-/* crypto/bn/bn_m.c */
-/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
- *
- * This package is an SSL implementation written
- * by Eric Young (eay@cryptsoft.com).
- * The implementation was written so as to conform with Netscapes SSL.
- *
- * This library is free for commercial and non-commercial use as long as
- * the following conditions are aheared to. The following conditions
- * apply to all code found in this distribution, be it the RC4, RSA,
- * lhash, DES, etc., code; not just the SSL code. The SSL documentation
- * included with this distribution is covered by the same copyright terms
- * except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
- * Copyright remains Eric Young's, and as such any Copyright notices in
- * the code are not to be removed.
- * If this package is used in a product, Eric Young should be given attribution
- * as the author of the parts of the library used.
- * This can be in the form of a textual message at program startup or
- * in documentation (online or textual) provided with the package.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * "This product includes cryptographic software written by
- * Eric Young (eay@cryptsoft.com)"
- * The word 'cryptographic' can be left out if the rouines from the library
- * being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
- * the apps directory (application code) you must include an acknowledgement:
- * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
- * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * The licence and distribution terms for any publically available version or
- * derivative of this code cannot be changed. i.e. this code cannot simply be
- * copied and put under another distribution licence
- * [including the GNU Public Licence.]
- */
-
-#include <stdio.h>
-#include "cryptlib.h"
-#include "bn_lcl.h"
-#include <openssl/stack.h>
-
-int limit=16;
-
-typedef struct bn_pool_st
- {
- int used;
- int tos;
- STACK *sk;
- } BN_POOL;
-
-BIGNUM *BN_POOL_push(BN_POOL *bp)
- {
- BIGNUM *ret;
-
- if (bp->used >= bp->tos)
- {
- ret=BN_new();
- sk_push(bp->sk,(char *)ret);
- bp->tos++;
- bp->used++;
- }
- else
- {
- ret=(BIGNUM *)sk_value(bp->sk,bp->used);
- bp->used++;
- }
- return(ret);
- }
-
-void BN_POOL_pop(BN_POOL *bp, int num)
- {
- bp->used-=num;
- }
-
-int BN_m(BIGNUM *r, BIGNUM *a, BIGNUM *b)
- {
- static BN_POOL bp;
- static init=1;
-
- if (init)
- {
- bp.used=0;
- bp.tos=0;
- bp.sk=sk_new_null();
- init=0;
- }
- return(BN_mm(r,a,b,&bp));
- }
-
-/* r must be different to a and b */
-int BN_mm(BIGNUM *m, BIGNUM *A, BIGNUM *B, BN_POOL *bp)
- {
- int i,num;
- int an,bn;
- BIGNUM *a,*b,*c,*d,*ac,*bd;
-
- an=A->top;
- bn=B->top;
- if ((an <= limit) || (bn <= limit))
- {
- return(BN_mul(m,A,B));
- }
-
- a=BN_POOL_push(bp);
- b=BN_POOL_push(bp);
- c=BN_POOL_push(bp);
- d=BN_POOL_push(bp);
- ac=BN_POOL_push(bp);
- bd=BN_POOL_push(bp);
-
- num=(an <= bn)?an:bn;
- num=1<<(BN_num_bits_word(num-1)-1);
-
- /* Are going to now chop things into 'num' word chunks. */
- num*=BN_BITS2;
-
- BN_copy(a,A);
- BN_mask_bits(a,num);
- BN_rshift(b,A,num);
-
- BN_copy(c,B);
- BN_mask_bits(c,num);
- BN_rshift(d,B,num);
-
- BN_sub(ac ,b,a);
- BN_sub(bd,c,d);
- BN_mm(m,ac,bd,bp);
- BN_mm(ac,a,c,bp);
- BN_mm(bd,b,d,bp);
-
- BN_add(m,m,ac);
- BN_add(m,m,bd);
- BN_lshift(m,m,num);
- BN_lshift(bd,bd,num*2);
-
- BN_add(m,m,ac);
- BN_add(m,m,bd);
- BN_POOL_pop(bp,6);
- return(1);
- }
-
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