1  //FIXME Not checked on threadsafety yet; after checking please remove this line


2  /* crypto/bn/bn_mul.c */


3  /* Copyright (C) 19951998 Eric Young (eay@cryptsoft.com)


4  * All rights reserved.


5  *


6  * This package is an SSL implementation written


7  * by Eric Young (eay@cryptsoft.com).


8  * The implementation was written so as to conform with Netscapes SSL.


9  *


10  * This library is free for commercial and noncommercial use as long as


11  * the following conditions are aheared to. The following conditions


12  * apply to all code found in this distribution, be it the RC4, RSA,


13  * lhash, DES, etc., code; not just the SSL code. The SSL documentation


14  * included with this distribution is covered by the same copyright terms


15  * except that the holder is Tim Hudson (tjh@cryptsoft.com).


16  *


17  * Copyright remains Eric Young's, and as such any Copyright notices in


18  * the code are not to be removed.


19  * If this package is used in a product, Eric Young should be given attribution


20  * as the author of the parts of the library used.


21  * This can be in the form of a textual message at program startup or


22  * in documentation (online or textual) provided with the package.


23  *


24  * Redistribution and use in source and binary forms, with or without


25  * modification, are permitted provided that the following conditions


26  * are met:


27  * 1. Redistributions of source code must retain the copyright


28  * notice, this list of conditions and the following disclaimer.


29  * 2. Redistributions in binary form must reproduce the above copyright


30  * notice, this list of conditions and the following disclaimer in the


31  * documentation and/or other materials provided with the distribution.


32  * 3. All advertising materials mentioning features or use of this software


33  * must display the following acknowledgement:


34  * "This product includes cryptographic software written by


35  * Eric Young (eay@cryptsoft.com)"


36  * The word 'cryptographic' can be left out if the rouines from the library


37  * being used are not cryptographic related :).


38  * 4. If you include any Windows specific code (or a derivative thereof) from


39  * the apps directory (application code) you must include an acknowledgement:


40  * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"


41  *


42  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND


43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE


44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE


45  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE


46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL


47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS


48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)


49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT


50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY


51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF


52  * SUCH DAMAGE.


53  *


54  * The licence and distribution terms for any publically available version or


55  * derivative of this code cannot be changed. i.e. this code cannot simply be


56  * copied and put under another distribution licence


57  * [including the GNU Public Licence.]


58  */


59 


60  #include <stdio.h>


61  #include <string.h>


62  #include "bn_lcl.h"


63  #include "openssl_mods.h"


64 


65  #ifdef BN_RECURSION


66  /* Karatsuba recursive multiplication algorithm


67  * (cf. Knuth, The Art of Computer Programming, Vol. 2) */


68 


69  /* r is 2*n2 words in size,


70  * a and b are both n2 words in size.


71  * n2 must be a power of 2.


72  * We multiply and return the result.


73  * t must be 2*n2 words in size


74  * We calculate


75  * a[0]*b[0]


76  * a[0]*b[0]+a[1]*b[1]+(a[0]a[1])*(b[1]b[0])


77  * a[1]*b[1]


78  */


79  void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,


80  BN_ULONG *t)


81  {


82  int n=n2/2,c1,c2;


83  unsigned int neg,zero;


84  BN_ULONG ln,lo,*p;


85 


86  # ifdef BN_COUNT


87  printf(" bn_mul_recursive %d * %d\n",n2,n2);


88  # endif


89  # ifdef BN_MUL_COMBA


90  # if 0


91  if (n2 == 4)


92  {


93  bn_mul_comba4(r,a,b);


94  return;


95  }


96  # endif


97  if (n2 == 8)


98  {


99  bn_mul_comba8(r,a,b);


100  return;


101  }


102  # endif /* BN_MUL_COMBA */


103  if (n2 < BN_MUL_RECURSIVE_SIZE_NORMAL)


