1656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* crypto/bn/bn_sqr.c */ 2656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * All rights reserved. 4656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 5656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * This package is an SSL implementation written 6656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * by Eric Young (eay@cryptsoft.com). 7656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * The implementation was written so as to conform with Netscapes SSL. 8656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 9656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * This library is free for commercial and non-commercial use as long as 10656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * the following conditions are aheared to. The following conditions 11656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * apply to all code found in this distribution, be it the RC4, RSA, 12656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * included with this distribution is covered by the same copyright terms 14656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 16656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * Copyright remains Eric Young's, and as such any Copyright notices in 17656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * the code are not to be removed. 18656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * If this package is used in a product, Eric Young should be given attribution 19656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * as the author of the parts of the library used. 20656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * This can be in the form of a textual message at program startup or 21656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * in documentation (online or textual) provided with the package. 22656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 23656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * Redistribution and use in source and binary forms, with or without 24656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * modification, are permitted provided that the following conditions 25656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * are met: 26656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 1. Redistributions of source code must retain the copyright 27656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * notice, this list of conditions and the following disclaimer. 28656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 2. Redistributions in binary form must reproduce the above copyright 29656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * notice, this list of conditions and the following disclaimer in the 30656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * documentation and/or other materials provided with the distribution. 31656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 3. All advertising materials mentioning features or use of this software 32656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * must display the following acknowledgement: 33656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * "This product includes cryptographic software written by 34656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * Eric Young (eay@cryptsoft.com)" 35656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * The word 'cryptographic' can be left out if the rouines from the library 36656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * being used are not cryptographic related :-). 37656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 4. If you include any Windows specific code (or a derivative thereof) from 38656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * the apps directory (application code) you must include an acknowledgement: 39656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 41656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * SUCH DAMAGE. 52656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 53656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * The licence and distribution terms for any publically available version or 54656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * derivative of this code cannot be changed. i.e. this code cannot simply be 55656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * copied and put under another distribution licence 56656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * [including the GNU Public Licence.] 57656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project */ 58656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 59656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include <stdio.h> 60656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include "cryptlib.h" 61656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include "bn_lcl.h" 62656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 63656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* r must not be a */ 64656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* I've just gone over this and it is now %20 faster on x86 - eay - 27 Jun 96 */ 65656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectint BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx) 66656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 67656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int max,al; 68656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int ret = 0; 69656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BIGNUM *tmp,*rr; 70656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 71656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifdef BN_COUNT 72656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project fprintf(stderr,"BN_sqr %d * %d\n",a->top,a->top); 73656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 74656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_check_top(a); 75656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 76656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project al=a->top; 77656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (al <= 0) 78656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 79656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project r->top=0; 80656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return 1; 81656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 82656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 83656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_CTX_start(ctx); 84656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rr=(a != r) ? r : BN_CTX_get(ctx); 85656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project tmp=BN_CTX_get(ctx); 86656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (!rr || !tmp) goto err; 87656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 88656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project max = 2 * al; /* Non-zero (from above) */ 89656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (bn_wexpand(rr,max) == NULL) goto err; 90656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 91656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (al == 4) 92656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 93656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifndef BN_SQR_COMBA 94656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG t[8]; 95656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,4,t); 96656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 97656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_comba4(rr->d,a->d); 98656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 99656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 100656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else if (al == 8) 101656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 102656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifndef BN_SQR_COMBA 103656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG t[16]; 104656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,8,t); 105656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 106656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_comba8(rr->d,a->d); 107656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 108656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 109656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 110656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 111656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#if defined(BN_RECURSION) 112656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (al < BN_SQR_RECURSIVE_SIZE_NORMAL) 113656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 114656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG t[BN_SQR_RECURSIVE_SIZE_NORMAL*2]; 115656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,al,t); 116656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 117656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 118656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 119656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int j,k; 120656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 121656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project j=BN_num_bits_word((BN_ULONG)al); 122656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project j=1<<(j-1); 123656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project k=j+j; 124656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (al == j) 125656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 126656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (bn_wexpand(tmp,k*2) == NULL) goto err; 127656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_recursive(rr->d,a->d,al,tmp->d); 128656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 129656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 130656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 131656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (bn_wexpand(tmp,max) == NULL) goto err; 132656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,al,tmp->d); 133656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 134656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 135656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 136656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (bn_wexpand(tmp,max) == NULL) goto err; 137656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,al,tmp->d); 138656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 139656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 140656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 141656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rr->neg=0; 142656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* If the most-significant half of the top word of 'a' is zero, then 143656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * the square of 'a' will max-1 words. */ 144656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if(a->d[al - 1] == (a->d[al - 1] & BN_MASK2l)) 145656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rr->top = max - 1; 