756 lines
16 KiB
C
756 lines
16 KiB
C
/* crypto/bn/bn_mul.c */
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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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* All rights reserved.
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*
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* This package is an SSL implementation written
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* by Eric Young (eay@cryptsoft.com).
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* The implementation was written so as to conform with Netscapes SSL.
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*
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* This library is free for commercial and non-commercial use as long as
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* the following conditions are aheared to. The following conditions
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* apply to all code found in this distribution, be it the RC4, RSA,
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* lhash, DES, etc., code; not just the SSL code. The SSL documentation
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* included with this distribution is covered by the same copyright terms
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* except that the holder is Tim Hudson (tjh@cryptsoft.com).
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*
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* Copyright remains Eric Young's, and as such any Copyright notices in
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* the code are not to be removed.
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* If this package is used in a product, Eric Young should be given attribution
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* as the author of the parts of the library used.
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* This can be in the form of a textual message at program startup or
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* in documentation (online or textual) provided with the package.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* "This product includes cryptographic software written by
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* Eric Young (eay@cryptsoft.com)"
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* The word 'cryptographic' can be left out if the rouines from the library
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* being used are not cryptographic related :-).
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* 4. If you include any Windows specific code (or a derivative thereof) from
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* the apps directory (application code) you must include an acknowledgement:
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* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
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*
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* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* The licence and distribution terms for any publically available version or
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* derivative of this code cannot be changed. i.e. this code cannot simply be
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* copied and put under another distribution licence
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* [including the GNU Public Licence.]
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*/
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#include <stdio.h>
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#include "cryptlib.h"
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#include "bn_lcl.h"
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#ifdef BN_RECURSION
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/* r is 2*n2 words in size,
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* a and b are both n2 words in size.
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* n2 must be a power of 2.
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* We multiply and return the result.
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* t must be 2*n2 words in size
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* We calulate
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* a[0]*b[0]
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* a[0]*b[0]+a[1]*b[1]+(a[0]-a[1])*(b[1]-b[0])
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* a[1]*b[1]
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*/
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void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
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BN_ULONG *t)
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{
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int n=n2/2,c1,c2;
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unsigned int neg,zero;
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BN_ULONG ln,lo,*p;
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#ifdef BN_COUNT
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printf(" bn_mul_recursive %d * %d\n",n2,n2);
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#endif
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#ifdef BN_MUL_COMBA
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/* if (n2 == 4)
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{
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bn_mul_comba4(r,a,b);
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return;
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}
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else */ if (n2 == 8)
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{
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bn_mul_comba8(r,a,b);
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return;
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}
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#endif
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if (n2 < BN_MUL_RECURSIVE_SIZE_NORMAL)