104  {


105  /* This should not happen */


106  bn_mul_normal(r,a,n2,b,n2);


107  return;


108  }


109  /* r=(a[0]a[1])*(b[1]b[0]) */


110  c1=bn_cmp_words(a,&(a[n]),n);


111  c2=bn_cmp_words(&(b[n]),b,n);


112  zero=neg=0;


113  switch (c1*3+c2)


114  {


115  case 4:


116  bn_sub_words(t, &(a[n]),a, n); /*  */


117  bn_sub_words(&(t[n]),b, &(b[n]),n); /*  */


118  break;


119  case 3:


120  zero=1;


121  break;


122  case 2:


123  bn_sub_words(t, &(a[n]),a, n); /*  */


124  bn_sub_words(&(t[n]),&(b[n]),b, n); /* + */


125  neg=1;


126  break;


127  case 1:


128  case 0:


129  case 1:


130  zero=1;


131  break;


132  case 2:


133  bn_sub_words(t, a, &(a[n]),n); /* + */


134  bn_sub_words(&(t[n]),b, &(b[n]),n); /*  */


135  neg=1;


136  break;


137  case 3:


138  zero=1;


139  break;


140  case 4:


141  bn_sub_words(t, a, &(a[n]),n);


142  bn_sub_words(&(t[n]),&(b[n]),b, n);


143  break;


144  }


145 


146  # ifdef BN_MUL_COMBA


147  if (n == 4)


148  {


149  if (!zero)


150  bn_mul_comba4(&(t[n2]),t,&(t[n]));


151  else


152  memset(&(t[n2]),0,8*sizeof(BN_ULONG));


153 


154  bn_mul_comba4(r,a,b);


155  bn_mul_comba4(&(r[n2]),&(a[n]),&(b[n]));


156  }


157  else if (n == 8)


158  {


159  if (!zero)


160  bn_mul_comba8(&(t[n2]),t,&(t[n]));


161  else


162  memset(&(t[n2]),0,16*sizeof(BN_ULONG));


163 


164  bn_mul_comba8(r,a,b);


165  bn_mul_comba8(&(r[n2]),&(a[n]),&(b[n]));


166  }


167  else


168  # endif /* BN_MUL_COMBA */


169  {


170  p= &(t[n2*2]);


171  if (!zero)


172  bn_mul_recursive(&(t[n2]),t,&(t[n]),n,p);


173  else


174  memset(&(t[n2]),0,n2*sizeof(BN_ULONG));


175  bn_mul_recursive(r,a,b,n,p);


176  bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),n,p);


177  }


178 


179  /* t[32] holds (a[0]a[1])*(b[1]b[0]), c1 is the sign


180  * r[10] holds (a[0]*b[0])


181  * r[32] holds (b[1]*b[1])


182  */


183 


184  c1=(int)(bn_add_words(t,r,&(r[n2]),n2));


185 


186  if (neg) /* if t[32] is negative */


187  {


188  c1=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2));


189  }


190  else


191  {


192  /* Might have a carry */


193  c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),t,n2));


194  }


195 


196  /* t[32] holds (a[0]a[1])*(b[1]b[0])+(a[0]*b[0])+(a[1]*b[1])


197  * r[10] holds (a[0]*b[0])


198  * r[32] holds (b[1]*b[1])


199  * c1 holds the carry bits


200  */


201  c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2));


202  if (c1)


203  {


204  p= &(r[n+n2]);


205  lo= *p;


206  ln=(lo+c1)&BN_MASK2;


207  *p=ln;


208 


209  /* The overflow will stop before we over write


210  * words we should not overwrite */


211  if (ln < (BN_ULONG)c1)


212  {


213  do {


214  p++;


215  lo= *p;


216  ln=(lo+1)&BN_MASK2;


217  *p=ln;


218  } while (ln == 0);


219  }


220  }


221  }


222 


223  /* n+tn is the word length


224  * t needs to be n*4 is size, as does r */


225  void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int tn,


226  int n, BN_ULONG *t)