146656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 147656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rr->top = max; 148656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (rr != r) BN_copy(r,rr); 149656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ret = 1; 150656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project err: 151656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_check_top(rr); 152656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_check_top(tmp); 153656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_CTX_end(ctx); 154656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return(ret); 155656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 156656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 157656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* tmp must have 2*n words */ 158656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectvoid bn_sqr_normal(BN_ULONG *r, const BN_ULONG *a, int n, BN_ULONG *tmp) 159656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 160656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int i,j,max; 161656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const BN_ULONG *ap; 162656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG *rp; 163656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 164656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project max=n*2; 165656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ap=a; 166656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp=r; 167656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp[0]=rp[max-1]=0; 168656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp++; 169656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project j=n; 170656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 171656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (--j > 0) 172656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 173656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ap++; 174656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp[j]=bn_mul_words(rp,ap,j,ap[-1]); 175656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp+=2; 176656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 177656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 178656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i=n-2; i>0; i--) 179656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 180656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project j--; 181656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ap++; 182656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp[j]=bn_mul_add_words(rp,ap,j,ap[-1]); 183656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp+=2; 184656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 185656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 186656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_add_words(r,r,r,max); 187656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 188656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* There will not be a carry */ 189656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 190656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_words(tmp,a,n); 191656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 192656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_add_words(r,r,tmp,max); 193656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 194656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 195656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifdef BN_RECURSION 196656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* r is 2*n words in size, 197656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * a and b are both n words in size. (There's not actually a 'b' here ...) 198656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * n must be a power of 2. 199656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * We multiply and return the result. 200656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * t must be 2*n words in size 201656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * We calculate 202656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * a[0]*b[0] 203656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * a[0]*b[0]+a[1]*b[1]+(a[0]-a[1])*(b[1]-b[0]) 204656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * a[1]*b[1] 205656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project */ 206656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectvoid bn_sqr_recursive(BN_ULONG *r, const BN_ULONG *a, int n2, BN_ULONG *t) 207656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 208656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int n=n2/2; 209656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int zero,c1; 210656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG ln,lo,*p; 211656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 212656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifdef BN_COUNT 213656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project fprintf(stderr," bn_sqr_recursive %d * %d\n",n2,n2); 214656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 215656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (n2 == 4) 216656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 217656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifndef BN_SQR_COMBA 218656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(r,a,4,t); 219656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 220656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_comba4(r,a); 221656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 222656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return; 223656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 224656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else if (n2 == 8) 225656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 226656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifndef BN_SQR_COMBA 227656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(r,a,8,t); 228656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 229656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_comba8(r,a); 230656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 231656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return; 232656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 233656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (n2 < BN_SQR_RECURSIVE_SIZE_NORMAL) 234656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 235656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(r,a,n2,t); 236656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return; 237656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 238656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* r=(a[0]-a[1])*(a[1]-a[0]) */ 239656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project c1=bn_cmp_words(a,&(a[n]),n); 240656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project zero=0; 241656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (c1 > 0) 242656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sub_words(t,a,&(a[n]),n); 243656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else if (c1 < 0) 244656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sub_words(t,&(a[n]),a,n); 245656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 246656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project zero=1; 247656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 248656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* The result will always be negative unless it is zero */ 249656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project p= &(t[n2*2]); 250656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 251656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (!zero) 252656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_recursive(&(t[n2]),t,n,p); 253656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 254656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memset(&(t[n2]),0,n2*sizeof(BN_ULONG)); 255656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_recursive(r,a,n,p); 256656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_recursive(&(r[n2]),&(a[n]),n,p); 257656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 258656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* t[32] holds (a[0]-a[1])*(a[1]-a[0]), it is negative or zero 259656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * r[10] holds (a[0]*b[0]) 260656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * r[32] holds (b[1]*b[1]) 261656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project */ 262656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 263656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project c1=(int)(bn_add_words(t,r,&(r[n2]),n2)); 264656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 265656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* t[32] is negative */ 266656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2)); 267656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 268656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* t[32] holds (a[0]-a[1])*(a[1]-a[0])+(a[0]*a[0])+(a[1]*a[1]) 269656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * r[10] holds (a[0]*a[0]) 270656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * r[32] holds (a[1]*a[1]) 271656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * c1 holds the carry bits 272656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project */ 273656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2)); 274656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (c1) 275656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 276656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project p= &(r[n+n2]); 277656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project lo= *p; 278656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ln=(lo+c1)&BN_MASK2; 279656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project *p=ln; 280656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 281656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* The overflow will stop before we over write 282656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * words we should not overwrite */ 283656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (ln < (BN_ULONG)c1) 284656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 285656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project do { 286656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project p++; 287656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project lo= *p; 288656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ln=(lo+1)&BN_MASK2; 289656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project *p=ln; 290656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } while (ln == 0); 291656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 292656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 293656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 294656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 295