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{
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/* This should not happen */
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bn_mul_normal(r,a,n2,b,n2);
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return;
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}
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/* r=(a[0]-a[1])*(b[1]-b[0]) */
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c1=bn_cmp_words(a,&(a[n]),n);
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c2=bn_cmp_words(&(b[n]),b,n);
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zero=neg=0;
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switch (c1*3+c2)
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{
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case -4:
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bn_sub_words(t, &(a[n]),a, n); /* - */
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bn_sub_words(&(t[n]),b, &(b[n]),n); /* - */
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break;
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case -3:
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zero=1;
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break;
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case -2:
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bn_sub_words(t, &(a[n]),a, n); /* - */
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bn_sub_words(&(t[n]),&(b[n]),b, n); /* + */
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neg=1;
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break;
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case -1:
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case 0:
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case 1:
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zero=1;
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break;
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case 2:
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bn_sub_words(t, a, &(a[n]),n); /* + */
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bn_sub_words(&(t[n]),b, &(b[n]),n); /* - */
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neg=1;
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break;
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case 3:
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zero=1;
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break;
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case 4:
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bn_sub_words(t, a, &(a[n]),n);
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bn_sub_words(&(t[n]),&(b[n]),b, n);
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break;
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}
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#ifdef BN_MUL_COMBA
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if (n == 4)
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{
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if (!zero)
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bn_mul_comba4(&(t[n2]),t,&(t[n]));
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else
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memset(&(t[n2]),0,8*sizeof(BN_ULONG));
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bn_mul_comba4(r,a,b);
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bn_mul_comba4(&(r[n2]),&(a[n]),&(b[n]));
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}
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else if (n == 8)
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{
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if (!zero)
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bn_mul_comba8(&(t[n2]),t,&(t[n]));
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else
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memset(&(t[n2]),0,16*sizeof(BN_ULONG));
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bn_mul_comba8(r,a,b);
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bn_mul_comba8(&(r[n2]),&(a[n]),&(b[n]));
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}
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else
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#endif
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{
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p= &(t[n2*2]);
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if (!zero)
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bn_mul_recursive(&(t[n2]),t,&(t[n]),n,p);
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else
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memset(&(t[n2]),0,n2*sizeof(BN_ULONG));
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bn_mul_recursive(r,a,b,n,p);
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bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),n,p);
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}
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/* t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign
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* r[10] holds (a[0]*b[0])
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* r[32] holds (b[1]*b[1])
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*/
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c1=(int)(bn_add_words(t,r,&(r[n2]),n2));
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if (neg) /* if t[32] is negative */
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{
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c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2));
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}
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else
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{
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/* Might have a carry */
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c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),t,n2));
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}
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/* t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1])