227  {


228  int c1,c2,i,j,n2=n*2;


229  unsigned int neg,zero;


230  BN_ULONG ln,lo,*p;


231 


232  # ifdef BN_COUNT


233  printf(" bn_mul_part_recursive %d * %d\n",tn+n,tn+n);


234  # endif


235  if (n < 8)


236  {


237  i=tn+n;


238  bn_mul_normal(r,a,i,b,i);


239  return;


240  }


241 


242  /* r=(a[0]a[1])*(b[1]b[0]) */


243  c1=bn_cmp_words(a,&(a[n]),n);


244  c2=bn_cmp_words(&(b[n]),b,n);


245  zero=neg=0;


246  switch (c1*3+c2)


247  {


248  case 4:


249  bn_sub_words(t, &(a[n]),a, n); /*  */


250  bn_sub_words(&(t[n]),b, &(b[n]),n); /*  */


251  break;


252  case 3:


253  zero=1;


254  /* break; */


255  case 2:


256  bn_sub_words(t, &(a[n]),a, n); /*  */


257  bn_sub_words(&(t[n]),&(b[n]),b, n); /* + */


258  neg=1;


259  break;


260  case 1:


261  case 0:


262  case 1:


263  zero=1;


264  /* break; */


265  case 2:


266  bn_sub_words(t, a, &(a[n]),n); /* + */


267  bn_sub_words(&(t[n]),b, &(b[n]),n); /*  */


268  neg=1;


269  break;


270  case 3:


271  zero=1;


272  /* break; */


273  case 4:


274  bn_sub_words(t, a, &(a[n]),n);


275  bn_sub_words(&(t[n]),&(b[n]),b, n);


276  break;


277  }


278  /* The zero case isn't yet implemented here. The speedup


279  would probably be negligible. */


280  # if 0


281  if (n == 4)


282  {


283  bn_mul_comba4(&(t[n2]),t,&(t[n]));


284  bn_mul_comba4(r,a,b);


285  bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);


286  memset(&(r[n2+tn*2]),0,sizeof(BN_ULONG)*(n2tn*2));


287  }


288  else


289  # endif


290  if (n == 8)


291  {


292  bn_mul_comba8(&(t[n2]),t,&(t[n]));


293  bn_mul_comba8(r,a,b);


294  bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);


295  memset(&(r[n2+tn*2]),0,sizeof(BN_ULONG)*(n2tn*2));


296  }


297  else


298  {


299  p= &(t[n2*2]);


300  bn_mul_recursive(&(t[n2]),t,&(t[n]),n,p);


301  bn_mul_recursive(r,a,b,n,p);


302  i=n/2;


303  /* If there is only a bottom half to the number,


304  * just do it */


305  j=tni;


306  if (j == 0)


307  {


308  bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),i,p);


309  memset(&(r[n2+i*2]),0,sizeof(BN_ULONG)*(n2i*2));


310  }


311  else if (j > 0) /* eg, n == 16, i == 8 and tn == 11 */


312  {


313  bn_mul_part_recursive(&(r[n2]),&(a[n]),&(b[n]),


314  j,i,p);


315  memset(&(r[n2+tn*2]),0,


316  sizeof(BN_ULONG)*(n2tn*2));


317  }


318  else /* (j < 0) eg, n == 16, i == 8 and tn == 5 */


319  {


320  memset(&(r[n2]),0,sizeof(BN_ULONG)*n2);


321  if (tn < BN_MUL_RECURSIVE_SIZE_NORMAL)


322  {


323  bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);


324  }


325  else


326  {


327  for (;;)


328  {


329  i/=2;


330  if (i < tn)


331  {


332  bn_mul_part_recursive(&(r[n2]),


333  &(a[n]),&(b[n]),


334  tni,i,p);


335  break;


336  }


337  else if (i == tn)


