+++ /dev/null
-/* crypto/bn/bn_sqr.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"
-
-/* r must not be a */
-/* I've just gone over this and it is now %20 faster on x86 - eay - 27 Jun 96 */
-int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
- {
- int max,al;
- int ret = 0;
- BIGNUM *tmp,*rr;
-
-#ifdef BN_COUNT
- fprintf(stderr,"BN_sqr %d * %d\n",a->top,a->top);
-#endif
- bn_check_top(a);
-
- al=a->top;
- if (al <= 0)
- {
- r->top=0;
- return(1);
- }
-
- BN_CTX_start(ctx);
- rr=(a != r) ? r : BN_CTX_get(ctx);
- tmp=BN_CTX_get(ctx);
- if (tmp == NULL) goto err;
-
- max=(al+al);
- if (bn_wexpand(rr,max+1) == NULL) goto err;
-
- if (al == 4)
- {
-#ifndef BN_SQR_COMBA
- BN_ULONG t[8];
- bn_sqr_normal(rr->d,a->d,4,t);
-#else
- bn_sqr_comba4(rr->d,a->d);
-#endif
- }
- else if (al == 8)
- {
-#ifndef BN_SQR_COMBA
- BN_ULONG t[16];
- bn_sqr_normal(rr->d,a->d,8,t);
-#else
- bn_sqr_comba8(rr->d,a->d);
-#endif
- }
- else
- {
-#if defined(BN_RECURSION)
- if (al < BN_SQR_RECURSIVE_SIZE_NORMAL)
- {
- BN_ULONG t[BN_SQR_RECURSIVE_SIZE_NORMAL*2];
- bn_sqr_normal(rr->d,a->d,al,t);
- }
- else
- {
- int j,k;
-
- j=BN_num_bits_word((BN_ULONG)al);
- j=1<<(j-1);
- k=j+j;
- if (al == j)
- {
- if (bn_wexpand(tmp,k*2) == NULL) goto err;
- bn_sqr_recursive(rr->d,a->d,al,tmp->d);
- }
- else
- {
- if (bn_wexpand(tmp,max) == NULL) goto err;
- bn_sqr_normal(rr->d,a->d,al,tmp->d);
- }
- }
-#else
- if (bn_wexpand(tmp,max) == NULL) goto err;
- bn_sqr_normal(rr->d,a->d,al,tmp->d);
-#endif
- }
-
- rr->top=max;
- rr->neg=0;
- if ((max > 0) && (rr->d[max-1] == 0)) rr->top--;
- if (rr != r) BN_copy(r,rr);
- ret = 1;
- err:
- BN_CTX_end(ctx);
- return(ret);
- }
-
-/* tmp must have 2*n words */
-void bn_sqr_normal(BN_ULONG *r, const BN_ULONG *a, int n, BN_ULONG *tmp)
- {
- int i,j,max;
- const BN_ULONG *ap;
- BN_ULONG *rp;
-
- max=n*2;
- ap=a;
- rp=r;
- rp[0]=rp[max-1]=0;
- rp++;
- j=n;
-
- if (--j > 0)
- {
- ap++;
- rp[j]=bn_mul_words(rp,ap,j,ap[-1]);
- rp+=2;
- }
-
- for (i=n-2; i>0; i--)
- {
- j--;
- ap++;
- rp[j]=bn_mul_add_words(rp,ap,j,ap[-1]);
- rp+=2;
- }
-
- bn_add_words(r,r,r,max);
-
- /* There will not be a carry */
-
- bn_sqr_words(tmp,a,n);
-
- bn_add_words(r,r,tmp,max);
- }
-
-#ifdef BN_RECURSION
-/* r is 2*n words in size,
- * a and b are both n words in size. (There's not actually a 'b' here ...)
- * n must be a power of 2.
- * We multiply and return the result.
- * t must be 2*n words in size
- * We calculate
- * a[0]*b[0]
- * a[0]*b[0]+a[1]*b[1]+(a[0]-a[1])*(b[1]-b[0])
- * a[1]*b[1]
- */
-void bn_sqr_recursive(BN_ULONG *r, const BN_ULONG *a, int n2, BN_ULONG *t)
- {
- int n=n2/2;
- int zero,c1;
- BN_ULONG ln,lo,*p;
-
-#ifdef BN_COUNT
- fprintf(stderr," bn_sqr_recursive %d * %d\n",n2,n2);
-#endif
- if (n2 == 4)
- {
-#ifndef BN_SQR_COMBA
- bn_sqr_normal(r,a,4,t);
-#else
- bn_sqr_comba4(r,a);
-#endif
- return;
- }
- else if (n2 == 8)
- {
-#ifndef BN_SQR_COMBA
- bn_sqr_normal(r,a,8,t);
-#else
- bn_sqr_comba8(r,a);
-#endif
- return;
- }
- if (n2 < BN_SQR_RECURSIVE_SIZE_NORMAL)
- {
- bn_sqr_normal(r,a,n2,t);
- return;
- }
- /* r=(a[0]-a[1])*(a[1]-a[0]) */
- c1=bn_cmp_words(a,&(a[n]),n);
- zero=0;
- if (c1 > 0)
- bn_sub_words(t,a,&(a[n]),n);
- else if (c1 < 0)
- bn_sub_words(t,&(a[n]),a,n);
- else
- zero=1;
-
- /* The result will always be negative unless it is zero */
- p= &(t[n2*2]);
-
- if (!zero)
- bn_sqr_recursive(&(t[n2]),t,n,p);
- else
- memset(&(t[n2]),0,n2*sizeof(BN_ULONG));
- bn_sqr_recursive(r,a,n,p);
- bn_sqr_recursive(&(r[n2]),&(a[n]),n,p);
-
- /* t[32] holds (a[0]-a[1])*(a[1]-a[0]), it is negative or zero
- * r[10] holds (a[0]*b[0])
- * r[32] holds (b[1]*b[1])
- */
-
- c1=(int)(bn_add_words(t,r,&(r[n2]),n2));
-
- /* t[32] is negative */
- c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2));
-
- /* t[32] holds (a[0]-a[1])*(a[1]-a[0])+(a[0]*a[0])+(a[1]*a[1])
- * r[10] holds (a[0]*a[0])
- * r[32] holds (a[1]*a[1])
- * c1 holds the carry bits
- */
- c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2));
- if (c1)
- {
- p= &(r[n+n2]);
- lo= *p;
- ln=(lo+c1)&BN_MASK2;
- *p=ln;
-
- /* The overflow will stop before we over write
- * words we should not overwrite */
- if (ln < (BN_ULONG)c1)
- {
- do {
- p++;
- lo= *p;
- ln=(lo+1)&BN_MASK2;
- *p=ln;
- } while (ln == 0);
- }
- }
- }
-#endif
projects / bcm963xx.git / blobdiff