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; 80c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root r->neg = 0; 81656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return 1; 82656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 83656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 84656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_CTX_start(ctx); 85656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rr=(a != r) ? r : BN_CTX_get(ctx); 86656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project tmp=BN_CTX_get(ctx); 87656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (!rr || !tmp) goto err; 88656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 89656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project max = 2 * al; /* Non-zero (from above) */ 90656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (bn_wexpand(rr,max) == NULL) goto err; 91656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 92656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (al == 4) 93656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 94656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifndef BN_SQR_COMBA 95656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG t[8]; 96656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,4,t); 97656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 98656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_comba4(rr->d,a->d); 99656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 100656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 101656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else if (al == 8) 102656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 103656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifndef BN_SQR_COMBA 104656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG t[16]; 105656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,8,t); 106656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 107656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_comba8(rr->d,a->d); 108656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 109656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 110656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 111656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 112656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#if defined(BN_RECURSION) 113656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (al < BN_SQR_RECURSIVE_SIZE_NORMAL) 114656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 115656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG t[BN_SQR_RECURSIVE_SIZE_NORMAL*2]; 116656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,al,t); 117656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 118656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 119656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 120656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int j,k; 121656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 122656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project j=BN_num_bits_word((BN_ULONG)al); 123656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project j=1<<(j-1); 124656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project k=j+j; 125656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (al == j) 126656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 127656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (bn_wexpand(tmp,k*2) == NULL) goto err; 128656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_recursive(rr->d,a->d,al,tmp->d); 129656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 130656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 131656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 132656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (bn_wexpand(tmp,max) == NULL) goto err; 133656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,al,tmp->d); 134656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 135656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 136656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 137656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (bn_wexpand(tmp,max) == NULL) goto err; 138656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(rr->d,a->d,al,tmp->d); 139656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 140656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 141656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 142656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rr->neg=0; 143656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* If the most-significant half of the top word of 'a' is zero, then 144656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * the square of 'a' will max-1 words. */ 145656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if(a->d[al - 1] == (a->d[al - 1] & BN_MASK2l)) 146656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rr->top = max - 1; 147656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 148656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rr->top = max; 149656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (rr != r) BN_copy(r,rr); 150656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ret = 1; 151656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project err: 152656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_check_top(rr); 153656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_check_top(tmp); 154656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_CTX_end(ctx); 155656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return(ret); 156656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 157656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 158656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* tmp must have 2*n words */ 159656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectvoid bn_sqr_normal(BN_ULONG *r, const BN_ULONG *a, int n, BN_ULONG *tmp) 160656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 161656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int i,j,max; 162656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const BN_ULONG *ap; 163656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG *rp; 164656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 165656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project max=n*2; 166656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ap=a; 167656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp=r; 168656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp[0]=rp[max-1]=0; 169656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp++; 170656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project j=n; 171656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 172656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (--j > 0) 173656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 174656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ap++; 175656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp[j]=bn_mul_words(rp,ap,j,ap[-1]); 176656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp+=2; 177656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 178656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 179656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i=n-2; i>0; i--) 180656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 181656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project j--; 182656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ap++; 183656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp[j]=bn_mul_add_words(rp,ap,j,ap[-1]); 184656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project rp+=2; 185656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 186656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 187656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_add_words(r,r,r,max); 188656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 189656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* There will not be a carry */ 190656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 191656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_words(tmp,a,n); 192656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 193656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_add_words(r,r,tmp,max); 194656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 195656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 196656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifdef BN_RECURSION 197656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* r is 2*n words in size, 198656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * a and b are both n words in size. (There's not actually a 'b' here ...) 199656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * n must be a power of 2. 200656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * We multiply and return the result. 201656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * t must be 2*n words in size 202656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * We calculate 203656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * a[0]*b[0] 204656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * a[0]*b[0]+a[1]*b[1]+(a[0]-a[1])*(b[1]-b[0]) 205656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * a[1]*b[1] 206656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project */ 207656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectvoid bn_sqr_recursive(BN_ULONG *r, const BN_ULONG *a, int n2, BN_ULONG *t) 208656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 209656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int n=n2/2; 210656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int zero,c1; 211656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project BN_ULONG ln,lo,*p; 212656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 213656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifdef BN_COUNT 214656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project fprintf(stderr," bn_sqr_recursive %d * %d\n",n2,n2); 215656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 216656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (n2 == 4) 217656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 218656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifndef BN_SQR_COMBA 219656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(r,a,4,t); 220656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 221656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_comba4(r,a); 222656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 223656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return; 224656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 225656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else if (n2 == 8) 226656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 227656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifndef BN_SQR_COMBA 228656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(r,a,8,t); 229656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#else 230656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_comba8(r,a); 231656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 232656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return; 233656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 234656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (n2 < BN_SQR_RECURSIVE_SIZE_NORMAL) 235656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 236656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_normal(r,a,n2,t); 237656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return; 238656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 239656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* r=(a[0]-a[1])*(a[1]-a[0]) */ 240656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project c1=bn_cmp_words(a,&(a[n]),n); 241656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project zero=0; 242656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (c1 > 0) 243656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sub_words(t,a,&(a[n]),n); 244656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else if (c1 < 0) 245656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sub_words(t,&(a[n]),a,n); 246656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 247656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project zero=1; 248656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 249656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* The result will always be negative unless it is zero */ 250656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project p= &(t[n2*2]); 251656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 252656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (!zero) 253656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_recursive(&(t[n2]),t,n,p); 254656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 255656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memset(&(t[n2]),0,n2*sizeof(BN_ULONG)); 256656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_recursive(r,a,n,p); 257656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bn_sqr_recursive(&(r[n2]),&(a[n]),n,p); 258656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 259656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* t[32] holds (a[0]-a[1])*(a[1]-a[0]), it is negative or zero 260656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * r[10] holds (a[0]*b[0]) 261656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * r[32] holds (b[1]*b[1]) 262656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project */ 263656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 264656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project c1=(int)(bn_add_words(t,r,&(r[n2]),n2)); 265656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 266656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* t[32] is negative */ 267656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2)); 268656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 269656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* t[32] holds (a[0]-a[1])*(a[1]-a[0])+(a[0]*a[0])+(a[1]*a[1]) 270656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * r[10] holds (a[0]*a[0]) 271656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * r[32] holds (a[1]*a[1]) 272656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * c1 holds the carry bits 273656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project */ 274656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2)); 275656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (c1) 276656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 277656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project p= &(r[n+n2]); 278656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project lo= *p; 279656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ln=(lo+c1)&BN_MASK2; 280656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project *p=ln; 281656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 282656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* The overflow will stop before we over write 283656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * words we should not overwrite */ 284656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (ln < (BN_ULONG)c1) 285656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 286656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project do { 287656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project p++; 288656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project lo= *p; 289656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project ln=(lo+1)&BN_MASK2; 290656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project *p=ln; 291656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } while (ln == 0); 292656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 293656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 294656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 295656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 296