338  {


339  bn_mul_recursive(&(r[n2]),


340  &(a[n]),&(b[n]),


341  i,p);


342  break;


343  }


344  }


345  }


346  }


347  }


348 


349  /* t[32] holds (a[0]a[1])*(b[1]b[0]), c1 is the sign


350  * r[10] holds (a[0]*b[0])


351  * r[32] holds (b[1]*b[1])


352  */


353 


354  c1=(int)(bn_add_words(t,r,&(r[n2]),n2));


355 


356  if (neg) /* if t[32] is negative */


357  {


358  c1=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2));


359  }


360  else


361  {


362  /* Might have a carry */


363  c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),t,n2));


364  }


365 


366  /* t[32] holds (a[0]a[1])*(b[1]b[0])+(a[0]*b[0])+(a[1]*b[1])


367  * r[10] holds (a[0]*b[0])


368  * r[32] holds (b[1]*b[1])


369  * c1 holds the carry bits


370  */


371  c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2));


372  if (c1)


373  {


374  p= &(r[n+n2]);


375  lo= *p;


376  ln=(lo+c1)&BN_MASK2;


377  *p=ln;


378 


379  /* The overflow will stop before we over write


380  * words we should not overwrite */


381  if (ln < (BN_ULONG)c1)


382  {


383  do {


384  p++;


385  lo= *p;


386  ln=(lo+1)&BN_MASK2;


387  *p=ln;


388  } while (ln == 0);


389  }


390  }


391  }


392 


393  /* a and b must be the same size, which is n2.


394  * r needs to be n2 words and t needs to be n2*2


395  */


396  void bn_mul_low_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,


397  BN_ULONG *t)


398  {


399  int n=n2/2;


400 


401  # ifdef BN_COUNT


402  printf(" bn_mul_low_recursive %d * %d\n",n2,n2);


403  # endif


404 


405  bn_mul_recursive(r,a,b,n,&(t[0]));


406  if (n >= BN_MUL_LOW_RECURSIVE_SIZE_NORMAL)


407  {


408  bn_mul_low_recursive(&(t[0]),&(a[0]),&(b[n]),n,&(t[n2]));


409  bn_add_words(&(r[n]),&(r[n]),&(t[0]),n);


410  bn_mul_low_recursive(&(t[0]),&(a[n]),&(b[0]),n,&(t[n2]));


411  bn_add_words(&(r[n]),&(r[n]),&(t[0]),n);


412  }


413  else


414  {


415  bn_mul_low_normal(&(t[0]),&(a[0]),&(b[n]),n);


416  bn_mul_low_normal(&(t[n]),&(a[n]),&(b[0]),n);


417  bn_add_words(&(r[n]),&(r[n]),&(t[0]),n);


418  bn_add_words(&(r[n]),&(r[n]),&(t[n]),n);


419  }


420  }


421 


422  /* a and b must be the same size, which is n2.


423  * r needs to be n2 words and t needs to be n2*2


424  * l is the low words of the output.


425  * t needs to be n2*3


426  */


427  void bn_mul_high(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, BN_ULONG *l, int n2,


428  BN_ULONG *t)


429  {


430  int i,n;


431  int c1,c2;


432  int neg,oneg,zero;


433  BN_ULONG ll,lc,*lp,*mp;


434 


435  # ifdef BN_COUNT


436  printf(" bn_mul_high %d * %d\n",n2,n2);


437  # endif


438  n=n2/2;


439 


440  /* Calculate (alah)*(bhbl) */


441  neg=zero=0;


442  c1=bn_cmp_words(&(a[0]),&(a[n]),n);


443  c2=bn_cmp_words(&(b[n]),&(b[0]),n);


444  switch (c1*3+c2)


445  {


446  case 4:


447  bn_sub_words(&(r[0]),&(a[n]),&(a[0]),n);


448  bn_sub_words(&(r[n]),&(b[0]),&(b[n]),n);


449  break;


450  case 3:


451  zero=1;


452  break;


453  case 2:


454  bn_sub_words(&(r[0]),&(a[n]),&(a[0]),n);


455  bn_sub_words(&(r[n]),&(b[n]),&(b[0]),n);


456  neg=1;


457  break;


458  case 1:


459  case 0:


460  case 1:


461  zero=1;


462  break;


463  case 2:


464  bn_sub_words(&(r[0]),&(a[0]),&(a[n]),n);


465  bn_sub_words(&(r[n]),&(b[0]),&(b[n]),n);


466  neg=1;


467  break;


468  case 3:


469  zero=1;


470  break;


471  case 4:


472  bn_sub_words(&(r[0]),&(a[0]),&(a[n]),n);


473  bn_sub_words(&(r[n]),&(b[n]),&(b[0]),n);


474  break;


475  }


476 


477  oneg=neg;


478  /* t[10] = (a[0]a[1])*(b[1]b[0]) */


479  /* r[10] = (a[1]*b[1]) */


480  # ifdef BN_MUL_COMBA


481  if (n == 8)


482  {


483  bn_mul_comba8(&(t[0]),&(r[0]),&(r[n]));


484  bn_mul_comba8(r,&(a[n]),&(b[n]));


485  }


486  else


487  # endif


488  {


489  bn_mul_recursive(&(t[0]),&(r[0]),&(r[n]),n,&(t[n2]));


490  bn_mul_recursive(r,&(a[n]),&(b[n]),n,&(t[n2]));


491  }


492 


493  /* s0 == low(al*bl)


494  * s1 == low(ah*bh)+low((alah)*(bhbl))+low(al*bl)+high(al*bl)


495  * We know s0 and s1 so the only unknown is high(al*bl)


496  * high(al*bl) == s1  low(ah*bh+s0+(alah)*(bhbl))


497  * high(al*bl) == s1  (r[0]+l[0]+t[0])


498  */


499  if (l != NULL)


500  {


501  lp= &(t[n2+n]);


502  c1=(int)(bn_add_words(lp,&(r[0]),&(l[0]),n));


503  }


504  else


505  {


506  c1=0;


507  lp= &(r[0]);


508  }


509 


510  if (neg)


511  neg=(int)(bn_sub_words(&(t[n2]),lp,&(t[0]),n));


512  else


513  {


514  bn_add_words(&(t[n2]),lp,&(t[0]),n);


515  neg=0;


516  }


517 


518  if (l != NULL)


519  {


520  bn_sub_words(&(t[n2+n]),&(l[n]),&(t[n2]),n);


521  }


522  else


523  {


524  lp= &(t[n2+n]);


525  mp= &(t[n2]);


526  for (i=0; i<n; i++)


527  lp[i]=((~mp[i])+1)&BN_MASK2;


528  }


529 


530  /* s[0] = low(al*bl)


531  * t[3] = high(al*bl)


532  * t[10] = (a[0]a[1])*(b[1]b[0]) neg is the sign


533  * r[10] = (a[1]*b[1])


534  */


535  /* R[10] = al*bl


536  * R[21] = al*bl + ah*bh + (a[0]a[1])*(b[1]b[0])


537  * R[32] = ah*bh


538  */


539  /* R[1]=t[3]+l[0]+r[0](+)t[0] (have carry/borrow)


540  * R[2]=r[0]+t[3]+r[1](+)t[1] (have carry/borrow)


541  * R[3]=r[1]+(carry/borrow)


542  */


543  if (l != NULL)


544  {


545  lp= &(t[n2]);


546  c1= (int)(bn_add_words(lp,&(t[n2+n]),&(l[0]),n));


547  }


548  else


549  {


550  lp= &(t[n2+n]);


551  c1=0;


552  }


553  c1+=(int)(bn_add_words(&(t[n2]),lp, &(r[0]),n));


554  if (oneg)


