805 lines
18 KiB
C
Executable File
805 lines
18 KiB
C
Executable File
#include "bn.h"
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#ifndef WITH_LIBCRYPTO
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//FIXME Not checked on threadsafety yet; after checking please remove this line
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/* 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 license 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 license
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* [including the GNU Public License.]
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*/
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#include <stdio.h>
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#include <string.h>
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#include "bn_lcl.h"
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#include "openssl_mods.h"
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#ifdef BN_RECURSION
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/* Karatsuba recursive multiplication algorithm
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* (cf. Knuth, The Art of Computer Programming, Vol. 2) */
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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 calculate
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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 0
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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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# endif
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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 /* BN_MUL_COMBA */
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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 /* BN_MUL_COMBA */
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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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{
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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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}
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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 c1, c2, i, j, n2 = n * 2;
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unsigned int neg;
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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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c1 = bn_cmp_words(a, &(a[n]), n);
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c2 = bn_cmp_words(&(b[n]), b, n);
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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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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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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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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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/* The zero case isn't yet implemented here. The speedup
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would probably be negligible. */
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# if 0
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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
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# endif
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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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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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{
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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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}
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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, 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 = 0, oneg;
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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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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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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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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;
|
|
break;
|
|
case 3:
|
|
break;
|
|
case 4:
|
|
bn_sub_words(&(r[0]), &(a[0]), &(a[n]), n);
|
|
bn_sub_words(&(r[n]), &(b[n]), &(b[0]), n);
|
|
break;
|
|
}
|
|
|
|
oneg = neg;
|
|
/* t[10] = (a[0]-a[1])*(b[1]-b[0]) */
|
|
/* r[10] = (a[1]*b[1]) */
|
|
# ifdef BN_MUL_COMBA
|
|
if(n == 8)
|
|
{
|
|
bn_mul_comba8(&(t[0]), &(r[0]), &(r[n]));
|
|
bn_mul_comba8(r, &(a[n]), &(b[n]));
|
|
}
|
|
else
|
|
# endif
|
|
{
|
|
bn_mul_recursive(&(t[0]), &(r[0]), &(r[n]), n, &(t[n2]));
|
|
bn_mul_recursive(r, &(a[n]), &(b[n]), n, &(t[n2]));
|
|
}
|
|
|
|
/* s0 == low(al*bl)
|
|
* s1 == low(ah*bh)+low((al-ah)*(bh-bl))+low(al*bl)+high(al*bl)
|
|
* We know s0 and s1 so the only unknown is high(al*bl)
|
|
* high(al*bl) == s1 - low(ah*bh+s0+(al-ah)*(bh-bl))
|
|
* high(al*bl) == s1 - (r[0]+l[0]+t[0])
|
|
*/
|
|
if(l != NULL)
|
|
{
|
|
lp = &(t[n2 + n]);
|
|
c1 = (int)(bn_add_words(lp, &(r[0]), &(l[0]), n));
|
|
}
|
|
else
|
|
{
|
|
c1 = 0;
|
|
lp = &(r[0]);
|
|
}
|
|
|
|
if(neg)
|
|
{ neg = (int)(bn_sub_words(&(t[n2]), lp, &(t[0]), n)); }
|
|
else
|
|
{
|
|
bn_add_words(&(t[n2]), lp, &(t[0]), n);
|
|
}
|
|
|
|
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 /* BN_RECURSION */
|
|
|
|
int BN_mul(BIGNUM *r, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
|
|
{
|
|
int top, al, bl;
|
|
BIGNUM *rr;
|
|
int ret = 0;
|
|
#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
|
|
int i;
|
|
#endif
|
|
#ifdef BN_RECURSION
|
|
BIGNUM *t;
|
|
int 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;
|
|
|
|
if((al == 0) || (bl == 0))
|
|
{
|
|
BN_zero(r);
|
|
return (1);
|
|
}
|
|
top = al + bl;
|
|
|
|
BN_CTX_start(ctx);
|
|
if((r == a) || (r == b))
|
|
{
|
|
if((rr = BN_CTX_get(ctx)) == NULL) { goto err; }
|
|
}
|
|
else
|
|
{ rr = r; }
|
|
rr->neg = a->neg ^ b->neg;
|
|
|
|
#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
|
|
i = al - bl;
|
|
#endif
|
|
#ifdef BN_MUL_COMBA
|
|
if(i == 0)
|
|
{
|
|
# if 0
|
|
if(al == 4)
|
|
{
|
|
if(bn_wexpand(rr, 8) == NULL) { goto err; }
|
|
rr->top = 8;
|
|
bn_mul_comba4(rr->d, a->d, b->d);
|
|
goto end;
|
|
}
|
|
# endif
|
|
if(al == 8)
|
|
{
|
|
if(bn_wexpand(rr, 16) == NULL) { goto err; }
|
|
rr->top = 16;
|
|
bn_mul_comba8(rr->d, a->d, b->d);
|
|
goto end;
|
|
}
|
|
}
|
|
#endif /* BN_MUL_COMBA */
|
|
#ifdef BN_RECURSION
|
|
if((al >= BN_MULL_SIZE_NORMAL) && (bl >= BN_MULL_SIZE_NORMAL))
|
|
{
|
|
if(i == 1 && !BN_get_flags(b, BN_FLG_STATIC_DATA))
|
|
{
|
|
if(bn_wexpand(b, al) == NULL) { goto err; }
|
|
b->d[bl] = 0;
|
|
bl++;
|
|
i--;
|
|
}
|
|
else if(i == -1 && !BN_get_flags(a, BN_FLG_STATIC_DATA))
|
|
{
|
|
if(bn_wexpand(a, bl) == NULL) { goto err; }
|
|
a->d[al] = 0;
|
|
al++;
|
|
i++;
|
|
}
|
|
if(i == 0)
|
|
{
|
|
/* symmetric and > 4 */
|
|
/* 16 or larger */
|
|
j = BN_num_bits_word((BN_ULONG)al);
|
|
j = 1 << (j - 1);
|
|
k = j + j;
|
|
t = BN_CTX_get(ctx);
|
|
if(al == j) /* exact multiple */
|
|
{
|
|
if(bn_wexpand(t, k * 2) == NULL) { goto err; }
|
|
if(bn_wexpand(rr, k * 2) == NULL) { goto err; }
|
|
bn_mul_recursive(rr->d, a->d, b->d, al, t->d);
|
|
}
|
|
else
|
|
{
|
|
if(bn_wexpand(a, k) == NULL) { goto err; }
|
|
if(bn_wexpand(b, k) == NULL) { goto err; }
|
|
if(bn_wexpand(t, k * 4) == NULL) { goto err; }
|
|
if(bn_wexpand(rr, k * 4) == NULL) { goto err; }
|
|
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;
|
|
goto end;
|
|
}
|
|
}
|
|
#endif /* BN_RECURSION */
|
|
if(bn_wexpand(rr, top) == NULL) { goto err; }
|
|
rr->top = top;
|
|
bn_mul_normal(rr->d, a->d, al, b->d, bl);
|
|
|
|
#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
|
|
end:
|
|
#endif
|
|
bn_fix_top(rr);
|
|
if(r != rr) { BN_copy(r, rr); }
|
|
ret = 1;
|
|
err:
|
|
BN_CTX_end(ctx);
|
|
return (ret);
|
|
}
|
|
|
|
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;
|
|
}
|
|
}
|
|
#endif
|