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* r[10] holds (a[0]*b[0])
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* r[32] holds (b[1]*b[1])
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* c1 holds the carry bits
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*/
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c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2));
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if (c1)
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{
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p= &(r[n+n2]);
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lo= *p;
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ln=(lo+c1)&BN_MASK2;
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*p=ln;
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/* The overflow will stop before we over write
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* words we should not overwrite */
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if (ln < (BN_ULONG)c1)
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{
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do {
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p++;
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lo= *p;
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ln=(lo+1)&BN_MASK2;
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*p=ln;
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} while (ln == 0);
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}
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}
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}
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/* n+tn is the word length
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* t needs to be n*4 is size, as does r */
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void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int tn,
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int n, BN_ULONG *t)
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{
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int i,j,n2=n*2;
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unsigned int c1;
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BN_ULONG ln,lo,*p;
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#ifdef BN_COUNT
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printf(" bn_mul_part_recursive %d * %d\n",tn+n,tn+n);
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#endif
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if (n < 8)
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{
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i=tn+n;
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bn_mul_normal(r,a,i,b,i);
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return;
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}
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/* r=(a[0]-a[1])*(b[1]-b[0]) */
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bn_sub_words(t, a, &(a[n]),n); /* + */
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bn_sub_words(&(t[n]),b, &(b[n]),n); /* - */
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/* if (n == 4)
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{
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bn_mul_comba4(&(t[n2]),t,&(t[n]));
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bn_mul_comba4(r,a,b);
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bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);
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memset(&(r[n2+tn*2]),0,sizeof(BN_ULONG)*(n2-tn*2));
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}
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else */ if (n == 8)
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{
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bn_mul_comba8(&(t[n2]),t,&(t[n]));
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bn_mul_comba8(r,a,b);
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bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);
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memset(&(r[n2+tn*2]),0,sizeof(BN_ULONG)*(n2-tn*2));
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}
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else
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{
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p= &(t[n2*2]);
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bn_mul_recursive(&(t[n2]),t,&(t[n]),n,p);
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bn_mul_recursive(r,a,b,n,p);
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i=n/2;
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/* If there is only a bottom half to the number,
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* just do it */
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j=tn-i;
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if (j == 0)
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{
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bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),i,p);
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memset(&(r[n2+i*2]),0,sizeof(BN_ULONG)*(n2-i*2));
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}
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else if (j > 0) /* eg, n == 16, i == 8 and tn == 11 */
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{
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bn_mul_part_recursive(&(r[n2]),&(a[n]),&(b[n]),
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j,i,p);
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memset(&(r[n2+tn*2]),0,
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sizeof(BN_ULONG)*(n2-tn*2));
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}
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else /* (j < 0) eg, n == 16, i == 8 and tn == 5 */
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{
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memset(&(r[n2]),0,sizeof(BN_ULONG)*n2);