555  c1=(int)(bn_sub_words(&(t[n2]),&(t[n2]),&(t[0]),n));


556  else


557  c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),&(t[0]),n));


558 


559  c2 =(int)(bn_add_words(&(r[0]),&(r[0]),&(t[n2+n]),n));


560  c2+=(int)(bn_add_words(&(r[0]),&(r[0]),&(r[n]),n));


561  if (oneg)


562  c2=(int)(bn_sub_words(&(r[0]),&(r[0]),&(t[n]),n));


563  else


564  c2+=(int)(bn_add_words(&(r[0]),&(r[0]),&(t[n]),n));


565 


566  if (c1 != 0) /* Add starting at r[0], could be +ve or ve */


567  {


568  i=0;


569  if (c1 > 0)


570  {


571  lc=c1;


572  do {


573  ll=(r[i]+lc)&BN_MASK2;


574  r[i++]=ll;


575  lc=(lc > ll);


576  } while (lc);


577  }


578  else


579  {


580  lc= c1;


581  do {


582  ll=r[i];


583  r[i++]=(lllc)&BN_MASK2;


584  lc=(lc > ll);


585  } while (lc);


586  }


587  }


588  if (c2 != 0) /* Add starting at r[1] */


589  {


590  i=n;


591  if (c2 > 0)


592  {


593  lc=c2;


594  do {


595  ll=(r[i]+lc)&BN_MASK2;


596  r[i++]=ll;


597  lc=(lc > ll);


598  } while (lc);


599  }


600  else


601  {


602  lc= c2;


603  do {


604  ll=r[i];


605  r[i++]=(lllc)&BN_MASK2;


606  lc=(lc > ll);


607  } while (lc);


608  }


609  }


610  }


611  #endif /* BN_RECURSION */


612 


613  int BN_mul(BIGNUM *r, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)


614  {


615  int top,al,bl;


616  BIGNUM *rr;


617  int ret = 0;


618  #if defined(BN_MUL_COMBA)  defined(BN_RECURSION)


619  int i;


620  #endif


621  #ifdef BN_RECURSION


622  BIGNUM *t;


623  int j,k;


624  #endif


625 


626  #ifdef BN_COUNT


627  printf("BN_mul %d * %d\n",a>top,b>top);


628  #endif


629 


630  bn_check_top(a);


631  bn_check_top(b);


632  bn_check_top(r);


633 


634  al=a>top;


635  bl=b>top;


636 


637  if ((al == 0)  (bl == 0))


638  {


639  BN_zero(r);


640  return(1);


641  }


642  top=al+bl;


643 


644  BN_CTX_start(ctx);


645  if ((r == a)  (r == b))


646  {


647  if ((rr = BN_CTX_get(ctx)) == NULL) goto err;


648  }


649  else


650  rr = r;


651  rr>neg=a>neg^b>neg;


652 


653  #if defined(BN_MUL_COMBA)  defined(BN_RECURSION)


654  i = albl;


655  #endif


656  #ifdef BN_MUL_COMBA


657  if (i == 0)


658  {


659  # if 0


660  if (al == 4)


661  {


662  if (bn_wexpand(rr,8) == NULL) goto err;


663  rr>top=8;


664  bn_mul_comba4(rr>d,a>d,b>d);


665  goto end;


666  }


667  # endif


668  if (al == 8)


669  {


670  if (bn_wexpand(rr,16) == NULL) goto err;


671  rr>top=16;


672  bn_mul_comba8(rr>d,a>d,b>d);


673  goto end;


674  }


675  }


676  #endif /* BN_MUL_COMBA */


677  #ifdef BN_RECURSION


678  if ((al >= BN_MULL_SIZE_NORMAL) && (bl >= BN_MULL_SIZE_NORMAL))


679  {


680  if (i == 1 && !BN_get_flags(b,BN_FLG_STATIC_DATA))


681  {


682  if (bn_wexpand(b,al) == NULL) goto err;


683  b>d[bl]=0;


