/* crypto/bn/bn_word.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"BN_ULONG BN_mod_word(const BIGNUM * a, BN_ULONG w){#ifndef BN_LLONG    BN_ULONG ret = 0;#else    BN_ULLONG ret = 0;#endif    int i;    w &= BN_MASK2;    for (i = a->top - 1; i >= 0; i--) {#ifndef BN_LLONG	ret =	    ((ret << BN_BITS4) | ((a->d[i] >> BN_BITS4) & BN_MASK2l)) % w;	ret = ((ret << BN_BITS4) | (a->d[i] & BN_MASK2l)) % w;#else	ret = (BN_ULLONG) (((ret << (BN_ULLONG) BN_BITS2) | a->d[i]) %			   (BN_ULLONG) w);#endif    }    return ((BN_ULONG) ret);}BN_ULONG BN_div_word(BIGNUM * a, BN_ULONG w){    BN_ULONG ret;    int i;    if (a->top == 0)	return (0);    ret = 0;    w &= BN_MASK2;    for (i = a->top - 1; i >= 0; i--) {	BN_ULONG l, d;	l = a->d[i];	d = bn_div_words(ret, l, w);	ret = (l - ((d * w) & BN_MASK2)) & BN_MASK2;	a->d[i] = d;    }    if ((a->top > 0) && (a->d[a->top - 1] == 0))	a->top--;    return (ret);}int BN_add_word(BIGNUM * a, BN_ULONG w){    BN_ULONG l;    int i;    if (a->neg) {	a->neg = 0;	i = BN_sub_word(a, w);	if (!BN_is_zero(a))	    a->neg = !(a->neg);	return (i);    }    w &= BN_MASK2;    if (bn_wexpand(a, a->top + 1) == NULL)	return (0);    i = 0;    for (;;) {	l = (a->d[i] + (BN_ULONG) w) & BN_MASK2;	a->d[i] = l;	if (w > l)	    w = 1;	else	    break;	i++;    }    if (i >= a->top)	a->top++;    return (1);}int BN_sub_word(BIGNUM * a, BN_ULONG w){    int i;    if (BN_is_zero(a) || a->neg) {	a->neg = 0;	i = BN_add_word(a, w);	a->neg = 1;	return (i);    }    w &= BN_MASK2;    if ((a->top == 1) && (a->d[0] < w)) {	a->d[0] = w - a->d[0];	a->neg = 1;	return (1);    }    i = 0;    for (;;) {	if (a->d[i] >= w) {	    a->d[i] -= w;	    break;	} else {	    a->d[i] = (a->d[i] - w) & BN_MASK2;	    i++;	    w = 1;	}    }    if ((a->d[i] == 0) && (i == (a->top - 1)))	a->top--;    return (1);}int BN_mul_word(BIGNUM * a, BN_ULONG w){    BN_ULONG ll;    w &= BN_MASK2;    if (a->top) {	if (w == 0)	    BN_zero(a);	else {	    ll = bn_mul_words(a->d, a->d, a->top, w);	    if (ll) {		if (bn_wexpand(a, a->top + 1) == NULL)		    return (0);		a->d[a->top++] = ll;	    }	}    }    return (1);}