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if (tn < BN_MUL_RECURSIVE_SIZE_NORMAL)
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{
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bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);
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}
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else
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{
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for (;;)
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{
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i/=2;
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if (i < tn)
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{
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bn_mul_part_recursive(&(r[n2]),
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&(a[n]),&(b[n]),
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tn-i,i,p);
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break;
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}
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else if (i == tn)
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{
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bn_mul_recursive(&(r[n2]),
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&(a[n]),&(b[n]),
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i,p);
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break;
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}
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}
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}
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}
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}
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/* t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign
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* r[10] holds (a[0]*b[0])
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* r[32] holds (b[1]*b[1])
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*/
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c1=(int)(bn_add_words(t,r,&(r[n2]),n2));
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c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2));
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/* t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1])
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* r[10] holds (a[0]*b[0])
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* r[32] holds (b[1]*b[1])
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* c1 holds the carry bits
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*/
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c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2));
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if (c1)
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{
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p= &(r[n+n2]);
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lo= *p;
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ln=(lo+c1)&BN_MASK2;
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*p=ln;
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/* The overflow will stop before we over write
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* words we should not overwrite */
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if (ln < c1)
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{
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do {
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p++;
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lo= *p;
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ln=(lo+1)&BN_MASK2;
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*p=ln;
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} while (ln == 0);
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}
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}
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}
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/* a and b must be the same size, which is n2.
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* r needs to be n2 words and t needs to be n2*2
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*/
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void bn_mul_low_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
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BN_ULONG *t)
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{
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int n=n2/2;
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#ifdef BN_COUNT
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printf(" bn_mul_low_recursive %d * %d\n",n2,n2);
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#endif
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bn_mul_recursive(r,a,b,n,&(t[0]));
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if (n >= BN_MUL_LOW_RECURSIVE_SIZE_NORMAL)
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{
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bn_mul_low_recursive(&(t[0]),&(a[0]),&(b[n]),n,&(t[n2]));
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bn_add_words(&(r[n]),&(r[n]),&(t[0]),n);
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bn_mul_low_recursive(&(t[0]),&(a[n]),&(b[0]),n,&(t[n2]));
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bn_add_words(&(r[n]),&(r[n]),&(t[0]),n);
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}
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else
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{
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bn_mul_low_normal(&(t[0]),&(a[0]),&(b[n]),n);
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bn_mul_low_normal(&(t[n]),&(a[n]),&(b[0]),n);
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bn_add_words(&(r[n]),&(r[n]),&(t[0]),n);
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bn_add_words(&(r[n]),&(r[n]),&(t[n]),n);
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}
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}
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/* a and b must be the same size, which is n2.