684  bl++;


685  i;


686  }


687  else if (i == 1 && !BN_get_flags(a,BN_FLG_STATIC_DATA))


688  {


689  if (bn_wexpand(a,bl) == NULL) goto err;


690  a>d[al]=0;


691  al++;


692  i++;


693  }


694  if (i == 0)


695  {


696  /* symmetric and > 4 */


697  /* 16 or larger */


698  j=BN_num_bits_word((BN_ULONG)al);


699  j=1<<(j1);


700  k=j+j;


701  t = BN_CTX_get(ctx);


702  if (al == j) /* exact multiple */


703  {


704  if (bn_wexpand(t,k*2) == NULL) goto err;


705  if (bn_wexpand(rr,k*2) == NULL) goto err;


706  bn_mul_recursive(rr>d,a>d,b>d,al,t>d);


707  }


708  else


709  {


710  if (bn_wexpand(a,k) == NULL) goto err;


711  if (bn_wexpand(b,k) == NULL) goto err;


712  if (bn_wexpand(t,k*4) == NULL) goto err;


713  if (bn_wexpand(rr,k*4) == NULL) goto err;


714  for (i=a>top; i<k; i++)


715  a>d[i]=0;


716  for (i=b>top; i<k; i++)


717  b>d[i]=0;


718  bn_mul_part_recursive(rr>d,a>d,b>d,alj,j,t>d);


719  }


720  rr>top=top;


721  goto end;


722  }


723  }


724  #endif /* BN_RECURSION */


725  if (bn_wexpand(rr,top) == NULL) goto err;


726  rr>top=top;


727  bn_mul_normal(rr>d,a>d,al,b>d,bl);


728 


729  #if defined(BN_MUL_COMBA)  defined(BN_RECURSION)


730  end:


731  #endif


732  bn_fix_top(rr);


733  if (r != rr) BN_copy(r,rr);


734  ret=1;


735  err:


736  BN_CTX_end(ctx);


737  return(ret);


738  }


739 


740  void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb)


741  {


742  BN_ULONG *rr;


743 


744  #ifdef BN_COUNT


745  printf(" bn_mul_normal %d * %d\n",na,nb);


746  #endif


747 


748  if (na < nb)


749  {


750  int itmp;


751  BN_ULONG *ltmp;


752 


753  itmp=na; na=nb; nb=itmp;


754  ltmp=a; a=b; b=ltmp;


755 


756  }


757  rr= &(r[na]);


758  rr[0]=bn_mul_words(r,a,na,b[0]);


759 


760  for (;;)


761  {


762  if (nb <= 0) return;


763  rr[1]=bn_mul_add_words(&(r[1]),a,na,b[1]);


764  if (nb <= 0) return;


765  rr[2]=bn_mul_add_words(&(r[2]),a,na,b[2]);


766  if (nb <= 0) return;


767  rr[3]=bn_mul_add_words(&(r[3]),a,na,b[3]);


768  if (nb <= 0) return;


769  rr[4]=bn_mul_add_words(&(r[4]),a,na,b[4]);


770  rr+=4;


771  r+=4;


772  b+=4;


773  }


774  }


775 


776  void bn_mul_low_normal(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)


777  {


778  #ifdef BN_COUNT


779  printf(" bn_mul_low_normal %d * %d\n",n,n);


780  #endif


781  bn_mul_words(r,a,n,b[0]);


782 


783  for (;;)


784  {


785  if (n <= 0) return;


786  bn_mul_add_words(&(r[1]),a,n,b[1]);


787  if (n <= 0) return;


788  bn_mul_add_words(&(r[2]),a,n,b[2]);


789  if (n <= 0) return;


790  bn_mul_add_words(&(r[3]),a,n,b[3]);


791  if (n <= 0) return;


792  bn_mul_add_words(&(r[4]),a,n,b[4]);


793  r+=4;


794  b+=4;


795  }


796  }

