 260         dl=(d&BN_MASK2l);
 261         for (;;)
 262                 {
 263                 if ((h>>BN_BITS4) == dh)
 264                         q=BN_MASK2l;
 265                 else
 266                         q=h/dh;
 267
 268                 for (;;)
 269                         {
 270                         t=(h-q*dh);
 271                         if ((t&BN_MASK2h) ||
 272                                 ((dl*q) <= (
 273                                         (t<<BN_BITS4)+
 274                                         ((l&BN_MASK2h)>>BN_BITS4))))
 275                                 break;
 276                         q--;
 277                         }
 278                 th=q*dh;
 279                 tl=q*dl;
 280                 t=(tl>>BN_BITS4);
 281                 tl=(tl<<BN_BITS4)&BN_MASK2h;
 282                 th+=t;
 283
 284                 if (l < tl) th++;
 285                 l-=tl;
 286                 if (h < th)
 287                         {
 288                         h+=d;
 289                         q--;
 290                         }
 291                 h-=th;
 292
 293                 if (--count == 0) break;
 294
 295                 ret=q<<BN_BITS4;
 296                 h=((h<<BN_BITS4)|(l>>BN_BITS4))&BN_MASK2;
 297                 l=(l&BN_MASK2l)<<BN_BITS4;
 298                 }
 299         ret|=q;
 300         return(ret);
 301         }
 302 #endif
 303