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* r needs to be n2 words and t needs to be n2*2
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* l is the low words of the output.
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* t needs to be n2*3
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*/
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void bn_mul_high(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, BN_ULONG *l, int n2,
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BN_ULONG *t)
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{
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int i,n;
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int c1,c2;
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int neg,oneg,zero;
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BN_ULONG ll,lc,*lp,*mp;
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#ifdef BN_COUNT
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printf(" bn_mul_high %d * %d\n",n2,n2);
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#endif
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n=n2/2;
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/* Calculate (al-ah)*(bh-bl) */
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neg=zero=0;
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c1=bn_cmp_words(&(a[0]),&(a[n]),n);
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c2=bn_cmp_words(&(b[n]),&(b[0]),n);
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switch (c1*3+c2)
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{
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case -4:
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bn_sub_words(&(r[0]),&(a[n]),&(a[0]),n);
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bn_sub_words(&(r[n]),&(b[0]),&(b[n]),n);
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break;
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case -3:
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zero=1;
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break;
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case -2:
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bn_sub_words(&(r[0]),&(a[n]),&(a[0]),n);
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bn_sub_words(&(r[n]),&(b[n]),&(b[0]),n);
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neg=1;
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break;
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case -1:
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case 0:
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case 1:
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zero=1;
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break;
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case 2:
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bn_sub_words(&(r[0]),&(a[0]),&(a[n]),n);
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bn_sub_words(&(r[n]),&(b[0]),&(b[n]),n);
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neg=1;
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break;
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case 3:
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zero=1;
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break;
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case 4:
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bn_sub_words(&(r[0]),&(a[0]),&(a[n]),n);
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bn_sub_words(&(r[n]),&(b[n]),&(b[0]),n);
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break;
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}
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oneg=neg;
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/* t[10] = (a[0]-a[1])*(b[1]-b[0]) */
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/* r[10] = (a[1]*b[1]) */
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#ifdef BN_MUL_COMBA
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if (n == 8)
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{
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bn_mul_comba8(&(t[0]),&(r[0]),&(r[n]));
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bn_mul_comba8(r,&(a[n]),&(b[n]));
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}
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else
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#endif
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{
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bn_mul_recursive(&(t[0]),&(r[0]),&(r[n]),n,&(t[n2]));
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bn_mul_recursive(r,&(a[n]),&(b[n]),n,&(t[n2]));
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}
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/* s0 == low(al*bl)
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* s1 == low(ah*bh)+low((al-ah)*(bh-bl))+low(al*bl)+high(al*bl)
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* We know s0 and s1 so the only unknown is high(al*bl)
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* high(al*bl) == s1 - low(ah*bh+s0+(al-ah)*(bh-bl))
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* high(al*bl) == s1 - (r[0]+l[0]+t[0])
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*/
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if (l != NULL)
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{
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lp= &(t[n2+n]);
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c1=(int)(bn_add_words(lp,&(r[0]),&(l[0]),n));
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}
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else
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{
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c1=0;
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lp= &(r[0]);
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}
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if (neg)
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neg=(int)(bn_sub_words(&(t[n2]),lp,&(t[0]),n));
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else
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{
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bn_add_words(&(t[n2]),lp,&(t[0]),n);
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neg=0;
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}
|
|
|
|
if (l != NULL)
|
|
{
|
|
bn_sub_words(&(t[n2+n]),&(l[n]),&(t[n2]),n);
|
|
}
|
|
else
|
|
{
|
|
lp= &(t[n2+n]);
|
|
mp= &(t[n2]);
|
|
for (i=0; i<n; i++)
|
|
lp[i]=((~mp[i])+1)&BN_MASK2;
|
|
}
|
|
|
|
/* s[0] = low(al*bl)
|
|
* t[3] = high(al*bl)
|
|
* t[10] = (a[0]-a[1])*(b[1]-b[0]) neg is the sign
|
|
* r[10] = (a[1]*b[1])
|
|
*/
|
|
/* R[10] = al*bl
|
|
* R[21] = al*bl + ah*bh + (a[0]-a[1])*(b[1]-b[0])
|
|
* R[32] = ah*bh
|
|
*/
|
|
/* R[1]=t[3]+l[0]+r[0](+-)t[0] (have carry/borrow)
|
|
* R[2]=r[0]+t[3]+r[1](+-)t[1] (have carry/borrow)
|
|
* R[3]=r[1]+(carry/borrow)
|
|
*/
|
|
if (l != NULL)
|
|
{
|
|
lp= &(t[n2]);
|
|
c1= (int)(bn_add_words(lp,&(t[n2+n]),&(l[0]),n));
|
|
}
|
|
else
|
|
{
|
|
lp= &(t[n2+n]);
|
|
c1=0;
|
|
}
|
|
c1+=(int)(bn_add_words(&(t[n2]),lp, &(r[0]),n));
|
|
if (oneg)
|
|
c1-=(int)(bn_sub_words(&(t[n2]),&(t[n2]),&(t[0]),n));
|
|
else
|
|
c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),&(t[0]),n));
|
|
|
|
c2 =(int)(bn_add_words(&(r[0]),&(r[0]),&(t[n2+n]),n));
|
|
c2+=(int)(bn_add_words(&(r[0]),&(r[0]),&(r[n]),n));
|
|
if (oneg)
|
|
c2-=(int)(bn_sub_words(&(r[0]),&(r[0]),&(t[n]),n));
|
|
else
|
|
c2+=(int)(bn_add_words(&(r[0]),&(r[0]),&(t[n]),n));
|
|
|
|
if (c1 != 0) /* Add starting at r[0], could be +ve or -ve */
|
|
{
|
|
i=0;
|
|
if (c1 > 0)
|
|
{
|
|
lc=c1;
|
|
do {
|
|
ll=(r[i]+lc)&BN_MASK2;
|
|
r[i++]=ll;
|
|
lc=(lc > ll);
|
|
} while (lc);
|
|
}
|
|
else
|
|
{
|
|
lc= -c1;
|
|
do {
|
|
ll=r[i];
|
|
r[i++]=(ll-lc)&BN_MASK2;
|
|
lc=(lc > ll);
|
|
} while (lc);
|
|
}
|
|
}
|
|
if (c2 != 0) /* Add starting at r[1] */
|
|
{
|
|
i=n;
|
|
if (c2 > 0)
|
|
{
|
|
lc=c2;
|
|
do {
|
|
ll=(r[i]+lc)&BN_MASK2;
|
|
r[i++]=ll;
|
|
lc=(lc > ll);
|
|
} while (lc);
|
|
}
|
|
else
|
|
{
|
|
lc= -c2;
|
|
do {
|
|
ll=r[i];
|
|
r[i++]=(ll-lc)&BN_MASK2;
|
|
lc=(lc > ll);
|
|
} while (lc);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
int BN_mul(BIGNUM *r, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
|
|
{
|
|
int top,al,bl;
|
|
BIGNUM *rr;
|
|
#ifdef BN_RECURSION
|
|
BIGNUM *t;
|
|
int i,j,k;
|
|
#endif
|
|
|
|
#ifdef BN_COUNT
|
|
printf("BN_mul %d * %d\n",a->top,b->top);
|
|
#endif
|
|
|
|
bn_check_top(a);
|
|
bn_check_top(b);
|
|
bn_check_top(r);
|
|
|
|
al=a->top;
|
|
bl=b->top;
|
|
r->neg=a->neg^b->neg;
|
|
|
|
if ((al == 0) || (bl == 0))
|
|
{
|
|
BN_zero(r);
|
|
return(1);
|
|
}
|
|
top=al+bl;
|
|
|
|
if ((r == a) || (r == b))
|
|
rr= &(ctx->bn[ctx->tos+1]);
|
|
else
|
|
rr=r;
|
|
|
|
#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
|
|
if (al == bl)
|
|
{
|
|
# ifdef BN_MUL_COMBA
|
|
/* if (al == 4)
|
|
{
|
|
if (bn_wexpand(rr,8) == NULL) return(0);
|
|
r->top=8;
|
|
bn_mul_comba4(rr->d,a->d,b->d);
|
|
goto end;
|
|
}
|
|
else */ if (al == 8)
|
|
{
|
|
if (bn_wexpand(rr,16) == NULL) return(0);
|
|
r->top=16;
|
|
bn_mul_comba8(rr->d,a->d,b->d);
|
|
goto end;
|
|
}
|
|
else
|
|
# endif
|
|
#ifdef BN_RECURSION
|
|
if (al < BN_MULL_SIZE_NORMAL)
|
|
#endif
|
|
{
|
|
if (bn_wexpand(rr,top) == NULL) return(0);
|
|
rr->top=top;
|
|
bn_mul_normal(rr->d,a->d,al,b->d,bl);
|
|
goto end;
|
|
}
|
|
# ifdef BN_RECURSION
|
|
goto symetric;
|
|
# endif
|
|
}
|
|
#endif
|
|
#ifdef BN_RECURSION
|
|
else if ((al < BN_MULL_SIZE_NORMAL) || (bl < BN_MULL_SIZE_NORMAL))
|
|
{
|
|
if (bn_wexpand(rr,top) == NULL) return(0);
|
|
rr->top=top;
|
|
bn_mul_normal(rr->d,a->d,al,b->d,bl);
|
|
goto end;
|
|
}
|
|
else
|
|
{
|
|
i=(al-bl);
|
|
if ((i == 1) && !BN_get_flags(b,BN_FLG_STATIC_DATA))
|
|
{
|
|
bn_wexpand(b,al);
|
|
b->d[bl]=0;
|
|
bl++;
|
|
goto symetric;
|
|
}
|
|
else if ((i == -1) && !BN_get_flags(a,BN_FLG_STATIC_DATA))
|
|
{
|
|
bn_wexpand(a,bl);
|
|
a->d[al]=0;
|
|
al++;
|
|
goto symetric;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* asymetric and >= 4 */
|
|
if (bn_wexpand(rr,top) == NULL) return(0);
|
|
rr->top=top;
|
|
bn_mul_normal(rr->d,a->d,al,b->d,bl);
|
|
|
|
#ifdef BN_RECURSION
|
|
if (0)
|
|
{
|
|
symetric:
|
|
/* symetric and > 4 */
|
|
/* 16 or larger */
|
|
j=BN_num_bits_word((BN_ULONG)al);
|
|
j=1<<(j-1);
|
|
k=j+j;
|
|
t= &(ctx->bn[ctx->tos]);
|
|
if (al == j) /* exact multiple */
|
|
{
|
|
bn_wexpand(t,k*2);
|
|
bn_wexpand(rr,k*2);
|
|
bn_mul_recursive(rr->d,a->d,b->d,al,t->d);
|
|
}
|
|
else
|
|
{
|
|
bn_wexpand(a,k);
|
|
bn_wexpand(b,k);
|
|
bn_wexpand(t,k*4);
|
|
bn_wexpand(rr,k*4);
|
|
for (i=a->top; i<k; i++)
|
|
a->d[i]=0;
|
|
for (i=b->top; i<k; i++)
|
|
b->d[i]=0;
|
|
bn_mul_part_recursive(rr->d,a->d,b->d,al-j,j,t->d);
|
|
}
|
|
rr->top=top;
|
|
}
|
|
#endif
|
|
#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
|
|
end:
|
|
#endif
|
|
bn_fix_top(rr);
|
|
if (r != rr) BN_copy(r,rr);
|
|
return(1);
|
|
}
|
|
|
|
void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb)
|
|
{
|
|
BN_ULONG *rr;
|
|
|
|
#ifdef BN_COUNT
|
|
printf(" bn_mul_normal %d * %d\n",na,nb);
|
|
#endif
|
|
|
|
if (na < nb)
|
|
{
|
|
int itmp;
|
|
BN_ULONG *ltmp;
|
|
|
|
itmp=na; na=nb; nb=itmp;
|
|
ltmp=a; a=b; b=ltmp;
|
|
|
|
}
|
|
rr= &(r[na]);
|
|
rr[0]=bn_mul_words(r,a,na,b[0]);
|
|
|
|
for (;;)
|
|
{
|
|
if (--nb <= 0) return;
|
|
rr[1]=bn_mul_add_words(&(r[1]),a,na,b[1]);
|
|
if (--nb <= 0) return;
|
|
rr[2]=bn_mul_add_words(&(r[2]),a,na,b[2]);
|
|
if (--nb <= 0) return;
|
|
rr[3]=bn_mul_add_words(&(r[3]),a,na,b[3]);
|
|
if (--nb <= 0) return;
|
|
rr[4]=bn_mul_add_words(&(r[4]),a,na,b[4]);
|
|
rr+=4;
|
|
r+=4;
|
|
b+=4;
|
|
}
|
|
}
|
|
|
|
void bn_mul_low_normal(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
|
|
{
|
|
#ifdef BN_COUNT
|
|
printf(" bn_mul_low_normal %d * %d\n",n,n);
|
|
#endif
|
|
bn_mul_words(r,a,n,b[0]);
|
|
|
|
for (;;)
|
|
{
|
|
if (--n <= 0) return;
|
|
bn_mul_add_words(&(r[1]),a,n,b[1]);
|
|
if (--n <= 0) return;
|
|
bn_mul_add_words(&(r[2]),a,n,b[2]);
|
|
if (--n <= 0) return;
|
|
bn_mul_add_words(&(r[3]),a,n,b[3]);
|
|
if (--n <= 0) return;
|
|
bn_mul_add_words(&(r[4]),a,n,b[4]);
|
|
r+=4;
|
|
b+=4;
|
|
}
|
|
}
|
|
|